You can't use an 8 speed shifter with a 10 speed cassette. The space between individual cogs is smaller than on an 8 speed cassette. The shifter moves the derailleur a fixed distance per shift, so it can't reach the position of the cogs if they are not spaced as intended.
The fact that you can use the 4 biggest and the smallest gear is pure luck, because the derailleur seems to match those positions good enough to make it work.
In conclusion, try to find an 8 speed cassette that fits on your trainer.


How do I locate and loosen the rear derailleur hanger bolt?

I've put a red circle around the hanger bolt.


Don't like upright position so which bike should I choose?

It’s awesome that you’re getting back into riding again. MTB style bikes have gotten a lot more sit-uppy in the years since you last purchased a bike. Their geometry has gotten a lot more slack and the headsets a lot shorter and the wheels are bigger so you tend to sit “in” the bike rather than stretched over the top of the bike.

This might be an occasion where you should talk to your local bike store to see if an MTB is still what you want or whether a gravel bike which is a modified road bike with fat tyres but still has drop handlebars, might suit you better. It really depends on the terrain you want to ride on.

A good store might be able to recommend changes like a slightly longer headset to an off the rack bike to stretch you out a bit too. Also some brands tend to be longer in the frame than others.

Good luck with your search.


Can I use denatured alcohol instead of isopropyl alcohol when servicing a fork?

Yes, denatured is fine to substitute for isopropyl. For regular shop use, the methanol is kinda nasty (debatably) from a toxicity/odor standpoint.

Everclear (which is 95% ethanol) is the other thing from around the house that can sub in.

Isopropyl is more a drug or grocery store item, although industrial suppliers do sell huge jugs of it.


regarding the amount of teeth on the sprockets/crankset:
 The ratio between the amount of teeth on the rear sprocket and crankset determines the gear ratio of the bike. Even though you have a gear hub the ratio between the sprockets will still determine your gear ratio. The smaller the sprocket in the back/the bigger in the front the higher your top speed is, but keep in mind it will take more force/less revolutions to keep your bike rolling at the same speed when in the same gear with such a sprocket ratio (small in the back large in the front).

check out the "gear ratio" section: https://www.whycycle.co.uk/buying-a-bike/bike-jargon-buster/bike-gears-explained/
general info regarding gears: https://www.sheldonbrown.com/gear-theory.html

If you want your bike to maintain it's current gear ratios either re-use the original sprockets or pick new sprockets with the same ratio of teeth (back/front).

the amount of total teeth on the belt should not really matter as long as: A) your belt isn't too short as in you cannot get it around both sprockets even when the wheel is adjusted so that it is the position most to the front of the bike as it can be B) your belt isn't too long as in you cannot get the belt tight enough with the available adjustment range (back to forth adjustment of the rear wheel) without the rear wheel falling out of the dropouts

A higher number of teeth on a sprocket means the force on the belt is distributed over a larger number of teeth. Which will reduce the wear rate of the sprocket and in theory also of the belt.

Regarding compatibility: This page suggests the CDN and CDX-EXP parts are compatible.
https://willem.com/blog/2018-02-24_creating-the-ultimate-commuter-bike/#continue

Judging from the story on the website above I'd say upgrading to CDX-EXP (especially the stainless steel instead of polymer rear sprocket) is worth it. As can be seen on the website the polymer sprocket doesn't seem to hold up all that well, especially when riding in harsh conditions.

This is after just 1800km according to the website:

CDN vs CDX-EXP sprocket:


I'd use a trailer for this.  There are ready-made ones like http://www.bobgear.com/bike-trailers or you could build your own.  Then a lot of the weight can go onto a dedicated trailer wheel (or two),  which should make it no big deal to carry two 60 pound batteries (assuming you have legs of steel, obviously).


To avoid changing batteries, you could opt to get an external USB battery pack and power it off of that.  That way you could get a continuous stream. If you got a big enough battery pack, you would most likely be able to power the iPhone and GoPro off of a single battery pack provided you found one that was big enough.


Can you help me identify the year of my specialized frame by serial number?

!
Above picture is the 1986 version of the Stumpjumper
And here is a link that may help you research the exact year of your vintage Stumpjumper: Vintage Mountain Bike Workshop


Which spokes go on the non drive side and which go drive side?

Yes, right side is the drive side. Assuming that both sides use the same "cross" arrangement the shorter spokes go on the drive side of the rear wheel, so that the offset due to the drive mechanism will be compensated for and the wheel will be centered.

If you swapped the L/R spokes, the drive side spokes would be to long and the non drive side spokes would be too short.

Note that if your spokes and spoke lengths are the same for both sizes this won't matter, of course.


There's a small chance you don't have as much hand/arm strength as you used to.  A coaster brake provides a way to slow while leaving your arms free to focus on steering.

That said, a coaster brake is a rear brake only.  The best stopping happens with the front brake, so ideally you'd have both, a coaster for the rear and a hand brake lever for the front.


Good Brands for Front Pannier Rack on Suspension Forks

Get the rack first or get them together.  You need the panniers to attach solid.  Not all racks have the same places to attach.  I have Surly Ortleib combo but that is like $200.

An over the top design like this gives you more storage.  And you could lash some stuff and maybe skip the panniers. Those two little tabs on the bottom are nice for lashing.

SurlyRack
Give yourself an hour or two to install.  Lots spacers and lots of positions.

And on a fork look for threads at the bottom of the fork and mid fork. That bike also has threads on the inside for another attachment point but don't worry about that.  Go to the gallery.
Vaya


Consider the design of a conventional axle.  This is a cutaway of a rear hub, so just look at the right-side and imagine that reversed on the other end.

In the middle is an axle of threadded rod.  A bicycle has maybe 15mm of this poking out on either side, and it is supported on the dropouts of the fork or frame.

If you replace this axle with a much longer one and only support it on one side, then you risk bending the axle just outside the locknut.

By comparison a wheelchair axle (aka a stub axle) has a short shaft but its much meatier.  In this image, #38 seems to be a collar or similar to spread the load.

Drive

Also consider that bicycle wheels do not take drive through their axle.  THe axle is fixed and the wheel rotates around that.

So your pedal car won't drive through the axle very well.  Instead you want the bearings to be on the body of the pedal car, and the whole axle and wheel should be locked up, something like this:

So the rear wheels are direct drive.

Safety avoid the temptation to make a three-wheel pedal car.  They are inherently tippy, and not recommended.

Steering A four wheel pedal car will probably need ackerman steering else its hard to turn.  Depending on your kid's weight this may not be an issue.


My understanding is that a car has two systems - the springs (leaf or coils) and the shocks/shock absorbers.

Springs absorb the initial impact, but springs alone would be bouncy.  So Shocks (should really be called dampers) are systems which resist change and slow down the spring.

In your bike's fork, one side is a spring and the other is a damper.   They act at different times, and act against each other.

Through axles were invented to help tie both fork legs together so this imbalance would be less of an issue.

In an ideal world you'd have both on both fork legs, but that would mean smaller springs and dampers, which are less effective even when there are two sets.


Cycling communities organized rides in Leipzig , Germany

Check out the website of the ADFC bicycle club in Leipzig http://www.adfc-leipzig.de. The "Termine" link has a list of their events including bike rides.  Also the "Radtouren"link might be of interest to you.  Of course everything is in the German language.


mountain bike chainsuck, replacing parts while thinking of future upgrades

Sounds like you are going to be replacing the middle ring. 'Bolt Circle Diameter' is the measure of chainring compatibility. You need another ring of the same BCD and you can check the specifications for that on the Shimano website.

Personally I would go for another Alivio ring because they are made of steel rather than aluminium alloy, this will last a lot longer, cost a lot less and the weight difference will be marginal.

The shark-fin look to the teeth is deliberate, they are individually sculpted so as to make shifting that bit easier. The bent tooth is the problem - and the missing teeth.

You can order in confidence from Wiggle and return the item if it is not the one you want, albeit with some postage to pay.

The chainring bolts do need an allen key at the front and a proper tool at the back. See if your big-fat-screwdriver can be used instead of the proper tool - tightening chainring bolts is not an everyday task so you may be able to skimp on getting yet another tool.


There are two parts to this - the cage length is the distance between the two jockey gears in the rear derailleur, and this limits how many links of chain it can take up while maintaining tension.  Longer cages (like MTB ones) could do 11-42 so a difference of 31 half-links.

Road bikes tend to be narrower, so a short cage might only take up 11-2x.  There are many in-between lengths.

So change to the bottom gear, and look to see if your lower jockey wheel could move further forward.
Then consider if the chain was a couple links longer and you're in a small/small combo, would the chain touch itself?

The second part of your question is whether there is space for a larger big cog on the back.

The eyeball technique would be to put the bike into its bottom gear, so 36/23.   Then look to see how much space is left between the top jockey wheel and the largest cog.  If the bike came with 23, then 25 is likely to work, and you might be able to get up to a 28 in there.

Otherwise you have to change the rear derailleur too, which is another cost.


In most cases a mild bike wash soap gets you past the minor services, no problem. Used in conjunction with a toothbrush or the like.

What you want to avoid is any cleaner that is oil based(petroleum, paraffin etc.). These leave residue and will affect your stopping power. I have even found citrus de-greasers leaving residue films behind.

During major services you want to get the wheels and brake pads out after the normal wash. You can then use isopropyl alcohol to bush the caliper out. Isopropyl is also great if you found the pads contaminated and can often save the day from having to buy new ones. In addition, isopropyl is also used to wipe down the rotors' surface and that is very important to keep clean.

Isopropyl alcohol is cheap and easy to find, often branded as some type of household cleaner. So you can add it to the shopping list or swing past a chemist/drug store. In addition, if you are working on brakes, this should be part of your standard tool kit. It is the go-to for removing and cleaning DOT brake fluid of the bike as well. Also, when you go to the auto parts store, they will have brake cleaner as well. Usually more expensive and mainly pressurized isopropyl alcohol.

Avoid sandpaper. This is the very last resort. Unless experienced, you are almost guaranteed to get the surface not flat and out of parallel with the other side and rotor surfaces. This will decrease stopping power, cause squealing and require the pads to be re-bedded. So effectively you'll sand away some of  the pad and the lose more trying to get it bedded again. Have used it in the past for very specific problems and then you'd be looking at 800+ grit, super flat working surface and circle motions.


Finding Geometry Information for Vintage Frames

For a 650B conversion, the length of the chainstay is mostly irrelevant, because a fat 650Bx42 tire has about the same outer diameter as a 700Cx25 racing tire -- so it's rare to have too short of chainstays for a 650b conversion. And most of the appeal of a 650b conversion is that you can get the handling and feel of a compact sporty bike with the softer ride of wide tires, so I wouldn't discount short chainstays from your search.

The most important thing to look at it whether the bike will physically fit the wide tires, and that comes down to the width between the chainstays and the width between the fork blades. These clearances are hardly ever given on geometry sheets, so you'll either have to take a look at the bike in person, or see photos showing how much clearance there is between the existing tires and the fork and chainstays. Remember that the widest point of a 650b tire is at a smaller radius than the widest point of a 700c tire, so a frame may have more clearance for 650b tires than it looks like.

The other thing to look at is how much reach your brakes will need. That's determined by the distance from the axle to the rear brake bridge in back, or from the axle to the hole in the fork crown in front. You want it long enough to clear the tire (+ fender if you're using fenders) but longer will just lead to spongy braking. If the bike you're looking at already uses 50+mm of reach to reach a 700c rim, it's longer than ideal.

The fastest and most reliable way to measure is just to try putting the wheels in the frame. If I were thinking of building a 650b conversion, I'd start by getting a 650b wheelset and tires and bring it with me while checking out craigslist frames.


Bouncyness* may not be the appropriate term for the behavior you need from your suspension.

Suspension has two main functions: Shock Absorbing and Dampening. Shock absorbing is what the fork does by compressing, allowing the wheel to travel upwards. In this process, kinetic energy from the shock is used to compress either a coil spring or an air spring. Once this has happened, this energy that is "stored" in the spring has to go somewhere, and this happens when the wheel is forced down again.

If no other mechanism is in action, this energy returns almost at the same speed as it was put in, so it would be transmitted to your hands through the handlebar, giving an unpleasant and dangerous ride. That's where Dampening comes in. Dampening is a mechanism that slows down the shock absorber's return, consuming the stored energy, usually transforming it into heat.

Most forks achieve dampening by having oil reservoirs, pistons and valves. The fork moves oil from one reservoir to the other (from one face of the piston's head to the other) and the flow of oil is partially obstructed by the valves. The oil gets heated a little bit as it is forced through the valves.

With this in mind, we can understand the two main adjustments that any decent fork should have. Preload and Rebound Speed.

Preload is HOW STIFF is the suspension, and it's related to how much force must be applied to compress it. More preload means you need more force (apply more weight) to compress the fork by a given distance or travel. Speed Rebound is HOW FAST the fork return to it's uncompressed size after absorbing a shock.

If you feel that it takes too much force to compress your fork, it means you have too much preload. You mention you are too small (not heavy enough) so it's likely you must turn the preload all the way to the side marked with a minus sign (-).

There is a process to calibrate a fork, and it needs a ruler and possibly an assistant. You must measure SAG. Sag is the amount of travel that the fork compresses by just applying  your weight to the bike in riding position. The user manual for your fork model should contain a table indicating the appropriate sag range for your weight. Preload is adjusted to achieve the desired sag, the more preload, the less sag and vice versa.

Chances are you weight too little for that fork. If this is the case, there may be some options: Change the spring, or change the fork. Some fork manufacturers sell different springs for some of their fork models, precisely to suit too big or too small riders. Refer to the fork owner's manual, It should bear the information. If you don't have the manual, It may be available from the manufacturer's web site.

If the fork is not serviceable or a softer spring for it is not available, you can change the fork for another one that fits your weight or that can be adjusted accordingly. An AIR fork  may suit perfectly, since the "preload" of an air fork is given by the pressure of the air in the chamber, which obviously can be lowered to zero.

There is no preload adjuster on an air fork, but there is a valve for adjusting air pressure. They often require a specialized pump to load the air chamber and calibrate it. If you have a local bike shop near you they should be capable of swapping the forks and calibrate the new one.

You must also take into account that you have a front suspension only bike, so you will feel almost zero suspension effect for shocks to the rear wheel, so depending on the terrain you ride, you must learn to act as a suspension for yourself. It also depends on the purpose of your ride: sport, leisure, commuting... as this allows you to choose routes accordingly.

A limited option is to use lower tire air pressure, but not to low. Too low pressure may result in a bike that is not very maneuverable and prone to "snake bite" flats.

*A bouncy suspension can be understood as a faulty one, it is a suspension with no dampening or rebound control. It does not absorb the shock, it just stores its energy for a very little while and then returns it. For example, a car without dampener keeps going up and down after hitting a road bump, or you see its tires bouncing like a basket ball after a pot hole. A suspension with this condition is risky because it allows the tire to loose contact with road, leading to loss of control of the vehicle/bike


Does anyone know of a machinist who could convert a dual ring Campy Nuovo Record chainset ('spider') to accept a 3rd chainring?

Drilling a crank that old is not a great idea. They weren't that strong to begin with and 40+ years of use hasn't made then any stronger. I would not do anything to further weaken them.

To be honest, if the pedals are frozen I'd think twice about using that crank. Aluminum corrosion expands and can create stress that crack the material ( similar to the way ice can expand and split a crack in a boulder).

All that aside, if you look hard enough you can find a "tripleizer" ring. This is a special inner ring that
includes the mounts for a smaller inner ring.

Vintage Trek Tripleizer Page

On a bike that old, there's a reasonable chance that you won't need a new bottom
bracket to allow the inner ring to clear the chainstays. Also, there's a pretty good chance the existing derailler cage will be low enough to allow use of the small chainring. Back then there was no such thing as a "triple" front derailluer.

Shifting will require a bit of practice compared to modern triples; you will drop the
chain, so get a Dog Fang or other chain catcher.

If you want components that are modern but look old and don't cost the insane price of
used campagnolo on Ebay; Check out Velo Orange Components This should bring back some
memories.

That crank is a 34/48 that I think would be a really good choice for an upgrade on a older bike.


Fixing broken STI shifters - plastic gear cable surround

Most shops don't carry spare parts for STI shifters. Most problems are internal and even if you can get spare parts, the cost in labor to replace most things (except clamps, hoods, and name plates) coupled with the cost of the spares exceeds the cost of a whole new unit.

The piece you need is called an outer support unit. Shimano does have part numbers for individual pieces like that, but in general, you'll have to go direct to Shimano to get them. The biggest bike distributor in America doesn't have them. This makes them a little harder to attain.

And then there's the other problem: you have old Sora components. Generally, Shimano engineers new stuff and drops support for the old, at least when it comes to spares.

That being said, you might look around but I'd say you have an incredibly small chance of finding the replacement part.

Not too mention, as I implied earlier, it's not trivial to replace things on STIs. If you're willing to take it on, you'll generally be on your own, as few shops do such repairs.

If you're ambitious, I'd just try to find a broken shifter that you can scavenge the piece from.

Another thing you could do is hack it. Fabricate a sleeve to cover over the housing stop that goes as far as your barrel adjuster. It might just be enough. Make sure the inner diameter is as close as possible to the outer diameter of the stop. I'd suggest something that isn't going to be too annoying if it rattles, which it probably will. This is one case where carbon fiber might be useful! ;-)

If you use this for competitive purposes, professional (on Sora? Probably not), amateur, or just for fun, I'd suggest STIs. Otherwise, bar end shifters are a technology that has been around a long time.  They're simple and anyone can figure them out. Plus, the friction mode is very useful. I'd give it some serious thought if you don't mind moving your hands off the lever to shift.


What is the average CdA to Weight relationship of a professional Road cyclist?

A very brief answer to part of your question. Perhaps you or others can leverage this to produce a more complete answer, unless Alex or Robert chime in :-)

As you probably know, CdA is the product of the frontal area, A, and a coefficient of drag, Cd. It is also known as the "drag area." In most cycling applications, the area is measured in square meters, so a cyclist with a CdA of 0.30 has a drag area of 0.30 m^2.

AFAIK there are few studies that have been released for pro cyclists, although these days several of the pro teams say they do wind tunnel testing. Maybe that's just PR.

There are multiple academic papers that relate to this. Once you have one you can follow the trail of citations to others. Currently the most famous is probably

  Martin, Millikan, Cobb, McFadden, and Coggan. Journal of Applied Biomechanics, 1998, 14, 276-291.

A copy can be found here

In their experiments they used six volunteers. Not pro cyclists. The volunteers rode in the time trial position.They say the average drag area was 0.264 m^2 for an average body mass of 71.9 kg. See the paper for more details.

In another post on this site Simmons measures his own CdA at 0.334m^2 on a road bike compared to 0.286m^2 on a TT bike, a 14% reduction.

Alex's post gives some other references that can be followed. Several of his other posts will be helpful also.

So the CdA depends on the cycling position. In my own models, I find a CdA of .3 m^2 gives a good fit for my performance on a road bike. I'm 70 kg.

Andy Coggan has also collected some rough rules of thumb for estimating CdA from anthropometric data like height and weight here.


What rear mech can I use with 105 shifter?

It depends on what you mean by big, which can now be interpreted many ways.

Without doing anything too tricky, you can run them with any 9-speed Shimano mountain derailer, some of which can natively handle up to a 36t, RD-M592 being a currently made and easily available example.

10 and 11 speed Shimano mountain rear derailers use different actuation ratios, so they can't go directly on your shifter, but they could be made to work using something like a Jtek adapter or Wolf Tooth Tanpan. If you wanted to run a 40 or 42, you could use a Wolf Tooth Goatlink on an applicable 10-speed RD that you also have a cable pull adapter on.

If you want to use a road RD, you can go up to a 40 with a Wolf Tooth Roadlink. It's important to understand that they increase the clearance but not the capacity of your RD, so whether it makes sense depends on what's going on up front. (True no matter what route you choose actually.)


Puncture resistant tire vs puncture resistant tube

My choice would be based on my current need. How often are you getting punctures? How efficiently can you make repairs? Are you commuting to work where the delay from a flat repair results in lost wages or potential job loss? Then go with puncture resistant tires. Then add the flat resistant tubes if needed. If your tires are fairly new but prone to punctures, I would go with new puncture resistant tubes based solely on the cost. If I needed new tires and was primarily concerned about punctures I would get puncture resistant tires then add tubes if needed.


4L of water and 2 max protein bars. Is it sufficient for a four hour ride?

I'll concentrate first on the carbs side, because the water depends on so many factors.

Gels are around 30% non-sugar carbs with the rest water, according to the SIS ones I have here.  They're actually a fairly heavy way to carry a small amount of carbs if you can get water along the way, but they're easy to consume while riding hard, and are meant to give a quick (but not too quick) energy boost.

Protein bars have more sugar (which you may or may not want) and a fair bit of protein, which is a poor energy source during a ride, and they're overpriced if you're using them as a source of carbs.

There are also energy bars.  One I have here is 67% carbs (about 1/2 of that sugar) and 4.9g protein.  It's based on oats and fruit.  These are probably better than protein snacks for use while riding.

Alternatives you may find easier to obtain are bananas and dried fruit.  Even bread-like carbs can be good  (second breakfast after an early start for me might be a wrap with a banana and chocolate spread in it, for example). It partly depends whether you can stop to eat or want to eat on the go (in France, for example, a bakery stop for fresh croissants is good).]  If you want to make something, flapjack is great (mainly oats, sugar, and  butter, add dried fruit/chocolate chips/crystallised ginger if you like).  Sweets have a place towards the end of a ride or for a specific effort like a big hill.  They're essentially flavoured sugar so your energy levels go up fast -- and down fast.  Jelly babies are popular in the UK, but they may not be available/suitable (gelatine tends to come from pork/beef).

It is perfectly possible to ride for that long without food (3.5 hour example in my case, after lunch), but you won't be as fast and you have to be careful. Make sure you're well fed to start with, carry snacks just in case, and don't even think about it if there are medical contra-indications.  I just chose to keep going without calories on the exploring/training ride I've linked, as I wanted to try running on empty.  I still got through a fair bit of water and the temperature wasn't much above freezing (I had to wait until after lunch for the ice to melt on the roads).

Water: on a hot ride I rely on topping up rather than carrying everything I think I'll need.  A recent hot ride got me through 6 litres in 12 hours, plus 1 before I started and another 2 when I got back.  That didn't feel like enough.  Bottled water seems pretty easy to buy in India, unless of course you're out in the countryside for the entire ride. I'd plan to pass somewhere with water available every couple of hours, at least until you've got a good idea of how much you get through.

Links are to arbitrary examples, including my own rides.  Products are ones I have lying around, usually because I picked them up cheap.


This style of bicycle was extremely common in this time period. There are no visible unique identifiers in the photo. Given that there were many manufacturers at the time, and even the major manufacturers (Columbia, Raleigh, Schwinn, etc.) or distributors (like Montgomery Ward) did not leave definitive identifying photos or descriptions of their bicycles, I am quite sure that this is an impossible task. I'm sorry, I know that is not what you want to hear, but I don't think you will get a better answer. It COULD be a Montgomery Ward bicycle, or an Elgin, or a Columbia, or a Colson, etc. It is not a Raleigh, nor is it a Schwinn. But even using the negative research method - what it is NOT - will not tell what it is. Unfortunately there were a lot of smaller manufacturers around then. For instance, look at this Colson: 1930's Colson. The top tubes and tank on the frame are similar, but note that the saddle appears different, as does the chainring. Pay special attention to the chainring when trying to identify a bike from this time period. They were made of stamped steel, and were frequently designed with a manufacturer specific cutout pattern. Examples are Raleigh's heron designs, Hercules "H", etc.

A good place for some beginning research is Dave's Vintage Bicycles.

However, using what you have found - that you think it might be a Hawthorn, and this page on Dave's Vintage Bicycles, we can see that the chainring cutouts match between the two photos. I think this is about as good as it gets when identifying old bikes like this! The handlebars are different, but that could have been a simple change from one year's offering to the next.


Effect of drinking coffee before riding?

A recent documentary on the BBC in UK covered some aspects of ingesting caffeine prior to exercise. A written summary is here:

http://www.bbc.co.uk/programmes/articles/23hqLh1TYQqZdql7GkqQZ1L/which-types-of-exercise-benefit-from-caffeine

Without reviewing the science in detail, it basically suggests that for endurance type activities, caffeine blocks receptors in the body, leading the brain to "perceive" less pain and fatigue, allowing someone to exercise longer. The article states an optimum amount of caffeine to be 3mg per kilo of bodyweight (somewhere between 1 and 2 large cups of filter coffee for average man / woman). To experience the benefit you should drink the coffee approximately one hour before starting the activity, and the effect will last for "a few hours". If you regularly drink a lot of coffee (or take other sources of caffeine), it is likely the impact will be reduced.

Your experience may just be the effect of the coffee / caffeine wearing off, plus any lessened impact due to the amount of caffeine you ingest on a daily basis.

Of course, other factors may be causing your fatigue, but your question specifically asked about effects of coffee / caffeine.


Are narrow-wide single chainrings compatible between 9, 10, 11 and 12 speed?

I would have thought that most narrow-wide rings would work with 9 through 12 speed chains. as they all have the same internal (roller) width.

Chains from 5 to 8 have an inner width of 3/32″ (2.38 mm), chains from 9 to 12 speeds have an inner width of 11/128″ (2.18 mm).

Looking at a Blackspire ring:

  For use with 9, 10, 11, or 12 speed drivetrains

  For 9 speed drivetrains you must use a 10 speed chain.

Same for Wolf Tooth:

  Compatible with all 10-, 11-, and 12-speed chains except Shimano 12-speed chains.

  If using a 9-speed drivetrain use a 10-speed chain( shifts and works well on a 9-speed drivetrain and fits the ring tighter for better chain retention)

They obviously think there is something about 9 speed chains that does not work with their rings as well as a 10 speed chain.


BS6102 is a British Standard for cycle safety.  Released in 1981, and compliance became mandatory in 1983.  It specifies rim dimensions, lighting/reflective gear, dimensions of spoke nipples etc.  Does NOT cover helmets.  So this bike post-dates 1981/2 and predates ~2005 when the European GPSR rules were adopted.  So that number is useless for anything other than a 24 year window.

  Personally, I'd make it mechanically sound and fun to ride, and then ride it.  Maintain it, care for it, store it inside, and it'll last decades more.

Universal Cycles were known for producing low end bikes, probably one step above a BSO but not particularly high end.

As for decals - you might want to simply clearcoat it plain over the paint, or make your own that say "KGBigman BMX Bespoke Model" or something.

You could even be horrible to a future researcher and badge the bike as something its clearly not.

  There are heaps of decal sets to order on the web, even ebay has plenty.


Do eliptical chainrings give you an advantage

No, they won´t give you any advantage. It didn´t show a benefit in comparison with normal chainrings since the transference in watts doesn´t change. If you want to get any advantage you should look for loosing weight as much as possible on the bike and having better performance parts will surely help but in the end, the only way to get advantage is training. Unless you do 28 hours a week, you should focus in your training first.


Removing lockring/ cups off head tube on vintage BSA bike

Park HCW-11 wrench to remove/adjust the BB cups:

https://www.parktool.com/product/adjustable-cup-wrench-hcw-11

RT-1 to remove the headset cups:

https://www.parktool.com/product/head-cup-remover-rt-1

or just a long flat head screwdriver and hammer to gently tap them out.


Brakes won't release after being applied?

Brake calipers have return springs to move open the caliper arms after closing force supplied by the force on the brake cable from the levers is removed.

If the calipers are not opening there are several things that can cause this:

Return springs are too weak
Caliper pivots stiff or jammed
Brake cable friction is preventing it from retracting through the housing, either due to contamination or poor routing.

Many linear pull or V-brake calipers have return spring adjustment screws near the pivot. You could try increasing the return force and see if that sufficiently opens the calipers.

Disconnect the cable from the calipers. With the cable removed do the calipers move freely? If you close the caliper arms by hand is there a reasonable return spring force opening them?

If the calipers look OK, try cleaning and lubricating the cables as in mattnz's answer.


Very roughly, you take the ISO size (on the side of the tire, in a form like "38-584"), add the two times the first number to the second number (eg, 76 + 584), and that gives you the wheel diameter in mm.

(There is the problem that the tire width value is far from exact, but it's about the best you can go on.)

If the application you're dealing with wants the circumference then you multiply the above result by pi (3.14).

From a web search I see that the original tires on the bike were likely 700x25c.  The "700" rim has an ISO diameter of 622.  The 25 width is probably close enough to the ISO value.  So 622 + 50 =  672 mm diameter, or 2110 mm circumference.  (Of course, divide the numbers by 10 for cm values.)

Or, of course, you can simply walk the bike along the floor for 5 or 10 complete wheel revolutions, measure the distance traveled, and calculate from that.


8 speed cassette increased from 25 to 30

With an old road bike it's impossible to tell just by looking. Many older derailleurs were designed when 28T was as big as it got, but they will still work with a 30T. But they might not, too.

If you're definitely going to make the change there's no real loss if you buy the cassette and try it. If the derailleur doesn't work, buy a new one. You might pay two lots of shipping, in which case the question is whether the second lot of shipping is enough to make it worth buying the derailleur anyway.

A better option would be to see if you can scrounge parts from a local bike co-op or tip shop. That way the cost is mostly your time, and if something doesn't work it doesn't take long to find a different one. Even if you end up running an MTB derailleur, the main thing is that it works.


Advice on tyres for a 109 mile charity cycle

Variations in this question must be one of the most asked on this site, but I can't find a good question and answer to direct you to, so I'll just answer it.

There are many rim width to tire width charts that can be looked up on the Internet. An example is on this Sheldon Brown page. It's highly unlikely that the tires supplied with the bikes are at the narrowest limit of the rims, so 1.5" tires will be fine.

If you are looking to decrease rolling resistance, go for a road oriented tire with minimal tread rather than an on/off road hybrid. Inflate to the upper end of the specified pressure range.

It goes without saying that you should have the bikes checked over and make sure the brakes and gears are properly adjusted. Also, make sure the drivetrain is super clean and properly lubed - that does actually net an improvement in efficiency.


(Saddle) rails is the correct term. They are part of the saddle/seat. I’m not aware of any saddle where they are replaceable.
You might be able to bend the rails back but it could compromise stability. Considering a new saddle only costs a couple of euros I’d just replace it.
For a crash to bend the rails like that it takes quite some force. I recommend a very careful inspection of the frame, seat post and all other parts of the bicycle.


There are a number of rubber overshoes that would work. Two of the most common brands are Totes and Tingley. Try a search for "rubber overshoes" on Google or Amazon.

These will protect your shoes, provide some traction, and can be rolled up and strapped to the frame or seat with velcro.

Below is an example of the Totes brand:


Assuming these are Drop handlebars, the second dimension would be reach or drop.

On the other hand, as you're buying a complete bike, not just bars, the second dimension is very likely to be stem length.


Is this a bike light and how do I turn it on? (I know it sounds stupid)

This is a halogen light. Such lights are usually powered by a bottle dynamo. That is a small electric generator that is driven by the front or the rear wheel. There is usually no switch. One simply engages the dynamo by pushing it down, such that a spring presses it against the flank of the tyre.

Some bikes have a hub dynamo instead. In this case there might be a small switch at each light. A hub dynamo looks like a very large front hub (central part of the wheel).

If you have such a dynamo make sure that the light is connected to it. Follow the wires from the lamp to the dynamo. On older bicycles with bottle dynamos there is typically only one wire. The bicycle frame serves as common ground connection.

Check if the dynamo is properly pushed to the tyre and that its wheel spins when you spin the tyre.

The bulb in the lamp might be defective or missing. Replacement bulbs are not very expensive. But they may be hard to find today. An inexpensive led lamp might be a better replacement, as such lamps are considerably brighter.

Finding the fault may be a little tricky without a volt meter or other means to test electrical connections. If you cannot got to a bike shop anyone who is handy with simple electrics may help you out. For example, electricians or car mechanics.


Clipless pedals are a matter of preference - you don't have to use them. There are alternatives such as "half clips" which might suit you better.

I've come to like mine, with mtb shoes and pedals that are designed to be rideable with clipless or normal shoes on either side. These allow you to ride in an alternative position (with the pedal under the arch of your foot if getting ready to stop, for example). It's often wet here and feet sliding around on the pedals can be a real nuisance. But since buying my clipless pedals & shoes I've also bought a pair of pedals with much better grip against the soles than my old plastic platforms, so you don't need clipless to keep your feet from sliding


Measure seatpost diameter on frame / Raleigh granada 1986

I ordered a 27.0mm seatpost and it fitted perfectly!


guide to correctly assemble a Walmart bike

If you are mechanically inclined most of the adjustments are straight forward. There are many on line tutorials, Park Tools website and the often mentioned Sheldon Brown are my personal favorites. As @ Batman has stated BSO (bicycle shaped object) can be frustrating to maintain. I have serviced them and the bearings don't get any smoother when I assemble it than it did from the factory. The primary concern from the design is will it function (not is it smooth ,is it light ,is it durable)  with parts from a certain pricepoint To use a comparison you may relate to. If I buy a tablesaw for $125 it may last me 20 years of occasional homeowner use, if you used it commercially it will fail much sooner. A Walmart grade bicycle will function fine for an occasional ride before it needs maintenance. A higher quality bike (not just when new but after years of use) will be easier to tune and stay in tune longer. It will be repairable and upgradable.


The idea used to be that a triple was just a double with an extra small, 'granny' ring (i.e. only grandmothers would need to use that one) so there was definitely some snobbery in a triple; that it was designed for those who needed a little more help. So on the club training run, you might be teased for it. (Google for 'triple granny ring' for various forum discussions and banter; don't worry, most of the responses are SFW.)

Practically, what it tends to mean is not necessarily a bigger gear at the top (i.e. big front ring & small back ring) but a much lower gear at the bottom, for the hills. So with the same rear cassette you might compare a 50/34 double for a 50/39/30 triple (although a 50/34 is probably more what is called these days a 'compact'). That range of triple combined with a typical rear cassette of 12-28 would work for most hills.

You also get a lot more options; so you'll get the similar effective ratios in several ways, because the ranges on the big ring overlap more with the middle, and the middle with the little one. Also, the gears are closer together - so you're more likely to find something that works well at the right time.

It is also easier to change on the front ring of a triple, on a compact you'll often need to change down a gear or two on the back when you move on to the bigger front ring, which means the chain is being yanked both ways and strained that bit more. But on the triple, you're not as far away, so you'll often not need to change the back at the same time as shifting the front.


Bar ends are typically banned from group/club rides because of the potential to hook another rider when riding in a tight group.  Because a flat MTB-style handlebar is wider than a drop bar, adding bar ends increases the likelihood of snagging another rider.  (drop bars still can cause crashes though, which I've seen first hand)

On the plus side, adding bar ends gives you more hand positions to choose from (similar to using drop bars).  This is very important on long rides (e.g. touring) since your hands can go numb and possibly suffer nerve damage if you keep them in one position for too long.  Some people find the hand position on bar ends more comfortable too.

Papuass has been injured by a bar end in a crash.  My experience is the opposite: the bar end protected my hand from sliding along the pavement at high speed, saving me a fair amount of skin.  So it can go both ways.

If you're not doing group rides where bar ends are banned, I would definitely consider trying them for the sake of having more hand positions.


Wobbly bottom bracket on Radford, need guidance to replace

What you have in the picture is a cartridge-style bottom bracket which contains the bottom bracket bearings. What you called the 'pedal stems' are the cranks.

Cranks should be removed from the square tapers on the bracket shaft with a special crank puller tool such as the Park Tool CWP-7. If you forced the cranks off by other means you have possibly damaged them. If re-installed on a bottom bracket they may keep working loose.

The bottom bracket is removed using a bottom bracket tool such as the Park Tool BBT-22 that fits into the splines in the cartridge body.


The metal "R" shaped piece is likely the brake return spring (#7,8 in the image below):

If it is visible as you describe, you are likely missing a brake pad, and the spring is contacting your rotor.

You will need to find or replace the pad to fix the issue.


I was able to connect to an unsecured WLAN with my Nyon. I updated the Nyon and tried to connect to a secured network again, but no luck! I'll try to contact Bosch support about that problem too. I see following possible workaround's in the mean time:

If you only need to sync your cycling data, you can use the mobile app and connect via Bluetooth.
If possible with your WLAN router, enable an unsecured guest network and connect your Nyon to it. Switch off the guest network if you don't use it anymore.
Remove security from your WLAN while you need a connection from your Nyon. Don't forget to restore security settings, as soon you are done working with your Nyon!

Be aware that as long as you run a unsecured everybody within reach of your WLAN router can access your network and listen to the traffic on this network. Best stick with mobile app/bluetooth and use unsecured WLAN only to download maps or update the Nyon software.


There are manufacturers in Taiwan and China that make bicycles for the major brands known around the world, including ons with carbon frames. It's not inconceivable that a brand known for cheap bikes could contract with one of them to make a carbon bike.

The only measurement you could easily make to judge this frame is weighing it. The highest quality CFC frames use a very careful and precise layup procedure which allows minimization of the amount of material used to get the required strength. The workers who carry this out have to be more highly skilled and take more time. Obviously this increases the cost considerably. Lower quality frames use more material as a margin of error against layup imprecision in a faster and cheaper process.

You or an experienced rider could ride the thing and get an idea of how it feels in terms of stiffness, compliance, acceleration etc., but it's subjective and influenced by the drivetrain and wheels


How can I remove a stuck bottom bracket cup?

You're going to need to replace the entire BB.

The drive side cup is reverse threaded. (This isn't true of older bikes of certain nationality, but the nylon cable guide suggests yours is new enough for this not to be a concern.)

To answer your questions:

The squareness of the cups is very important for the BB to function.
To get the cup out without special tools, there's a few things to try depending on what's available to you. It would be a good idea to soak in some penetrating oil, just because anything you can do to reduce the torque required will help. If possible, clamping the wrench flats on the cup in a bench vise and using the frame as your leverage might be the easiest way to get it started. Another approach involves making a fixed cup removal tool out of a large bolt, nut, and washers, as explained by Sheldon Brown. This sort of tool usually works very well even on the most stuck cups, and is cheap to put together.

After you get the cup out, you'll have to address the condition of the threads, i.e. is some kind of thread repair going to be necessary to get the new BB in. More minor examples of cross threading, like where a cup got started cross threaded, usually don't require anything special here, but what you have could be pretty chewed up. Presuming you're replacing with a cartridge, probably the first thing to try is, after cleaning and greasing the threads, try to start installing it by hand (ie holding on to the splined installation tool) and, looking at it from the left side, keep it visually centered in the shell as you push with the tool, even as it wants to wander off axis. It may be rough starting and will probably go in rough, but that's not a dealbreaker as long as you can get good enough thread preload in the end.
All traditional cup and cone BB cups are made of hardened steel. If doing some repair of the threads is needed and paying a shop to just run a tap through it isn't in the cards, getting an old scrap fixed cup to use as a rudimentary chasing tap is something else you could try. (The one you have is likely too mangled for this). Doing the same with whatever new cartridge BB you get isn't necessarily a good idea because it might get damaged.
I'm not entirely sure what you mean about the grooves on the spindle, but that spindle is too mangled to be put back in.
Pressing on the cup would probably damage the threads further if it does anything, which it likely won't. Trying to just notch it over into place isn't going to work. To my awareness, this kind of thing happens when someone at the factory is going too fast with an impact tool.
Cutting it out down the middle given the hardness of the material and how easy it would be to cut into the frame threads is probably not very realistic.


What to look for in bicycle travel cases

Make sure it is sized to your bicycle.  The one time I flew a commercial airline with my bicycle I planned to use my father's travel case.  But with the wheels, cranks, seatpost and handle bar/stem totally removed my frame would not fit.  (A 64cm road frame).

Because it was for a one time, one way trip I got some shipping boxes from my local bike shop.  I got creative with the foam and packing tape.  Bike made the trip just fine :)


Trying to identify an old Helkama I have recovered

Helkama Oiva is more or less a civilian version of the bikes used by the Finnish army. They are known for being very heavy but quite fragile for their weight. The rear rack is very sturdy and perfect for carrying M85 backpack with shoulder straps wrapped around seat stay and support strut. The lock, chain guard and dynamo mount are additions for civilians.

The unique stem clamp where instead of usual expander cone or wedge, the steerer tube clamps around the stem, is a major security hazard. The steerer tube has normal threads and a cutout to allow deforming the tube. The threads provide a great starting point for cracks. The stem should be replaced with one with wedge immediately, or at least at the first time you notice that the handlebar feels loose. I had one of these bikes (non-military style) that I loaned to a friend and it failed at traffic lights. Fortunately it failed when he was starting, not when riding. No photos, because this was before digital cameras.

The steering geometry is unusual by modern road bike standards, but common with old work and touring bikes. The low trail reduces wheel flop, and wide low pressure tires provide the stability. These bikes are meant for heavy loads, slow riding and gravel roads.

The bike is very probably from 90s, even though the one piece crank was already obsolete at the time. I recall Helkama using that logo at the time, and the Rautaruukki sticker is a response to to "Tange Hi-Ten" stickers that were appearing on MTBs at the time. Rautaruukki is a steel foundry most known most for building supplies. They have specialized in high strength steels in 2000s, but those are not marketed for bicycles.

The white paint on rear mudguard was required in Finland at some point. I don't know the exact history, but I think the rule was removed in the 70s. This one looks like hit has been painted afterwards.

I do not recognize the logo on register plate. My guess would be that it has belonged to a saw mill or pulp mill. The old logo for Forest Administration that you can still see in national parks is a bit similar, but not the same. The broken frame lock and spray paint imply it was stolen at some point.


Where can I find a wheel of this design?

This type of wheel is fairly common on "tadpole" design recumbent tricycles, meaning that there are two front wheels and one rear wheel. Therefore, many companies sell such wheels in this size. Look for stores that sell replacement recumbent trike wheels.
The exact axle size is variable, so you should decide on the wheels that you are getting before you drill the hole in the frame to accept the axle, and then drill an appropriately sized hole.
A second consideration is brake mounting. The n55 instructions recommend mirrored drum brakes or disc brakes, but do not provide instructions for mounting disc brake calipers. You will need to work out how to do that. Using drum brakes will eliminate this issue, but wheels with drum brakes are much less common than those with disc brakes.
UPDATE: OP has indicated in comments that 1) brakes are not necessary and 2) cost is a concern. Given those constraints, some other options are

find a discarded wheelchair and take the wheels
DIY a one-sided wheel by acquiring two discarded BMX bikes with over-sized axles (20" wheels will be much easier to find than 24"). Remove the axles from the wheels and replace the front wheel axles with the longer ones from the rear wheels, adjusting the cone positions so that the excess axle length is entirely on one side. You may need to cut additional threading into the axle to accomplish this.
If 24" size is extremely important, find a kids mountain bike with 24" wheels with the same spoke count as the BMX wheels and lace the BMX hubs to the 24" rims. You may need to get new spokes to do this. There are many nonprofit bicycle co-ops that have free or inexpensive BMX bikes for salvage to do this project.


Help identifying this rear-wheel part (photo)

It is indeed a broken rear axle.
If you nave no proper tools (freewheel/cassette remover, cone wrench 15mm, wrench 17mm, new QR axle, 2 rings of new bearings), get it to an LBS to replace it.
It's also recommended to check the wheel bearings cups for defects, it maybe a good time to replace the wheel - all depends on the shape of other parts, and the cost to bring it to proper state.


I believe the central spline pattern is proprietary to the X-Flow crank. Basically you will not be able to get a single aftermarket chainring to fit.

If you want to go 1x10, you cheapest option is to get a used 3x crank that fits your bottom bracket bearing, ditch the rings and install a narrow-wide ring in the middle position.


Are torpedo 3 gear shift cables a standard or are there different sizes?

In my experience the normal shift cables (and housing) work fine, but there is a special end cap on the cable that fits into this hollow rod-like thing in the lower left corner of the picture. Normal cable end caps do not fit into this, because they are too thick. The original part made is out of brass and squeezed on with pliers. It's the center piece in this picture:

You can also find some hollow brass rod in a model train shop or similar and clip off a small piece. It just has to fit inside the rod.


Out front attatchment for mobile phones/GPS

DriKase and Drikase XL (for large phones or phones with cases) are good waterproof phone cases which mount to your stem and keep your phone dry while being able to operate it through the liner. It doesn't set it out front of your bars though.

http://shop.alt-gear.com/c/bikase


Bottom bracket length without knowing front chainline (fixed gear)

Presuming a replacement is necessary, and not a new build, can you remove the cranks and measure the the spindle length?  You can do it with the BB still installed if the caliper arms are 'deep' enough.

While you are in there with calipers, its probably worth getting the BB Shell diameter and width too.

Another variation is the thread's hand orientation (left/ right).  I forget now side is the variable one.


My SPD shoes + cleats won't clip in to my SPD pedals

Generally the cleats come with some shims for exactly this problem. If you have the box with the original pedals look around for some thin cleat shaped shims.

If you can't find them, you can hand make shims out of plastic milk bottles, or ask around at the dealer to see if they have any spares handy.


Shimano Tourney rear derailleur 34t support?

That's just what the combination of the 34T rear cog and Tourney derailleur looks like. Here's mine, using the 38T chainring:

Using the 28T chainring doesn't move the top derailleur pulley any farther from the cog, so using a longer chain won't make any difference.

It doesn't seem to cause any problems for me, though I don't use the 34T rear cog very often: it's too much of a jump in gear ratios from the next one down, which is a 24T.

However, I don't have the same model of Tourney derailleur as you. Your derailleur looks like the RD-A070 and Shimano's compatibility listings indicate that this is only compatible with freewheels whose largest cog is a 28T.


Start by checking the tension on the spokes of your wheel. To do this you'll need a spoke wrench that fits your spokes. There are lots of fancy tools for the job, but all you have to have is the spoke wrench.

Within reason, the tighter the better. Ideally what you will have is even tension on all of the spokes on one side of the wheel. There are fancy tensiometers to show you what you've got (and very effective and inexpensive apps for smart phones like Spoke Tension Gauge), or if you've got a good ear you can pluck the spokes like a guitar string and get an idea of how even the spoke tensions are by the pitch you hear.

This is especially important on the rear wheel where the gear cluster means that the hub isn't symmetrical and more tension is required on the drive side (right) spokes to keep the rim centered and true. If the drive side isn't tight enough, then the non-drive side will be too loose to support the rim adequately. One way you'll notice that the spokes are too loose is that you'll hear "pinging" noises from the wheel as you ride.

With disc brakes you can get away with a lot of wobble in the wheel, so I'd really encourage you to try it yourself before having a "pro" work on your wheel. It is fun and kind of meditative – just remember that everything affects everything else, and once the wheel is getting up to tension it makes sense to make balanced changes – tighten one spoke and loosen the spokes it pulls against.

If you want to know more about building and working on wheels, see if your library has The Bicycle Wheel by Jobst Brandt, Sheldon Brown also has posts on wheel building and truing and other repairs.


Have you thought about a bike cover or bicycle wheel covers ?
This seems the most logical form of protection for little outlay, the most effective method would be to move the bike out of reach of the cats but if that’s not possible then a cover of some sort may suffice.

If the cover isn’t suitable or the cats destroy it, you could easily make a bike stand from some 6mm mdf, make it wide enough to stand the bike in but tall enough to cover the wheels
If I was on a PC i would draw up a quick image / diagram of a simple stand.
If you have hydraulic brakes do not stand your bike upside down.


Why does bicycle floor pump not show pressure reading?

Does the pressure reading slowly drop to zero from non zero values when you stop pumping? If so, it means that the air is leaking from the gauge, and generally from the pump. There are three places where it can happen.

From the tube itself, meaning it is damaged. It has to be a pretty huge hole for the depressurization to be immediately apparent. Basically, the tube won't hold air at all. In such case, fix or replace it.

From the pump, meaning it is damaged. Given that it is a new pump, it is unlikely, but if this is the case, your best solution would be to replace it by warranty claim.

From the connection between the tube and the pump, specifically at the chuck/valve. This means the pump head does not sit tight on top of the valve. Disconnect the chuck and reattach it again, it may take several attempts to achieve a tight enough connection. Be sure to put it squarely and press lightly on it when closing.

12 psi is also a quite low value. Traditional floor pumps have their gauges going up to 120 psi at least. As it is for basically any mechanical gauge, the lowest 10% of its range are not accurate at all (I mean relative error of 50% — 100%) because of friction in the gauge itself. The readings are basically random, especially on cheaper pumps. Besides, the arrow will jump around simply because you apply varying pressure to handle when pumping. The readings will become more stable once you reach values of 30 psi.
If you really need to pump your tires to a very low value (< 20 psi), you are  in need of a separate precision pressure gauge. When I pump my fat bike tires (desired pressure is between 10-15 psi), I ignore the pump's gauge readings and purposefully slightly over-inflate them. Then I use a separate digital gauge which has precision of 0.1 psi, and actually deflate the tires back until I obtain desired pressure values.


Is the XTR Di2 battery compatible with Ultegra Di2?

According to BikeRadar, "The battery unit as well as the wiring for XTR Di2 are identical components to the ones used in Shimano's electronic road groups. The battery can be mounted on a bottle cage, in a seat tube, frame and can even be contained within the steerer unit of certain forks (via the use of PRO's new Tharsis components)."


I came across this article that somewhat explains why it is angled.

Basically what it does is provide a slight angle without having to use a stem that is adjustable.

What it fails to mention is that you can't place spacer rings above the stem meaning your handlebars must be at the top of steerer tube. Too add to all of that nonsense you have to use a top cap that has a hole that is off center to accommodate the angle.

It seems really stupid to me but if those extra few degrees of angle are what you need to dial in your fit then I suppose having an angled shim would be useful.


Roadmaster Chromium Edition rear wheel falls off

As @ Daniel R Hicks has suggested you need the proper hardware. From the photo it appears you have conventional/automotive nuts. You need flanged nuts or oversized washers with a serrated face or both. The oversized washers are thicker and have a larger overall diameter but the correct size hole for the axle.The dropout is the slotted section of the frame that the axle slides into. You may have an issue with the condition of the dropouts. If the rust has pitted the frame enough, the hardware may be biting into the high spots resulting in insufficient grip by the nut. Clean the clamping area with some emery cloth, wire brush or a file then clamp the nut tight. The Park Tool BlueBook has a torque value of 22-33 footpounds as a guideline. To give you a comparison that is about 1/3 of what you would tighten a cars lugnut.


What is the best pedalling technique to heal and prevent patellar tendonitis?

I ended up researching this topic with other sources.  And, the feedback I got from a very avid biker (frequently bikes 80 miles a day on his own on the weekend) and a tennis colleague of mine that suffers from the same condition is described below.

The pedaling technique is key.  The majority of bikers push down on their pedals with their toes first, so the feet when coming down are at a 45 degree angle (the heel being up and the toes down).  That actually stresses out the patellar tendon.  What you want to do is pedal by pushing down with your heel first.  When you do that correctly, your foot should remain as parallel to the ground throughout the entire pedaling circle.  A friend of mine described this technique as think of dragging your foot flush on the floor as if you want to remove some clay under your sole that is stuck throughout the entire sole of your shoe including the heel.

I have started this technique, and it seems to work pretty well.  I also noticed that indeed the majority of bikers do not bike that way.  Well they are young and don't have patellar tendonitis issues, so they are fine (until they are not).


How to / is it possible to straighten a bent seatstay/chainstay on a steel frame? At home or inexpensively by a professional

Rear triangle rear alignment of a steel frame is well within the scope of a home mechanic. There are professional tools available but functional versions can be made cheaply from lumber and generic hardware.

RJ the Bike Guy has some good videos on his YouTube channel (embedded below) that show how to measure how far the stays are out of alignment, how to re-align them and how to re-align the dropouts

You will of course have to make a determination as to whether your frame is too deformed to be safely re-aligned. Once you have determined how far the stays are out of alignment you can seek advice and make that decision.


What could be the reason for chain skipping

The reason was the sprocket after all. Changing the freewheel resolved the issue. I had some problem finding a service which has the wrench for that old Sachs/Maillard freewheels. Replaced it with standard Shimano 6-speed, and everything works smoothly now!

Thanks all for help.


Can I combine SRAM Rival 22 Levers and Shimano 105 Rim Brakes?

For BR-5700, BR-5800, and BR-R7000 they run off the various new school Shimano not-quite-short-pull cable travel numbers. SRAM road levers are all basically traditional short pull, which is less cable pull than Shimano Super SLR et al.
The mismatch in this direction results in less pad movement but with more leverage than intended. It can typically be made to work, but needs to run with commensurately smaller pad gap, which usually means the caliper QRs won't open up enough for an on-trend tire. Feel will be mushy and indecisive but power will be good as long as you can get the pads close enough that you don't bottom the lever. By the same token, you have less ability to use the Doubletap reach screw.
It does function, but it always feels like a way of making a mediocre system out of good components. The pre-5700 brakes are normal short pull.


What type of paint to use for a bike frame

Basically any paint that could be used on a car will work on a steel bike frame.

The better the paint the more robust it will be. Two-part epoxy based paints or powder coating are probably your best bets, but require specialized equipment. I think there are epoxy paints that do not require curing in an oven but you still need a spray gun.

You can probably use aerosol can paint with a self etching primer, meticulous preparation and good technique.


Ideally, no.  Bearing balls are of such fine tolerance that a random substitution is likely to be bigger or smaller than your existing ones.
The best solution is to buy a set, then replace all the bearings on both sides of the axle.  That way they've come from the same batch and will be all the same size.   You can get bearing ball sets from your local bike shop or just buy 20 of the above.
A proper bike shop won't even reuse a new bearing that has dropped on the floor by accident, they'd just get another from the same batch.

Why is size such an issue?   Imagine if your single replacement was slightly larger.  The two balls either side of the new one would not take as much load, and may be free floating due to the bigger new ball taking extra load.
This leads to extra pressure on one ball and premature wear and failure, and at least two balls simply sliding around and not rolling.  This generates wear because of a lack of preload on those balls.
Upshot is Spalling where the big ball looses chunks, which adhere to the race, and then peel off leaving dents.  When this happens, your cones need replacing and/or the hub is dead.
If the new ball is too small, the same thing happens but the new ball simply slides and the two on either side take more load.
In short, a set of new bearings is cheap, just do it.  You can get loose balls or you can get balls in a cage which are more convenient, either is fine.

On the flip side, I have sometimes used a spare bearing ball to repair an old donor bike at a fixup.  A kids bike that might only do a hundred miles travel in its entire life would probably be fine for this fix, compared to a race bike doing a hundred miles a ride, or a long-distance commuter who does a hundred miles a week.
A bearing ball in a bicycle is not a high-load nor a high-speed application, so physically the bearing ball would function at the RPM and temperatures of a bicycle hub.  The size and tolerance is the main issue.
So it's up to you and the expected longevity you expect from that wheel.


What's that thing at the bottom of the fork steerer?

I think by steerer you mean a quill type stem

The diagonal cut part is a wedge. It's pulled up by a long bolt that runs down the stem and locks the stem in the fork steerer tube.


Just like buying sneakers or dress shoes (or really any piece of clothing/footwear), you can't just buy cycling shoes based on size, even within one manufacturer due to shape differences and size differences within a line (especially when going from mountain -> road or vice versa). Try them on and see how they work. If you can't try them on, you're going to have to do some guesswork with ordering and hope for a good return policy if the fit isn't good.

Even if they're the right size, you may find moving to a different shoe will make you more comfortable or confident, so you do have to shop around for them.


Is it OK to leave my bicycle unlubricated for a day after a hose-down?

No, of course not. Having your bike wet and unlibricated for one day won't damage it in any way. Washing it and letting it unlubricated for long period of time will cause you some issues. But one day is not a problem...


Nearly getting hit by reckless vehicles. What can be done?

What would happen to the driver if I had recorded this incident and
  reported it? Do I need video evidence? What is the official law? To
  me, a vehicle can be used as a weapon, and not paying attention could
  clearly be fatal.

The relevant law is most likely Driving without due care and attention (Road Traffic Act 1988):

  A person is to be regarded as driving without due care and attention
  if (and only if) the way he drives falls below what would be expected
  of a competent and careful driver.

The Highway Code (Rule 180) states that when turning right "Do not cut the corner", so it seems quite likely that doing so and nearly hitting someone would constitute careless driving.

The driver could be given a fixed penalty (probably 3 points), or made to go on a driving course, or taken to court, or let off with a warning.

If the driver came up with a different version of events to yours then a video recording or a reliable and credible witness would be useful. There might be other evidence, e.g. skid marks on the road.

  How would these consequences for the driver make the roads safer for
  cyclists in general?

In general, it probably wouldn't make any difference. The particular driver might improve their driving, but it's difficult to see how this would have a wider impact.

  What actions are the government taking to make the roads safer for
  cyclists?

Not much. There's £316 million over the next 5 years to fund cycling and walking infrastructure. That's a tiny amount compared to how much countries like Denmark and The Netherlands spend.


How can I tell if a rim is bent or if the wheel is just out of true?

The common qualification here is an important one: truing is a skill that benefits from practice and experience (chicken, meet egg). Your wheels are important, and it's important to have somebody who knows what they're doing at least check your work if you're just learning (or if you're disinclined to trust your well-being in dense traffic to wheels you trued yourself).

Having said that, a rim that isn't bent should have more or less even spoke tension across all the spokes when it is true. On the other hand, a bent rim will require higher tension in some spots and lower tension in others. So, noticeably uneven spoke tension in a true wheel is one sign that the rim might be bent.


Difference between UD, 3K and 12K carbon finish?

UD, 3K and 12K specify the carbon weave pattern. 3K means there are 3,000 filaments per "tow", 12K means there are 12,000 and UD means unidirectional (no pattern):

The construction of bike parts is always UD, only the top layer when naked can be specified to these different finish types. Also there is usually an option to choose between matte or glossy. Matte results in more stealthy look, glossy will make the pattern pop:

When the frame is painted it's UD underneath (usually branded frames are all painted).

As for physical properties, UD is the strongest, then there is 12K and last 3K. The finish is only the top-layer so the differences are only cosmetic.

You can also encounter a 18K weave (usually on road rims) which looks like this (glossy/matte). Its similar to 12K (but a bit bigger) and you can also see how a seam looks like:

12K is well recognisable from distance, 3K and UD you can differentiate when standing closer and they also usually look better up close than 12K (there are more visible irregularities in 12K weave than 3K up close). This is how 3K looks up close:


Self adhesive patches are less reliable. I carry them (because they are so small) with my spare tube with my tubeless tyres to get home when the crap hits the fan but I witnessed some repeated struggle with some. I cannot comment your particular brand but my colleague had to re-apply some every 20 km or so.

I would use them to get home when the spare tube got punctured too. To permanently repair a tube use the traditional patches with a vulcanizing glue.

On my bikes that use inner tubes I carry the traditional patches. I want the reliability of those and have the space for them.


Similar to the other answers it would be worthwhile getting a professional to assess your current bike fit (and potential modifications that may be required).  If possible I would suggest a sports physiotherapist that specializes in bike fitting. They exist, I have used one before.  A physio will be best qualified for assessing how changes in position can affect your hip and knee functioning.  While many bike fitters have some training (and often good intuition), dealing with severe dysfunctions may be out of their area of expertise.  Alternatively, you may need to facilitate a relationship between your physio and bike fitter if you cannot find a single person who can wear both hats.

To give you hope that it is possible to tweak a standard bicycle here are some things that could help (with the right guidance):

leather hammock saddles (e.g. Brooks) break into a custom form fit for each rider. During the break-in phase you are physically tearing the taut leather until the pressure is equalized across the saddle.  This results in custom form fitting that can accommodate different pelvic tilts and orientations.  Be warned however, the break-in period can be long (although water break-ins can speed this up considerably at the cost of leather longevity).
Shoe shims exist to help angle the foot differently to optimize knee alignment. Also foot orientation on the pedal can be used to help modify knee tracking.
Shoe shims can also be used to accommodate for structural leg length differences.
You may consider flat pedals over clip-less so that you can continually modify your positioning to reduce the likelihood of repetitive stress injuries.


Electric Bike (eBike): Freewheel or Regenerative braking?

Freewheeling is almost always better.

If a freewheel ebike control system fails, it reverts to being a regular bicycle and you can pedal home. Otherwise, you might find that you cannot even push it home if the motor is stuck on heavy regen.

Furthermore, there is very little energy that you can regenerate from a bicycle. There just isn't enough mass or significant enough velocity to make it worthwhile. The regen also makes braking more complicated than it has to be as you need to swap out your brakes/brifters with ones that have brake-switches in them.

On a vigorous discussion on the EndlessSphere forum, Justin Le pulled out data from his cross-country trip. While he did get 18% regen going down mountains passes, he also only got 1-2% regen touring over rolling terrain. His urban regen data was 11% which is close to the 10% figure that is used as the rough estimate of range extension possible.

  So, although this is a just from a single run, you could easily conclude that we'd expect about 5% regen for city riding in mostly flat terrain, 10% regen for city riding with lots of moderate hills, and probably more like 12-14% regen if there are really steep hills.

Since e-bikers tend to recharge every day and each recharge is only 1-2 cents of electricity, increasing range and efficiency  a modest 10% just isn't  as important as it would be with a hybrid or electric car.


How to replace a Sturmey Archer's cable?

You are correct. This is different than "regular" cables. On regular cables you pick the end you want and cut off the other. Thats because the connection on the cut-off end is usually a clamp. You run the cable under a screw/nut and tighten it down.

Then you just put a cable crimp on the end to protect the cut cable

However, your internal hub cable is differnet. The cable and housing is really one piece. You have to replace it all together. I have a similar issue on my Shimano internal 3 speed hub. Luckily you can get an entire replacement set (cable and housing).You can get something like this from Harris Cyclery (I only hype them because a Sheldon Brown article was helpful to this post.)

You'll have to make sure that the barrel is the same threading as your "adjusting part" and that you get the length you need. A sales person (or phone call) should get you the exact part. It would probably help to know the model of your hub. It should be engraved or stamped somewhere visible.


How do you know if your wheel is correctly centered?

If your brakes are rubbing, or the wheel is rubbing on the frame then you probably need to adjust the wheel or the brakes.

The quickest way to check is to use the brakes.

1) Pull the brake lever for the front wheel as far to the handlebar as it will go. It should be at least a finger width from the bar at full compression.

2) While watching the brake pads, the part of the brake touching the wheel, let up slowly on the lever until the pads are almost touching the wheel but not quite.

3) The pads should both be clear of the wheel. If one come clear first then either the brake needs adjusted or the wheel is not centered in the frame.

4) If both brakes clear the wheel at the same time then start turning the wheel slowly while continuing to hold the brake just clear of the wheel. If there's a problem with the wheel one side or the other will hit a brake pad.

You can take it to a shop if the wheel needs to be trued.


How should I remove a tyre that's stuck to the rim with old sealant?

Before looking for a product to solve the problem, try this. Many tubeless rims grip the tire very tightly when one is just trying to push the tire very inwards to unseat it. The trick is often to push the bead section more straight down in the direction of the rim well, with a slight scooping motion inward.

Sealant isn't glue and doesn't have all that much tensile strength. It's usually the case that you're more up against the mechanics of how the bead locks in place.


How to stop foot clipping front mudguard

I have a very similar setup (SKS Chromoplastics), and can say the following:

I installed a suspension forks and then the former length of the metal wires bacame too long for the setup. I BENT them in a sharp turn to run parallel to the mudguard (of course it can be bent in any suitable direction, just NOT point straight back like yours). Haven't had any issue yet. I DIDN'T CUT them because there is always a possibility to use the mudguard in other bike with a larger wheel (I use 26in), or to put the rigid fork back. If that happens, I'd just unbend the wires again.
Rotating the mudguard backwards is always good. The more backwards, the less water flying below you. If you have clamped the little "L" shaped metal plate in front of the fork, you can change it to the back part of the fork. There are only two relative caveats:

The front part of the mudguard might become too short, and some drops might start getting on your face at high speeds on rainy or wet days;
If you go down some step or curb, you should take extra care not to hit the rear part of the fender against the obstacle.

Any mudguard like yours is suitable to the bike. Your main problem, as DanielRHicks correctly pointed, is that you should have got the wires short (either by cutting or by bending). Even then, it is acceptable to have a minimal toe overlap. Since you ride platform pedals, I would suggest you to watch yourself if you are pedalling with the foot too much forward ("arch pedaling"). Perhaps you might like to use straps or clipless pedals.

About using a flap, I am ABSOLUTELY CONVINCED that it is very very welcome and extremely useful. Some designs are more flexible, and that work better, but yours is fine, specially if you manage to get the whole mudguard lower than this. I use to say that I'd rather ride without all the rest of the mudguard than without the flap, because it is the actual responsible for a clean and long-lasting chain, and not-so-wet feet.

Hope this helps


Where did I go wrong with this frame painting procedure?

Painting is tough and the artist in me (tongue-in-cheek) is never satisfied with finished product. Your prep seemed meticulous enough and you express satisfaction with the finish where it hasn't been marred. Given the work put into the prep, why go with bargain paint and risk the poor quality of it?  Give you props for using the same "brand and series" of paint.  That tip is frequently included in DIY paint tutorials.
The two most popular brands of spray paint here in Midwest, USA are Krylon and Rust-Oleum. I bring this up to share a couple of things common to the directions for use printed on these cans. Despite the myriad of differing formulations and applications within a brand here are some common advisories they share: Priming is especially recommended on bare metal or wood.  Apply multiple, thin coats, waiting a few minutes between.  Apply additional coats within one hour, OR AFTER 24. Some types will state "recoat (or apply clear coat) within one hour OR AFTER 48."  This is under ideal drying conditions of 50% humidity and 70°F.  Finally, it's commonly noted that on plastic, "maximum paint adhesion and durability is achieved in 5-7 DAYS."  I realize your bike is not  likely to be plastic but I think that tip can lead us to believe that the paint will continue to cure and become most durable quite some time after the "ok to handle in such and such hours."  If your paint job is being marred right down to bare metal as you say, the paint is not nearly cured enough. Certainly 12 hours isn't enough time to expect it to hold up.


Replacing 'cone nuts' on a damaged coaster brake

The term "cone nut", on a bike, generally refers to the nuts that comprise the outer half of a bearing race (the inner half being formed into the wheel hub or whatever).  The "cone" side, which faces inward, has a concave profile so that the balls will roll smoothly in it.

It's hard to tell what you have from your description.  I do vaguely recall some cases of nuts on coaster brakes with slots like that, apparently intended to be operated by a "spanner wrench" (which is a redundant expression in the UK, but means a wrench with pins rather than flats in the US).  Presumably this allowed the nut to be more readily adjusted while everything was assembled.  (Current bikes require a thin "cone wrench" for the same adjustment.)  If this is all it is then a hex-sided/flat-sided nut (with similar thread/profile) should work just fine.

I've also seen, internal to some coaster hubs, various plates and nuts with slots or teeth, intended to engage mirror-image features of the hub or an internal rotating piece.  These would be quite specific to the particular hub.

And it may be that this nut is a cone nut for internal bearings, such that the nut cannot be reached for adjustment with a regular wrench (even a thin one).  In that case you'd have to figure out something.

It's remarkably hard to find a good image of a cone nut.  Here is the best I could find:

This one has a sheet metal dust shield fastened to the outer diameter -- the nut itself is inside of the inner flange of the shield.  On the back side is a regular (though fairly thin) hex nut or (more often) a cylindrical body with two flats, sized to take a thin open-end wrench.

(It should be noted that it's become common to refer to any nut that secures a bike bearing as a "cone nut", even though it may be securing a sealed bearing cartridge and hence lack the conical extension.  This adds a lot to the confusion.)


I figured it out.

I needed to screw the adaptor on the presta tire valve, then attach the pump head. I was instead putting the adaptor in the head and then pushing it on the value but it needs to be screwed on first.

I feel dumb but at least my tires are now inflated


Is a 650B wheel good enough for a tandem?

The rim size is immaterial to the strength of the set you choose.

Many rim brake 650b rims out there would not make good tandem rims, but there are exceptions. The VO Voyager or Diagonale in 36h are the main ones I can think of. Sun CR-18s are another, cheaper possibility. Also Velocity Cliffhanger or Atlas.

650b is likely the right choice for a conversion. If you happen to be maxing out your brake reach at present that could be a curveball, but at a radius difference of 1.5mm it's probably fine.


Bike Setup: Correlation between seatpost offset and stem length?

Saddle setback is a fixed position for each rider.

It is necessary to place the saddle in the position which places your knee in alignment with the pedal spindle, when at the correct saddle height.

Arbitrarily changing the saddle setback can interfere with a proper fit.

You should set your saddle height, then fore/aft position to align your knee correctly, then choose a stem length that makes the saddle position reasonably comfortable.

If the 20mm setback post is necessary to align your knee, then, yes, you may need to subtract that extra distance from your stem. But that will leave you with a very short stem in this case, which will affect how the bike handles.

I would expect that if that change is necessary, you are on the wrong frame size.


A CX-50 is usually fitted with 46-36 and is 10 speed. Occasionally I replace the 36 with a 34 on mine. Any flat 110mm BCD ring of 50/52 will fit instead of the 46 ring and the 36 is the usual combination with a 52.

The chain will have to be 2-3 links longer and the FD must move up by one or two mm to clear the big ring.

(Note: You may even change the rings without having to remove the crank from the bottom bracket, as they can easily be manoeuvred around the arms and the pedal.)


Can I approximate how much air pressure is lost from disconnecting the hose?

Can I calculate (approximately) how much air pressure is lost by measuring the hose length and diameter?

No, you cannot tell how much pressure is lost based on the size of the hose. This is not because there is not enough information to tell but because the hose is irrelevant.

You seem to be under the impression that there is some total amount of pressure in the hose and in the inner tube, and when you disconnect the pump and release the pressure in the hose, some of it is lost.

This is an incorrect understanding of what pressure means. Pressure is an intensive property — it is something that is the same for of all the air no matter how you divide it up within the connected system. The pressure in the hose equals the pressure in the inner tube, which equals the pressure in the whole pump-and-hose-and-inner-tube system.

In the tradition of physics education, let's consider the ideal case with a separately controllable valve on the tube. This is what would happen:

With the pump attached to the inner tube, you open the valve. This causes the pressure in the hose and tube to equalize: this is when the gauge on your pump jumps upward. At this point, the pressure in the tube has reduced, because some of the mass of air in it moved into the hose to pressurize it.
You use the pump to increase the pressure as desired, according to the gauge.
You close the valve on the tube. The pressures on each side of the valve remain equal to each other and to that read by the pump's gauge.
You disconnect the hose. The extra air in the hose escapes to the atmosphere.

As soon as you closed the valve, the inner tube became a closed system: the pressure in it is no longer affected by anything about the pump. It will stay where the gauge said it was while you were pumping.

Now, in a real valve and pump chuck, there isn't a separate control to close the valve (pumps may have moving center pins to push the valve open as part of the “lock” but they aren't always exactly the right length — but I've never used a Presta valve so I may not have this right for those), and it is instead closed as you pull the chuck off the valve. This may release some air from the tube, due to the valve not being fully closed before the connection starts being open to the atmosphere. However, the amount of air released from the tube depends on the valve and how fast you let it close. It does not depend on the volume of air in the hose (except insofar as the pressure in the hose opposes the pressure of the tube even though both are also flowing out to the atmosphere, which is probably a minor effect).


Ideal distance between chainring and chain stay

4mm at the closest point is about the safe spot. 3mm is about the sane bare minimum you can go to if you want to push things. Less is asking for trouble. Note that frames, cranks, rings, and spindles do vary in how flexy they are and riders vary in habits and strength, so one can only approximate here. If you stacked the movement from a bunch of flexy things under a strong rider, 4mm probably wouldn't be enough. But it works well as a rule of thumb.

A simple way to actually do this kind of measuring is slipping an allen wrench in the gap, essentially using it as a feeler gauge, or just eyeballing it with one. 2, 2.5, 3, and 4mm wrenches are conveniently sized for the purpose.

It sounds like you're sacrificing an optimal chainline to make use of an 18t cog you already have. I kind of hate that idea; having perfect chainline is one of the big payoffs to all the work you're doing here, and makes fixed/singlespeed bikes work like they should. If this is fixed I would just go for a 14t cog instead. It's true that it will wear out faster, but I think it's worth it.

With steel, another approach is just to dimple the frame, if the clearance that could be gained by doing so would be enough. It's less of a big deal than it may seem like. Frames get squished in the chainstay area at the factory in ways that aren't terribly sophisticated. Usually techniques for doing this involve making a wood form to cradle the back of the stay while you push something rounded into the front, using a vise or clamp.


DIY wooden bike rack -- looking for plans

If you don't mind punching some holes into the wall, the style my roomy and I have in our living room is very space efficient, and quite cheap.

It is basically a 2x4 screwed to the wall, with hooks placed into it at a 45 degree angle.  Because we both ride year-round, we put plastic don to save the walls, but being in the garage this may not be necessary.  The plastic does make a good white-board, however (garage decorations!).  Basically the wheel at the top is in contact with both the hook and the wall, and the bottom wheel is touching the wall.  Alternating hanging the bikes by the front and rear wheel means you can put the hooks closer together, and put more in the same space.  It is a very strong design, with ~8 drywall screws holding it to the wall.  Strong enough to hold a Big Dummy (though the rear end of the Big Dummy does sit on the carpet), a Pugsley, and 3 other bikes.

The size of hooks may vary.  For example, I have a large one for my Pugsley:

The plastic we used is also very cheap.  I think it was ~15$ for 100 feet of the stuff.  We plan to replace the plastic once it gets dirty, and I estimate the sheet we have will last 4-5 years.  We also used patches of duck-tape where the tires hit the plastic in order to prevent the tires from wearing through too quickly (especially important for the bikes with studded tires).

The most expensive part of the build was the hooks, the most expensive of which were ~15$ (going from memory).


Turn your head before your face hits it. There might be rocks and dental work is expensive.

Seriously, more than about 50mm of mud and it's both faster and easier to carry your bike. Other than that it's just a sticky version of riding on loose gravel. So:

stay loose on the bike - off the saddle or at least slightly unweight it. Be ready for the bike to move in its own direction.
try to keep traction. If you hit a solid bump, pour on the power to get max benefit.
learn to handle losing traction on the front wheel. Practice.
if you're floating and don't have traction, power on and try to either dig through it or power over it. The difference is how much weight you put on the back wheel.

But any of this is only good for short sections. Note the liberal use of "power". If you've got 20km of mud you just have to slog through it, probably on foot. Touring on a mud-over-gravel road is about as miserable as it gets.


Recently washed road bike now squeaks when pedaling or coasting

When does it squeak?
If it squeaks even while you are coasting it can’t be the bottom bracket, chain, pedals or rear derailleur. If it only squeaks while you are coasting it could be the free wheel.
If it squeaks all the time it could be the brakes (should be more of a rubbing sound) or hub bearings (though those usually don’t “squeak”).


Can I replace a 3x8 1999 Sora crankset with a Claris FC-2403?

Well, one consideration is that this particular Claris crankset (2403) mates to an Octalink bottom bracket.  The particular model of Octalink BB required is popular and as a result costs about twice what many others cost.

Additionally, if you don't change your cassette (& it's always a good idea to pair it with a new chain), you're really not getting any easier gearing on the low end as tooth count on the small ring remains 30.   The cost of improving your ride is becoming significant and the value of the new crankset alone is near-equivalent to the Jamis' value (looking at numbers from Bicycle Blue Book).

A new road bike with a Claris groupset can be bought for around $500. They have compact and sub-compact options for cranksets and paired with a cassette with a tooth count  range of (for instance) 11-32, there's plenty of low gear for the hills.  Good bike shops will have staff that will help you with a good fit.  Take lots of test rides too. That's the best way to discover the bike for you.


A large vice can be used to clamp the cup and the frame should provide enough leverage, especially since you've almost completely disassembled the bike. Use some penetrating oil from the inside of the BB. Give it some time to seep into the threads. A hair-dryer could be helpful but a hot air gun might damage the paint.
French BBs are usually right/right and on assembly, thread-locker may have been applied to the fixed cup. If the right cup is 35mm, the BB is French. The British standard is either 1.370" or 1.375", according to Sheldon Brown. https://www.sheldonbrown.com/gloss_bo-z.html#bottom
The article also gives suggestion for removal of the fixed cup.


How many days does it take for an absolute newbie to bike 330km?

Don't do it, unless you're an athletic teenager!  You haven't toughened your backside or your hands to endure riding for hours.  Your lower back, which complements the legs, would develop incredible aches, as would your shoulders, which are used to keep your head up.  The good news is that your knee would probably be fine, assuming that your pedals allow some "float" (right-to-left rotation).  I assume that you have a quality bike that has been recently checked by a mechanic and fitted to you, because little things like the exact seat position matter for long rides.

How much training you would realistically want to do prior to the event would depend upon your age and your state of fitness, but I'd suggest at least a month of riding three days a week.

I've read lots of stories from people who have tried long-distance events with no preparation, and many of them survived, but they all said they wished they had prepared!  You might be able to survive, but would it be an enjoyable experience?  I doubt it...  If the event is coming up soon, I'd recommend to skip it this year and start training for next year's event.


How to mount clipless pedals on a tandem?

Tandem cranks are special. The pedal thread directions on each arm are oriented correctly to prevent loosening from precession, as on any other bike. You just need two sets of normal pedals.

If somehow non-tandem cranks have been installed such that either of the left cranks are right-threaded or the right captain crank is left-threaded, that situation is not acceptable and threadlockers will not make it so given the danger level of the crash that could result. Either get tandem cranks or get the offending crank(s) helicoiled to have proper thread orientation to resist loosening.


Replacement rear wheel to match an existing front wheel

Any regular mountain bike wheel with diameter 26 inches, rim width between 20-30 mm and a freewheel would likely to work. Cheap wheels in this category cannot be too wide for you, and absolutely most of them have 135 mm hub width and QR skewer to attach the wheel, which should be what your frame's rear dropouts will accept.

You will also need to buy matching tires (anything from 26" × 1.5" to 26" × 2.1" to your liking), inner tubes (almost any marked as 26" will do) and a cassette that fasts to the wheel's freehub. The choice of cassette depends on how many gears your rear derailleur has; for an 8-speed derailleur you will need a cassette with 8 cogs etc.


Mixing GRX crankset with Deore groupset on 2021 Trek Dual Sport 4

It will be fine, as it's just a one-by ring for 11speed. You could also use a sram apex1, a miche graf, or any number of other options.
You will also need the matching bottom bracket for your chosen crank.
Fwiw, most manufacturers spec a cheaper crank, wheels and/or brakes to meet a certain price point, to avoid cheapening the frame or headline components.