If I am using DRY lube, do I need to clean my chain between applications?

Yes you should clean the chain occasionally.  Where does the dirt go if you don't clean it off ?

True that dry lubricants are not as sticky as wet ones, but there's still dirt there and it needs to come off, not get further into your chain's gubbins.


Can old, stiff friction shifters be made serviceable?

Based on my personal experience with friction shifters, they are relatively easy to keep serviceable. Mine have adjustments to add or reduce friction which I generally leave set to a generally usable amount of friction between maintenance cycles. The level of friction should hold them in place, but it shouldn't be a workout to shift gears. Maintenance for me mostly consists of replacing cables and the tubes which the shift cables travel through, along with some cleaning.


How much does number of gears matter for a front derailleur?

The cages for a double and triple are shaped differently, so you need to get the derailleur for the right number of chainrings in the front. The derailleur also needs to have enough capacity to shift between the chainrings you have as well as clear the largest chainring. As usual, Sheldon is a good person to start with regarding FD selection. The number of rear speeds (the 9 in 2x9) marked for a front derailleur isn't too important, but the cage of the derailleur may be thinner for higher number of rear speeds (so if your chain isn't designed for high enough speeds, you may have some rubbing on the cage, especially if you don't adjust it properly) -- as Sheldon points out though, the distinction based on number of cogs in the back is primarily for marketing.

Obviously, you also need to make sure the derailleur will be able to be mounted on whatever type of mount your frame uses (this includes how the cable is pulled - bottom or top).

And finally, you have to worry about cable pull ratio, so if you're using brand X, buy a brand X front derailleur, and if it is a road (mountain) FD, buy a road (mountain) FD if you have road (mountain) shifters (which should obviously be matched with the number of chainrings in the front).

In summary,

1) Number of rear cogs doesn't matter - the shifting in the front is effectively independent of whats going on in the back.

2) Number of front chainrings does matter, but there's more to it than just matching the number of chainrings.


If you are looking for an exact replacement the part # will be stamped on the inside (wheel side) of the parallelogram linkage. This is the middle section of the derailleur it is the part between the mounting or "B" knuckle and the jockey wheel cage. The numbers will be small and are read more easily with the derailleur off the bike. It should begin with RD followed by four digits or RD M followed by three digits. You will also want to measure the distance between the jockey wheel mounting bolts to get the correct cage length as this will effect tooth/gear capacity.


I've got numerous bikes, bike frames, wheels, etc.that I'd like to donate

The best option would be to find a local bicycle co-op and offer them the parts. (They would probably welcome bikes, rims, and tools.)
You may not be near a co-op; if that's the case, there are numerous "pay it forward" threads on bicycle forums, but you'd end up paying postage; useful for small or esoteric parts. (I've given away a lot of stuff that way.)
You could also try Freecycle, but since that's more of a general audience, I doubt many people on those lists would even know what, say, a bottom bracket is, let alone how to use it. For giving away a complete working bike, this might be an excellent option. (Hey, their logo includes a guitar and a bike!)


Freehub: why are the pawls on the inside surface not the outside?

I am going to combine the comments into an answer - feel free to improve.

The main benefit is the larger circumference of the ratchet surface.

This means for the same torque on the wheel, there is less total force on the ratchets holding the freewheel. It also means there is room for more pawls, meaning less force on each individual ratchet. This allows smaller ratchets and pawls, meaning you can have more of them, meaning even less force.

Additionally smaller ratchets and pawls allow smaller angles before engagement of pawls locking the free hub - less slop when starting to pedal after free wheeling.  The smaller angle before pawls engage also means the pedals have less time to accelerate - meaning the forces and wear and tear on the engaging pawls are lower.

Having more pawls means the freewheel is more likely to operate if one fails to engage.

Conversely, a smaller diameter ratchet would be able to support fewer pawls, which would have to be much stronger or likely to be less reliable and engage less quickly when pedaling is resumed after freewheeling


Tips for amending apartment/condo bylaws around bike storage

Even if it does pass do you realize how hard and emotional this would be to enforce.  You are going to need to tell someone their bike is not high end.  Just give them all the option.  Better yet fix the security issue in the bike room.


Quad QHD-4 Axis Disc Brakes stuck (can't push open)

You pretty much have nothing to lose by disassembling the calipers and attempting to free the pistons. They are useless now, so if you break something it does not matter.

You may try contacting the manufacturer (Hayes?) and asking if they have a service manual.

The silver cap with the Torx socket does seem to be the way into the internals. If you can measure the point-point distance with some accuracy (1/10 mm) you can look up what size it is. The Wikipdia page on Torx drivers lists the sizes. If not, take a caliper to the tool store and try different sizes until you get the  right one.

It's the inboard piston that is stuck so if you can take the outboard one out you should be able to carefully drift the piston back in with a short length of wooden dowel or brass rod (old door hinge pins work well) and a hammer.

I could not find any info on these particular brakes online but you could look for other videos about how bicycle disc brakes work so you know what to expect when you get in there. Park Tool posted one recently. It's informative, if a bit silly at the beginning.


Why is the Shimano R3030 FD not compatible with the 3503 FC?

This is from a long time ago, but for the sake of others, I believe it's because of the cage size, I was trying to do the opposite with an r3030 crank and 3503, and I was not able to get it to shift smoothly until I paired the r3030 crank with r3030 front derailleur.


Putting brakes from a fat frame onto a skinny frame

The difference is usually in the length of the threaded insert that goes in the frame, and that the caliper bolt threads into.
The inserts are available separately, and must be sized correctly for the frame.
There may be some older calipers where the bolt itself is too long, but a Ti/Carbon frame sounds pretty new for that.
They come in 16mm and 22mm lengths. A steel frame would normally use the shorter 16mm version. See photos.

____________ 16mm _____________________________________________________ 22mm _________________________


Answering my own question with some observations I gathered from other forums:

The bolt boss (the knurled metal ring) in the picture is visible only because the chainring was installed incorrectly. When I tightened the bolts properly, the metal boss settled inside the crank spider and I gained at least 1mm clearance. New clearance in the following picture:

Both chainstay and crank arms are objects that don't flex much, unless they are of poor quality, but this is not the case for my build.
The biggest risk is the chain dropping and getting trapped in that small gap. In my case the gap is small enough that it shouldn't happen. Moreover, given that it's a fixed gear setup without front mech, the chance of chain dropping are very low.

Source: https://www.reddit.com/r/FixedGearBicycle/comments/4ck3h9/crank_arm_spider_and_chainstay_clearance_should_i/


Potholes cause impact punctures (also called pinch punctures or snakebites) when the force of an impact is sufficient to compress the tyre all the way to the rim.

Options to reduce the risk:

Increase tyre pressure
Reduce impact energy by reducing weight or reducing speed
Use larger tyres, which would increase the distance between the rims and potential hazards and could also be more comfortable.
Use your arms and legs as suspension to absorb some of the impact force.
Ensure your weight is not excessively biased to the front or rear of the bicycle.

Measure your frame and fork to check your maximum tyre size:

Slick bicycle tyres tend to have circular cross-sections so the tyre should be as high above the rim as their width. (Unless your chosen tyre has a thick extra layer of rubber to prevent penetration by glass and thorns, e.g Schwalbe's "Plus" models)
Regulation EN 4.10.2 "Wheel/Tyre Assembly - Clearance” states a minimum tire clearance of 6mm between any part of the frame or fork. I suggest you maintain this clearance.


In some spots, the tire doesn't fully clear the brake

I take this to mean that the wheel isn't straight, and the tire rubs at certain points in its rotation. If you spend some time truing the wheel, you might be able to get it straight enough that it doesn't rub. The advantage of this approach: you don't have to buy anything.

Another option: keep an eye out for cheap cyclocross forks with cantilever mounts.


Campagnolo have 2 types of 10 speed chain, 6.2mm and 5.88mm (Ultra Narrow).

If you have the older C10 chain you will need a 6.2mm master link.

Measure the chain to confirm the width but this is likely the issue.


How can I check tire pressure without a pressure gauge?

Unless you have got correctly inflated tyres then you do not know what you are missing. No rule of thumb can make up for this. Tyre inflation is really important and your best bet is to get a track pump with valve to check your tyres with. Do this every fortnight, leave it to every month if your journey times are not important to you. I cannot stress enough the importance of getting a track pump, however, that is not what you asked.

Several answers here have mentioned that you should take a peek at how much your tyres splay when you are riding the bike. This is definitely a useful check, however you must bear in mind that a correctly inflated tyre is not a solid tyre and it will bulge out sideways anyway. Only when drastically under-inflated will it show an easily discernible extra bulge. But do watch for that, particularly if you go over a bump and the bike 'thuds' more than normal.

There is also the ride-through-the-puddle test. Go through a puddle and onto a dry surface, e.g. a pavement or a hallway. If you look at how much water has been left behind you can get a comparative idea of how much of your tyre is in contact with the road. If you know what you expect and if the trail is thicker than that, e.g. with a lot more than the centre ridge making contact, then you may want to get the track pump out again.

Returning to the weight-on-the-wheel and how much the tyres splay idea, you can also roll your bike slowly over a kerb and see how much it deforms. At speed it will do so more than under the static situation, so try it slowly and there should be no danger to your rims and 'snake-biting' your tyres.

As for squeezing the tyre after inflating it as best as I can with a mini-pump, when I get to the track pump with gauge I am always surprised at how many tens of P.S.I. I was off the mark. Squeezing the tyre is a waste of time.

If you had car-type valves (which you don't) then you could get those valve caps that some car-part shops sell. These go red when you lose 5-10 P.S.I. They are good but not available in Presta to my knowledge.

Personally I find the best gauge to be how the bike feels and how fast it goes. On some parts of my commute I like to go quicker than the 20 m.p.h. speed limit (as cars cannot over take me then), however, there are times when I am not able to hit my expected speeds, as measured on the bike speedometer. With a bit of extra air in the tyres I can usually get back to where I expect to be.


There are two ways for air to leave a tube - an actual slow leak in the rubber or a faulty valve.

Since you've checked the tube and changed it. this could be a technique thing where you're pinching the tube creating a small hole that is not big enough to show up in a water test.

Try inflating your naked tube to a pressure of about 10 PSI.  It will double in diameter, and could burst if you go too high.   Mix some dishwash liquid into your lukewarm water to help break surface tension.  Put the tube into the water, starting at the valve, and work around the whole thing.  Flex the tube back and forth and take time.

A slow leak is hard to find, but its probably there somewhere.

Last chance is your tubes are all super-light and the air can permeate the surface.  If this is the case, buy heavier tubes.


Stop Kickstand on Plate Shifting into Crank Arm

Kickstands are fiddly, and things tend to move unless really locked off. It's possible the bolt is loosening and the plate movement is the first symptom of loosening. To stop my bolt loosening, after adjusting everything to my liking I added a jam nut (a nut tightened against the already threaded part). This happens to be a self locking nut as that's what I had in the right size.  This is on a double kickstand similar to the one in the question.

Mine also came with a thin rubber pad to go under this plate. That helped, but when it broke I used a piece of inner tube cut to fit, which worked just as well.

Some of these plates are thicker, actually cast into a shape that should settle evenly across the chainstays. You could emulate this by attaching (probably gluing) a piece of plastic or aluminium to the plate, so that it sits between the chainstays. It would only need to be a few mm thick (around 1/4 inch) to prevent movement but would need to be nicely shaped and firmly fastened


What is the maximum recommended rider weight for using a dual suspension bike?

Most department store, BSO (Bicycle Shaped Objects), and entry level bikes carry an advertised weight limit of 250lbs (113kg), which is also I imagine on the safe side, or what some would call a lawyer number. So you should be fine if you decide that is the route you want to go.

A steel framed cheap full suspension will be very heavy, and I would recommend starting with front suspension only, and an alloy model of bike if possible to save some weight – that same company offers several. Then if you ride the bike for a few years and really get into it, save up and spend a little more on a decent full suspension if you want. I ride full suspension and don't necessarily "need it" but I enjoy it more and I do a lot of trail riding with technical features. A higher end full suspension will have different levels of lock out which is a big plus when riding pavement or anything other than trails and off-road.


Is my rear shifter broken? Ultegra 6800 shifter, 11 speeds, 9 clicks, only 8 causing cable tension change

You’ve taken the derailleur out of the system and still see the problem, next thing I would do is replace the cable. They have a bad habit of getting chewed up by the shifter and misbehaving, but you can’t see the damage. Very rusty cables give issues too but you’re unlikely to have a low quality cable, and would be able to see the poor condition.

Give it a try and update the question if there’s no improvement... which would only leave the shifter as a culprit.


There is no quick fix pedal for knee issues. Speedplay's non-centering wide float allows the least amount of outside force working on your knee while clipped in but requires more rotation and some force to exit the pedal regardless.

An ACL issue may be more harmed by the extra rotation and the angle at which release force is required, than it is helped by the non centering, wide float. I've listed several pedals and the float options and release tensions below. (Feel free to add others, if anybody has details. I will as I find them.)

  "Float" is defined as the degree of movement offered by the cleat
  within the pedal before release begins. This can be highly important
  to prevent damage to knees, as most peoples' legs do not remain in a
  single plane as they pedal.

Look:

Keo Easy/Max/Carbon System:
Offers Zero(black cleat), 4.5 degree(grey cleat), and nine degree(red cleat) float, adjustable only by cleat replacement. No release tension adjustment.

Keo Blade system:
Offers Zero(black cleat), 4.5 degree(grey cleat), and nine degree(red cleat) float, adjustable only by cleat replacement. Release tension is either 12Nm or 16Nm. Stock is 12Nm, and adjustment requires changing the carbon leaf spring in the pedal. (Specific tools required.)

Look Delta:
Offers Zero(black cleat) and nine degree(red cleat) float, adjustable only by cleat replacement. Pedal design obsoleted but still common on older bikes.

Shimano:

Shimano SPD-SL (Current Shimano road pedals):
Offered in Yellow/Black 6 degree float or red/black zero float. All SPD-SL pedals from Tiagra level to Dura Ace offer adjustable release tension, from 1Nm to between 12Nm and 16Nm depending on pedal component level.

Speedplay:

Speedplay pedals are unique in that they do not rely on spring tension for cleat retention in the pedal. There is a spring, but is only active during pedal entry and release. This means there is no "centering" action on the pedal. This is the reason that they are often offered to, and can have some benefit for persons with knee trouble. They do require more rotation to reach the point of engaging the release spring, and the release requires some force.

Zero:
Float adjustable on cleat from zero to fifteen degrees. Release tension approximately 8Nm.

Light Action:
Fifteen degrees non-centering float. No adjustment possible. Release tension approximately 6Nm.

X-Series:
Fifteen degrees non-centering float. No adjustment possible. Release tension approximately 10Nm. Obsolete, replaced by light action pedal. Cleats still available.

I hope this is helpful.


Hydraulic brake cable invisible leak. Possible?

Generally speaking it is possible. But you should also make sure that the pistons on the rear caliper are not pushed out too much which could lead to possible oil leak, usually but not necessary when the brake pads are too worn (say less then 0.5mm). I had lots of leaking problems with one of the Shimano brakes in the past, and like you I couldn't identity the problem.

You could start by replacing the brake hose with the new one, which should help narrow the problem. Other than that the canister cap on the brake lever knows to give problems sometimes. Make sure the cap is well tucked in in the right place, also don't forget that there is usually a small piece of thin rubber between the canister cap and the lever which also stops oil going out. One more major thing that can also go wrong with the lever is the small piston below the thing you actually press to brake. One piston pushes the oil from the lever, and the other two pistons (or four in same cases) push the brake pads.

Maybe the best way the determine where oil leaks is to fill the system with new oil, push out the air if there is any and leave it a couple of days to sit like that, but also wrap some toilet paper tight around places that could possibly leak oil, around both hose ends, canister lever and piston and caliper and inspect the t.paper every couple of hours for oil marks. It may sound silly but can actually help.


Buying rear rack during pandemic crisis - go real bottom, up high, or wait?

25kg on a rear rack is already very hard to handle, especially if it’s on the top of the rack. Start leaning the bike unconsciously while standing at a red traffic light and you’ll suddenly do a very embarrassing dance trying to prevent the whole thing (+you) from toppling over. Carrying more than 25kg on a rear rack is really not a good idea. I doubt the bolts and bolt holes of the frame can survive much more. It’s also quite hard on the rear wheel, so make sure you have a sturdy rear wheel if you plan to carry this much load.
I never had a use for the spring clamp on my first rack and removed it after some time for weight savings. It’s really only useful if you quickly want to transport something small and easy to clamp, like a sweater. Even then it’s hard to keep it away from the rear wheel. I’m commuting and traveling by bike and I’m more than happy with my Ortlieb Backroller panniers (Vaude makes very similar ones). They are extremely sturdy, roomy, waterproof and quick to take on and off.
As Qwerky mentions in the comments, bungee cords are much more useful and flexible for securing things to the top of the rack. I’m actually using the detachable shoulder straps of the Ortlieb panniers for the purpose.
One more tip from experience: Tighten the rack bolts to appropriate torque and use threadlocker, they tend to come loose.


Which parts of a bike have reversed (left-handed) threads?

Fixed gear hubs have left-handed threaded lock rings, so that they can't be loosened when the cog that is on right handed thread is turned counterclockwise.


Vulcanization is used to describe the chemical process of hardening rubber. Essentially, Vulcanizing rubber cement is the same thing as rubber glue, but contains accelerators to speed up the drying process, which is why it's handy for patching tires, since you want a fast drying adhesive for patches.

There shouldn't be any issue using it to adhere LED strip lights, just avoid covering the LEDs themselves with the cement as it'll cause them to heat up, and heat is what kills LEDs. Also avoid covering the solder patches with cement if you plan on using them down the line. Otherwise, the product is fairly inert and won't damage your LEDs.


First, if you use a 26" wheel in back, you won't have any brakes as they won't reach (unless you have rear discs).

Second, because you mention that you want a sprocket chain on the left hand side going to the motor, I assume you're going for some kind of off-board solution.  These have been really deprecated with the rise in good hub motors as well as mid-drive solutions.

Update: you clarified that you wanted both the motor and the regular chain on the right hand side. As far as I know, there aren't any freewheels that are split so that they can take two chains that freewheel separately. The best you can do in this scenario is to use a regular freewheel and put a one-way bearing on the cog that's on the motor. It'll mean the motor chain will not freewheel -- but it'll also mean the cranks will move when the motor is moving (with the real possibility of breaking your ankles). The safer way is to use a flip-flop hub or disc-brake mount to put the sprockets on the left hand side using either a left-hand freewheel or a one-way on the motor. That way, the bike's freewheel will make sure that you can't break your ankles.

tl;dr It'd be so much easier for you to get a 29" hub motor wheel -- or to keep the current wheel and go mid-drive.

Not an answer to your question about left-hand sprockets so feel free to ignore.


Ultegra 6800 front hub plastic cover loose

The plastic cover is there to protect the wheel bearings.
It prevents dust from entering in.
So it's totally fine if it's loose.


How to separate ODI grips from lock on clips?

If you put a flat blade screw driver into the bar whole with the blade between the clip and the grip and gently pry it away from the grip by leveraging on the opposite side of the clip, it should pop off. Or just pull hard with your hand.


freewheel removal tool for Shimano MF TZ21

Yes, the Park FR-1 (or something compatible) is your friend.


Minimizing the pain in Biceps and Shoulders due to Mountain Cycling or Offroad cycling

Four factors I can think of

bike
tires
riding style
conditioning

If the bicycle has full suspension then less vibration.  Carbon frame will absorb vibration.    The fit of the bike is a huge factor.

Larger tires at lower pressure will absorb vibration.  Can run tubeless tires at lower pressure.   If you are running smaller tires then go to a bigger tire like 2.2 - 2.4 if your frame will allow.

Riding style has a lot to do with arm and shoulder fatigue. Try and relax. Move your body forward and back. Don't muscle the bars. Get in the middle and let the bike rock under you. Even if you can just learn to relax between the ruff sections you will gain a lot as the muscles get a chance to recover and get more blood flow.  Watch a good rider on ruff downhill - they are relaxed and a beginner will be tensed up fighting it the whole way.

The more you ride trails the more you will condition those muscles.  In the gym push up, pull up, fly, ...  Whatever is sore find the exercise that engages that muscle.


Replace a double ultegra crankset for a triple ultegra crankset. Is that possible?

Most people go the other way. Many new bikes now only come with double chain rings. And compact crank sets give almost the same gear range as triples.

But it should be possible. The distance the front derailleur travels is about the same. You may need to adjust your limit screws though. And of course you need to change the front shifter to a 3 speed version.


There is no way you can accurately assign a distance to disk brake replacement.  Someone commuting in a stop and go method in a wet climate like the pacific northwest will get much less life out of their setups than someone living in a drier/cleaner climate and a more continuous commute.

Anyone can determine the relative life left in their setup by looking at their brake pads.  The pads are the wear point for a set of disc brakes and DO need to be replaced with normal use.  Almost all other aspects of the system are likely to last near indefinitely with normal use (except perhaps the cables on a cable actuated system).

For your part, you would do well to check you brake pads IMMEDIATELY.  If you wear all the way through the pads and do not replace them you have a high chance of ruining your piston as well as possibly your rotor.  Ruining the piston will essentially result in needing to replace the entire caliper and/or unit.  Hopefully the horrible noises you are hearing are just the pad backing tearing against your rotor and you haven't damaged your pistons yet.  You may get away with just new pads and/or rotors.


New Tubeless Tires leaking from Molding Sprues. Manufacturing defect?

Sounds like a defective tire. The rubber has not fully filled the mould at the injection point.

Don't mess around trying to fix it. Take it back to the bike store and have them swap the tire for you. That way you'll know you have a good tire that will not fail on you later.


They're basically arm warmers. They have to be close fitting to stay in place. I suspect you're not sweating as much more as you think, but it's not evaporating as quickly - her way you can easily end up sweatier.

Some arm warmers/sun protectors are better than others - thinner and better at wicking sweat away. So you may have been a bit unlucky. Light colours are also helpful in the sun, but I'd rather use suncream even if that means carrying some and topping it up. I found that using sleeves like yours as sun protection left me with little gaps that kept opening up where they met my jersey sleeves, and I got sunburnt there. Yours may fit better.


What would you upgrade first on a road bike?

Honestly?  Nothing.   Assuming your bike functions correctly and is not yet worn out?  I'd not change anything on the bike mechanically.

Perhaps think about comfort, what would allow you to spend longer on the bike, or to go harder?  What hurts at the end of a long ride, and how can you improve that?

Changing Contact points can help, so better gloves/bartape.  Perhaps shoes and cleated pedals, but there's nothing wrong with flats (its really hard to walk around the shops in cleats)

If you do night riding, then some decent lights can be wise, two front and two rear (so a primary and a backup in each direction)

Clothes make the ride more enjoyable too.  Close fitting fabric is faster than loose baggy clothing, and it often weighs less too.  So a riding top and tights/leg warmers might be of interest.

As for progress - if you're data-driven then using a service like Strava or mapmyride or similar can help you know that you're improving.  They offer free levels, and more for a subscription.  These services may work on a standard smart phone, or you might choose a fancy bike computer.

But seriously, wear parts of your bike out before upgrading.  That's fiscally responsible.

When your tires wear to the point they get a lot more punctures, then replace them with something nice like GP5000 or similar race tyres.  But not earlier.


What kind of road bike wheels do I need to replace my stolen ones?

Your hub widths are correct for non-disc wheels (disc rear wheels are 135 mm).

You need a non-disc road wheelset with a 10-speed hub which is Shimano/SRAM compatible. Your cogs need to be a 10 speed set from Shimano or SRAM, and you want to have similar gear sizes. The particular set of replacements will depend on what rear derailleur you're running (which will set limits on the max cog size and a few other things).

The rim width doesn't have to match exactly, but should be matched (roughly) to what size tire you want to run. See Sheldon Brown (or any of a variety of other sources, e.g. the Schwalbe website) for a table of what rim widths are good with what sized tires. These aren't hard and fast rules, but if you exceed them grossly, you may have issues.


What do I do about a hydraulic disk brake piston that won't retract correctly?

Every Shimano hydraulic brake uses mineral oil. The material used for the seals is known to be incompatible with DOT brake fluid so I suspect using conventional grease may have caused the seals to swell irreversibly.

You should never need to grease the pistons of any bicycle hydraulic brake, since the fluid is a lubricant and the pressure seals so tight that they would wipe grease off the piston as it retracts. Grease may also become less viscous when heated, allowing it to drip onto your rotor with catastrophic effects, or may catch fire.

In future, you can use spacers and clamps to restrict the free piston so all the pressure goes to the sticky piston. Ensure the piston doesn't move so far that it leaves the seal. Clean with brake fluid and a soft cloth or q-tip. Push back in and retest. If cleaning isn't enough, the piston's seal surface, the seal or the caliper may be damaged, or one fluid passage inside the caliper could be blocked. Such issues are rarely user-serviceable.

Shimano uses easily-damaged ceramic pistons in its XTR brakes, I'm not sure whether any XT models also have them. Ceramic pistons are definitely Service Center only.


Clipless pedals: Why clipping in so darn difficult?

This is part comment, part answer, but too long to fit in a comment, so here we go.

Personally, I use SPD, and when I ride with a group, everyone else has SPD-SL or LOOK.  I'm usually clipped in and across the intersection before they're clipped in.  Either I'm just really good at clipping in, or SPD are designed to be easier to get clipped in to. Even the very experienced riders tend to have problems with clipping in from time to time.

Personally I don't know what advantage SPD-SL offers over SPD. People say that the larger platform allows for better power transfer, but I don't see how that makes difference. The foot pushes on the hard sole of the shoe, and sole of the shoe pushes on the pedal, which is made of rigid metal. Assuming there is no flex in the pedal or the sole of the shoe, it doesn't matter how large the attachment point is.

Personally, I would recommend you try out a pair of SPDs. Borrow some from a friend or see if the shop has a demo pair and see if that works better for you. Too many shops will push you towards road pedals (either SPD-SL or LOOK) because you're riding on the road, and you will break "Rule 34" if you use mountain pedals on a road bike. I think that SPD pedals are a much better solution unless you're an actual road racer and only plan to unclip at the end of the ride.


I don't know why you think bicycle degreaser products are 'weaker for more money' when you have basically proved to yourself that gasoline (petrol) is a very poor cleaner because it evaporates very quickly.
I've had success with a basic citrus degreaser available at Home Depot that costs $4 for a reasonably sized bottle. It's effective at loosening dirty chain lube, minimal brishing of the chain and cassette is required and it rinses off with water taking the dirt with it.
I should point out that you are likely over-cleaning your chain. Too much solvent/degreaser removes the lubricant from deep between the link plates and rollers. I've found I get much better chain life by only wiping down the outside of the chain with minimal degreaser.


Why is it easier to balance a non-moving bike standing up than sitting down?

Just speculation, but I suspect that when we balance standing up, we move our hips laterally to make fine adjustments to the relative position of our center of mass over the wheels. When doing so, we push laterally from our feet on the pedals, which are low enough and far enough below the center of mass to make adjustments relatively easy to accomplish.

With your backside planted on the seat, the main mechanism to laterally adjust your center of mass is to move your shoulders and chest relative to your hips. Now you have a smaller mass on a relatively short lever anchored relatively high up. So a movement of the shoulders mostly results in a countermovement of the hips in the opposite direction. That makes it not only fairly difficult to get much movement of the center of mass relative to the wheel-ground contact, but also difficult to do so in a controlled manner.


Are bikes with sloping top tubes lighter than bikes with horizontal top tubes?

So are bikes with sloping top tubes lighter than bikes with horizontal top tubes?

No.
The frame may be lighter but the total bicycle ain't. The larger bending moment at the location where the seatpost enters the frame must be supported, and it means the seatpost requires more material besides needing to be longer. Even if the seatpost is not made more sturdy (which would mean you're not comparing apples to apples anymore, as you can't just increase the seatpost length and have an equally durable seatpost), a given length of the seatpost would weigh more than the same length of the seat tube.
The reason for sloping top tubes is something entirely different. Just look at the relative saddle and handlebar heights of the two bikes. The horizontal top tube frame has low handlebars, whereas the sloping top tube frame has high handlebars.
Now, you can have high handlebars on a horizontal top tube frame you can stand over, but it would require lots of spacers around the fork steerer tube, or alternatively a high-rise stem. Many people consider the look of either of these solutions ugly.
I have a Surly Long Haul Trucker I built myself. It has a 17 degree stem flipped down, so the stem is horizontal in addition to the top tube. It indeed requires a very very large number of spacers around the fork steerer tube. This is despite the fact that the height of the top tube above the ground is such that I can barely stand over the frame.
If you want to have handlebars at the same height as the saddle, either you require a sloping top tube, a lot of spacers or a high-rise stem.
This of course doesn't affect those of us who prefer a low racing style handlebar height.
So, the reason for sloping top tubes is most likely the fact that we have nowadays threadless headsets (aheadsets) and the stems that clamp around the fork steerer tube. When horizontal top tube bikes were the norm, we had quill stems that don't require spacers.


Can I use a bike for commuting 10km everyday at Jönköping (Sweden)?

As long as the bike paths and roads you'll be traveling along are reasonably well cleared of deep snow, this would be no big issue.

You can order basic Schwalbe Winter studded tires cheaply (around 40euro a pair) from Bike24. You should probably be able to find a basic used bike for 110 euro.

Studded tires aren't strictly necessary for winter riding, but they do provide peace of mind on days with a freeze-thaw cycle.


Route planners with route avoidance features

https://brouter.de/brouter-web/

Allows you to draw no-go areas.
Allows you to specify cost for ascents or descents. I’m not sure it’s possible to tell it to completely avoid streets above a certain incline. You could set the cost very high and set the cutoff to whatever you like. Disadvantage of this approach is that inclines below the cutoff are not considered for routing (i.e. it doesn’t try to avoid shallower inclines anymore).
Allows you to specify a plethora of other parameters and can be scripted.


Whether it's possible or not, it's a bad idea.

With any suspended system, there's sprung weight and unsprung weight. Sprung weight is the weight carried by the suspension system, and unsprung weight is the weight that's "downstream" of the suspension system (the wheels, etc). In any suspended system, the goal is to maximize the weight that is sprung, and minimize the weight that is unsprung.

When you go over a bump, your unsprung mass gets pushed up, then recoils and goes down, and this cycle repeats until the energy in the system has been damped out (vocabulary aside: although we casually refer to suspension as "shock absorbers", real shock absorbers only damp out the recoil, not the initial impact). Adding unsprung mass makes that recoil much harder to damp out. If you put, say, 2 kg of rack + bag on your front forks, and another 7 kg of load, you're exceeding what the front suspension was designed to handle by a factor of 4 or so. Not so much in terms of the initial shock (which I imagine can be many Gs) but in terms of absorbing recoil.


As an interim answer, it sounds like the plastic track has been wallered out and now has play between it and the metal track.

  Topeak UNI Super Tourist DX Disc Carrier stock photo showing rail in the middle

Topeak MTX Trunk Dry Bag stock photo showing underside.

First guess is that the grey plastic foot has worn through insertion/removal over time.  I doubt the metal has worn, but it may have unfolded a little.

You need to look at your bike and see which is the cause.

Your options are:

Check that the foot is not wobbling on the bag - as ChrisH points out they're only rivetted together, so it may be sloppy there.  Drill out the old rivets and install some small bolts with washers, and nyloc nuts to stop them coming apart.
Pack the gap between plastic and metal using a strip of additional plastic.  I hear sugru is the bee's knees for this kind of repair but it probably wears even faster than the original.  Or you could use a long thin piece of brass or aluminium, which would wear faster than the steel, but may need one on each side.  This might be called a "Gib" in the machining world.
If the metal runners are bent outward, you may be able to bent them back in with pliers or a vise or a big clamp.  Risk is snapping the steel, or potentially weakening it.  I doubt this part is available as a service item.
Replace the plastic foot completely.  I do not see this as a service item to purchase, which is somewhat surprising.   You might try to 3D Print a replacement, after taking careful measurements of your existing one and of the rack track.  Or if you lean more to woodworking, a hardwood rail with the right dimensions could bolt on in place of the worn plastic one.  You could mill the new foot out of aluminium too, depending on what access you have to tools.


Yes, that bolt was the closing side of the ball bearings, your current axle is probably a "cup and cone" hub.

You opened the cup, so the ball bearings that where rolling on the cone just fell off.

You have to replace them (same diameters and possibly same hardenss ...), clean and grease all the parts (rusty and not rusty, it does not really matter).

Finally, you can replace the axle with a quick release skewers, but it must be of the same (internal) length as the one you are replacing (130mm, probably).

Giving the exact bike model or at minimum a picture of the wheel&hub may help us help you.


Are all the Ultegra brake pads the same?

If you have carbon rims (with a carbon braking surface) you will need appropriate brake pads, so as not to damage the rims.  You do not have to use shimano brake shoes- most (possibly all?) rim brakes will take any brand of shoes.

There is a carbon rim insert for Dura Ace, which might fit the ultegra shoes.  However if there are no compatible pads for your brake shoes/ rims, you may have to buy a new set of shoes - not especially pricy, and they will come with pads.


No  Those lugs are for mounting a rear mudguard/fender or a rear rack, not a brake caliper.

They are far too weak for a caliper, too close to the axle and would be torn off quickly by the leverage if you did somehow use them to mount a caliper.

Remember that rear brakes are only 5-10% of your overall braking.  If you desperately want to add discs to this bike, either find a front fork with disc brakes, and a suitable front wheel with a rotor.

Otherwise you need to look out for a newer/better bike.


If your tire has begun to lose air slowly (loses 10 PSI over 2 days), it has lost the liquid carrier in your sealant. The remainder of the sealant is dry or lumpy and can't travel to the new thorn. It was ammonia or environmentally friendly antifreeze (not ethelene glycol) that evaporated. Like the original liquid is pretty much gone.

Our riding club carries Orange seal and Stan's in portable 3 ounce bottles. We use it interchangeably any time a member gets a low tire on the trail. Never had an issue.


I have seen this effect with several different optical based wrist HRM's. Your HR is not 90, but likely closer to 180. Optical HRM's generally have a longer lag to track changes in the heart rate and sudden jumps can be interpreted by the software as drops rather than increases.

I've found that for long sustained efforts, the HRM eventually tracks back to the correct value, but can be wildly off for shorter efforts. There is also the physiological lag in HR vs effort. Early on in a workout, your HR doesn't track your effort particularly well.

Many of the coaching/training blogs I follow are suggesting that perceived effort should always trump HR based training, particularly as HRM's struggle to track correctly at high heart rates. If you're breathing heavy and think you're working hard, you're working hard regardless of what the HRM says.

For a recreational athlete I'd suggest just living with it. I find the convenience of wrist based optical sensors far outweighs the occasional data inaccuracy. Most professional bike riders still use electrical chest based straps for this reason, but they also all use power meters to gauge their efforts during training.

If you want to learn more about the limitations of your device, I recommend searching for reviews on DCRainmaker.


Best methods to sell a bike will vary depending on where you are located.

If you are in North America local Facebook marketplaces oriented to bikes or bike gear can be good. See https://www.facebook.com/groups/dcusedicyclemarketplace/ as an example.

Pinkbike has a buying and selling section https://www.pinkbike.com/buysell/ but it seems to be dominated for really high end bikes (think > US$5K).

The general rule is that if you can't sell something you are asking to much for it. Try checking Bicycle Blue Book https://bicyclebluebook.com to get an idea of how much your bike is worth. Many folks will say BBB values are BS, and I partially agree as values are dependent on many factors, but at least you'll get an idea what you should be asking ($100s vs $1000s).

Post Christmas winter is probably a bad time to try to sell a bike. Wait until the warmer spring weather appears and you may have more luck.


How can I mount a pannier rack on my (carbon fibre) Trek Madone 4.5?

There are some racks that mount directly onto the seat tube and utilise a quick release clamp; they only take a small load tho.

This would avoid clamping onto the carbon. As others have hinted its not such a hot idea to do this as carbon is not designed for that kind of compression. You can find evidence of this with car racks where carbon frames are not recommended for down tube clamp racks.

You should be able to get some p clips that go onto the skewer but may require modification for your drop outs.

That chain look like its fit for the bin.


Help! Want to convert 8 speed Kona road bike to 1x drivetrain

I think you need to ask yourself why you want a 1x drivetrain. What is that going to do for you that your current system does not?

Presumably you want more rear derailleur gears than your current 8 (why would you want an upgrade otherwise?) That means you will have to get new shifters as well as rear derailleur, cassette and chainring. You can run a single ring on a double crank but you'll end up cross-chaining on either your highest or lowest gears, so a new crank is advisable.

It's likely that the cost of all that, plus having a shop install it for you or buying the special tools required if you do it yourself can be significant compared to the purchase price of the bike.

If you really want to do it you have a few choices:

Lower level of dedicated 1x11 system such as SRAM Apex 1. Obviously the best but most costly option. Note, this option may also require a new rear wheel in addition to the items listed above as 11 speed road cassettes generally need 11 speed compatible freehub bodies.
9 or 10 speed mountain derailleur with a 9 or 10 speed road right hand shifter. I believe Shimano mountain and road systems used the same cable pull ratio up to 9 speed. SRAM mountain and road systems use the same pull ratio throughout (at least for older systems).
Road 9 or 10 speed rear derailleur and right hand shifter, use a derailleur hanger extension to enable running a larger range cassette. (Road derailleurs usually support a 28, 30 or sometimes 32 tooth max sprocket. You will probably want 34 or larger.) This is a bit of a hack but ensures compatibility between derailleur and shifter at 10 speed. See this recent GCN Tech video for info on this method.

By the way, for road riding you will not need a clutch derailleur as the chain will not be bounced around. You could use a narrow-wide chainring for better chain retention, or just leave the front derailleur in place to keep the chain on the front ring.


Pedals hits the ground too often while turning at relatively high speed

It's definitely possible that the bottom bracket height is lower than your previous bike and/or your crankarm length is longer.

The BB could be lower to improve handling and I have definitely seen longer crankarms on large bikes.  A typical measurement is 175cm but you could see 170 on a small frame or 180 on a larger frame. The longer crankarm would be to accommodate your longer legs.

Look on the inside of the crankarm, you should see the length stamped in there, or you could measure from the center of the bottom bracket to the center of the hole where the pedals are.

I don't think it's an inherent design issue but it could be a different design that doesn't work well with your riding style.

Side note: When cornering hard if you are going to have a foot down, you want your outside foot down.  This lets you keep your weight over the tires for maximum traction.  If you really want to continue to corner hard and fast you could ride hard in, drop the outside pedal, corner hard and then standup out of the corner and hammer on!

But, back to your original question, if you want to try and track down the issue, I would measure the bottom bracket height and look for/measure the crankarm length.  One or both of those measurements compared to your old bike would give you some insight.


Abus Folding Lock: Adding Damping to Joints

I use an ABUS everyday. Keep the lock orientated on its side, the friction in the joints will help it keep its form.  The friction is essentially the dampening units you interested in.  If you maintain this orientation you can set a shape and carefully pass it around something.  The moment you change the orientation, to something more vertical, the friction in the joints will lessen and the lock will take the lowest energy form (typically straight down, hitting you in the shin or chipping the paint on your frame - hrrmm...).

I am sure ABUS could add nylon washers to act as explicit dampers, furthering this friction effect, but this would likely increase the cost (for an already expensive lock) and could wear overtime adding slop to the joints.  Slop could be bad as it could make it easier for theives to insert wedges to try and attack the joints (arguably the weakest point of the lock).


You'll just have to make sure that the rotors match the type of brake pads you use. Shimano mark their rotors for 'resin pads only' and the like! –


This is actually an easy fix, but requires some special tools.
On Shimano cranks, the left hand crank arm clamps the axle. When this is installed the crank and axle are pulled together by tightening the plastic cap that threads into the axle through the crank arm. This sets the bearing pre-load and removes any axial play.
From the video it looks like you have lost the cap and that has allowed your crank to slip off the axle a little resulting in that axial movement.
Once you have a replacement cap. all you need to do is loosen the crank pinch bolts, finger tighten the cap to set the pre-load (the cap should not be over tightened) and re-tighten in pinch bolts.
However, you need a special tool such as the Park Tool BBT 1 -2 to tighten the cap. Also you really need a torque wrench to tighten the pinch bolts properly to avoid over-torquing them and stripping the threads. Conversely, under tightening the pinch bolts allows the crank arm to walk around on the steel axle which deforms the splines in the arm. Both are rather emotionally traumatic experiences as you realize you now need to buy a whole new crankset.
This is a good video showing how the crank is removed and re-installed, including setting the bearing pre-load.


New puncture resistant tires punctured after 2 min ride

While we don't do product reviews, note that puncture resistant doesn't mean puncture proof -- with any air based system, you're going to run the risk of cutting the tire and tube and getting a flat. Some tires are better than others in terms of puncture protection, using things like kevlar belts. The tires you bought trade off for some more the weight and handling performance versus durability to road hazards (by fitting a kevlar belt rather than whatever lighter thing they put in there) so that you have less protection from road hazards than say, a Schwalbe Marathon Plus.

Don't ride through glass and in general avoid road hazards is the best thing to do.


SRAM 2x10 shifter-derailleur combination

The SRAM road derailleurs and road shifters you've selected should work together.

However, the bigger problem might be that you need a 10 speed cassette (for which you'd have to look up the hub to see if its 10 speed ready). It seems like the 2015 YVR model has a 10 speed compatible hub, but check yours. If you don't have a 10 speed ready hub, you'll probably want to get a new rear wheel.

You also need to make sure the SRAM FD/RD can shift your chosen chainrings + cassette.

As for buying the best parts, note that the more you spend, there are diminishing returns, and you can get excellent shifting with well below Red 10 -- e.g. with Apex or similar. It doesn't really make sense to equip a cheaper bike like the one you have with top of the line components, especially since you probably wouldn't notice the difference from a lower end group. You can also get a mountain RD since the cable pull is the same and save some more money. I personally wouldn't go up to the Red level on this. Also, ask yourself if you really need 10 speed -- 8 or 9 speed is cheaper to run (chains, cassettes) and buy, especially if you rack up a lot of miles.

And you're upgrades cost close to what the bike is worth or more, so you may want to just sell the bike and get another one with higher end parts.


Internal cable routing blocked on '80s steel frame. What are my options?

I'm sad to say that I solved my issue by adding a clamp-on cable stop much like this one:

.

If going down this route an optional extra is to poke the blockage with such force and frustration that your poking stick (coat hanger) breaks off and is stuck forever inside the chainstay. I elected to go down this route, but my understanding is that it's not compulsory.


What is this cable/hose management clip? (picture)

Bike parts.com lists them as Sram rotating dual line hooks # BPC 147851.


Does a chain ever need to be loosened by bending sideways with Shimano reinforced pins?

I've certainly had a stiff link at the join on my 8-speed hybrid. I usually use IG51 on that, but have used HG71 so I can't remember which one gave the stiff link. Since using master link chains on my newer bikes I've started to prefer them, but could only get HG53 recently, with a special pin. That didn't stick, but like you I was half expecting it to.


It sounds like your derailleur cable has a bit of slack in it. You will find this video useful, its easier to give you this link with a lot of good footage than try to explain it myself.


I have a Specialized pump which works very well for both high-volume and high pressure tires.

I've also used a couple of different Joe Blow pumps from Topeak, which worked pretty well.

In light of this, I'm of the opinion that your best bet is to hit up your LBS and see what they have, and what you like using.  For me, handle shape and size plays a big part (you need comfort to pump up a 26"x4" tire).  Plenty of pumps work for both types of valve, and your LBS should be able to point out which pumps can do this.  Some require you to screw off a cap and flip something over, others can have a two-sided head, and others (like my Specialized) have a head that works for both without any changes.


Why is my chain slipping/dropping on the smallest chainring when pressure is applied?

You say the cassette and chain have been replaced but the front rings have not. You also mention that the front rings look ok, which maybe so, however it seems there is still a meshing issue between the new chain and older front rings. Assuming the frame or bottom bracket are not misaligned. I would take it back to the bike shop and have them check the chainrings over fully.
Your not just looking for worn teeth on the rings but the way the chain locates on it.. Even slightly worn teeth can cause issues with a new chain.
Also check for a loose chain side crank arm or cracked/loose chainring bolt.


On one of my bikes I've set things up so I can hold the bars, brake, and use the bell all at the same time. I did this by mounting the bell underneath the handlebar instead of on top, which gets a low one much closer to the grip.


Failing hub bearings on a beater bike (freewheel) -- time to replace the bike?

A new 26" freewheel repair wheel starts at around $40US from a bike shop or Amazon, and there are also literally millions of used ones around, so even if it does need a new wheel, if it's an otherwise working bike then this shouldn't be the problem that totals it. The bike in question is old enough that it may be 126mm or 130mm in back as opposed to 135 like you'd find on most repair wheels, but that's an overcomeable problem if so, either by jamming up to a 5mm difference, respacing and redishing, or getting a 130 wheel.

As for fixing the hub, the first thing to do, before taking anything apart, is check to see how bent the axle is by spinning the left side with your hand and observing how warbly the right side is, if at all. That can easily cause a lot of resistance and bad feels in the hub, but if it hasn't been too bad too long the rest of the hardware might be usable, and a new cheap axle is only a few dollars. (Note that we're not talking about a nice one, ie Wheels Mfg. We're talking about the other kind, a generic unpackaged OEM-level replacement, which may even come with cones that may be helpful.) The next question is whether the cups and cones are totally disintegrating or just rough, i.e. heavily pitted but still have their basic shape. If the former you need cones or a new wheel if it's the cups, but if it's the latter then a new axle, new bearings, and new grease will generally be fine for a low-mileage bike.

If you do need new cones, old random freewheel hubs often use one of a couple different common basic shapes, and so cheap no-name cones often can be made to work, especially if you find a shop that has some different ones to choose from. This is actually the main application where cheap little generic "axle sets" such as the one linked to above can be useful. Determining suitable replacement cones and getting the hub properly set up with them is a larger topic; one place I know of you can read a lot about it is older free copies of Barnett's Manual floating around the internet.

Cones can be re-ground to an extent. You can get pretty sophisticated with it, but a very simple method is put the cone and a locknut on a nice straight axle in an electric drill such that the drill chuck is right against the locknut, so as the cone spins there won't be much run out. Find some kind of dowel or shaft of a diameter that matches the profile of the bearing, probably 1/4" in this case, wrap it in sandpaper or emery cloth, and clamp that in a vise. Hold the spinning cone up to it to resurface it. Go slow so it doesn't get too hot. You don't have infinite material to lose with this approach before the cone isn't the right shape anymore, but it generally works pretty well.


Once you unlink the cable from the hub slide the sheath away from the cord.
Then, slide the plug marked on the photo to open the hole.

Set the shifter to 7th gear.
Push the cord toward the shifter. The cord ending should appear in the hole. Pull it.


Do Shimano MTB shoes in half-sizes make a perceptible comfort difference?

Simple maths will show that for 50% of the population, a half-size will be closer to their “true” foot size than an integer size.

But the same maths will mean it won’t make a difference for the other 50% of the population.

We can’t tell which half of the population you’re in and whether you’d benefit.

P.s.  this assumes that the sizes of human feet are a continuous rather than discrete range. This is not a trivial assumption as long-term wearing of discrete (integer) shoes may deform half-size-feet into a shape closer to integers. It also assumes the same foot size on both feet which is definitely a dangerous assumption.

Version 2 of my answer.

If we want to assume different size left and right feet we have to do more stats.

So ... assuming you have different size feet, that the shoes have to be bought in the same size, and that half sizes are available, I think the statistics would be 1- (50%*50%) = a 75% likelihood that one or both feet will be closer to a better fit when you have half sizes.

This is compared to only a 50% likelihood when using integer sizes.

There’s lots of false assumptions in v2 but the simplification (most notably the difference is size between two feet is assumed to be random) would lead to a lower likelihood and thus its likely that the actual improvement is greater than +25%.


Is going without a helmet more aerodynamic?

I did not do exhaustive literature review, but the first hit, Aerodynamics of ribbed bicycle racing helmets has wind resistance measurements for several different aero helmets with vented helmet and bare head as controls. Bare head had similar air resistance to aero helmets at low yaw angles and the lowest resistance at large angles. The paper's conclusion is that for helmets (or bare head) that do not have huge number of vents, cross sectional area has more effect than the shape of the head or helmet.
This is of course purely academic, since competition outside sanctioned events doesn't count and in official competitions (excluding special cases such as hill climb time trials) you are required to wear a helmet anyway.


Can Park Tool CG-2.2 kit work with the bike upside down?

Yes.

All those tools require is that the chain moves through them. They do require the chain move through in a particular direction so you will probably find that you end up with the handle on the bike side of the chain rather than on the outside, which will be mildly inconvenient. But it beats not being able to clean your chain at all.

Here's what I do, I took the handle off and set it up so the rear derailleur is pulled forward far enough that the chain cleaner can rest on the mech rather than hitting the idler. That lets me pedal with one hand and have a hand free for wiping the chain, chainrings, idlers etc. I also find disposable gloves essential for this, there's no chain lube that's good for your skin.

You could do the same thing with the bike upside down, but you'd need to rearrange things a little.

The question body makes it clear but the original title didn't, so just in case it's not obvious, if you have the tool upside down it will not work - there's a reservoir full of fluid at the bottom, if you invert it that won't hold the fluid.

(note that the above photo is a bit of a cheat, it's of a 406 wheel bike with hub gears so the derailleur is used as a chain tensioner and the chain only runs over one idler. But I do the same thing with my 622 wheeled road bike)


That's an awesome bike - would be called a MTB back in the day, but now we'd call it a rigid MTB.
You probably have to replace the brake pads (the rubber blocks, 4 in total) because they go hard with age/ozone/UV and don't brake as well.   That style of brake is called a cantilever and while less-common now, they can still work perfectly well when tweaked correctly.  If you did replace the brakes, then your options are more canti's, or V brakes.  It may take long-reach caliper brakes, but those generally have lower performance than your existing ones.  You cannot have effective safe disk brakes on that bike as-is.
Gears - they likely need a clean, lubricate, and then adjust the cable tension.  I see friction shifters on your handlebars, which may feel vague compared to modern trigger shifters.  However there's nothing wrong with them.
The cassette appears to be a 7 speed, so it could be a cassette or a freewheel.  If you wanted, it could potentially go to 8/9/10 speed, but that would need a new wheel, rear derailleur, cassette, chain, and right-hand shifter.
There's nothing wrong with leaving the front mech as a friction shifter if the rear was updated.
If the tyres show cracks or perishing, then you might want to consider new tyres. For normal street riding, aim to get less~no tread blocks which will allow you to go faster.  If the current tubes hold air fine, then just ride it and get some wear out of the existing tyres, and delay spending on replacements for now.   The current tyres are relatively street-oriented.
Finally - I really like that paint job.  Its a great looking bike and sure beats walking.  And since you can't get anything else right now, any bike is better than no-bike.


Bike purchase advice: looking for a fast tarmac/gravel bike

This is a potentially complex question, because we don't know exactly what 70% tarmac and 30% light gravel means. Light gravel might mean a dirt or crushed limestone road, or it might mean smaller bits of gravel. A roadie might think of light gravel differently from an MTBer.
Consider the surface
Cyclingtips recently proposed a grading system for gravel. I'm posting the sample photographs and descriptions of two grades that could be classified as light gravel.

Grade 2
Suggested tyre size: 700×28 – 700×35

Dirt roads. The native habitat of our crew in Boulder, where well-made, hard-packed dirt roads offer a road-like experience but without the traffic. A 2WD car will have no problems getting along here; a road bike will be mostly fine but some rutting and looseness will mean that it’s getting a little out of its depth. At times, may be even smoother than bad paved surfaces.

At the rockier end of the dirt road spectrum, you start to approach…

Grade 3
Suggested tyre size: 700×32 – 700×38

Reasonably smooth gravel. Discernible small rocks over a hard-packed surface mean that you’re struggling to pick a line on narrower tyres; a bigger volume tyre allows you to keep your speed up. In wet conditions, there’s a fair bit of muck kicked up from the surface so rim brakes, even if they allow the tyre clearance, might not be ideal.

The types of surfaces that are available depend on where you live and where you want to travel. Also, a rider's experience, preferences, and handling skills might allow them to handle a higher grade of gravel on a more road-oriented bike.
From personal experience, I took my road bike on a ride that had about 40% grade 2 or maybe 2.5 gravel, and the rest tarmac. The bike had nominal 25mm tires, which actually measure a bit over 27mm. It was totally fine. On the sectors with some visible gravel stones, I had to be more careful about picking a line. If there were a significant amount of real grade 3 gravel, that bike would not be my first choice.
Also, rain and mud would have modified my preference. I did one ride later in the that was 70-80% on grade 2-2.5 gravel, but it had snowed some and the roads were muddy. I used my gravel bike, and I know that I would have regretted my road bike.
Indeed, the Belgian Waffle Ride in the US explicitly says this in its FAQ:

The kind of bike you ride will depend on the type of rider you are and how comfortable you are in the dirt and during long races. The uniqueness of the BWR is that it really causes great consternation as to what weapon to bring to the fight. Too much bike and the 90 miles of road will zap you. Too little, and the rocks, sand, gravel and water will make you suffer or flat ...

On race day, you will notice there are road bikes with 25mm tires; plenty of Canyon Ultimates will devour the course from the front. There will be plenty of Canyon Grails, a unique gravel bike that provides clean comfort in any dirty detour. There will also be a lot of cyclocross type bikes, like the Canyon Inflite, where 32mm tires and plenty of clearance make for a speedy steed. Still others will be on the Canyon Endurace, with its endurance-optimized relaxed geometry, enhanced control features and race comfort; this bike is as at home on the road as it is in the gravel. You will even see mountain bikes, like the Canyon Lux, a light, full-suspension XC ATV. What you won’t see are e-bikes, time trail bikes or tandems.

The bike you should ride is the one you are most comfortable on for both road and dirt...
Road and gravel bikes are both evolving
Another complicating factor is that the road and gravel bike markets are evolving. Briefly, endurance and even performance road bikes can accept wider tires. This enables them to take on rougher surfaces. If it matters to you, some aerodynamic wheels are even becoming optimized for wider tires (usually nominal 25-28mm tires, paired with internal widths of 23-25mm). Simultaneously, the gravel market is bifurcating into a road-like sub-market and a more adventure-oriented, MTB-like sub-market.
NB: Any specific bikes mentioned here are simply the ones I've read about recently. They're not an exhaustive list. This biases the list towards bikes that have been reviewed, and the named examples tend to be from major manufacturers, or at least ones that are prominent to me for some reason.
The 2020 Trek Domane is an endurance road bike. However, it can accept 38mm tires, and it even has built-in pseudo-suspension. The 2021 Trek Emonda, which is a semi-aero climbing bike, is officially rated for 28mm tires, but it appears has enough space to fit significantly wider tires than that. The article stated that there was 42mm of lateral space at the narrowest point on the frame between the chainstays, and typically about 5mm clearance is recommended, implying that you could run tires measuring 32mm, perhaps a bit wider if you can accept some risk. The Specialized Venge, an aero road bike, was described as being able to accept a 32mm tire.
On the gravel side, one part of the market offers bikes that are like endurance road bikes with clearance for tires up to about 45mm on 700c wheels. As of 2020, the Trek Checkpoint, 3T Exploro, and Cervelo Aspero would clearly fit in this category. All-road bikes may be a synonym for this type of bike. They basically handle similar to endurance road bikes. This type of handling is more than capable off-road. In my view, especially as an owner of a bike like this, these bikes are less fun to handle on singletrack, i.e. in repeated tight turns, with steep descents, on very rough terrain. I have completed some singletrack loops for fun on my Parlee Chebacco. It was fun just to do them, but they were clearly not that bike's ideal terrain.
Some gravel bikes are taking more design cues from MTBs. I've heard them referred to as adventure bikes. In terms of geometry, this tends to mean longer top tubes, shorter stems, and slacker head angles. These produce much higher trail than road-like gravel bikes. This design improves the bike's stability at high speeds and on loose terrain. It makes bikes descend much more confidently on steep singletrack descents, whereas on my Parlee I felt like I might risk flying over the bars (NB: I didn't). This design also produces a larger amount of wheel flop, which makes the front wheel more willing to accept a steep turn at slow speed (e.g. on singletrack). In terms of other equipment, these bikes can take even wider tires, e.g. 50mm tires on 700c wheels. They also may have more equipment mounting points, which can help for things like carrying bikepacking gear and water.
What might this mean for you?
As stated in the FAQ, we prefer not to make product recommendations. Specific bike models might be discontinued, or they might evolve significantly (e.g. the Specialized Diverge was a road-like gravel bike, but it is evolving towards the MTB side of gravel bikes). Road and gravel bikes might evolve in ways we can't anticipate. You have not stated your preferences in bikes, but even if you had, this might boil down to having to take a test ride.
Given the spread of bikes that you already have, you might want to consider a performance road or endurance road bike. As stated, these perform more than acceptably on tamer off-road surfaces. However, you indicated that you have an MTB background in comments. You might actually prefer a more adventure-oriented gravel bike, as it will handle more similarly to the bikes you are used to. This type of bike will still perform more than adequately on road with slick tires.
One minor thing to consider is the gearing. If you intend to do group road rides, road riders often prefer to have narrower-range cassettes. This enables them to attain their ideal cadence at the group's chosen speed. You might have 50x34 chainrings with a 11-28 or -30 cassette. I have that chainring with a 11-34 cassette on my gravel bike. The gearing is not ideal for cyclocross, and it's ill-suited to singletrack. It's relatively steep gearing for gravel, but it's still acceptable.
A 1x setup will have big jumps between gears, which can be annoying in a group road ride. Smaller front chainrings may not quite be steep enough gearing for group road rides. Again, there may be compromises.


how to adjust the derailer - apart from the L/H limiting screws

You need to loosen the screw that holds the cable and pull that cable out a little bit.

The limiter screws that you've used so far are rather used to prevent the chain from falling off, and it's a finer tuning than you appear to need now. Thus it would be useful to level them out before pulling the cable. After you adjust the cable, take a few minutes to make sure the derailleur does not throw the chain over the outer gear.


Fixed gear wheel NOT stopping when feet stop. Any ideas why?

That bicycle you had long time ago had rear brake (actuated by pedals turning backwards), the one you have now has no rear brake and you have to fight force of inertia with your feet to stop it. One might be tempted to add that this is the exact reason why brakes were invented and added as standard equipment to bicycles.


When I make a repair, I also do the following extra steps, to make sure that the patch holds. I have never had a patch come off/leak when using this technique.

Use a little bit of sandpaper to remove any ridges on the area to be patched, such as a manufacturing join.
Clean the area to be patched, this makes the glue/solution adhere better to the tube. Especially so if you have sanded the area. I would usually use methalyated spirits and a lint free cloth of some sort.
Once the patch is applied, apply some chalk dust to the area, this makes sure that the solution/glue does not bond to anything else.


Any idea which model & year my Giant bike is?

It's a Giant Seek 1, maybe "Ltb" edition, circa 2011-2012. Here's another one.


What sort of wipes should I use to clean a bike with disposable wipes?

Of course you may use moist wipes. Although, it certainly is not faster than very quick and rough techniques, for example, simply pouring water over it.

Using wipes is certainly less effective than pouring water over the bike, flogging it dry with an old rag and wiping of the drive train with another one.

A thorough cleaning may be done in three-and-a-half minutes.

Finally, there is the amazing panacea to all our muck related problems, the jet wash!


Front derailleur will not sit properly on large cog without chain rub

You say you replaced the the derailleurs, crankset, brifters and pedals, but not the bottom bracket.

My initial thought is that your crank is too far outboard because it requires a shorter bottom bracket axle than your previous crank.

The location of the square taper hole relative to the rings is different for different cranks, so different axle lengths are required to get the correct chain line (distance middle ring from center plane if the frame).

In your first picture the distance between the cranks and bracket shell does appear to be quite large.


What's in a good all purpose city commuting winter tire?

Your best bet for all around tire in the winter is going to be a cyclocross tire. They are made to race in grass, snow, on pavement, in sand, singletrack, and just about any way possible. They also have different types of treads for different conditions. You can't beat the Hutchinson Bulldogs, if you are looking for something more affordable, maybe the Maxxis Locust CX. CX tires offer low rolling resistance in the center of the tire, and have good grip on the sides. A less aggressive tread would be found on something like the Kenda Happy Medium. Give those a shot this winter and you shouldn't be disappointed.


adding to Chris H 2018-04-30 post... I'm going to take a stab at some basic math...

BLDC motors can put out their rated power at high RPM partly due to air cooling enhanced by the high RPM (like computer chips, if you add active cooling, they can go even faster... it's all about how much heat they can dissipate).

At lower RPM the motor gets less air cooling as a by-product of the RPM, so it dissipates less heat, even though it might be delivering the same amount of power (pulling more weight).

However, if you're pulling the same weight at 6 km/h as at 25 km/h, you're going to be drawing a lot less power out of the motor for mechanical work, so it'll be generating less heat and probably not need to dissipate heat from RPM-based air-cooling, to keep the motor windings from melting their insulation or the wires themselves from fusing.

I'm new to BLDC controllers, but if there's one that allows you to set an RPM-biased torque limit, or RPM-based power limit on the throttle, you could protect your motor from thermal overload. You could chart a few operating ranges or give it a function with a curve to limit torque or power according to RPM. At 100% rated RPM, it could use 100% power. At 75% RPM, 75% power. At 50% RPM, maybe 40% power, and at 10% RPM, maybe 5% power.

A simple thermal cut-out might be a bummer if it happened while toting a heavy load up a hill in hand-cart mode. If the controller just limited motor power, you might be able to keep going.

If you've got a motor rated 1000 W at 1500 RPM, it might be rated 250 W at 100 RPM. At the higher speed, it's doing 1000/1500/60 Watt-hours of work per revolution, or 1/100 of a Watt per revolution. With 250 Watts at 100 RPM, it would be doing 250/100/60, or 0.042 Wh of work per revolution, so it could be moving a load 4x as heavy, and 1/15th the speed. (1/4 power applied to 4x the weight should get 1/16th the speed, I guess?, but I had rounding in my calculations above).


I once noticed something similar to this when climbing up a hill. The "grinding" sound was coming from a couple loose spokes.

For a complete diagnosis you will need to provide more information and I can update my answer from there.

First step, check the tensions of your spokes. Are there any obviously loose spokes? Tighten any loose spokes you might find.

Second step, figure out which wheel is giving you the grinding sound. Do you have a second wheelset? If so, Replace the back wheel, go on a ride, see if the noise is present, if it is, then the problem wheel is the front, otherwise you can assume that the problem wheel is the rear wheel.

Third step, check the spoke tension on the problem wheel again. I assume that you do not have a tensiometer. Use a credit card and pluck the spokes. They each should make a similar tone. Higher pitches means higher spoke tension. Lower pitches means lower spoke tension. If the problem wheel is the rear wheel, then the drive side tone/tension will be higher, and the non-drive side will be lower.


Yes. You should follow the normal guidelines for oiling your chain. If it is squeaking, you know you've left it too long. Do the following every two or three weeks:

Thoroughly clean the chain with some degreaser.
Let it dry off. If the new lube comes into contact with degreaser, they won't be happy with one another, and the lubrication will not be as good.
Apply one drop of chain lube to each bushing on your chain. Apply these on the bottom run of the chain, below the chain stay. Gravity and the centrifugal force in step four will help to work the lube into where it needs to be.
Let the bike sit for a minute, then spin the pedals for 2 or three minutes. Be careful while spinning the pedals, especially on single-speed drive chains there is a real risk of injury from getting a finger stuck between the chain and the chainring.
Clean as much lubricant off the chain as you can. It only needs to be inside the bushings. Any left on the outside of the chain will pick up debris and increase wear.


Is it safe to wear a helmet without a plastic covering?

The foam protects the head from impacts by deforming. The plastic cover obviously protects the foam from wear and aging. However it also serves safety aspects in most helmets:

A good helmet has a smooth outer shape, preferably close to a ball, to allow it to slide over tarmac or other hard surfaces in an accident. The hard and smooth plastic outer shell helps this by reducing friction and it prevents snagging.

A reason why we want the helmet to slide rather brake ones horizontal movement is to prevent rotational acceleration of the skull. Due to its inertia the brain resist that acceleration. This in turn exerts a force on the brain (warning, oversimplification the brain is in large parts mechanically decoupled from the skull by a gap filled with fluid). This so called rotational impact is thought to be an important contribution to concussion (cf Kleiven 2013).


You have the correct tires.

This does not have anything to do with tire width. The diameter determines whether tires will fit or not, unless there is a huge width mismatch. Rims and tires are both made to a tolerance, and you just happen to have an unusually large rim and small tire. I have had the opposite problem with some Schwalbe tires, they were so loose that they kept slipping off the rim when installing.


Adding disc brake to a bike without rear disc brake mounts

It doesn't look like that bike includes the caliper mounts, and the wheels hubs do not have rotor mounts.

Converting a bike like this to disc brakes would require custom frame work, a new fork and new wheels (or at least new hubs and a wheel build).  From a financial standpoint it makes a lot more sense to buy a bike already equipped with disc brakes.

This question covers the pros and cons for different braking systems.

EDIT I stand corrected on the issue of 'required frame work' as @cbamber85 mentions below, there is a product called Brake Therapy Conversion Kit available that will allow you to mount disc brakes on your rear triangle.  Looks like the cost is about $150 USD and you would still need new hubs.


How to chose the correct hydraulic disc brake rotor size for touring bike?

There's no one right answer.

Most get by with 160 front and rear. There can be some virtue in going to 180, especially in front, to help manage heat and ensure a good power level when descending mountains heavily loaded, if that's going to be a thing you do much. Not every frame/fork is strong enough or has clearance for 180, however. The forks on more MTB-ish/adventure/bikepacking type bikes will often be able to handle it, while more road type forks may chatter and flex too much.

Running 140 either front or back, as often see on road or cross bikes, would generally be not adequate for loaded use.


I see three possibilities:

Your tire pressure is too low and you are getting pinch flats. As a reference point, with 25mm wide tires and your 74kg weight I’d use at least 6bars (600 kPa) of pressure, better 6.5 or 7. Refill every week or so. Usually with pinch flats you’ll have two holes in opposing sides of the tube, like a snake bite (hence why they are also called snake bites).
Spoke ends or burrs are poking into the tube. Check that the rim tape is seated properly and nothing is sticking out of the rim. Also check that  nothing is sticking out of the tire. Sometimes the piece of glass which caused the previous flat is still sticking in the tire.
Bad luck or lots of sharp debris on the road. You could use more puncture proof tires, use tire sealant or go all the way and go tubeless.


How to tell if Hollowtech II bottom bracket cups are aligned?

No, there's not a way of measuring it on an assembled bike. (On a bare BB shell, one could hypothesize some ways of measuring the parallelism, but it's not something anyone really does.)

In an extreme example you would find it was impossible to adjust correctly for adjustable preload types such as Shimano, or was tight and didn't turn freely in automatic (wavy washer or elastomer) preload systems.

Usually it's more subtle than that though, with the only real diagnostic method being, "Gee, for some reason this isn't spinning as freely as it should, let's face it to eliminate that factor." Or it's suspected someone is wearing out BBs seemingly prematurely, especially if a fresh one seems to not spin well.

Just pre-emptively facing and chasing the BB is really the way to go. That's the only way to actually know it's right.


They look like standard Shimano-type cartridge brakes. No need for new blocks, just get a set of pads.
I recently got these and they are really good - far better than the standard shimano ones: http://www.wiggle.co.uk/kool-stop-dura-aceultegra105-pair-of-cartridge-inserts/

Go for the salmon if you have non-carbon rims.

EDIT: I seems your brakes do not in fact have cartridges but the brake pad is a single piece that connects directly to the caliper arm. The dura-style cartridges (like the ones you linked to) will fit on your calipers and is a worthwhile upgrade. You will be able to more cheaply and easily replace pads and have a wider choice.


Comparing 'upright-ness' across several endurance road bikes

You're almost there. You can quantify "uprightness" as the stack/reach ratio. Just add another row to your spreadsheet and insert that formula.
I'd say anything over 1.5 is pretty upright; down around 1.4 is pretty racy. You can compensate to some extent with spacers and stem length.


Cracks in the wheel rim do generally need attention. If the cracks are around the nipple and you're a gambling man you can keep an eye on the crack's propagation and maybe use it a little, if they're in the side/wall, it's possible failure will be a little more exciting.
If you purchased them recently you may wish to return or exchange them.
Welding is probably not an option (assuming they're aluminium).


Cruiser bottom bracket is clicking and grinding

Yeah, the first thought would be a loose crank arm, and if it isn't tended to immediately (if it's not too late already) the crank arm and possibly the spindle will be destroyed.

The other possibility, if this is a cartridge BB, is that the cartridge is slightly loose.  But in that case the noise is usually only present under high load.

[I'll add that tightening the crank arms is one of the half-dozen or so items that should be taken care of during the free once-over (after a few months use) that you should get from a bike shop if you buy a bike there.]


Clunking noise only when pedaling at higher RPM not low RPM. Video of Issue linked

Given that the cassette lock ring was torqued properly and the play between the cassette and free hub was similar to that found on friends bikes, I moved on to checking other parts.  I removed, cleaned and lubed both rear derailleur pulleys. This reduced the clunking sound about 90%. The pulleys currently installed are original and I'd guess have about 700 miles on them.  In any event, I plan on replacing both pulleys with new ones with the hope that this completely eliminates the clunking sound.
My guess is the old pulleys weren't turning as freely as they should and this resulted in less tension on the chain, which created the slack between the cassette and hub that enabled the clunking sound.  My thinking is the new pulleys will have a slightly larger diameter that will allow the rear derailleur spring to provide just a tad more tension on the chain thus completely eliminating the clunk. The reduction in chain tension may have resulted from a combination of pulley wear and slight chain stretch (but not enough to register on a chain stretch tool).  New derailleur pulleys will do the trick. Thanks for taking the time to read this.


If the rim is tubeless (fully sealed) and the tire is fully tubeless then correct you do not need to use sealant.

Tubeless ready tire then you do need to use sealant.
A benefit of the sealant is to also repair small holes.
Fully tubeless is a heavier tire.
Tubeless ready with sealant is more common set up.

Some tubeless rim manufactures such as Stans recommend tape to protect from corrosion from the sealant.


The reason behind the "full less one" is that you need at least half the race full (rounded up) for it to work and performance improves with more balls past that point, but if it's too full you get a dramatic loss in performance. So "full less one" is an easy guide.

In practice most bearings spread a little as you tighten the cones so "full" when you're adding balls is not actually full in use. You can usually see this - when you're adding balls they generally sit in against the axle, then when you add the cone it spreads the bearings slightly. So filling the race is almost always fine.

Don't be tempted to add one more to fill in the extra space created when you tighten it up, this is exactly the situation the "full less one" guide is trying to avoid. That "full plus one" means all the load is on one bearing (and one section of the cone), plus the bearings are really grnding against each other as the wheel rotates. If you're lucky the wheel won't rotate in this situation, but if you're unlucky you're wreck the cups and have to replace the cups (or hub, if the cups are not replaceable).


There's very likely something wrong that's causing a fluid leak. Hose connection, piston damage, or some other mechanical defect. They did the prudent thing before by seeing if it was a one-off/fluke situation, but now it's likely proven that it's not. What's really needed at this point is for a mechanic to inspect the hose connections in case that's where the problem is, and go to caliper replacement if not. This stuff happens not infrequently on new bikes these days, and in part depending on the brake model there can be some different reasons how it came to occur on both brakes at once. The shop I work at would cover this under warranty no question, and if it is as you say we would likely cut to the chase and just do two new calipers.


Tightening torque: 5Nm, 40Nm... how do I tell?

You do this with a tool called torque (sometimes called dynamometric) wrench.
Without a tool you can estimate it this way:

Make yourself familiar with a weight of 1 kg
Apply the force with your simple wrench 10 cm from the bolt in question

This will give you 1 Nm of force. To get 5 Nm, use 5 kgs of weight or increase length to 50 cm. The math is simple:

  τ = r * F

Where τ is torque, r is radius and F is force (1kg has 10 Newtons of force)

If your bike is expensive racing machine, this tool is a must. By applying too much force you risk making cracks in lightweight materials.


Gear cables replacement - inline barrel adjusters

Yes. Barrel adjusters are reusable.
More useful for the front mech which doesn't have any on-the-fly adjustment.
And useful for the rear mech for quick adjustment without having to get out of the saddle.


Gear shift rubber cover liquified, post cure possible?

Once the rubber has gone gummy, its game-over for that part.  You have two real options.

Cheap answer - Cover the gummy partI've put cheap heatshrink tube over some bar grips that were deteriorating.  That was ~5 years ago and they're still working fine on my MTB.   Since its not a round part, you might get away with a layer of tape.Downside is that the goop will soak through most tapes, and plastic tapes will be harsh on your hands.
Outright replacement of the hoods. Find your shifter's model number and start searching.  I see plenty on ebay, selling for 10 pounds to 20 dollars.  Expect to pay more for brand-originals, but they're more likely to fit.

Doing nothing is not really an option - they'll only ever get worse, sticking to you and your skin and gloves.

You might choose to cut the old hoods off, and ride bare, but that will expose some of the internal gubbins to the elements and to your sweat.  Also this would give sharpish edges that will chafe and irritate your hands.

I'd suggest you tape them temporarily, and start searching for new replacement hood covers.


What options to transport both heavy backpack and gym bag via bicycle

Get a rear rack for your bike and strap the gym bag to it. A low cost and much safer approach.


Thanks everyone for your contributions! Some were actually really helpful, some not so much lol; thanks anyway for taking your time to post.

So, to summarise, there isn't a 29er frame that will take a compact road crankset, or at least people don't know about it. However there are workarounds which will ALMOST achieve my desired result.
Thanks everyone!

P.S. I'll update this post if I find a frame like that, I wouldn't bet on it coz of clearance + chainline issues


I accidentally found the answer to this question by... listening to Judas Priest. Yep.
Here's a picture of Judas Priest "Painkiller" album cover:

You can see the exact same "double fork" imagery, which reminded me of this question I read months ago (it's actually a common logo they use, not just on that album cover).
It turns out a company named Amity did produce Judas Priest BMX frames. Here's that frame courtesy of VitalBMX:
https://www.vitalbmx.com/product/guide/Frames,7/Amity/Judas-Priest,4046
We can see part of the logo on the second picture (I haven't found a picture of that frame from the front):

This is further confirmed by that integrated seat post clamp hole, that we see on the question's full view of the bike. It's not that common of a setup, so this + the partial view of the logo above means it's pretty much certain that...
The frame is an Amity Judas Priest Frame


Is it ok for a kid's bike to only have a front brake?

Small children usually do not have a grip strong enough to brake effectively with brake levers on the handle bars.
Neither do they have enough coordination to modulate brakes. This means if they were able to brake the front wheel effectively they would indeed be at risk to go over the bars.
Typically, children's bikes have coaster brakes. These allow to stop by back pedaling. Which is an elegant solution: If the child is capable of accelerating by pedaling, the child is also capable of braking by performing the inverse motion.


Can I replace post mount disc brakes calipers with flat mount calipers?

I think there are no adapters on the market to use flat-mount calipers on a post mount fork, so your options are:

Get a flat mount fork and Ultegra caliper you want. I actually did that, the additional price will depend on new/secondhand and no-name/open mold/brand name factors.
Get any post mount Shimano hydraulic caliper, those are all compatible. There's no actual Ultegra post mount calipers, but prior to R8000, Shimano made a non-group, Ultegra-level ST-RS685/BR-RS785 shifters/calipers, so you might use a BR-RS785 or slightly older BR-R785 (actually an XT).


You should be fine with the parts you choose. Just be sure that you get a 10x Shifter as right lever and you are good to go.

You can adjust the chainline to minimize a too great angle. You should check if the chainline is better if the 1x chainring is mounted where currently the bigger chainring is mounted or where the smaller one is mounted.
Chainline is good if the chain has minimum angle on the 5th/6th sprocket.

You can't mount a too big chainring on the inner position. But you could check how much space is left from the small chainring to your chainstay and buy one accordingly. Depends on how big of a ring you want to buy.

Otherwise you could optimise the chainline according to the sprockets you use most of the time.


Bottom bracket conversion with rare cups

Depends on

How much you value originality,
The thickness of the metal at the cup threads
The internal diameter of the cup hole.

Either keep it totally original, which means scouring ebay for old bike parts (expensive)

OR look at retapping the BB shell to accept a modern cartridge bearing unit.  This is probably beyond the home mechanic because it will require a large tap and a way to keep it completely straight.  A frame builder might be your best contact.   A BB cartridge is cheap, common, and easy to change IF the threads match, and the width is workable.

OR see if there's some combination of press-fit BB that will fit in the BB shell.  I'm not familiar with these, but there was one where two parts entered and threadded themselves together in the middle, allowing a hollowtech axle to go though.  Would increase Q factor and might look a bit weird.

OR your proposed hack should work just as well on the Raleigh as on your bike.  Downside is if it needs servicing and you're not available to do it.

This is an interesting question - please consider posting your own answer, ideally with progress pictures.


Derailer  adjustment is easy - at least in theory. When it comes to fine adjustment you may find that you cannot easily get this problem fixed without making something else worse - i.e. its a compromise. Its a good opportunity to learn how to adjust derailers- make adjustments slowly, one step at a time, and count the turns so you can go back to the start if needed.

Given you should not be spending any time in this gear combo, and its not really doing any damage to the bike components, one option is to leave it alone and learn to switch to the smaller chain ring sooner.

It is worth taking it back to the bike shop and seeing if they can tweak it, but do make it clear to them that you do not want to compromise gear shifts to get it fixed.


The Wikipedia section on chain widths glosses over some history/is wrong.
Pre-indexing derailleur chains, i.e. what would have come on a 6-speed bike in 1980 and what many would call or label as a 6 or 5/6 speed chain, have a pin length of at least 7.6mm and usually around 8mm. New chains of this type are still produced and available but are not stocked very commonly in many places in the world. The ultra low end repair market is a bigger deal in some places than others. They can be replaced with 8-speed chains (most of which currently produced having a 7.3mm pin length) at essentially no detriment to performance. Here is a picture of one sold under J&B Importers (one of the largest US bike parts wholesalers) house brand:

Contemporary 6-speed freewheels for indexed shifting have ramping etc and are mostly designed to be used with 7.1-7.3mm (aka 8-speed chains). I don't actually know much about what happens when you put the above 1970s style chain on them because I almost never touch those. I believe it works to drive the bike as the spacing is still right, just the shifting is bad or suboptimal with an indexed shifter.
The "going a speed generation narrower is fine" line for more modern index 8-12 speed bikes is bad, overly broad advice that's parroted much too frequently. Doing so causes laggy shifting in back and the mismatch with front derailleur cage inner width usually causes compromised performance in front. There are some various situations people get in that lead them to do this, a big one being putting an n+1 speed crank on an n speed bike and finding that the n speed chain rubs on the big ring in the inner/middle-small combinations, but there's almost always a better solution. In my experience, the issues with this are a little less pronounced with 9-speed-chain-on-8-speed-bike than in the latter generation mismatches, and that's where the notion may have come from.


Converting from 7-speed to 10-speed rear wheel

You may be interested in this .. The 1992 Bridgestone catalogue (8meg PDF)

The bike is the lower end of the range (MB-6 being lowest), meaning its not worth that much and never started out as a great bike. As its steel (one redeeming feature), its possible to cold form the frame to widen the rear drop outs to take a 10speed, so technically its possible......

Practically its not worth it. The bike is old and low end. To upgrade to 10Speed you would need

Complete Wheel (at least a new Hub and cassette)
Dérailleur
Shifters
Chain rings

Probably

Shifter Cables
Chain