It looks like a chain jam from a wrongly adjusted rear mechanism. The paint finishes on these bikes tends to be fairly hard and a good smack will chip the paint.

The next question is what's been done to the frame. Without testing, x ray type inspection, history etc. Its impossible to tell. So that just leaves whether you trust it enough not to lay out for a new frame. Me, I'd trust that sort of catch if there is nothing obvious in the carbon layup and it rides ok. Go easy to start, build confidence in it; or not. You decide.


What is the tiny hole on the inside of the rim for

Rims usually have small holes inside to vent the inner chambers of the rim extrusion.
All rims need them, but rims with welded seams need to have more and larger vent holes because otherwise the welding process will cause pressure to build up in the closed chambers and "spit" the molten metal. The spoke and valve holes are not sufficient venting because rims are rolled and welded before the spoke holes or valve hole are drilled. Plus, the spoke and rim holes don't always go through chambers at the edge of the rim. Often you see vent holes at the edge for this reason. Bike frame tubes always need some kind of vent hole for the same reason (welding and later draining).
I just built up a Rhyno Lite XL rim last night that had 8 different vent holes! I always make sure the holes get covered with tape, but some of these were at the corner where a regular rim strip wouldn't cover them. So perhaps it is OK to put the tube directly over them? I would welcome input from other mechanics about whether the inner tube can always be placed directly on these holes. My road bike, which I run at 120 psi, was built up without the vent holes covered. Because I was fighting mysterious flat tires, I used epoxy to smooth over the rather large vent holes (no room for tape in that case).
Even if the rims don't have a welded seam, they may still need to vent the hollow extrusion to keep water or pressure equalized.


I take your question to mean you have road style 3 bolt cleat shoes, but want to use them with Shimano SPD type pedals that need a 2 bolt cleat. You are looking for a way to attach 2 bolt SPD cleats to the 3 bolt shoes.

Another way of putting it is you need a Shimano SPD to SPD-R adapter (SPD-R (road) cleats use 3 bolt attachment).

Yes, there are adapters available. Specific product recommendations or shopping help are off topic here so I wont link to a specific product, but try Googling 'Shimano SPD SPD-R adapter'.


There are spacers that are sort of in the vein of what you describe. They look like this:

However, these are intended to be used as a matched set and aren't adjustable, so using just one of them probably wouldn't just do what you're wanting here. You could probaby file one down to make it do that, however.

Another thing to bear in mind here is that it's actually very common, especially in the bike boom era, for manufacturers to use the horizontal dropouts of their frames to give themselves room to be a little sloppy with the symmetry of the left and right chainstay/dropout assemblies. As long as the paths of the axle slots are parallel, having the start and end points be off by a few mm doesn't matter much. In other words there are a lot of horizontal dropout bikes where if, say, you pulled the axle all the way back in the dropouts on each side, the wheel would be off-center in the frame, and where using spacers like the pictured ones wouldn't work unless you nudged one ahead of the other the right amount.


What is the purpose of plastic insert/plug in Deore FD-M590?

You can search Shimano's Technical Documents site for manuals.

Here's the manual for the M590 BB, crank and front derailleur: https://si.shimano.com/pdfs/si/SI-6SA0A-001-ENG.pdf

The red insert is apparently a 'Pro-Set Alignment Block' and is there to help set the height of the cage above the large chainring.


I weight about 40 lbs (18 kg) more than the weight limit for the trike I can afford

Answer: Maybe - speed isn't the problem.

While most "limits" have generous tolerances, your manufacturer's warranty could be unusable if there was a structural problem.

Your brakes would have to dispel more momentum while stopping, so that will increase wear and runout distances.

Riding is a great way to get exercise, and I've successfully ridden road bikes while being at the upper boundary of weight.

Suggestion: can you try a spin bike at a gym?  Could give you the cycling motion without needing to be on a bike at all.  They are heavy, solid and stable so you're not going to fall off.


Why is my Ultegra 6600 much noisier when cross chaining compared to my Deore XT M8000?

I am not sure this is a fair comparison. 6600 ultegra is now three generations old (6700, 6800 and now R8000 come after).

I rode 6600 for many years, rear shifts are still among the fastest out there. But as you noticed cross-chaining was not great.

I moved to 6800 last year. Shifting speed was compatible (I still feel that a well maintained 6600 is faster, but we are splitting hairs), but cross chaining is much better.

When 6600 came out in early 2000s 11-25 was a monster road cassette for climbing. My current road bike has a 12-32 and I would not go back to a smaller cassette unless I was racing cat 1/2 again.

By comparison XT M8000 became available on bikes just a couple years ago so it represents a much newer group set. A lot has changed in intervening years, and Shimano has tweaked their offerings to match market demand/ current trends.


Will Sram GX Eagle grip shift trigger work with 11sp cassette?

Unfortunately it will not work due to the cassette spacing, even using an 12 speed shifter and derailleur, it will not shift correctly due to the increased space of the 11sp cassette which has 3.8mm between cogs while the 12sp cassette has 3.65mm between cogs.

  [For a 12sp cassette] The spacing between cogs has been reduced, from 3.8 mm to 3.65 mm, and the 50 tooth cog cups the drive body more, thus bringing it closer to the spokes

  ....The shifter had to be redesigned to provide for 12 clicks and to incorporate revised cable pull to deal with the narrower cog spacing.

Source


How should exactly the brake cable be fixed to V-brake caliper?

Picture 2 is correct. The washer should prevent the cable being damaged or pulled by tightening the bolt.
However, on some cheaper brakes the bolt and washer are such poor quality that they turn together and the benefit is lost.
I will add that your cable in picture 2 isn't seated deeply enough behind the washer.

Note that i usually leave more cable and tuck it away behind the spring. This photo is OK for reference to clamping though.


I think that letting the (inner) cables rub against the seat post is a bad idea. It will cause wear on the cable, scratch your seat post (or seat tube) and probably create noise every time you hit a bump.

Why not go for your third option? Put a cable stop before and after the seat post and run a short length of (almost straight) cable housing around it. Works fine on normal bikes as well, after all.

The first option (continuous cable housing) causes squishy braking, even on normal bikes with shorter cables.

Can’t you run the shifter cable in a straight line along the bottom tube?

I wouldn’t run the cables on the side of the top tube, it causes problems when you lean the bike against something.


Is white spirit a too aggressive degreaser?

How do you forget to lubricate a chain after cleaning?  If this is a possibility, you a would be better not to clean the chain at all.

White spirit is a generic name for different products, exactly what it means depends where in the world you live.  Some have a flash point of 20–30°C — extreme care is needed using it. Others with higher flash points and lower volatility are safer (but not entirely safe). All are hydrocarbon based and environmentally unfriendly if disposed of improperly. Care should be taken using them

To understand the arguments of what cleaner is best, you need to understand chains.

New chains come factory lubed with a very robust and long lasting lube that is much better than anything you can apply. The last thing you want to do is use a cleaner that will strip this lube off the chain, in fact, for the first few hundred kilometers no cleaning is probably best.  White spirit is one of those cleaners. Once the chain is older, and this lube is worn off, it needs replacing. Stripping the replacement lube off completely is not problem — it's easy to lube the chain and get the same level of lubrication as you had.

So should you use it on new chains? No way. On old chains, it won't matter. Question is when does new become old? Who knows. Easy answer and most (profitable for bike shop) is use a dedicated bike chain cleaner (you buy from them).

In the end I don't think it matters, as long as you are cleaning the chain regularly and lubing it properly.

There are plenty of questions on this site and discussions on the internet about the various religions of chain maintenance you can delve into if you desire.


What should I expect from a GPS logging device?

I had a small tracker for a while and after faffing with it for a while sold it on eBay. So I may not be the best person to answer. But here goes.

You need to decide on the basic parameters:

what is the longest ride you want to log? (distance)
how long will that take? (time)
how often do you need to log? (I find that every 10m is necessary in urban areas because there are often a lot of route choices, 100m is fine for offroad and every few kilometres is ok for touring).

That tells you how much battery life you need and how many data points you have to store. I'd expect that the data points answer will be less than 10k. Battery life is what mattered to me in the end - I was uploading every few days and recharging when I did it. What ended up killing the idea for me was the lack of display on the thing. I wanted to be able to see how much battery life and memory it had left without plugging it into a computer. It couldn't do that.

edit: for single-day use note that there are only 80k seconds in a day, and most small loggers need a second or so to take a reading. So a 30k point GPS could log every single second you were on your bike each day. More reasonably, logging every 10 seconds means at most 8600 points in 24 hours. So a 10k point logger will be fine.

I think more important points will be GPS reliability, robustness and how waterproof it is. If you have to tape an antenna to the top of your helmet to get reliable reception that will suck, and likewise if it stops working because you went over a bump or through a creek. So I suggest looking at those features rather than focussing on battery life or data points. Work out where you want to mount it and run from there (in a backpack is quite different from in a pannier or handlebar bar, and different again from under the seat or on the handlebars.


The 2 dimensions listed for each shock are;

The eye to eye length (sometimes listed as i2i, this is the distance between the 2 mounting points)
The shock stroke, i.e. how far the the shock shaft will move

If the two shocks have the same eye to eye length and the same stroke then the Monarch will physically fit into the frame and allow full travel without fouling the frame (See note below).

The other thing to consider is the damping tune of the shock. Shock manufactures produce a variety of shock tunes to suit different suspension designs (and a large company like Trek might even commission custom tunes). While this will not stop a shock from working in a frame it may result in undesirable handling. Typically the damping tune of a shock can be altered during a service (full service not air can service).

In your case I would expect that the Monarch will be just fine. Be careful to check the clearances before riding.

Note: some shocks are wider or have a piggy back reservoirs. Care should be taken to make sure the new shock does not foul the frame at any point during its travel. Typically you would do this by removing all air from the shock and cycling the suspension by hand and checking the clearances.


Diagnose grinding sound from single rear cog

This could conceivably be a cross-chain issue. Hypothesis: when the chain is on the second cog, it extends toward the chain ring at such an angle that there is interference from the teeth of the larger, third cog.

This kind of thing can't be diagnosed remotely without detailed pictures at suitable angles showing the chain line, derailleur and cassette details and so forth.

Like user zipzit commented: get it in a stand and try to pinpoint the source of the noise. When you find it, slow down to a crawl and try to find the exact location of the metal-on-metal action. If it needs load to reproduce, have someone apply the brake to the wheel.


Convert 2019 Giant TCX Advanced Pro 2 1x to 2x

Response finally came through from Giant:

Yes, you should be able to route cable for a front derailleur.


Can a team car ride ahead of the peloton to support a cyclist?

Generally teams have two cars, and one is allowed to move forward to service the breakaway when the gap exceeds 30 seconds


Get some Factory Effex Frame Protection Material, It's a vinyl that you just stick to you frame. You can get it in Black, Clear, or Carbon.


You don't reverse the direction mid-way, as this would involve cutting the bar tape. You basically have two options:

Do as stated in your link and start with an outward direction. You'll end up the other way round as shown in your video, which means you'll have to cut the tape the "other way".
Start with an inward rotation in order to finish the same way as shown in the video.

Cool thing is, there are no limitations as there are no breaks. A few ideas:

Go-naked carbonite:

Simple and pure (with an outward rotation at the start):

Fancy (see this video for instructions):


What causes a slight rhythmic knock in the pedal?

It can be many kinds of stuff. The obvious to look for are the pedal bearings, the bottom bracket bearings or the interface between the crankarms and the bottom bracket (for 3-piece cranks) or the interface between the crank spindle and the left crank (2-piece crank), but many other things could do it.
It is useful to test the pieces in isolation. Disconnect the chain and try to turn the crank. Try to turn the pedal on the pedal spindle. Do you feel any grinding or clicking? That would point to the right spot. Try to tighten the cranks to the required torque (depends on the exact type, 2-piece vs. 3-piece, the brand...).


No, they are basically identical.
neither of them will have fabulous life expectancy.


How is Sir Bradley Wiggins 3D printing his titanium handlebars?

This is how. An engineer explains:

Basically, it's a layering process. Layer by layer, the 3D printer lays down a thin sheet of powdered titanium and a laser melts and fuses that titanium where the part needs to be. It starts at the bottom and works up. When it's all done, you simply remove the unfused titanium and voila, a new part emerges.


Sheldon has a chart that shows what width of tire fits on what rim based on the width of the rim. He also notes that people often exceed the recommended widths with no adverse effects. He also notes the possible problems with straying too far outside the recommended widths.

It's also worth noting that tire width measurements aren't well standardized. Much like shoe and clothing sizes, some manufacturers' sizes may run a bit large or a bit small. They're really more like guesstimates.

This is due to a couple of factors. Manufacturers are under market pressure to produce the lightest components possible. If they can shave off a few grams by calling a 24mm tire 23mm, they just might do that. There's also the fact that the rim width effects the overall inflated width of the tire. If one manufacturer is building a tire with the intent that it's mounted on 17mm rim and another builds the exact same tire but bases it on a 21mm rim, the resulting measurement will be different.

Two millimeters over the recommended maximum is probably still going to be just fine.


Compatibility Look-Keo/Look/SPD-Sl Plates & Pedals

Look Keo 2 and Look Keo are Look's current/previous range and they are compatible with each other.

Look Delta are Look's earlier range. I'm afraid they are not compatible with Keo's or Keo 2's

SPD-SL are Shimano's version of road pedals. These aren't compatible with Look products, (neither therefore are Look products compatible with them).

Checking out Look's web site, you don't see Delta pedals on there any more, but if you look at the various Keo pedals, they are clearly a different shape to yours.

Doing a quick web search for Look Delta reveals many images, including some on this page (Exustar pedals which are compatible with Delta's - I haven't embedded the image here in case there are copyright issues). What do you think?

Note lastly that even within the "Look Delta" genre, you can buy different cleats. The difference between them is how much your foot is allowed to move whilst in the pedal (known as floating). Red cleats offer 9° float, whilst Black cleats are fixed (0°). The general rule is to go for the more flexible red cleats unless you have a reason to do otherwise. (This applies to spd-sl and keo also, in fact for spd-sl there are three options.)


Relative efficiency of different commute bike setups

Jan Heine performed some wind tunnel tests of "Real World Aerodynamics" a few years ago. A link to a blog post (and the results published in Bicycle Quarterly) can be found here. Those tests cover only one component (the aero drag component) of commuter-type bicycles vs. "racing" bikes.

If you want to make your own apples-to-apples comparisons of performance potential between any number of bikes of any type there are five pieces of information you need to know:

how much power you produce on that particular bike;
how much (you and) the bike weighs;
the Crr for that bike;
your CdA on that bike; and
how much of your power is lost in the drivetrain.

With those five bits of information you can compare the performance of a road racer to a TT bike to a penny farthing to a velomobile to a MTB; on a hill, on the flat, on a descent, on a velodrome. Of course, those five variables won't tell you if the bike fits, or if it handles well, or if it has a way to carry your groceries and laptop and change of clothing, but as far as performance goes, that's all you need to know.

A good bathroom scale will help you measure 2). Since you have a power meter, there are field test methods and protocols that will help you determine 3) and 4).

1) explores whether you can produce more power on one bike than another, because of positioning (for example, many riders find they produce lower power in a TT position than in a traditional road racing position) or crank length or gearing (for example, some riders find they produce less power on a single-speed than on a multi-geared bike).

Finally, 5) measures losses in the drive train, such as in a fixed-gear or with an internally-geared hub like the Alfine. In general, measuring losses in the drive train can be expensive because you need a way to measure power at each end of the drive train. See Kyle and Berto here, for an example of a rig used to measure losses. A similar rig was used by Spicer here. However, if you have a crank-based power meter (and, if you're using an Alfine then I suspect you must), it is possible to use the crank-based power meter to measure power at one end of the drive train and then use "virtual elevation" methods to measure the power at the driving wheel. A detailed description of the protocol is long but a quick description is to climb the same hill on a calm day with different configurations. Since the hill is the same and the conditions are calm you know that the "virtual elevation" should match the true elevation profile of the hill; so if you can measure power at the crank then differences in observed VE must be the result of differences in losses in the drive train.


I'm not completely sure, but those bearings look like sealed units.  They likely get replaced rather than serviced.

I would start by getting more information on the specs of your bike frame.  The manufacturer will have details about the size of the bearings, and should be able to show how to get into it further.

Your last resort is to take the bike into an LBS for a service, and ask if you can assist/watch.  Can be a great learning experience.

To remove them, you probably need a drift to push them out from below/inside-the-frame.

This goes through the bearing, the four legs click out, and then you tap it from below with a rubber hammer.  You will probably need a headset press to reinstall them, and maintain parallelism.


The reflective brand name tab on the rear of that seat bag is a light holder. You will most likely need to remove the light from the seat post. Hopefully it has a clip styled mount, otherwise you can get a light that has a clip mount.


What are these markings on a Shimano FC-M770 crank?

The only people that can answer this with 100% genuine authority would be Shimano's R&D team.
Clearly those marking are not there by chance so lets presume what is a reasonable reason :

Weight Saving (it's going to be a fraction of a gram at best) but some people are picky
Reduced Drag (it could be a fractional difference while spinning at 90rpm as opposed to 70rpm)
Intentionally built in to make them harder to clone in the manufacturing process

Your best bet is to get in touch with Shimano and ask them, they will either tell you or they wont.


Can given crankset have limit on spindle width?

You are taking the right approach to figuring your chainline per a given spindle, but yes, there can be other limiting factors.
If you go too far, it is possible for the crank body near the spindle interface to smack into the bottom bracket shell or the cartridge body, or be low-clearance enough that flex and grit wear a groove into the crank. Low-profile cranks increase the likelihood of this. Using something like a Phil BB that has zero protrusion from the shell can avoid the problem where a Shimano or similar will run into it, which can be useful if you absolutely need a certain spindle length.
The above is not super common, but you can get it to happen in some situations. I've seen it mostly when putting 135mm-oriented era touring triples, i.e. the Sugino XD600 and XD300, on bikes with older chainline numbers or when trying to get the Q minimized. I think I've seen it at least once when someone was configuring a road crank for track chainline with the ring in the clean-looking outer position.
Interference between the ring(s) or spider and the frame is also possible.


Left side of my foot -- 8 inches up leg numb?

I've heard that sling bags are terrible for your back. They don't distribute the weight evenly at all, and can cause major problems I don't know why they are so popular. I guess backpacks look too "high-school".  But I would start by getting a backpack. They make a few of them that are specially equipped for carrying laptops.

If it's the bike, you might want to check that everything is aligned properly.  Ensure that your seat is straight and level.  Ensure that you handle bars are properly aligned. Check for a bent axles in the wheels and bottom brackets, although that may be less likely.

I guess a couple clarifications could help diagnose some other posibilities.  Do you have brakes on your fixie? If you do have brakes, do you use them? Do you wear bike shoes or have toe clips?  Is the pain always there, or only after a prolonged ride? If it's continuous, I'd definitely get myself to a doctor. That's way too long to be numb in such a large part of your body.


What is the consistency of the Finish Line Dry Teflon?

I'd guess the old bottle has lost some of its carrier fluid (the clear liquid that separates on-top when the bottle is left to stand) and when shaken, the old bottle has a lot more of the lubricant compared to the newer bottle.

Either chuck the old bottle, or add a very small amount of something volatile like methylated spirits perhaps and use it up on a junker bike.

Only use the newer stuff on your good bikes.


Vibration and wobble after replacing chain

The axle is a single piece and it has 2 functions. The first is to secure the bike to the frame but it is also the stationary part of the hub that transfers the forces on the frame to the wheel through the wheel bearings.

Since the axle is a single piece, Tightening the frame to axle bolts could be tightening the hub to bearing torque. The wheel will feel gritty when you rotate it.


Can single-sided Power meters cause unnatural Bilateral asymmetric pedaling?

I am unaware of any controlled study that directly addresses your question.

However, a recently published study by Bini et al. addressed the converse of your question: can the provision of information on bilateral symmetry or asymmetry be used by riders to alter their pedaling dynamics? The Bini et al. study did not address whether riders would benefit from decreased bilateral asymmetry -- it only addressed the limited question of whether it was changeable. The answer appears to be that it can, sometimes. So although your exact question was not addressed, if these results are replicated and verified then a reasonable implication is that if one were to supply the riders with incorrect or misleading information on symmetry the riders might also be able to adjust their pedaling.


I am a physician (not practicing anymore), a biker, and an office worker. And I ride fixie. And I sometimes have knee discomfort. So, my few cents:

Depending on HOW YOU SIT DURING WORK, specially how you rest your legs/feet, your knee might be twisted for a long time (hours a day). Watch yourself if it is happening or not.
Take a rest on the fixie. I noticed it is only nice when you are "energized". Sometimes we are a bit tired or "low mood". These are not good times to ride fixed, I think. So, take an abundantly-geared beater or something, until you get better.
If you don't get the rest, try not to accelerate or decelerate too fast. If you ride in traffic, give up riding faster than motor vehicles, for a while, until your knee gets better. I think speed is not so important (spinning is winning, Stephen said), but bursts of acceleration or deceleration put a stress on the knees.
Watch yourself while pedalling. If you notice some movements reproduce the pain you feel, change your habit, avoid them as much as you can. But try to keep efficient. If you have to create an anti-natural position so as not to feel pain, things are starting to get ominous!

Other factor: you mentioned your cycle is short, less than 15min (so is mine). I found this to be a problem, because you always ride "cold". Perhaps you could warm-up and stretch, at home (learn how to stretch thigh and calf properly, first), or even take a LONGER way to work, so you can ride lightly for more time, thus pumping some nutrients inside your joints' tissues instead of just hammering'em cold.

At last, seeing a doctor (preferrably specialized in sports medicine) and doing some physical therapy is always something to consider. But don't think that is more important than self-observation, self-knowledge and self-control.

Hope it helps.


If your tyre says 700x28c, that means your wheel has 700c of diameter and your tyre is size 28. You should buy a tube that perfectly fits this, and this is very easy as because tubes have, in the box, the diameter of the wheel they were made for, in your case 700c, and the range of the tires they are made for. So if the tube says 24-26 that is ok for you, if it says 24-28 that is also ok for you, etc. According to your description you bought the correct tube, so what the hell is wrong?

A few things might have made your flat, in particular there are three typical suspects:

a) Maybe your tyre has a glass or a small nail in it, and you didn't check. You removed the old tube and get the new one and the this fragment remained on the tyre, so it flat after a while.

b) Your rimstrip is weak and does not hold the pressure, forces the tube against the holes on the rim and they end up puncturing.

The solution for a) and b) is pretty simple. When you have a flat, remove the tube very careful so that you know it's original position on the tyre. Check if the position of the flat in the tyre and see if there anything stuck in it. If the hole on the tube is on the inside, then it's time to change your rimstrip to something more sturdier.

c) You did a bad job installing the tube. Make sure the tube sits perfectly inside the tyre, and that no parts remain stuck between the tyre and the rim before inflating. To do this it might help to inflate the tube a little but before installing, and check everything after installation but before inflating. Check this guide for detailed instructions.

As a side note, I personally don't like fixing tubes as the patch does not expand as well the the rubber of the tube when you inflate and you create a week point there prone to give some problem in the future.


What features should I look for in a cool helmet?

The most important thing to look for when shopping for a helmet that will keep you cool is that air flows all the way through it from front to back.

Put the helmet on and look in the mirror. If you can see all the way through the back of the helmet, it'll probably keep you relatively cool. And the more you can see through it, the better.

Higher end helmets will also sometimes have vents that scoop air down into the helmet. The vents are raised at the front and lower at the back to force air down into the helmet as you ride along. I don't know what your budget is, but you'll probably pay a pretty penny for one of these.

You could also try wet bandana on your head. That works wonders for me.


How to choose MTB bike tyre: hookless, tubular or clincher?

You should use the tyres that fit the rims on your bike. If you were a professional you'd use whatever your sponsor told you to, so that's a bit of a side issue.

Tubulars are back in the MTB world, but they're still rare and it's unlikely your bike has them. I suggest not buying a tubular wheelset, let your sponsors do that when they decide it's a good idea.

Hookless rims have some advantages but not to the point where I would throw away hooked rims to buy them. That assumes you're running tubeless, the advantages of a hookless composite rim with tubed tyres are pretty imaginary.


How to protect yourself from pollution in city cycling

There is really nothing you can do. Anti-pollution masks are mostly placebo, and beside making breathing harder, they have close to zero efficiency in terms of air filtering.

Military gas mask would do the job, but for obvious reasons it is not appropriate for biking.


Please do not write in and tell me not to install the wheels - I agonized over this so long, and am only doing it as a last resort.

I know you don’t want to hear this, but at least for children there has been a trend in recent years to skip training wheels completly. It just leads to children trusting in them and never learning to balance. Where did you find strong enough training wheels for a grown adult anyways?

Just like Daniel R Hicks in the comments I suspect the bicycle for being at least partly responsible. I’ve never ridden one of those cruiser bicycles myself but the seating position generally looks horrible.

Can’t you borrow a more normal bicycle, adjust the saddle height (hiiiigh!) and ask someone to assist you i.e. keep you steady so you can reach speed? (it’s much easier to balance a moving bicycle)


One of the best ways to build stamina is through interval training.

The best book I've found on the subject is: The Time-Crunched Cyclist: Fit, Fast, and Powerful in 6 Hours a Week by Chris Carmichael. The book includes a lot of info on lactate threshold, energy metabolism, nutrition, race and century training plans, etc. I first tried out his methods after reading one of his articles in Bicycling Magazine on century training prior to the release of The Time Crunched Cyclist.

Basically, Carmichael's methods are a form of interval training where you are doing things like hill-repeats, power intervals, fast pace intervals, etc. There's a lot of info out there on interval training. One of the more common is called HIIT (High Intensity Interval Training).

Another resource relating to interval training is here on Dr. Mirkin's web site where he discusses how sprinting improves endurance.

FWIW - I've made interval training my primary method of training for long distance riding. I do multiple centuries during the summers and rarely do training rides over 60 miles. Prior to 4 years ago, my mode of training for long distance was a gradual distance build-up and had mixed results. With interval training, my performance on long distance rides has improved significantly in both speed and how I feel afterwards. Seriously, this plan works.

And...related: What exercise should I do in the gym to assist with hill-climbing?


holes on the inside of metal fork blades, what are they

On steel forks the tiny holes at the bottom end of the fork-blade are vent holes for the brazing process. The brazing produces fumes the fumes and the heat expands the air in the blade which makes that these holes are needed to evacuate both. On steel frames you may find similar holes in the seat-stays and in the chain-stays where they are usually close to rear drop-outs.
If you're worried about rusting because of moisture that could go inside spray some wax-coating or tar-based antirust inside, or a periodic jet of penetrating oil as I do.


My guess is that if you have 12-28, you might not have a Shimano 9 spd hub. Generally Shimano road clusters top out at 27t. That sounds more campy-like to me. That's the first thing to figure out. Shimano and SRAM clusters are interchangable, Campy are not.

If you have a shimano hub, it's very easy to build 'custom' cassettes with Shimano 9spd parts. It's just not cheap. If you've got the tools to remove the cassette, you can get an 14-25

http://www.chainreactioncycles.com/us/en/shimano-tiagra-hg50-9-speed-road-cassette/rp-prod387

and mix and match with your current cassette to get the gears you want. It may be possible to do the same kind of mix/match with campy 9spd cogs, it's just more expensive. You can get 14-28 campy cassettes.

http://www.universalcycles.com/shopping/product_details.php?id=5047&category=40

If you can find them, junior racing cassettes are a good solution. Junior racers have gear limitations so they tend to have clustered but lower gears. Currently they only seem to be available for 10 speed cassettes, but you can get 16-27
cassettes.

If you poke around enough on the web, you can find small companies like IRD that will make all kinds of custom cassettes. They aren't cheap though.

http://interlocracing.com/cassettes_steel.html


You could try rubber cement however, you will probably still have a slow leak.

You best solution is to prevent the valve from separating from the tube. To do this, I don't put the retaining nut on until after I have fully inflated the tire. Once the tire is inflated, I screw the nut on just tight enough that it won't fall off. You could add some loc-tite but I don't and haven't had a problem. If you over tighten the nut, you are going to cause the valve to separate from the tube.


What is this headset's name per the Standardized Headset Identification System

Yes ZS56/40 - Zero stack with 56 mm bore diameter and 40 mm fork crown race.
It is zero stack because it is a black cup containing the silver bearing, but the bearing ends up inside the frame tube (i.e. not external). The 56.10 mm dimension gives a snug interference fit with a 56 mm head tube ( bore diameter). The 39.95 or so is about the 40 mm dimension that interfaces with the crown race/steerer tube. That last measurement seems slightly tight but possibly measurement error, tolerances aside it would be called a 40 mm.


"Vibration" could indicate a bad chain angle or a misadjusted derailer.  On the other hand, it's typical to have smoothest operation near the middle of the cluster and some very slight noise/vibration higher and lower.  Hard to say whether you have a problem or not without knowing the precise nature and severity of what you're experiencing.

Note that a chain will last roughly 2000mi or 3000km (+/- 50%).  After that it's sufficiently worn that it's beginning to cause excessive wear on the sprockets.  A rear cluster will last roughly 5000mi/8000km under normal use but will wear faster if a worn chain is being used.  Also, if you're on your third cluster your front chainring is likely fairly worn, though the condition of a single front ring is usually not a major issue.


I'm under the impression that Nexus 8 and Alfine 8 shifters and hubs straight interchange... but even if I'm missing something there, Shimano themselves says you can use the Alfine SL-S503 Rapidfire shifter with Nexus 8.


The derailleur hanger appears to be installed correctly.

Notice there is a small bolt forward of the axle, that obviously goes in a hole in the  dropout and stops the hanger falling off when the wheel is out. The hanger also aligns with the dropout slot to allow the wheel to be removed.

I think your confusion comes from the fact that hangers on more modern bikes tend to have the lug where the derailleur mounting hole is located behind the axle, but these bikes also have downward facing dropout slots rather than rearward facing ones.

Edit after comments clarifying question:

The only new derailleurs that are designed for a 5 speed bike are Tourney. You could actually use any 8 or 9 speed derailleur as the actuation ratios are the same, but I doubt that would work any better than a Tourney derailleur on the 5 speed freewheel.

If you want to fit a different derailleur what you want is a 'conversion' derailleur hanger for horizontal dropouts that is held in place by the axle nuts and provides a standard M10 threaded mounting hole.

Googling for 'derailleur hanger horizontal dropouts' should get you started. What you are looking for is something like this - note I'm not sure if that's exactly what you need and I'm not making a recommendation.


Clear glasses without "ghost" double images?

Anti-reflective coating is the first solution that comes to mind.  No brand of clear-lens safety glasses occurs to me, but you might try a trick I used many years ago when I commuted by motorcycle in less than optimal lighting or weather: Car-wax the lenses.  Keeps softer plastics from scratching as badly, and changes the surface characteristics of the more modern and harder plastics.  Give the wax plenty of drying time or the fumes will make your eyes burn.  You might want to have an eye exam as well.  Second surface reflection could be a symptom of something a professional could correct.


Allen Coggan Table - Formula for a best fit to time frames

I believe you are asking two different questions: the first, how to use Coggan's Power Profile; and the second, given power at one duration, how to extrapolate and predict power at other durations.

But first, an historical aside: Coggan's Power Profiles pre-date the publication of his book with Hunter Allen so really should be thought of as Coggan's own. The Power Profile is an empirical summary: the top of each column is pegged to a "world-class" effort, the bottom of each column is pegged to a typical effort for an "untrained" but non-sedentary adult of normal health and fitness, and the range between the two were split into 40 equal-sized steps. The reason it was done this way is because Coggan lacked actual observed data on the true distribution of watts/kg in the population; he knew the top (="world-class" or "world-record") and he had a reasonable idea of the bottom but he didn't have a histogram of the actual percentages at each value of watts/kg in between. Importantly, the "category labels" were always considered to be just a labeling device to help readers understand the approximate levels -- Coggan had no specific data to support their semi-arbitrary assignment. In fact, in an early revision of the Power Profile Coggan removed the "category labels" because he felt that readers were mis-using them. There was great hue-and-cry and promises of good behavior and intelligent usage so he subsequently replaced the labels, though making them "overlap" rather than have sharp boundaries between categories as in his first edition. This is all preface to Coggan's intended and widely stated use of the Power Profiles: to identify relative strengths and weaknesses in a given rider's power. He intended that riders circle or highlight their watts/kg in each column, draw a connecting line between the highlighted values, then ignore the actual values and just look at the pattern described by the line. If the line sloped downward from left to right, it meant the rider was relatively stronger at short durations than at long, and either should work on "bringing up the right" or else exploit his (or, in later editions of the Profiles, her) skills as a sprinter. If the line was relatively flat, the rider was an "all-rounder." Importantly, the line was based on "best" efforts at those durations which would not typically occur during the course of a single ride but rather be pieced together from specific efforts from several rides. All of the modern cycling analytical software products can "extract" the best 5 second, 1 minute, 5 minute, and 1 hour efforts from your data. Some products can do so for any arbitrary length of time, for example 495 seconds.

So the bottom line for the first part of your question is that if you climbed a hill at 3.23 watts/kg for 8 minutes 15 seconds, you shouldn't use the Power Profile as a way to predict your power at other durations. The Power Profile wasn't meant for that purpose.

Which brings us to the second question: how, then, would one go about predicting power at different durations given power at one duration? This is a very common question but a full answer is complicated. That said, a simple answer (and the one that Coggan himself might advise) is to go out and ride a different duration and see what you can do.

The full answer from a modeling point of view is complicated because we have mainly two different "energy production pathways" to help us produce power (commonly though inexactly) called the "aerobic" and "anaerobic" systems, and we each fatigue and renew at different rates. Therefore, you would need several parameters in order to characterize a particular individual's power-duration curve, and there would be some (potentially, a lot of) error in the estimation. In short, at a minimum, you would need estimates of the parameters for "anaerobic" capacity, "aerobic" capacity, the actual work over time that caused fatigue, and for recovery from fatigue.

Coggan has recently hinted at what may be an empirical, non-modeling, approach. He has recently claimed that if given an estimate of a rider's FTP (functional threshold power) he can produce an estimate to within 5% of the rider's steady-state power at durations from 2 minutes on up.


Is mountain bike good for long distances?

10-15 km is not a particularly long distance. You can certainly ride and MTB on roads to commute to work. Obviously an MTB will not be as efficient to ride as a bike designed for road use (such as a flat-bar commuter, road oriented hybrid or drop bar road bike).

You can make your MTB more efficient by fitting narrower tires with a road tread (or no tread) and inflating them to the higher end of their pressure range.


Short answer: No.

Long Answer: I would not use carbon rims for commuting for several reasons:

They make the bike look more shiny than you want, attracting all kinds of unwanted attention.
I ride my commuter bike in any weather without too much maintenance. Should the carbon rim fail at some point, I at least won't notice a hairline crack until the wheel breaks. Carbon wheels will mostly break catastrophically, and that's not what I'd want while wedged between an SUV and a 40-ton lorry.
If you're using rim brakes (which the OP doesn't), pure carbon rims do not have the same braking performance as alloy ones, especially when wet.
With a seller on eBay, you probably don't have anyone to go to if the wheel is faulty from the start, e.g. arrives broken/bent or some such. Basically, you don't get any warranty.

So, I'd rather spend a more for custom-built wheels with alloy rims if you want maximum stability.


What to do after an accident with a child?

Where I live there is a legal requirement to report any injury accident to the police, and from past experience they would call a bleeding little finger an injury. However, I personally would not bother for such a minor injury, they will fill the report and forget all about it.

As far as other legal issues (Again, speaking from my own) - you stopped, ascertained injury and damage and rendered assistance - you fulfilled you legal obligation.

It appears that you did way more than was really needed, and had/have real concern for the other person -  there is little else anyone can do, especially if offers of assistance are turned down and advice is shunned.

On the issue of lights and helmets - there is not much you can do about it and you went beyond what is morally required (Sounds like mum probably thinks way beyond).

A couple of weeks ago a friend of mind had a teenager (No helmet) T-Boned her car at an intersection - he came off a foot path at high speed and could not stop. He and bike flew over car bonnet leaving a small dent, he cracked his head on landing. Although dazed, he refused offers of help and a ride home etc, and rode off before an ambulance was called (Here there is no cost for medical treatment for accidents), despite several bystanders "suggesting" that he needed to be checked out. What else could she do?  These things happen - especially with kids and teenagers, as long as no one is seriously hurt, it's a good day


The front tire of my Huffy 3 speed rubs against the right fork as it spins

Hmmm. Thats a bad thing. You want to fix that.

Most likely the front axle isn't centered in the fork when tightened down.  I'm guessing you have axle nuts and not a quick connect skewer?  You want to loosen both nuts, hold the tire centered underneath the headset (where you can easily see that the gap between the tire and the front fork is the same on both sides.)  Then carefully tighten the two nuts holding the axle to the fork (I think you need a 15mm box / open wrench for this.)
Its possible the rim is out of true so when the axle / hub is mounted straight the rim is off to one side or the other.  Generally you see this when there are loose or broken spokes.  Tool to fix this is a simple spoke wrench and a whole lot of patience.
It's possible you have loose or missing wheel bearings at the hub.  When you spin the wheel is everything buttery smooth? Is there any noticable slop between the axle shaft and the hub? If so, that will have to be fixed (need more tools here, including a very thin hub wrench, grease, cleaner, possibly new bearings, etc...)


Unless your body proportions are very unusual, I would expect two different calculation methods to produce similar results. But yours aren't. You're slightly taller than me, with slightly longer legs.
First, I'm curious where you found these two calculation methods.
Second, different manufacturers size their bikes differently. Bikes are sometimes sized by their "virtual" seat tubes, that is, the seat tube is extrapolated to a point where it meets a horizontal line extended from the top of the head tube (this is a holdover from when top tubes were horizontal, and seat tubes really were that long). Sometimes they're sized by the actual seat-tube length, and I've even seen one or two manufacturers size their bikes by top-tube length. So if you found one calculator at one manufacturer's site, and another at another's, you shouldn't expect they'd produce the same results.
My own guess based on your inseam is that you'd fit a 56-cm bike (using "virtual" seat-tube sizing), so 58 cm isn't far off. For a hybrid that has a significant slope to its top tube, I wouldn't be surprised if the actual seat-tube length were in the range of 43–47 cm.


What causes a wheel to suddenly go out of true?

If you haven't hit anything and you haven't parked your bike on a busy bike rack (other tires getting accidentally rammed into your spokes), the most likely culprit is a nipple vibrating loose.

You can see if this is a likely possibility fairly easily...one, maybe two, of your spokes will be noticeably loose...less tension then the surrounding spokes (compare to spokes on same side if a rear tire...can be different tension to each side).

If this is in fact the case, it's something to be a little bit worried about in that you shouldn't just true the wheel and go on. If a nipple is working itself loose you will need to do something to keep it from doing so again. Generally a nipple will only work loose if it's damaged or if there wasn't spoke prep (similar to loctite) on the spoke when it was built.

For damage you'll notice a crack upon close inspection or it may be "squashed"...no longer square...this happens when someone bottoms out the nipple while building it or in some cases of too much tension...this out of square can quickly lead to the nipple cracking. If this is the case, remove the nipple and replace. Retrue, check round and dish and get back on the road.

If it's just loose, you're (MOSTLY - see below) in luck as it's the easier fix. Loosen the spoke even more, add some STUFF (see below) to the spoke threads and then retrue, check round and dish and get back on the road.

STUFF - You need to put something on your spoke's threads to keep the nipple from working loose under vibration. The purists will claim that only spoke prep should be used and that loctite will ruin your wheel. I disagree. I've built several sets of wheels when I didn't have spoke prep around and fixed many more and I'm happing using blue loctite (NOT RED). If you can find it green loctite is probably an even better choice. If you have money to burn, go ahead and pick up some spoke prep...it's good stuff, just pricey for someone who is not getting paid to build wheels. If you use blue loctite, just a tiny bit will do it. If you use spoke prep, make sure to let it dry a bit before tightening.

MOSTLY - I said that you were mostly in luck. The downside is that if there was no spoke prep on this spoke, there may not be any on other spokes. You'll want to check it. Some spoke prep has a bit of color and you can back a nipple a couple of turns and see (barely) a bit of blue or orange. Loosing a spoke during a fast decent can be very dangerous so if in any doubt take the wheel to someone who builds them and have it checked.


What are the advantages of having a road bicycle frame with lower tyre clearance?

It could allow for slightly better aerodynamics and a slightly lighter frame. It allows for a shorter wheel base and you don’t have to worry about toe strikes (toe overlap) too much. It also looks better.
I can’t think of any other advantages. It’s obviously possible to build frames with huge tire clearance without running into great trouble, so it stands to reason that there are very few disadvantages in ample tire clearance.
With very wide tire clearance you run into problems regarding chain line and the front derailleur (hence why most fat bikes don’t have a front derailleur or need some very awkward solutions).


Freewheels do require lubrication sometimes.

I suspect that if you drip some oil (I've used air tool oil, which is pretty light, but anything will be OK) in there with the bike tilted so the is freewheel up the pawls with become unstuck and it will work fine.

In my experience it won't take much oil or time, it should free right up if lubrication actually is the issue.


How much is too much - spokes protruding into the rim

That is poorly built and unacceptable (in my book) as a paid for product.  If all of the spokes are protruding some, and several more than others, it means that the wrong length spokes were used.

The reasons for this may or may not be the wheelbuilders fault, it's possible that some component of the wheel build had incorrectly listed sizing and the spoke length calculation was off because of it (component manufacturer fault).   However, it's also possible that the wheel builder didn't have the proper size spokes.  The right way to do it in that case would be to take longer spokes and run them through a spoke cutter to get the proper length.

In the first case, rather than rebuild the wheel the extra spoke should have been filed down to the level of the nipple.  This is acceptable as long as there is enough thread left to properly true the wheel.  If too much is sticking out the wheel will need to be rebuilt or it will likely fail at a future truing when the nipple no long has enough threading to secure purchase on the spoke.

If the second case is true, and the builder doesn't have a spoke cutter and didn't want to order the proper size, I'm calling foul and would not send future business to them.

Unrelated to all that, it may be possible to get a rim strip thick enough to sufficiently protect your tube, but you really shouldn't have to go to that trouble.


It can be many issues, but a click in the hub which is a rotary noise, is usually the Chain guard or the dust cap on the hub behind the cog which has popped out of place, or possibly cracked.

The noise is not detrimental to the safety of the bike, but you should find a shop that has experience repairing these hubs, and get them to do a rebuild.


Installing solid tires without locking pins?

A seller of airless tires in 2013 demonstrates how to install his product onto a (spokeless) rim, pushing it in place, using a zip tie cinched tight to hold it for starters as he progressively levers the tire over the rim flange with a large, plastic prying spatula, finally kneading it all round, inch by inch, to seat the tyre.

This writer suggests it may go easier if the tire is warmed up. Cursing may do the trick.


I don't believe these are "better" or "worse" than other lights, rather they are a supplement to other lighting systems. I think the inventors' claims about forward and rear illumination are somewhat questionable as it won't compare to a real head/taillight of similar cost.

However, I think they would provide some improvements in side and off-angle visibility. They are "eye catching" because they are distinct which is a very important factor to being noticed by other road users. There are actual lights which also provides superior visibility to any reflector-based solution available on the market today. Based on what they claim (and what is visible in the videos), these will provide nearly 360 degree visibility.

Mathew's answer makes some excellent points about weight and relative brightness. However, I disagree with his point about using a reflective materials as a potentially better solution. I have used many types of reflective materials ranging from reflectors to polished metals to 3M SOLAS-grade reflective tape. When you are within the "optimal" range of angles, they provide an incredibly bright surface for a long distance. However, when viewed from an off-angle or when the light is not directly shining on the reflective surface, their illumination characteristics are relatively poor--even when using a the high beams on a car.

There are many situations where a car's headlights are not illuminating the area the driver is looking (i.e. the driver is looking left or right) and the amount of light striking the reflective surface is minimal. Products like the revolights and the down-low glow tube are attempting to solve that type of problem--i.e. anywhere that reflective materials may not be reliable and your "normal" headlights won't provide adequate visibility.


How to Remove Specialized OSBB Aluminum Inner Shell

I have a carbon framed bike with a press fit BB. Recently the non-drive side bearing disintegrated, and having the Park tool to remove/install the cups I thought I'd be good to go.

The drive side cups popped out no problem, but the non-drive one had frozen solid in the way that aluminium seatposts can in carbon frames. Despite hammering it like all bezoomny, to the point where bits of metal were breaking off the inside of the shell where the tool rests against, it would not budge.

In the end I got a dremel and very very carefully cut through the remaining bearing shell and then the BB cup, and it still took some pretty good whacks with a hammer against a wooden drift for it to finally give up.

So, get the right tool, or take it to an LBS/mechanic who does. Its surprising how easy the cups can pop out when done properly. Failing that, and as a total last resort, you can cut them out with a steady hand.


Shimano Nexus 7 speed IGH, high gears tight shift

I am a fan of the Nexus drivetrain. Just had to say that. Anyways, the symptoms appeared when you removed and reinstalled the wheel. There are a couple of washers on each side of the axle that aid in spacing and keep the wheel in place. Two of these washers are called anti-rotation washers. They have tabs that fit into the channel of the frame and are square in the middle so they lock into the hub. My guess is that these are not installed properly. Under torque (high gear out of seat pedaling) the hub is shifting in the rear dropouts. The Nexus are sensitive to misalignment. The washers have to be inserted properly. The tabs must fit into the frame.  Then the bolts have to be on tight, but not super-tight. Good luck!


Probably what you want is a "hybrid" or "commuter" bike. Flat handlebars (like a mountain bike), smooth road tires (but a bit fatter than on a racing bike), usually the right stuff for mounting a rack and fenders.

Go down to your Local Bike Shop and look at what they have. Make sure it's a store that basically just does bicycles, not a department store that does everything.  Tell them you're looking for a hybrid or commuter or "urban" bike.

It all depends on pricing in your area, but pretty much every shop has 2 or 3 hybrid bikes in the $500-$1000 price range, typically the same basic model with an upgrade option or two.

If you're worried about a steep hill, when you look at the bike, make sure that the front includes a fairly small cog and that the back includes a pretty big cog. Something where the biggest rear cog is about the same size (or even a little bigger) than the smallest front cog. That kind of thing is common on hybrids of this type.  If you're looking at online specs, the front will be called a "crank" or "crankset" and have 3 numbers (you don't want one with only two front gears) such as "48/38/28" and the rear (or "cassette") will typically say something like "11-32, 8 speed" (note in this example that 28 is smaller than 32 so this does match what you're looking for). Sometimes there's marketing terms like "megarange" for this kind of thing, but the marketing terms aren't important, only having a low enough gear is.

All the major bike manufacturers make "hybrid" or "commuter" type bikes.  Trek FX, Specialized Sirrus/Vita, Giant Escape, etc etc...  There's differences, but the most important thing is which one fits you well and which one you like.

If $1000 is what you have to spend, consider getting a bike that's under $750 and using the other $250 for accessories like lights, fenders, a rack or basket, etc.


The shifters+front derailleur don't care about the type of chain rings you're using (just that they're sized appropriately and you're running a double/triple as you were before).

On the one hand, the adapter you linked is about 75 dollars + the cost of regular rings (which should work fine). On the other hand, replacing the crankset means a new bottom bracket (octalink v1 isn't exactly popular anymore,but its not hard to find replacement octalink v1 bottom brackets) and a new crankset.

I'd probably personally opt for the new crankset and BB, since I don't know about the reliability of these adapters and the price difference is pretty small (maybe 15 dollars). Plus, then, you don't risk someone putting a Octalink v2 BB on there some point and then ruining the crank.


How can I extend my rear rack backwards?

That phenomenon is called "Heel Strike" and its really annoying while riding.

I managed to extend my rear carrier rack.  The purpose was to line it with plastic to make a pseudo mudguard rather than add more pannier length.

Mine had a plastic part across the rear which popped off, so I used two convenient lengths of brass pipe to extend the side rails, and simply inference-fitted the whole lot back together.   Worked for my need, but did not move the carrier clamp backward at all.

Your other option is to extend the "arms" that fasten to the seat stays.  If they were longer, the whole rack would be moved backward.  Being more extended it will be wobblier though, with more leverage on the mountings.

However I think you should be looking at your Panniers first.  It probably has two clips at the top and a third centered and toward the bottom.  Something like this:

The lowest clip goes near your rear dropout, which is a fixed location on the bike.  The two top clips are also somewhat fixed in they have to be evenly before and after the bottom clip, and share the load.

If you extend your carrier rack, it won't move your pannier unless you change the clip locations as well.

So the red one pictured above can be adjusted with screwdriver to move the hooks, or you might be looking at saddlebags that look something like these, which clip under the carrier's clamp and are held on by equal weights on both sides.

Other options could include

to put stuff on your carrier rack, not beside it.
front-mounted basket for carrying items
small items can go in a saddle bag (dangles under the saddle, often used for tools/spares)
diamond frame bag where the items sit inside your main triangle, in a cloth retainer. (not always possible)
Bike jersey pockets - they generally have three large/oversized pockets for carrying stuff
backpack - horrid things on a bike but universally available.  Bad in an accident.

Finally, consider not carrying the thing at all - I have a work computer and a home computer and I do not move either one about.  Instead I use VPN over the internet to control one from the other, should the need arise.


Running multiple dynamo lights on a single dynohub

Most bike dynamos produce roughly constant current, so if you ride fast enough, doubling the resistance by wiring two lights in series gives 12v, neatly split between the lights. The classic setup in old days was two lights in series and switch to short circuit one when riding slowly, so that the other would get the full voltage.
Some new LED lights designed for dynamo can take advantage of this feature even with single light, so it would make sense to not add any current limiting to new models. The only way to know if it works for any specific model is to try.


I agree with Criggie's answer, but there's another way to look at it. Speed is mostly a function of power output. And you can quantify a cyclist's fitness in terms of their power-to-weight ratio, that is, W/kg.
This article shows what cyclists of different levels can produce in terms of W/kg, how long they can maintain different levels of output, etc. There's a lot there.
You can take that information and plug it into this calculator to estimate speed based on power and other conditions. You'll note that it takes a lot of additional power to go just a little faster.


Why are disc brakes rare on road bikes? (circa 2010)

2016 Update

Disc brakes are now common on road bikes, even racing road bikes in the professional peloton. Most of the major bike manufacturers offer disc and non-disc options for most of their bike models. Some "endurance", "adventure", and "cyclocross" (drop bar bikes sold under "road" category, but intended for some off-road use) models only offer options with disc brakes now.

However, there is some opposition to their use in certain types of road racing. If a rider's leg contacts a disc rotor while the bike is going fast, that rotor will likely cause a serious injury (it's spinning fast and pretty thin, so cuts flesh easily).

The advantages of disc brakes are primarily in wet and/or muddy conditions. In dry conditions, a good rim brake can lock both wheels up just as well as a disc brake. So for road-racing under dry conditions, there's no real advantage to disc brakes, and appears to be some disadvantages.

Many of the "racer" style road bikes follow what's allowed for professional road bike racing, so it's possible that the current opposition to disc brakes in professional road racing will eventually lead to them becoming less popular on road bikes.

Personally, my next new bike will definitely have disc brakes. I don't race in a peloton, I do sometimes ride in the wet, and it's much cheaper to replace a rotor than to replace a rim or wheel. (rim brakes eventually wear down the rim and make you replace it)

Original answer

I think it mostly comes down to one primary thing: disc brakes weigh more and road bikes are supposed to be light.  Also, you need a heavier wheel and heavier fork to handle the forces of disc braking, which compounds the weight.

Additionally, the advantages to disc brakes (working better in mud/dirt, easier to work with a suspension, work with really wide tires) generally don't apply to road bikes or aren't what the road bike was designed for.  For any bike on the road the only likely advantage of disc brakes would be that they're more likely to work after you've ridden through something nasty (mud, puddle with oil on it, etc) that's deep enough to get on the rims, and you probably want to be avoiding any puddles you can't see the bottom of anyways.

Probably the final reason is simply that disc brakes (generally) cost more than rim brakes.

I have seen bikes made for the road that had disc brakes, but they're generally not the typical "go fast" road bike.  (Example: Kona Sutra)


(My experience, for context: my girlfriend and I have ridden tandems quite a bit -- in the last 6 months we put in a few thousand touring miles on our tandem, and we've been riding tandems for several years now.)

There are several factors to consider when deciding who's going to be the stoker (at the back) and who's going to be the captain (at the front):

The first and most important consideration is who's comfortable with what.  If one of you is a lot more trusting (or trustworthy), that's your primary consideration.
Another thing you should take into account is weight.  The person driving the bike should ideally be the heavier person.  This is just a matter of physics -- the heavier you are, the more you can affect how much the bike turns.  In a pinch, it's better to have a heavier person who can more readily avoid obstacles.  The better your communication and teamwork, the less important this is.
The last consideration is Geometry.  If the bike is built for a taller person in the front and a shorter person in the back (most tandems are), you should probably put the taller person in the front.  Assuming you're both at around the same fitness level, this should fit nicely with the previous rule, because taller people tend to weigh more. :-)

Tandems are a whole lot of fun, but you need to go into it with the right attitude.  With the wrong attitude, you'll hate it, and you'll likely make each other miserable.  Here are some tips:

Communicate more than you think is reasonable.  Especially at first, you should both be talking a lot.  The more you talk, the better it'll be.
Remember you're part of a team now.  If the cadence is good for you but bad for your buddy, it's bad for both of you.  You'll both need to adjust some and meet in the middle.
Be trusting.  If you try to do the other person's job, you'll both be unhappy.  Communicate your needs and let your buddy do their job.  (This is especially important for the stoker.)
Be understanding.  If you're driving and your stoker says they're getting nervous about how fast you're taking corners, slow down.  Yes, you're probably doing just fine, but riding with an unhappy stoker is going to make you slower in the end.  Conversely, if you're the stoker and the cadence is messed up, understand that the captain is probably doing their best to keep the cadence in tune -- it's not as easy as you might assume!
The stoker is in charge. This sounds weird at first, but it's important.  The stoker tells the captain where to go and when to turn; the captain figures out how to get there.  If the stoker says "stop", you stop.  In a situation where two experienced cyclists are riding together, this balance of power is crucial for everyone to remain happy.  The stoker is going to feel powerless by nature of their fixed handlebars, so the captain needs to give something back.

Tandems are fun.  They go bloody fast, and you've got somebody to talk to all the time.  You've got incredible amounts of power, and you can cruise at 30 mph with reasonable effort.  Don't forget to stop and enjoy the moments of speedy bliss, and you'll have a great time.

A couple of additions:

To answer the final portion of the original question, it doesn't matter who sits where in terms of strength.  You're both equally connected to the drivetrain, and can both give as much power as your legs will produce.
Don't periodically swap.  Figure out who's going to be where, and practice before the ride.  If you're going to be pack riding, be very very careful, as tandems aren't as agile as single bikes.
The stoker position feels bumps a lot more than you normally feel them on a road bike.  Part of this is their position directly over the rear wheel, and part of it is an inability to see the road.  Suspension seat posts are a good idea for the stoker position.  Most importantly, warn your stoker if you see bumps coming, and coast briefly so they can stand up.


Cylinder volume of hydraulic brakes and levers

Is it not a sealed system though?

If the reservoir holds 30ml fluid the only difference will be the fluid within the brake lines adding to the total capacity of fluid needed or used.

Even when pads get low you don't lose fluid, it may seem like you have as the reservoir will look like its gone down, it has but you still have the same amount of fluid you started with.


I had the same problem as you when I bought my rollers, the best advice is to place the rollers in a door frame. Start by holding onto the doorframe and get used to spinning with one hand on the bike.

You should always try to maintain a high cadence (and speed) when you first start, the momentum will help you balance. The plan is to pedal in a perfect circular motion, no pedal mashing! Focus is very important too, keep your body calm and try to focus into the distance to aid your balance.

Aside from that, it'll take a few weeks to get used to it. But once you have, the benefits of rollers are incredible, you'll notice it on rides out.

Good luck!


No. Those eyelets are for mounting mudguards or fenders.


Using an axle much smaller than the hole it fits into is sure to end badly.  However, you can make up the difference with a sleeve bushing.  Maybe you can find a standard size bushing that fits well, or maybe you'll need to invent one e.g. from copper plumbing pipe.  If you want to try the pipe approach, use 3/8" copper surrounded by 1/2" copper and you might just find a good enough fit.

You don't want the wheels to wobble...if they do, they will wear out rather quickly, and the vehicle's--ahem--performance may be adversely affected.


I would recommend this based on my experience when I was starting to get into the sport and also bit of your other post.

I would encourage you to get an endurance fit road bike. It sounds like you will primarily be riding on concrete or asphalt vs. gravel or mountain biking. Plus it seems like you have a need for speed which is totally fine as I do too. Also, modern disc endurance fit bikes can do some light gravel rides since you can fit up to 32mm tires on them.

You do not like drop handles bars. I think you need to understand a racing drop handle bar has 3 positions on it.

Tops you are pretty much straight up and is used as a recovery
position or when cruising and you do not need access to the controls.

Hoods is where most road riders ride at and is still pretty
comfortable and upright. This is where most road bikers spend most of
their time and is similar to being upright on a flat bar.

Drops are used to gain full aero or for aggressive cornering/fast
descents. Most road riders on the road will not be in this position
their whole ride.

Based on your last post and being in the U.S. I would recommend going to a Trek Corporate store to find your next bike. Ask to look at a Trek Domane SL5. If you are between 5'7'' - 5'10''ish you will probably be a 54 size frame in Trek and probably Specialized too in my experience. Here are some reasons why I recommend this frame and made a similar decision in 2019 when I bought the same model (I have several thousand miles on that bike and do not regret the purchase one bit).

Endurance fit road bikes get you most of the aero a full aero bike
gives you, but you can usually get a more comfortable fit that allows
you to ride for long distances.

Again since new endurance bikes allow for wider tires, you have
some options to do light gravel rides with the same frame. Also this endurance fit frame gives you vibration absorbing bushing to make uneven pavement fell less jarring without losing much if any power transfer.

That model bike gives you 105 groupset, which in short is identical
to what the pros ride except ever so slightly more heavy. The good
part is as you wear out parts, you can upgrade to Ultegra or Durace,
which is exactly what the pros use.

Trek has bike fitters at their stores. I would ask a fitter to make
sure the frame is the right size for you. Note based on my personal
experience never riding a road bike, I wanted to chose a smaller size
frame, but fortunately the sales person was a former bike racer and
fitter. He basically said don't do it and when I asked why he said you
and I are the same size and there is no way I could ride a 52 frame. I
am glad he intervened as right now, I am progressing to making my fit
more aero and aggressive. Had I gone with the smaller frame, I think I
would have been way too jammed up riding vs. feeling like I can get in
a tuck but still easily pedal.

Trek has a no questions 30 day satisfaction guarantee on the bike.
I have never had to use this, but have used other Trek warranties. They
stand behind what they sell and usually do what is right by the
customer is what I experienced.

The other thing to make sure you do is make sure you have them ensure the seat is the right size for you. I would recommend something that has a cutout and short nose. This is what I use - Bontrager Aeolus Comp Saddle. I initially had the wrong size saddle and struggled to do 50 mile rides with padded riding shorts. With the right size saddle, I have no issues doing 50 miles with normal shorts on. I think a lot of people lose interest in the sport because of bad saddle fit and even worse is the advice of get more padding or padded shorts does not really address the root cause of a seat that does not fit your sit bone width.

Last piece of advice after making your purchase is go talk to your insurance agent and get a personal articles policy for your bike through the same people you have your renters or home owners policy. Also let them know you want it to cover damage from a crash. The personal articles policy will cover any damage to your bike without a deductible (e.g. crash, transport damage, theft, etc.) and it is pretty inexpensive peace of mind for a purchase that is 4 figures. I do not recommend a bike specific insurance as they are not as well regulated and are usually by off brand insurers that probably will charge more.

I personally would avoid hybrids, ebikes, gravel bikes because I feel they are not purpose built and I am sure I will get flack for it in some way shape or form via a comment below. Also, I would avoid expensive aluminum bikes due to stress cracks and other reasons. I also would avoid the desire to upgrade anything like wheels, handlebars, etc. until you hit a few thousand miles on the bike. I do not at all advocate buying speed as I think some people try to do that vs. training, but that is their prerogative.


Disc brake pad replacement, or replace whole caliper?

If you cannot find replacement pads, many cheap off brand disk brakes use BB3 pads, have a look and see if they are the same. Changing the yourself is straight forward enough. Sometimes its as cheap and easier to replace the caliper, especially if paying a mechanic to source hard to find replacement pads. If you do, get one that is major brand, or at least takes major brand pads.

If you want to do it yourself and cannot find pads, there are two mountings for calipers, IS and Post. Generally buying same style caliper as you already have makes it a simple replacement. Adapters will probably cost more than a cheap caliper.

Disks come in two mounting standards as well. 6 bolt and center lock. If you want to replace the disk you will need the get the same type.


You should use a rearview mirror because:

It allows you to look behind you by moving just your eyes. This will help you not accidentally swerving into the traffic coming up behind you you're trying to get a look at.
You can (almost) look behind you and in front of you at the same time because it just takes a small eye movement rather than a huge head movement to go from looking ahead to looking behind and back.
It actually shows you a useful part of the road behind you despite the small size (try it)
All the other reasons I don't know about for which they are mandatory on motorized vehicles in (almost?) all countries all over the world.
They actually cost less than a good pair of socks.

You shouldn't use a rearview mirror because:

You'll look like a dork, same as with a helmet.
You're an experienced bicyclist and you know enough to stay out of danger
It'll add extra drag.
It'll add extra weight.
They cost more than a cup of coffee.
They'll screw with the sleek lines of you fixed gear machine.

I bought one after a few days of cycling in new zealand. Narrow roads, wide cattle and log trucks with sleepy drivers, some near misses, and constant warnings to be very afraid of drunk drivers made it an obvious choice. Especially because of the swerving point above, which seems aggravated when riding a bike with 20kg of luggage strapped to it uphill. I've used it on all my cycling holidays since.

Then again, I don't use a rearview mirror in city traffic in my hometown either.


11-42T cassette of State All-Road to Shimano Deore XT 11-46T?

This State Bicycle All Road has the same specs you pointed out.  It appears as though it comes with State's own brand of derailleur with a long cage.  The single ring crank has 42 teeth, the same as the big, low gear sprocket of the cassette.  To determine if you can run a cassette with a larger low sprocket of 46 teeth as you propose, the rear derailleur must be spec'd for that capacity. Due to the odd, State branded rear derailleur, there isn't much information available about it's specs. Reviews of the bike, in discussing the shifting, are mixed to poor, and in cases where the reviewer has experience with SRAM or Shimano drivetrains, the State derailleur doesn't fare well in comparison.
You probably would be ok going up 4 teeth in your max low sprocket with a little adjustment of the B-screw to move the derailleur cage down a bit to accommodate the larger low sprocket.  Then again, it may have trouble where shifting is less smooth to the larger cog or it could even fail to get the chain onto it. With the dearth of specs for the State derailleur, I cannot say if the thing has a B-screw adjustment even.
The Shimano XT cassette, 11-46t is designed to be used with a 1x drivetrain--thats a single chainring up front, but usually it's a chainwheel with a tooth count in the 30's. The 11-46t version has a very large jump of 9 teeth from the second largest rear sprocket of 37 teeth to the top 46 tooth.  That's basically a bailout gear akin to the use of a granny ring on a bike with a front triple.  My point in all this, is to advise that if it is lower gearing you seek, it would likely be better and less expensive to change your front chainring to a smaller tooth count. For example the current 42t chainwheel combined with the proposed 46t low sprocket yields a gear ratio of 0.91.  Changing to a 38t chainring and keeping the 42t rear cog yields a ratio of 0.90. virtually the same low but you've preserved the tighter range of the 11-42t cassette so the jumps between gears is less making the ability to maintain a comfortable cadence more possible.  The draw back is you'll lose a little off the top end, where the current high ratio of 3.81 drops to 3.4.  (I'm strapped for time to figure the mph change of those differing ratios for a given cadence, but it will fairly minimal). Depending on how and where you ride, that may be of some significance.
Discussion of prices on SE is off topic due to the changing nature of them as well as their wide variation from place to place and through time.  I will offer that at this time, a single chainring will run you somewhere around 50-60% the cost of the XT cassette.  The chain will have to be resized as well. The smaller chainring idea means cutting a few links from your current chain. Adding a new, larger cassette will require adding a few links to the chain, which is problematic in a case where you've purchased the whole bike because it's not common for the seller to include the extra links, if any, yielded from the manufacture or assembly of the bike. It may be you'll have to purchase another chain with the larger cassette to get to an appropriate length. Minor point but possible source of extra cost.


what kind of grease to use on front shocks

It sounds like the fork was non-functional or stuck.  Simply greasing the uppers isn't going to resolve the problem - you likely need to rebuild the entire shock assembly, replacing seals, lubricating internal parts, etc.  Every fork is a bit different, so you'll need to find service instructions for the specific manufacturer/model you own.  Or, have the local bike shop do it - it shouldn't be more than a few hours labor.


Is there a way to estimate contact patch size given tire size plus tire volume and rider weight?

Basically: weight/psi = square inches.

Has to be combined weight of rider and cycle. And it's approximate. And much easier with a unicyle: with a bicycle you need to know weight distribution, which can change during a ride.

Minor things that make it only an estimate:

Compression from weight increases psi, making contact patch smaller than estimate.
thickness of material could increase contact patch size. In fact, I think this math gives you the area of the part of the interior surface of the inner tube that's pressed against the part of the tire pressed against the ground
stiffness of tire materials could decrease contact patch size
tread features (knobs, grooves, etc) could do all sorts of things to contact patch size.
bumps, jumps, etc momentarily increase "weight" (downward force on wheel or upward force on contact patch), contact patch size and psi.

No idea about new fallen snow.


Suggestions for budget mountain bike with opportunities for upgrade

Assuming a new bike, look at the Scott Aspect 30, 20, or 10, depending on your budget.
They all use the same frame, and the only difference is components.
When you buy a bike with the intent to upgrade, realize you will spend far more long term, than if you bought your bike ready built with the same components you upgraded to. I understand why it can be better to do it that way to break up the cost, but it does cost a lot more money overall.
I would make sure you buy a bike with good wheels, a good frame, and a good fork. Those parts are astronomically more expensive to upgrade to than to buy on the bike.
Your budget is fairly low, so if you have the option, save a bit more before you buy. A budget of $800-1000 is more appropriate if you can afford to make it work. It allows the wheels and fork to be quality enough that upgrading the other components becomes worthwhile.
If you can make that budget work, then look at the Scott Scale line.
I like and recommend Scott bikes for you because they are readily available in Europe, and they make high quality bikes at a reasonable price.
I hope this is helpful to you.


Good pedal and shoe combination for summer touring

My preference is for SPD clipless pedals and "walkable" clipless shoes.  But I still have a pair of lightweight "tennis shoes" in my gear for campsite, days off, etc.

Another option, if you can still find them, is the old-fashioned "touring" shoes and regular toe straps.  "Touring" shoes are (or were) quite walkable, and it's reasonable to walk miles in them (whereas you'd not like to do that in even "walkable" clipless shoes).

It is a little tricky setting up clipless shoes -- the cleat position needs to be positioned correctly.  Partly this is trial and error (be sure to get your setup early to try it out), but a shop can help you get the right "initial conditions".

(For those who've never seen them, touring shoes look superficially like bowling shoes, with relatively flat, smooth soles, to more easily slip into and out of toe clips.  Unlike bowling shoes, however, the soles are reasonably stiff -- flexible enough for easy walking but stiff enough so that the pressure of the pedal is reasonably well distributed over the bottom of the foot.)


Avid BB5 asymmetrical pad rub position and squeal

Having seen some mechanical disk brakes over my life, the Avid's 9 out 10 will emit some sort of sound.

You indeed are correct about how a mechanical disk brake works, by bending the rotor. So it's most important to set them properly. This is my procedure:

Take the caliper off, and check that the pads are parallel. Clean them if necessary.
Check if the rotor is tightly bolted to the hub.
Set the fine adjustment bolt on the lever and the caliper to none(all the way in)
Mount the caliper and bolt only using your hands
Bolt the cable lines.
Set, the static usually, adjustment to lock the rotor, then set it back half a turn.
Now, hold the handle with a ziptie and lock the brake.
Meanwhile use a hex tool to tight the caliper bolts
Finally, fine adjust the brake line.

Hope this will help you.


What parts do I need to replace for my bike?

Provided the bike has been kept dry in the intervening years then lube it up, possibly replace the tyres and you're good to go.  However I suspect the problem is your increased height, and to a lesser extent, weight. For your weight, the only things to consider are tyre pressure and maybe stiffening up the forks a little if that is possible.

However, to get the bike to suit your height will be tricky, a 17.5" frame is pretty small for a 6'1" person.  I'm 5'10" and my Specialized of the same size and era feels small after riding properly sized modern era bikes.  You'll probably require an extended seat tube and maybe a longer stem.  The cranks are likely to be 175mm anyway, so you'll have limited choices for anything longer.  But I think it'll end up being less than ideal, the highly extended seat post in particular being a weakness.

I think if you were to try a modern bike for size you'd find the long frame / short stem geometry and 27.5" wheels to your liking.  You're going to need to go to a bike shop to get the seat post and any other bits anyway, so there's no harm in trying.  If you don't like the feel of the new bikes, do up your old one so it kinda fits.  Otherwise shine it up and make back some money to help fund your new purchase.


Asymmetric wheel. Which side should the "asymmetry" be on?

For the sake of clarity and a simplified answer:
Typically MTB front and rear have the asymmetric rims opposite from each other.

Put the 'fat' side of the rim towards the the hub flange closest to the axle center (this pushes the holes towards the center of the flanges so to speak).

On a disc front wheel, the rotor mount takes up the most space, pushes the flange in and therefor takes the 'fat' side of the rim.
Opposite for the rear, where the driver typically takes more space that the rotor mount, so the 'fat' side goes to the cassette.

Below left is what you are after for rear, opposite for front.

Seeing you asked this question, I think you will benefit from this build guide. It goes through a few concepts, and then later the specifics that would apply to get it right for an asymmetric build.

This is the reason for my answer as the wheel will be flipped and flopped as you are finding your way with the spokes and then it's easier to recall "fat side - sort flange" logic IMO.


MTB with gears or non gears, suspension or non-suspension for stunts?

If you want to learn BMX type tricks then rigid

BMX bikes come rigid
BMX bikes also come single speed

Suspension and gears cost money.
Put that money into better frame and components.

In a mtn bike don't worry about dedicated single speed.
A single speed conversion kit lets you go to gears later.
Even if you don't want to convert it for yourself it will tend to have better resale

Get mtn bike with a low slung frame and a tube that lets you go way down with seat
(some seat tubes have a bend).

Consider a 26" used mtn bike with a nice frame that has a worn out shock and gears and convert it to rigid single speed.
Since mtn bikers want 29" there are some really good deals on used 26" mtn bikes.
Especially 26" mtn bikes without disc brakes.
You don't want to go so old that it has the 1" treaded fork.
You want a 1-1/8˝ threadless steerers.


Wrench to be used with a bottom bracket tool?

The tools being used there are:

Bottom bracket tool
Large socket to engage with the large hex head on the BB tool
Sliding T-handle socket driver

Some bottom bracket tools such as the Park BBT-22 have a 3/8 socket drive built in, so the large socket isn't necessary.


if the clicks happen when you're pedaling hard or uphill, try tightening the pedals more.


Z7 is one of if not the only 7-speed specific chains still made. It won't work right on 8-speed.


If you were able to shift into all of the gears prior to your adjustments then it would make sense that you need to readjust.  It sound like you you have adjusted it too far outboard.  I would take it in significantly so that when in 1st gear position on the shifter you are on the largest cog.  From there you can make fine adjustments for shifting between gears.


Help me build a 2x11 crankset with a 40t/42t big ring and bashguard

Regarding removing a ring from an lower end triple crank. That won't work: the two rings you are left with will be biased toward the outside of the bike; the spacing of the rings on a 8 or 9 speed crank will be too wide to work well with an 11 speed chain.

You should check that you frame has chainstay clearance for larger rings. This can be a problem on newer bikes that are designed for small chainrings.

To select a crank that is compatible with your frame you need to consider two things, the bottom bracket standard and the chainline.

You say you have a frame that takes a 92mm pressfit BB, that's either a BB92 compatible with Shimano 24mm axles or a 392EVO compatible with 30mm axles. See here for a summary of BB standards. If you  have a 392EVO and you want a Shimano crank there are adapters to step down to 24mm axles, or manufacturers like Wheels Manufacturing sell BBs that adapt from a frame BB geometry to a crank BB geometry.

Chainline is connected to the rear hub spacing. Wider hubs require wider chainline. Manufacturers specs will tell you what chainline a crank provides and rear spacing (sometimes called OLD for over-locknut-distance) compatibility. As an example Shimano provides extensive and detailed specs. Here is the MTB cranks spec page.


180 km is a long way for someone who only normally does 20-30km (to quote @PeterH in chat).

To my way of thinking, you could do it, with some pre-conditions

Do some longer rides, where you ride 30km to somewhere, have lunch, and ride back.
Ride on some of the potential routes, to understand the traffic situation.
Plan ahead, so that you do it over two or more days.

I would check out where other people ride. For example

Strava activities near Bucharest
Strava activities near Focșani. A lot of these go into the mountains, but you may find some that go where you want.

And use Google Street View for reconnaissance.

A few related questions and answers

What is the necessary equipment on longer bike rides?
Help for a 169 mile bike ride
Training involved to ride 175 miles (281 km) in a day


Can this crack in the steel chain-side dropout be welded?

You need to consult in person with someone local to you who can make a qualified recommendation.

"It is Steel so can be welded"  is mostly true, but there are always exceptions.  A good welder will give you their professional advice.  Don't bother asking someone with a stick welder in their garage.

I've personally just got a quote on welding a crack in a seat tube, and that came in at $100 NZ.  The bike cost me half that to buy, but I can't replace the frame for anything like that.

When you do find someone local, prepare the frame by stripping everything off the bike.  Everything that is not frame needs to be removed, and you should cover and protect all the threads/bearing surfaces with rags and tape.

Yes, I would remove the fork and headset, and the bottom bracket, leaving just Frame and Paint.

The only non-frame thing I might leave in there would be an old scrap axle bolted into the dropouts, to help keep everything in line and not getting extra-stressed while manhandled.

Also, clean the bike.  Noone likes getting dirty, and your welder is more likely to agree if its not filthy.

If the welder suggests unbrazing and replacing the dropout instead of welding, then you should take that advice.   They may suggest a sleeve or fishplate for strength — take that advice.  Figure out if it will interfere with your chain/cassette or fitting of the rear wheel.

And lastly, if its not safe to fix, or if its super expensive, consider retiring the frame and put those costs toward another bike.


Dawes Galaxy OLN and horizontal dropouts

You have a few options:

Find an older steel frame and spread the frame.
Buy a different frame, such as a Surly Cross-check.


Quill stem diameter not matching the fork...possible to get around this?

There are products that do this, but they rely on the quill fitting inside the steerer.

You can also get threadless clamps that allow you to run a fork with no stem, and effectively DIY that product. They're mostly used by recumbent bikes that have a second pivot holding the handlebars, rather than by people not using handlebars at all.

If you're lucky you might be able to find a different quill stem that will fit inside your steerer tube. But then you have an aluminium steerer being pushed on by a steel quill in a way that the designer never thought about. That's why the commercial product clamps the quill rather than using the wedge bolt it was designed for.

But since the quill won't go into the fork steerer tube, that's never going to work. Milling out the inside the of the steerer tube, even a small amount, is risky. It's one of those "probably ok, but if it's not your face hits the road" things.


Does anyone know of a lightweight motorcycle style open face helmet for eBiking?

Track racing helmets have a built in visor, but these usually only cover the eyes.

You can probably achieve what you want with a combination of a non vented helmet, wrap around glasses or goggles and a half-face mask or balaclava.

There are numerous bicycle specific helmets made for commuting or casual riding that have minimal vents, or closable vents. Some have cold weather liners that fit to the chinstrap to cover the ears.

There are half-face masks made for skiing, cycling or other cold wether use that are semi-rigid so that there is space between the mouth and nose and the mask.


I've had my fair share of hydraulic brake woes this year so I'll list the things I'd check - I am aware that you've done some already. Firstly some questions though:

Are these brakes using mineral oil or dot fluid? If it's dot fluid, when attempting to bleed the system you may want to take extra care and de-gas the liquid like with Avid brakes.
The comments suggest cable actuated hydraulic brakes, this is a new one on me for bikes so I'll assume that the cable has been checked and is moving freely / not rusted.

Things to try:

If you've cleaned the rotors and pads lately then you might need to go through a decent bed-in procedure to transfer some braking material to the disc rotor.
Bleed the brakes (if you need the Avid kit to do it, buy the pro kit, the other one is awful).
Sand the pads.
Check that both the pistons are moving freely in the calliper.
Degrease the whole area - isopropyl alcohol (IPA) will clean most of the muck. Use paper towel or new rag rather than an old greasy rag.
See if you can get some life back in the pads by heating them with a gas flame from either a blowtorch or gas ring on the hob for 30 seconds (be careful, use pliers to hold the pads). See if you get flames or lots of smoke which indicate contaminants.
Try new pads, swap to another brand or compound. Sintered is good for wet, grit and mud. Organic has better initial bite but not as good in the sloppy conditions.
Check the hose and connection points (banjo bolt & bleed nut) for leaks.
Check around the pistons for bubbles that indicate a leak.
Look for areas around the calliper where dust and grit has stuck to any oily residue that could have come from a leak.
Take the rotor off the hub and give it a good clean in the sink with degreaser, washing up liquid and finish off with IPA.
Take some pictures and video of the calliper so we can see if there's anything that more eyes can pick up.
Enlist the help of your local bike shop - show them some (financial) love and build up a good relationship with your local mechanic(s).

Make sure that your isopropyl alcohol is as pure as possible so as to make sure it doesn't leave its own residue.

Try a few more things and report back soon.