Try adjusting the tire pressure you may be to high or to low. If it is low the sidewall can squirm inturns making handling inconsistant, too high and the tire can be so hard it bounces off the surface when hitting any imperfection.


I will answer my own question, I think I have figured it out.

The Shimano skewer is slightly thicker diameter than the skewer which originally came with the hub. (However, the skewer which came with the hub is poor quality and doesn't close very well.)  I think that the end cap is slightly too small diameter to let the Shimano skewer all the way through the axle and move freely.

I have a Bontrager skewer from another wheel set which seems to work.  Looking at the two skewers side by side, I can see where the Shimano gets larger diameter closer to the threads than the Bontrager skewer.

The hubs in question are branded "Pure" and the wheel set came from Bicycle Wheel Warehouse. Note that a Shimano skewer worked fine in the rear hub.

Not sure what I will do, as the Shimano skewers have the nicest cams.

If you see the comments, I was able to fix this problem by purchasing a new Shimano Ultegra skewer.  The threading was different on the Ultegra model, and it is compatible with these hubs.


For the wicking action to work you need to wear something that is relatively taut on the skin. Any common jersey should do the job. I and others have had success with light weight wool jerseys like from ibex.

Generally speaking, cotton is not a good choice for the base layer next to your skin. It will work for a while but as soon as it gets drenched with sweat you'll be miserable.

Layering is key for colder weather. First knee and arm warmers, then a cap under helmet, and shoe covers, then a lightweight jacket or winter training jersey. After that, a "dicky" for your neck and tights over the bibs


Are you worried that the cogs skip on the hub? I'd consider this extremely unlikely.

The most likely reason is that the old chain has worn down the teeth of the cassette, especially when you ride on small cogs because the same load is distributed over fewer teeth. If you happen to have the old chain around, measure the length over 10 elements (see my comment above): if 10 elements are longer than 25.9mm (from pin to pin), the old chain damaged the cogs and you need to replace the cassette. The chainring in the front is often still good because it has more teeth and wears down slower.

The image shows the interaction between a new chain and a worn-out cog. It is from technical documentation by Rohloff.

Having watched the video, I do think that the cassette is unusually loose. While it would not cause the chain to skip, it will damage the hub. I found this discussion on this site relevant: make sure to tighten the ring that holds the cassette in place. A mix of road and MTB components could be the root of that problem.


Help determining spoke length along with an education

There are other questions about this but honestly I think the answers in them are a little oblique when it comes to actually doing it.

There's a classical formula you can find in many sources. It models the wheel in a very simple abstract way. The hub flanges are circles defined by the centers of the spoke holes and the rim is a circle defined by the end points of all the spokes when they have optimal engagement with the nipples (this is also the commonly understood definition of Effective Rim Diameter, or ERD). Here's how it appears in Brandt's The Bicycle Wheel:

You don't have to touch any real math to calculate spokes, however, because there are many different spoke length calculators out there that are based on this formula where you just plug in your hub and rim dimensions.

One of the sticky points of spoke length calculation is that the classic formula only takes into account the raw geometry, i.e. it's just describing a bunch of circles and triangles, but in real life, the rim compresses a bit when tension is applied, and the spokes elongate. How much depends on the particulars of the rim, namely its cross sectional area, and the gauge of the spokes, respectively. There are some sources out there that give specific numbers to show how to compensate fairly precisely for these effects, but in practical terms you just round down a bit, and how much depends on having a feel for what you're working with. Rounding up from the number the formula spits out is dangerous when calculating spokes because you risk running out of spoke thread, which can lead to situations where you have to struggle and maybe fail to get the final tension you would have otherwise chosen.

Many spoke length calculators invisibly do this rounding for you, but I like to use ones that don't, so that I don't have to wonder how much they're rounding, which direction, whether the amount was chosen based on the spoke gauge I'm actually using and what the tension will be, etc. The free spreadsheet-based calculator Spocalc is what I usually use. It's an .xls but opens fine in free spreadsheet software in my experience. It uses the terms "width from center to left flange" and "width from center to right flange" for the measurement your hub's page is calling "flange width." The page doesn't specify a spoke hole diameter, which is fine because you can just use 2.6mm as a generic one for most hubs. Here's how it looks with these hubs and rims plugged in:

Conventional wisdom for these wheels would be go 3 cross because that will give the spoke angle closest to perfectly tangent with the hub flange. That's generally true of 32 spoke wheels with not exceptionally large flanges.

So, at 3x we see an output of 295.6mm in front and 295.2mm in back.

Presuming the published ERD is correct, and in real life I never, ever gamble it is even though most of the time they are, in back I would do 294 with any gauge of spoke, and in front I would just do 294 as well, although with straight gauge 2.0 I'd also feel okay with 295. In this case, presuming the ERD was measured properly to represent a spoke with its tip flush with the top of the nipple, I'd expect 294 to get them both right about in that perfect range of somewhere between the base and the top of the screwdriver slot in the nipple, and with no danger of poking out the top, which I avoid at all cost. Realistically 295 would likely be fine for the front, as it may cause a slight bit (0.1-0.3mm-ish) to protrude out the top, but not more than most spoke/nipple combinations can handle. I just play it safe.

Also, everything here presumes 12mm nipples, the most common choice for handbuilt wheels. Longer nipples have more thread and change your ERD.


What's the ideal balance (forward/backward) in the saddle on an endurance road bike?

Should I feel completely balanced in the saddle, or is a little forward pressure normal?

There should be some weight on your hands when riding.  Not too much of course, but your setup is already slid back as far as it can reasonably be (saddle aft, 80mm stem), and chasing some abstract notion of fit when you're already at the extreme end of adjustments doesn't make much sense.
What's completely missing from your post: what happens when you actually ride the bike?  Is there any specific problem?  If not, just ride.  And maybe think about neutralizing your adjustments a bit as an experiment--if you put the saddle 1cm forward of max-aft, does the bike become uncomfortable?


Disassembling crank on a 2006 Trek Pilot 2.1

I would try reinstalling the drive side and non drive side cups to the frame (to keep the spindle centered).  Then I would recommend a game of whack-a-mole on the spindle with a rubber mallet.  I have often had to remove a crankset this way.  A rubber mallet should be in pretty much any home mechanics tool kit.  The rubber mallet has almost no chance of damaging the spindle.  Provided you don't smash/dent your frame with it, it should be fine.

With the cups on tightly and nondrive side crank off, you may also try rocking the drive side crank arm back and forth some as you rubber mallet the spindle.


I have slipped off my bike 3x in the last 2 months - will changing tyres help?

Wet metal plates on the road have an astonishingly low grip, on par with a sheet of ice.
There's very little you can practically change on your bike to improve this - changing to wider tyres at low pressure would help, but the rest of your commute will be like slogging through treacle, and highly unpleasant.
What you can do - change your technique.   Never turn or brake while crossing a metal plate.  Keep the bars and therefore front wheel straight and roll over it.
If the plate is on a corner (and many are)  then try to avoid going over them at all.  Take a left or right position and bypass the plate completely.  Naturally this requires local knowledge and for you to anticipate what's coming up.
It may be possible to participate in activism - write to the local council or similar roading authority, and request the plate be replaced with a textured one, or surfaced with bitumen.  This is a slow process but is not impossible.
Your very last resort is to react quickly should the bike start to slide, and take whatever action helps to restore your balance.  That may be a shift in body weight, which could potentially put you into the path of traffic.
The counter here is that when your bike is sliding, it happens really quickly and its hard to react in time.
Or find a route that avoids this corner/plate completely.


How can I adapt my pedals to account for a difference in leg length?

Be very careful about making leg length adjustments on your bike. There are several red flags about this. All of which you may be aware of or may not. 1st, a leg length difference is very difficult to diagnose, ecept with an experienced physio, or an X-Ray/MRI.

Most good physios will send you for an X-ray if they suspect a leg length difference is causing you an issue. 2nd, The body will naturally compensate for up to a 2cm leg length difference with pelvic tilt, and while that is less helpful on the bike, you don't automatically need to add stack height if you have a leg length difference.

And last, a 1cm difference in length does not mean a 1cm compensation, even if you do need to compensate. It is something that needs to be looked at professionally, and any compensation needs to be worked in slowly. Generally, adjustments in the 2mm range in one go are considered appropriate. More than that can(not always, but quite often) cause bigger issues than they solve.

Long story short, be careful what you do, go see a professional medical bike fitter, preferably a physio with extensive bike fitting experience, and follow their instructions. Oh, and be prepared to pay for the privilege, while realizing that it will take time to sort you out properly. There is no magic bullet fix here.

Look up the Boulder Center for Sports Medicine. They specialize in issues of exactly this type, and they designed most of the equipment to diagnose and correct them. Like the 3D bike fitting camera systems.


What kind of portable pump should I carry when riding on a fat bike?

I have/do carry an Lezyne Allow Drive pump.  I have spent a lot of time pumping fat tires in really cold temperatures and although it's not as quick, it's compact and packs well.  That Lezyne floor version doesn't look too bad, but it is still a bit big to pack for my tastes.  It looks like they have a specific HV hand pump out that is designed like their others.

I would recommend against ANY pump with ANY plastic parts if you ever intend to ride in cold weather.  I have seen far to many pumps (like the Mountain Morph) that have plastic parts get brittle in the cold and snap.  Being able to pump up a tire in two minutes less doesn't mean anything if the pump breaks.  I would only ever recommend pumps for cold weather that have a non-plastic screw on attachment and no plastic structural parts.


Why do cycle paths always have to be bumpy?

I think it is an issue of foundation mostly. Because roads get very heavy (as in weight) traffic roadbuilders spend a lot of time on the groundwork, compacting, digging away soft and unstable earth or sand layers and replacing them with gravel or other heavy rocky debris before the tarmac is laid down.

Because a bicycle path only sees light bicycles less time has to be spent stabilizing the base before the tarmac can be placed. Unfortunately this means there is less of a hard pack underneath the pavement to keep roots away, and there is not as much heavy rocks and other stuff underneath the pavement stabilizing inevitable small shifts in the ground. So bicycle paths shift a bit more, and they are more vulnerable to getting pushed up by roots.

What it comes down to -I think- is money. Building a solid foundation takes time and materials, and hence money. For a bicycle, anything paved is better than what was there before (nothing or running the gauntlet on the open road) so I assume municipalities choose to get the bicycle paths out there fast and cheap rather than roll them out slow but more expensive. Spending a lot of money on car-load resistant bicycle paths also just doesn't make economic sense for most municipalities.

The good news: Here in the Netherlands a lot of municipalities have realized over the years that the cheap bicycle paths cost a lot more in maintenance and repairs, so the quality is steadily improving.


Changing cassette shouldn't require you to pull the axle (4) from the hub body.

To get all this put back together you're going to need at least 1 15mm or 17mm (depending on hub) cone wrench and a little bit of know-how.

I would assemble what you have there as 4-6-9-6-5 starting from the inside. The tricky part is getting the locknut (5) tight against the rest without upsetting the load on the bearings.

Start by tightening the cone (4) against the bearings the the amount you want, no play, but not tight.
Then hold the cone still with a cone wrench and the opposite cone and locknut still with another wrench.
Add the washers.
Tighten the locknut against the whole assembly with either another cone wrench or an open ended wrench of the correct size (some locknuts are too small to manage this).

This is all much easier on the none drive side unless you have the tool to pull the freehub apart.


How easy is it to explode a tubeless tire whilst seating, and how do I avoid this?

I remember I heard a small pop and stopped inflating

The pop is what you are waiting for when inflating. It means that the tyre has become seated on the rim and will stop leaking  air fast and it is now enough to just add the air as necessary.
For 35c gravel tubeless tyres I would use pressures about 35-40 PSI or somewhat more if you are heavier than me (many people are). For the initial seating I would go up to 50 get some proper pressure. There is no reason to go to 60 but it won't explode unless the tyre is not connected to the rim properly - but then the explosion would rather be a fast burp of air, the tyre would remain intact.


Generally speaking you can tell if a bike is good quality by the attention they paid to finishing it.
So, for example, and expensive bike has the welds ground off and sanded, so that the joins between the tubes look smooth. This also reduces the chance of rust getting in.
The chrome plating will also be higher quality and very shiny (and easy to polish as a result). If the chrome is tarnished and peeling, it's a sign of less attention being paid in the factory.
To me it just looks like a mass produced bike. Perhaps not bottom rung quality, but not the best either.
The weight test is another simple way to tell. Cheaper bikes can also double as boat anchors :)


What to consider when repainting fork from black to white

I hope there is some kind of industry standard when it comes to the color.

Surly offers such a service for its bikes:

  RAL is a color code number system used by paint manufacturers.

Not so sure about other vendors.

  Do I need to remove the black paint first or can I just color over that?

You do not need to remove existing paint. However, it is recommended to use a primer before applying new color layers, and also a clear coat on top of that.

I used spray rattle cans (primer, color and clear coat) to repaint a suspension fork on one of my bikes. Not the best tool for a fine paint job, and even that required a couple of attempts to gain the experience to do it right. However, I am satisfied with the result, given that the fork is on a beater bike.

Good advices on hand repainting of bicycles can be found here. There are other good web resources that I used to learn about the process. Or, you can leave it to professionals — there certainly are services for quality paint jobs.


Pendulum motion when riding out of the saddle

You lean the bike in the direction of the leg pushing down? That's quite unusual.
When you sprint, you're effectively throwing all your weight on one leg, then the other. If you were to just stand on one pedal with the bike vertical, you'd flip over the bike from the one-sided force. To counteract this asymmetry, most people lean the bike opposite to the downwards leg.
This also gives you an effectively longer crank for more leverage, as the leaned-up side will have the pedal higher than normal max, while the leaned-down side will have the pedal bottoming out at lower than normal minimum height.


Where can I find a 9mm x 26thread axle nut?

You might want to check out are your local hardware store.  They tend to have much more exotic parts and have huge catalogs of parts they can order from.


I put a 2.1 tire on rim that usually uses 2.0. When I pedal the rim bends on the sides

Judging by your last photo you have somehow unscrewed your cup&cone bearings at least partly, making your bearings extremely loose.
Bearing play should be carefully adjusted. You usually need special, thin wrenches to adjust bearing play.
You might have lost some bearing balls in the meantime. While you are at it you should re-grease them. Probably best to visit a bike shop.


Changing the wheels on a hybrid giant escape

It will work fine provided you put an appropriate speed cassette on it -- they have the same hub spacing, both are 700c and both ship with Shimano compatible freehubs (so you can indeed put an appropriate cassette on both of them).


What is the difference between "front" and "rear" disc brake?

The length of the cable/hose and the braking lever - Left for front, Right for Rear. There really isn't any real difference. If you change out the cable/hose you can hook either up and they will work the same.

This is generally true for most brakes, the differences generally deal with bolt, spacer, and cable/hose length.


If 17mm is the internal width, 21mm tires are probably a bad idea. According to Sheldon Browns (admittedly conservative) chart, 25mm is the lowest recomended width on 17mm rims. You could also probably contact Bontrager and ask for this specific rim though.

As an aside, I'm not totally sure why you'd want to use 21mm tires. Barely anyone makes them anymore, they're less comfortable and have higher rolling resistance.


Why did my chain start coming off on the right side of the chainring sometimes when I am pedaling in high gear?

Chains life spans have huge differences, depending on both conditions and maintenance and quality of the chain itself. If you have 2000 miles on the chain and it has been exposed to road salt, it is very likely that it has been worn out. If you are lucky, you can fix it by just replacing the chain, but if the chain is badly worn you may have replace the cassette and at worst case the chainring too.

If you have to replace the chain ring, there are so-called narrow-wide chainrings that are designed to hold the chain better in single chainring setups.


Why are folding bike warranties so short?

Sounds like you're looking for opposing features.  A good/great folding bike will cost more than the equivalent full-sized bike.

A cheap folding bike will have the bare minimum warranty permitted in your location.

For example, the warranty on a Giant bike is

  LIMITED WARRANTY
  Giant warrants for the original owner only the frame, rigid fork, or original component parts of each new Giant brand bicycle to be free from defects in material and workmanship for the following specified periods:
  Warranty of lifetime for - The bicycle frame, except on models intended for downhill purposes.
  Warranty of ten years for -  Rigid forks.
  Warranty of three years for - Frames on models intended for downhill purposes.
  Warranty of one year for - Paint finish and decals
  All other original parts, including rear shock linkages, but excluding non Giant Brand parts, suspension forks and rear shock absorbers. (All non Giant brand parts, suspension forks, and rear shock absorbers shall be covered exclusively by the stated warranty of their original manufacturer.)

Their only folder is $819 NZ or about $600 USD.

By comparison a top folder like a brompton has a 5 year warranty on the frame, and only on material and manufacturing faults.  This will not cover accident damage or wear and tear.

  If your bicycle has a material or manufacturing defect, we will replace the defective part free of charge if we are notified within five years (in the case of a frame part) or two years (in the case of other parts) from the date of first purchase of the bicycle.

Their folders range from £800 to £2200, so $1100 to $3000 USD.

In short, you get the warranty you pay for.


What you are asking is engineering. Even if you can calculate the correct thickness for all "reasonable" impacts and forces thrown at a bicycle, you still need to take into account that the bicycle will be used, so the material will undergo hysteresis.
A frame can stand a single impact providing a force of X, but it may fail after one hundred impacts of smaller force X/1000 (yes, you are reading correct, standing a single impact of force X, but failing after a cumulative impact force of 1/10 of X).
If you then bring into the picture a material that evolves with time, like wood, you should expect ... a lot of trial and error.
An example: you draw your ideal wood bike, knowing the tensile strength and other parameters of wood you calculate that the top tube should be long 30cm, have a diameter 1.8 cm and a thickness of 2 mm. However, with the use you realize that such a tube will produce some resonance and some vibration, so for some unlucky reasons hysteresis will cause the connection of the seat stays (calculated to be long 22 cm, diameter 1.2 cm, thickness 1.9 mm) to fail on average after 500 km.
You try to reinforce the connection, but the solution maybe is just to have a top tube with a larger diameter, or shorter, to dampen the vibrations/resonance.
How to proceed? you have two choices:
[scientific/industrial approach]

the mechanical engineer way, such as this page hosted on sheldonbrown site
https://www.sheldonbrown.com/rinard/fea.htm or you check the latest peer reviewed research: https://journals.sagepub.com/doi/full/10.1177/1687814017739513

[empirical approach]

you take some frame building courses, where you get the experience of learning by doing, so you have a "feeling" for what is the right thickness/shape/angles etcetc.

It is not that the calculation of forces is complex or there are industrial secret preventing us from its understanding (well, there are industrial secrets on why a certain thing is built a certain way, but physics is not an industrial secret :D ).
The fact is that we have a very rough understanding of reality and forces at the microscopic scale, but we can obtain insight on the resulting macroscopic behavior of materials only via:

engineering/advanced calculus/tests and experiments (use Finite Element software to calculate stresses and plastic behavior of the material and then you obtain the composite tube shapes of a Kestrel road bike https://www.compositesworld.com/articles/ultralight-carbon-fiberepoxy-road-bike-from-kestrel )

Kestrel co-owner Preston Sandusky credits the low weight to the bike's
"modular monocoque" frame, fabricated from three individually
bladder-molded parts: the triangular front frame, and two two-pronged,
U-shaped forks, which form the seat stay section (running from the top
of the seat tube to the rear wheel dropouts) and chain stay section
(from the bottom of the seat tube to the rear dropouts). Developed by
former aerospace engineers at Kestrel's headquarters in Santa Cruz,
Calif., U.S.A., using Pro-ENGINEER and RHINO 3-D Solid Modeling
software (PTC, Needham, Mass., U.S.A.), the frame structures are
fabricated

via empirical reasoning (Columbus steel tubes works great to build a bicycle with drops, why? because it does! )

I would NOT be surprised if, after doing some calculation based on very simple principle, you would find out that a steel frame with thickness 0.1mm and a weight of 500 grams would be able to stand all the forces related to a standard cycling scenarios.


Safety guidelines for cycling in traffic

A lot of cyclists promote vehicular cycling in which you act just like a car, obeying all of the rules of the road.  This includes respecting all stop signs & lights, travelling in the same direction on the same side of the road as motorized traffic, and using the full lane (taking the lane), often ignoring marked bike lanes if they are too small or marginalized.

To me, vehicular cycling means acting like you belong on the road and that you have the legal right to be there (which you do).  I think a lot of bicycle accidents happen because the cyclist is trying to stay out of the way of cars and in doing so becomes very difficult for cars to see.


Help identifying problem with bike crankset/bottom bracket

I would start by trying to align the front derailleur. If the problem persists, drop your chain and check the chain rings to ensure they are straight and no teeth are bent. With your chain off, you can also check your bottom bracket/cranks. Make sure there is no wiggle in your cranks towards and away form your frame. This could be a sign of a few things. If the wobble is only on one crank, make sure it is tight. If the wobble goes through from one crank to another (if you pull the top of one crank away from your frame and the other moves towards your frame) you have more than likely blown up your bottom bracket.


Long back-rev for a coaster brake to engage?

I have used plenty of coaster brakes and you do not need to coast before you can brake.
Move your feet till one of them has enough leverage when you start braking, change direction of movement and the brake engages.

If you need more time your brake needs adjustments or even repairs.
Braking should be as instant as it is with any other type of brake.


Why 2021 top-tier road bike are so dark? Is black/dark better looking or good looking is nothing at all anymore?

The short and, I am afraid, only answer is "fashion". The "tan" walls on the tires that are present on the two first images are another trait of the fashion.
There is nothing wrong with that, but, if you really are on high-end bicycle market, there are smaller manufacturers and third-party companies ready to customize your frame paint. Customization services like Orbea MyO come directly from the vendor.

And, most of them, the bike brand is even invisible.

Personally, I am fine with that: I hate being a moving advertisement for anything.


Rear derailleur at limit, chain still rubbing

If aligning the hanger doesn't work, it's not a tweaked derailleur, the guide pulley isn't slopped out, and it behaves the same with zero cable tension, the fix is then to put a spacer under the RD mounting bolt. In shops this would be a 1mm M10 axle spacer, but you can improvise with whatever.
It's unusual to need to do this on aluminum bikes, so I kind of suspect it's something else, but in a pinch the spacer may be a solution of sorts anyway.


You can use a spray bottle with diluted degreaser to spray down the chain and wipe it with an old towel to get most of the dirt off; or if it's really sandy or muddy you can use regular soap and water and a sponge. Then clean and lube the chain the way you normally would.

After using several different plastic mechanical chain cleaners my favorite method is also one of the cheapest. I use a small can, like a soup or a tomato sauce can, put a little degreaser in it and clean the chain with an old toothbrush.

Using the bottle is okay, but stay away from using gasoline, kerosene, paint thinner or other harsh liquids.  These will penetrate deeply into the links and will displace the lube you try to reapply, as well as creating a significant fire hazard. Some people like to use diesel fuel which is okay. In my opinion, I'd stick to a quality degreaser product.


Does Campagnolo have a groupset model number system?

If compatibility is what you're after, you should know that it's not always necessary to use the same group. Many times, you can mix and match different groups,  even different manufacturers.

As far as I know, all 10-speed Campy geartrain components should be compatible with each other. You have to consider the capacity of both derailleurs relative to your gearing, but you have to do that even if using the same group for everything.


In theory, a smaller wheel is stronger than a bigger wheel if hub and rim section are the same.
This is largely due to the length of the spoke and it's contributions to the stiffness/flex vs spoke braking force.
Whether the difference between a 27.5 wheel and a 29 wheel is in of itself enough to mean a real world differe, I don't think so.
I think a strongly made (ie specially made for heavier rider) 29er wheel, will be stronger than a generic OEM (for the masses) 27.5 wheel.
I would strongly suggest you pick the bike you will enjoy riding more, and replace the wheels with a stronger wheelset when you need to.
This is exactly what my friend (125kg) did, he bought a bike, and I built him a stronger rear wheel with a Hope Pro 4 hub, DT Swiss eBike specific spokes (brass nipples) and a downhill rim. It was heavy, it will outlast his bike frame...


It's not a touring bike: touring bikes would have mounts for front and rear racks, as well as mudguards.  This bike has mudguard mounts (the little "eyes" near the front and rear axles) but no rack mounts.  Rack mounts would be bigger versions of the same things near the axles, and also mounting points near the saddle and at the top of the forks.

Honestly, though, don't focus on the name. You say that you need a bike to cycle to school, so focus on finding a bike that will be suitable for that.

If you don't want to carry a rucksack while you ride (which can get quite sweaty in hot weather), you'll need something that has mounting points for a rack.
Unless rain is rare where you live, you'll want something that has mounting points for mudguards.
Assuming you're riding on roads or paved/gravel cyle trails, you won't need suspension or knobbly tyres.
If your ride is quite long (say, more than about 15km each way), you'll probably want something with drop handlebars to give yourself more hand positions for comfort; if your ride is fairly short (say, 10km or less; yes, I know I've left a gap in the middle), it won't much matter what kind of bars it has. For longer rides, you'd probably also want a bottle cage, though you can get cages that mount with a strap around one of the tubes, instead of screwing into mounting points.
For commuting, you might want to replace whatever tyres come with whatever bike you buy, and get something more puncture resistant. Being 45 minutes late for class because you got a puncture (in the rain; it's always in the rain) is no fun at all.


Removing an internal headset before pulling the fork?

This is the compression ring. It does the same thing as the silver one on the Colnago in your picture.

Your fork is stuck because it's wedged in too tight.
You need to whack the top of the steerer hard with something that won't hurt it, and you need to have the fork off the ground while you're doing that. Hit it as though you're trying to send it flying out of the bike. Support the frame under the top tube or down tube with your other hand. You're trying to move the steerer inside the compression ring. Using a rubber mallet or dead blow on the end of a steerer will usually hurt the tool. A block of wood is a good idea. You can tape it on if you run out of hands.
Digging out the ring by putting a screwdriver in the slot can also work, but could also tear it up if it's really tight. There's some advantage to doing it this way if you can because then you're not hammering on your bearings. But it usually doesn't work, and upper headset bearings have an easy life anyway.


Bottle dynamo wiring a headlight and taillight on 1980s bike

@Plasma says: I got it working! You're right @Carel, the frame itself wasn't negative, but the back fender somehow was. I didn't check if the entire frame was positive, though, so can't say anyrhing about insulated wires or not. Anyhow, the problem seems to have been a missing connection between the positive and the taillight bulb. I DIYed a new socket for the bulb and did some (possibly redundant) new wiring to connect everything properly.

(because I don't like unanswered questions)


What bike is better 2010 Trek FX 7.5 or 2015 Trek FX 7.2?

At the level of bike you are looking at (2010 Trek 7.5 FX), most of the components will be easily found at your local bike shop or online. At this level, most manufacturers will use standard components which are easily obtainable, mostly because using any non-standard components would end up costing more, as they would only be produced in low quantities. Also, because they use standard components, and many other bikes use the same components, there is a big market for replacement parts, which means that finding replacement parts should be easy and inexpensive.  Assuming the used bike is in good condition, you shouldn't be worried about being able to find replacement parts when the time comes. As you move up to more exotic/expensive bikes, you'll start to see more unique parts that may be harder or more expensive to replace on older models.


Since I have not ridden in Lausanne, I rely upon Stava. I don't know if you can follow the links posted below without being a member, if not then you can join up for free.

Once on Stava, going to the Activity Search page, I enter Lausanne, Switzerland and hit search.

A few interesting rides come up ... there are many others too ...

Along the lake side to Chexbres and up Mont Pèlerin 55 km, 2:45-3 hrs, 860 m climbing, 8 x cat 4 climbs, 1 cat 3.
Mt Tendre 82 km, 3:25-whatever hrs, 1527 m climbing, 5 x cat 4 climbs, 1 x cat 2, 2 x cat HC climbs.
Col de la Croix 145 km, 6 hrs - whatever, 3,283 m climbing, 10 x cat 4 climbs, 3 x cat 3 climbs, 3 x cat 2 climbs, 1 x cat 1 climb.


There should be a hex socket at the end of the axle, inside the crank. Use a long hex wrench to unscrew the pedal.

The textured part is for disassembling the pedal.


cable housing with braided metal hard to cut?

I can't confirm, but it's worth noting that if the reviewer was a do-it-yourselfer, then they might've been trying to cut it with a pair of regular wire cutters instead of a bicycle-appropriate pair of cable cutters. As long as your cable cutters are sharp, you should be able to snip it without excessive trouble.


Brake pad squeal when wet is not unusual. If they do not squeal in dry conditions, the brake pad is the most likely suspect. Some brake pads perform better in wet conditions and some are much quieter. I like Kool-Stop pads ... the Salmon or Dual compound pads would be a good choice.


I want to add a front caliper brake to a bike with only coaster brake - is this safe?

This is common practice and many DIY types do that.
The problem for the shop is that by doing to work they become liable for the result, and if something does go wrong the general result is that your face hits the road, hard. That's expensive almost regardless of the details, and no bike shop wants to take the rsik.
Partly because a replacement fork already drilled is cheap compared to the labour cost of pulling the fork out drilling the hole/prepping a new fork, then reinstalling it. You're looking at about 30 minutes labour ($50?) and probably $20-$30 for a new fork. I'm disappointed that the shop didn't quote you for that option, which may mean they don't do that level of bike mechanicing.


Why have my crank arms started corroding?

In the content of the post concern about corrosion between the pedal and crank is discussed.
Summary: The crank arm has been abraded allowing the aluminum to corrode (oxidize). The pedal and crank connection is corroding due to exposure to water or a water/salt combination.

The issue in the orange circle is abrasion followed by corrosion.
Something has abraded the black coating off of that area of the crank, exposing it to air and allowing aluminum oxide to form. In aluminum - as Criggie says in the comments - the oxidation forms a protective coating and does not eat into the metal over time like iron oxide, rust.
Causes for the abrasion seem to be identified in the comments as road grit. Something is rubbing on that spot.
The corrosion is natural for aluminum exposed to the air.
You could

lightly sand the abraded area, removing the corrosion and any paint that is not adhering to the crank arm
Tape off the rest of the crank arm
Use an appropriate paint to cover the area

The issue in the red circle is corrosion between the pedal and the crank arm. Pedal axles are made of steel, the crank is aluminum and they will seize up if something isn't done.
During assembly the pedal threads should have been lightly greased to prevent seizing.
It would be best to:

Remove the pedal
Clean the pedal - use a wire brush or steel wool on the rusted surfaces
Clean the crank arm
Put a light coating of grease on the threads
Reinstall the pedal.

The cause of the pedal to crank arm corrosion is exposure to water. Water is a solvent.

We need to take the statement "Water is the universal solvent" with a grain of salt (pun intended). Of course it cannot dissolve everything, but it does dissolve more substances than any other liquid, so the term fits pretty well. Water's solvent properties affect all life on Earth, so water is universally important to all of us.
www.usgs.gov - Water, the Universal Solvent

Water and salt is especially deadly.

The galvanic corrosion of aluminum is usually mild, except in highly conductive media such as slated slush from road deicing salts, sea water and other salty electrolytes. The contact area must be wetted by an aqueous liquid or humidity in order to ensure ionic conduction.
Fixing Corrosion Between Anodized Aluminum and Steel

Bikes can get wet but should not be left wet. A wet bike needs to be able to dry out or to be dried off.


I change cleats when they're worn to the point of a corner/ledge is missing chunks.

At this level of wear, the cleat can unclip easily and sometimes spontaneously.  In this state I can still ride, though not as aggressively on take-off or high power.

If you have an event coming up, like a race, a long ride, a group ride, or similar, then change your cleats before they get to the "pieces missing" stage.  Do get at least one test ride in before your event to make sure the new cleats are positioned well.

For your photo, I would call the cleats MARGINAL .  Certainly change those for an event this weekend, but if you're just commuting then there's a month or two left in them.

I guess you're a left-foot down rider (like me), cos the shoe on the right of the photo seems to have more wear than the other.  I always save my worn cleats, sometimes getting months more wear out of two former-right-foot cleats.  A pair of utterly-knackered cleats make for great inserts so you can ride the bike in flat shoes too.  Good for a shopping trip.

Do notice that cleat wear is almost exclusively from walking about in your shoes.  There is almost no wear imparted from riding, other than putting your foot down at a red light or stop.

Cleat wear can be minimised by not walking on concrete, and by avoiding spin-turns on the ball of your feet when walking.  You can get cleat covers, but they're easily lost and still hard to walk in.

I sometimes wonder if aluminium cleats would be practical.


How do I know I should replace the chain?

The most common way is to use a "Chain Wear Indicator Gauge" tool. (google for product pages).

If you don't have access to (or don't want to buy) one, you can use a ruler: http://sheldonbrown.com/brandt/chain-care.html


Choosing a foldable 20" bike: Schwinn S2280 vs. Citizen Bike Miami

I think the real difference is the weight: Schwinn 47 lbs, Citizen 32 lbs. That's substantial. If your dad is going to be carrying it much that 15 pound difference will really count.

My impression is that the Schwinn is compromised to get the low stand-over height, and everything follows from there. That can be important if your dad has limited mobility, but if it's not essential don't buy a bike that adds 15 pounds to get it.

Realistically the rest doesn't add up to much - they're both bottom-of-the-range folding bikes that use cheap components and will probably not last very long (a thousand miles or so). I think you need to be clear what you want the bike for and what you expect from it. If your dad is too heavy or rides too much the bike will fall apart quite quickly. Both bikes will be heavy, unwieldy luggage when folded.

I would be concerned about the wheels on the Schwinn, the "6 spoke" pattern wheels look like a gimmick to me. they might go out of true easily and look hard to fix. But they look pretty. The Schwinn is 7 speed, the Citizen 6 speed, but that's pretty irrelevant as neither bike will cope well with hills or high speeds.

The Schwinn comes with a bag, for the Citizen the bag is $29 extra. If that's important to you, it adds 15% to the price of the Citizen. But I think the Citizen is a (slightly) better bike - they've focused on a basic bike with basic components rather than paying extra for marketing bullet points ("sprung saddle", "pretty wheels"), so they can spend a tiny bit more on slightly better parts.


It will really depend on what you prefer, but here are some recommendations based on my experience...
Helmet mounted

Terrible. Absolutely worthless. In order to see traffic behind you, need to have you head at just the right angle. You end up having to tilt your head side-to-side in order to get a good view of cars behind you. I also tend to be pretty rough with my helmets when I am not wearing them (strapped to backpack, hooked on bike frame, regularly dropped, etc), and the mirror just ended getting beat up.
I imagine that glasses-mounted-mirrors are the same, by I have not used them.
Drop bar mounted

I used one of these once. It was ok, but you need to lower your head to check traffic behind you. It's easier to tilt your head to the side to check traffic. I do not recommend.
Side handlebar mirrors

I have not used these, but on a cruiser/bike with relaxed riding position, they might be nice. In theory, you could just move your eyes to the side to check the mirror. However, you run the risk of getting these knocked off by other cyclists, pedestrians, car mirrors, etc.
Conclusion
In my opinion, the best method for being aware of traffic and cyclists behind you is to evolve highly specialized ears over 100s of years, allowing you to pinpoint the exact location of other road users just keep your ears open, and cautiously glance behind you from time to time. You don't have to worry about the depth perception problem,  and you don't have to worry about having blind spots in your mirrors.


Achieving Correct Beltline for Gates Carbon Drive

I did end up completing this project. I talked to several people, just calling up bike shops that sold or specialized in belt drive bikes and asking for opinions.
I spoke with someone—I think it was a fellow at Ben's Cycle/Milwaukee Bicycle Co.—who had lots of experience fitting belt drives to frames. He had even worked with Gates on building several belt drive-specific bikes. His take was that I was worrying about nothing. A 45 mm belt line was well within what he would expect to work without issue, even if it was specced for 43.7 mm. I even tried to let him talk me into buying a fancy Phil Woods bottom bracket or a Gates crank and BB set. He said it would not be worth it in this instance. 45 mm was close enough to work.
At that point I just went ahead and installed my 103 mm bottom bracket and the Sugino RD2 cranks. I finished the bike and have been riding it pretty much daily since. I don't think I'll go back to chains if I can help it. The Alfine hub shifts super smoothly. The whole setup is quiet and reliable. It's great not worrying about keeping a chain clean and oiled. I highly recommend it.


Theft deterrents (in addition to locking up a bike)

In addition to locking your bike securely with a good lock, there are several strategies you can use:
Location
Where you lock up can be nearly as important as how well you're locked up. If you're in a public, well-lit area, a thief might think twice about stealing a bike. A rack in an isolated, dark area may look more attractive to steal -- there aren't as many potential witnesses.
Beater bikes
While some may not have a choice in this matter, if you know you'll have to lock up in a sketchy neighborhood fairly often, you might consider getting a cheap, used mountain bike if possible. Save the flashy carbon expensive-looking bike for club rides and longer road rides.
Take the bike with you
There may be situations where you don't have to lock the bike up. Many supermarkets and big box stores will let you take the bike with you, if the aisles are roomy. Take care to stay out of the way of other customers. If asked to take the bike outside, you can either comply with the request or take your business elsewhere, but be nice about it either way.
Folding bikes are great for this, especially when you can fit the bike into a shopping cart.
Uglify your bike
I've heard it said that you just need to lock up your bike better than the next bike in the rack. That may or may not be true, but consider making your bike uglier than the bike next to it. A terrible rattle-can paint job (i.e., spray painted) will make a nice bike look like a jalopy of a ride.
You can also approximate this by putting a plastic grocery bag over the saddle, using ugly/old bar tape, fenders that are scratched up, and so on.

More here: Reduce Resale Value to Avoid Theft?

Quick-releases
Wheels and saddles with quick-release hardware are a target for thieves. Much of this can be combatted by locking them up properly (feed a cable through the saddle rails or the spokes of the wheels), but consider replacing these with hardware that needs a tool to open. Maintenance will take longer, but locking up (and unlocking) will be quicker.


Upgrading straight handlebars to drop handlebars

I did this on my previous bike, and while it was a lot of fun (and I enjoyed riding the resulting bike) it was also quite expensive, almost half the cost of the bike.  You should also be prepared to put in a fair amount of research to determine if all the parts will work together.

Here's what's involved:

New bars (of course)
New stem -- unless you can find drop bars you like that match your flat bars' diameter.  Most road bikes now use "oversized" bars, which requires a stem with a larger clamp.
New shifters.  I went with "brifters" (integrated shifters + brake levers) but these can be quite pricy.  Bar end shifters (on my current bike) can be considerably cheaper and should fit most bars.  Down tube shifters also cost less but your bike probably doesn't have the mounting points.  Of course, if you're very clever you may be able to keep your current shifters if you find a smaller diameter bar and mount the shifters on the flats.  Road and MTB shifters are interchangeable (within the same manufacturer and # of speeds) so compatibility is not a problem.
New brake levers, if not using brifters.  But road bike brakes use a different amount of cable pull versus MTB brakes, which means...
New brakes!  This is where it can get fairly tricky (and where I almost gave up) as you'll need to find something that will fit your wheel & brake mount combination.  I went with cantilever brakes but this had the added problem of needing cable hangers in the front and rear.  Another option is to choose drop bar brake levers which are designed for MTB brakes (they do exist), but this rules out using brifters.
New brake cables and housings.  Your existing cables will likely be too short for drop bars so you'll need to replace all four cables plus the sections of cable housing that reach the bars.

So if you're trying to keep the costs and headaches down, look for bar end shifters and brake levers designed for MTB brakes.

Is it worth it?  If you really want drop bars, enjoy working on your bike and it costs less than buying a new one, then yes.  But make sure you plan & price it out.


The exact spec differences:

Rockshox Judy Silver vs Fox 34 Rhythm GRIP

GRIP refers to the variety of damper, an IFP type

Rockshox have a similar damper type, which is called the Charger R or Charger RC, on some of its forks but not on forks like this.
Rockshox Judy refers to a 30mm stanchion with 'boost' spacing, and Silver means 'steel stanchions'. Note that 30mm vs 34mm means that the Fox should be significantly stiffer. In addition, it has the 'TK' or Turnkey damper.
TK damper is an unsophisticated design, which comes below the 'MotionControl' damper which itself is below the Charger R/Charger RC design in Rockshox line-up.
This is Turnkey:

Whereas this would be MotionControl, which these forks can possibly be upgraded to by changing the internals (but you'd need to check, as Silver is steel and has a different thread pitch to aluminium Gold)

The drivetrain spec is completely different:

SRAM have their 'low-cost' 11-50t cassette for HG freehub https://www.sram.com/en/sram/models/cs-pg-1210-a1
Shimano have a full 10-51t cassette for all their 12-speed drivetrails (11-51t is relegated to 11-speed).

Because of the cassette differences, the Canyon 8 has a newer freehub design, Shimano's Microspline design, which is better designed when used with lightweight freehubs made of aluminium - the HG design tends to suffer damage when the freehub is made from aluminium. Therefore the MT410-B is likely to be more durable than the MT400, even though both are constructed in much the same way. Microspline is also required (or SRAM's equivalent) for use of cogs smaller than 11t. https://bike.shimano.com/en-EU/technologies/component/details/new-tech-microspline.html
If you went with the 11-50t system then you'd not be able to upgrade to 10-50t without replacing your wheel or freehub. So 11-50t here is inherently a cheap-out given that the Eagle system is designed around a 10t small cog.
As you say, there are many reports of SX Eagle snapping in the upper knuckle, whereas Deore XT has a good reputation, and compared to cheaper derailleurs it uses sealed-bearing jockey wheels, which will have longer service life than cheaper ones.
As far as the tyres go, if you read the spec more carefully they are in fact Rapid Rob on the rear of the Canyon 7, and Tough Tom on the front.
These are OEM parts https://www.schwalbe.com/en/mtb-reader/tough-tom https://www.schwalbe.com/en/mtb-reader/rapid-rob which are designed for low cost.
Both of these have fairly minimal tread, though they are not said to have great rolling resistance because cheaper tyres will tend to use fewer different rubber compounds compared to more expensive ones, though it's no issue to change this.
The Canyon 8 has a Nobby Nic SnakeSkin Evo at the rear and a Nobby Nic Performance at the front.
https://www.schwalbetires.com/bike_tires/off-road_tires/nobby_nic_hs463
'Evo' refers to Schwalbe's highest-quality range, using three different rubber compounds, whereas Performance is a cheaper version. According to Schwalbe's specs, Evo has better rolling resistance, which is more important on the rear of the bike. This tyre is one that does not need to be upgraded, although some people might replace it for something with more or less tread, depending on their riding style.


How to avoid getting swindled when buying used cranks?

I've actually never seen bent cranks, so that's probably the least of your worries. And if they are bent, then I don't think you'd be able to tell until they're mounted on the bike.

Bringing pedals is a good idea - not to check for straightness, but to check if the pedal threads are damaged. If they're square-taper cranks, you should also check the dust cap threads - if they're messed up, you may not be able to take the cranks off again.


Which type lockring removal tool do I need

I think the smallest sprocket is the lockring on this cassette. I believe you need two chainwhips to remove it.

The smallest sprocket looks very badly worn. I'd replace this cassette rather than re-use.


Rear dynamo light (tail light) or reflector without rack?

Rack upper eyelets of that sort don't have a standard distance between them, so there are no off-the-shelf brackets that would attach to both of them and center the light, if that's what you're thinking.
Busch and Mueller makes a bunch of brackets that let you mount 50mm and 80mm generator lights (yours is 50) intended for rack mounting and stick them to other things.

You could use this one to attach that light to one of the eyelets, but it might stick out too far to the side.
If you want to do it in a way that's free and made out of trash, one thing I've done several times is take the plastic 50mm/80mm light bracket that comes with Topeak racks and also has the vertical two-hole pattern for reflectors, then bolt it to a seatpost reflector bracket.


How to achieve a tighter turning radius?

Some tips:

Look at where you want to go (the exit of the turn) and not ahead or at your front wheel.
Slightly turn your hips and waist to point to where you want to go (the exit of the turn). Also, thinking that you want to point your belly button there helps achieve this movement.
Outside foot down (pressing the bike down), inside foot up.
Outside hand pulls, inside hand pushes.
Lean the bike slightly more than your body.
Lean your body less than your bike. Try to keep your head horizontal to the ground though.
Trust the tyres and commit to the turn.
Don't touch the brakes.
Make sure you don't loose the front wheel. If it washes out then you are done. You ensure that by maintaining pressure on the handlebars. So keep your weight in the center of the bike (don't crouch back to the saddle).

Also, it is obvious that new tyres help.

Lastly, when you approach the exit of the turn start pedaling again to gain what you've lost while cornering.

Note that the above tips is what I do on mountain biking. There is a possibility that tip #4 doesn't apply to road or track bikes, but I am not sure.


3 week old brand new Montra Rock 1.0 front gears don't change as well chain slips frequently

Ensure the shifter is set to the low position - the position where the chain is on the smallest chain ring.  Give the cable a tug, it should be taut but not tight. You can make minor tension adjustments by turning the barrel adjuster near the front shifter-to-cable housing connection.  If you can not take up enough slack with the barrel adjuster, screw it in about 3/4 the way and then loosen the cable at the front dérailleur and pull out the slack in the cable and retighten. Make the final adjustments with the barrel adjuster near the shifter. It should take about 2 minutes for correct.

If you continue to have shifting problems it can be the angle of the derailleur or the position of the set (stop) screws. In that case if you are comfortable making adjustments look to YouTube for instructions, otherwise, take it into a shop.


Almost certainly you will damage that pivot and possibly the suspension action. I've used a trainer with a normal quick release skewer, and it tends to mash up the drive side, even if it's a metal end. Plastic ones get destroyed - that's a lot of weight to be putting through something that isn't designed to be weight bearing in that fashion.

My trainer came with a big chunky metal QR skewer that weighed about twice as much as a normal one, but was designed to fit firmly in the trainer, for this reason, but I suspect from what you've said that won't be compatible with ABP.

Given that your setup is perhaps even more risky than using a normal skewer - damaging a fundamental part of the suspension, rather than a cheap QR skewer - I really wouldn't recommend using that bike with a trainer.

Have you considered rollers instead? They're a bit scary at first, but once you get used to them they're a lot less dull than a trainer, plus they're better for developing a smooth pedalling technique.


I see no way for the pictured setup to occur while riding.

The silver bushing is bolted or rivetted to the cage plates
Cage plates are contiguous plates of steel with no gaps
Lower jockey wheel is also bolted to chain plates.

These three items form a box through which the chain runs.  No amount of folding or flipping the chain would get it out of that box.

The only options I can think of are

Someone misassembled the chain in the first place - Plausible because the chain is low tension at that point, and you may not notice the clattering.  I've personally ridden with a group ride up a gravel track and someone else only noticed the same problem halfway up (hi Brendon!)
Notice the scarring on that bushing - the chain has been running on it for a while.
Someone has fiddled with your chain while the bike is out of your sight. Unlikely because its a dirty business messing with chains and that's a long way to go for a joke

If your chain has a quicklink then fixing is easy and can be done roadsize with pliers, or some people can split them by hand.

Opinion  If the bushing is only attached on one side. then its not doing you a lot of good.  Consider removing it completely and see how things go.  Store the small part, in case it gets worse and you need to refit it later.


is this derailleur short cage or long cage?

Campagnolo derailleurs come in three lengths, short, medium and large.

To determine the size measure it. The centre to centre distance between the sprockets is 55, 72.5 and 89 mm and my guess is that you have a medium flavour rear derailleur...

How much are you selling it for, b.t.w.?


App for displaying 30s rolling average power

I'm not convinced you'll find an entirely satisfactory app, as most people who invest in a pricey power meter would tend to use a separate device such as this one
https://www8.garmin.com/manuals/webhelp/edge530/EN-US/GUID-53FC7978-187F-4E53-AA33-04853F86B05F.html
This app seems like it might have what you are looking for
https://www.jepster.nl/features.html
There don't seem to be too many users, but the app was recently updated (11 October) and the author seems to respond to feedback, so possibly if it's not quite what you want you might get improvements made!?


Replacing thick wheels with thinner ones

Your problem is that you're riding a BMX bike.  While you can certainly go narrower than 1.75, you can't go much narrower -- maybe to 1.5" (3.8 cm) with the same ISO 406 wheels.  You might be able to switch to a slightly larger ISO 451 rim and get down to 1-1/8" (2.8cm) width, but it would be quite expensive to swap the rims and spokes, and the tires might not fit your frame anyway.

If rolling friction is an issue for you you'd be advised to switch to an "adult" bike.  Just about any "adult" bike, new or used, will roll significantly easier than the BMX bike -- they're designed for hot-dogging, not riding any distance.


How to remove this eccentric bottom bracket?

Those are self extracting crank bolts.

Sram / TruVativ use them. They work like a charm.

The BB cups require a special wrench. The BB should be a Sram / TruVativ GXP.

These require a special wrench that will be referenced as having 16 notches, as there are 16 depressions in your BB.

You can find cheap ones or expensive ones. Up to you.

Remove the BB cups, clean everything really well, grease generously and put a new GXP.

They are well priced, and in my experience they are reliable and efficient. Also you couldn't get any easier to adjust. Good luck!


How to calculate elevation gain for a route not recommended (by Google) for cycling

I highly recommend https://brouter.de/brouter-web for bicycle route planning. It also calculates elevation gain/loss and tries to avoid elevation changes.

Keep in mind that elevation data can be inaccurate since it’s usually using Digital Elevation Models which are based on satellite data. For example it might miss things like bridges entirely and display a huge elevation gain/loss for crossing a gorge. See https://brouter.de/brouter/elevation.html


Prevent xtracycle hooptie rattling noise

You have several options, and not one is going to be the correct one, so wiki it is.

Use old inner tube inside the mounting clamps.  Looks like there is some standard U-shape pipe clamps on the underside?
Grease the side rails where they slide into the main body.  I would do this anyways because getting those ball bearing latches apart later is a pain.  It may reduce the metal to metal contact.
Black electrical tape on the side rails.  Related to #2, if you stretch the black tape enough, it may get thin enough to wrap around the ends and insert them into the main body.
Bar tape.  Somebody else suggested this, but wrap the whole top with bar tape.  You won't be able to take the sides off after (unless you do something else), but at least your kids won't complain about the cold, wet metal.


Heavy Rider (300lb+) - Please recommend a 26" tyre to avoid tyre pinch

As a heavy rider personally, I don't have many issues with flats.

A normal tire on the high/maximum pressure works fine to avoid pinch flats.

The key is to check tire pressure every time you get on the bike. Even a day will allow a tire to soften 10 psi, and that will allow flats to occur.

Road hazard flats are not avoidable except by avoiding the hazard in the first place. :)

Edit: to be clear, my answer is that it is most likely that your existing tires are not fully inflated, rather than that a different tire is needed.


At what height should I have my seat on a road bike?

There are a number of ways to determine the seat height for a road bicycle. But you should also pay attention to how you feel while riding your bike at different heights. In addition, it is important to consider your entire position, not only the seat height. Finally, if you are riding a lot, change your seat height in small increments over time to avoid injury.

Here are some of the popular methods for determining seat height:

There should be some bend in your knee at the bottom of the stroke;

your seat is too high if you should have to wobble your hips with each pedal stroke to reach the pedal.
Your seat is too low if your thighs hit your stomach

Sit on the bike, put your heel on the pedal, and your leg should be fully extended. This provides a good starting point
Another good starting point is Greg Lemond's recommendation from "Greg LeMond's complete book of cycling" states that the distance from the top of the seat to the center of the pedal should be 0.833 times the distance from the floor to your crotch, measured with your back and heels against a wall. If you use clipless pedals, subtract 3cm;
if you drop your heels at the bottom of the pedal stroke, decrease the height and if you point your toes, increase the height  relative to these recommendations.
When you need more control (crit racing, urban cycling, bicycle polo) lower the seat; for more power (hill climbing, time trialing), increase the seat height.

Again, once you get these starting points, you can adjust until it feels right. I would also suggest getting a professional fit, especially if you ride a lot or are planning to purchase a new bike. Probably the most important attribute of a new bicycle is it's fit. A proper fit will do more for your riding enjoyment, skill, and speed than any component or frame material (excluding department store bikes).

Some good online resources include:

http://www.peterwhitecycles.com/fitting.htm

http://www.caree.org/bike101bikefit.htm

Here is a list of references found in the chapter on Body Position for Cycling from the book "High Tech Cycling" by Ed Burke. The entire book can be read at google books.


Freewheel engaging sporadically when turned backwards at low speed

There's a sprung pawl mechanism that is responsible for allowing the cassette to drive the wheel in one direction and coast in the other direction.
The problem you're having is indicative of something not right inside that mechanism. Possible examples are the pawls or springs being out of place, mangled, or not made to spec.
Freehubs not breaking in correctly is something that happens, and there's not much a user can do to either cause or prevent it. One path to issues occurring is if the lubrication inside is too thick, it can cause the pawls to not spring up fast enough, which can cause partial engagement, which can in turn cause damage. Once any of the parts are damaged, the problems escalate.
It's possible that if you were able to disassemble the freehub body completely, there might be a correctable problem. Actually doing that for a looseball cassette hub is seldom done and usually requires special tools. It's also finicky and on the advanced side. And, it's more likely that at this point something is damaged inside.
In my experience, when a freehub is giving the symptom you describe of taking force to break free and rotate in the coasting direction, something is destroyed inside and fixing it is impractical. There are many freehub problems that can be solved with lubrication or thinning out the existing lubrication, but this isn't one of them.
You should take it back to where you bought it for warranty help. The ideal solution is to put a new freehub body on it, which is a quick fix if one is available. Shops have an unfortunately hard time with having access to replacement freehub bodies for bikes they sell, so this is not always practical. From there the options are either new hub or new wheel, which likely won't be OEM graphics/color-matched. I would be accepting of either.
If getting it warrantied isn't an option, it probably makes the most sense to just go for a new wheel, or re-hubbing the existing rim if you want a project. Continuing to ride it is a recipe for it failing at an inopportune time.


How do I know what size tyres can I fit on my rims?

measure the interior rim width (you need to remove your tyre to do this)
look at this chart, from Sheldon


To remove the freehub the axle has to come out. Before you start source two new bearings as it is likely they will need to be replaced after you remove the axle. You can try to "gently" tap on the axle with a soft faced hammer (hard plastic or brass). In a pinch you can also place a block of wood on the axle and hit the wood with a steel faced hammer. One side may slide out easier than the other so try both sides. Once the axle is out of the way insert a large (most are 10mm but some are 11)  allen wrench into the nondrive side and unscrew the retainer. An 11mm allen can be hard to find, I use a 7/16" which is easier to find and cheaper.


I don't think anyone can give you a valid answer from a photo.  Is there a fine crack there?  Who knows?  Certainly, no one can tell from a photo.  Are the forks bent unevenly or beyond their design specs, leading to handling problems?  Again, who knows?

Personally, I would replace it without further ado.  It's steel, so although that does mean it can possibly be straightened, it also means it shouldn't be very expensive to replace.  A fork is an awfully safety-critical component to gamble with, so I would just replace it.  I want my forks in unquestionably perfect condition.  But if money is a serious constraint, I would, at an absolute minimum, have it inspected by a bike mechanic and take their advice.


A dedicated grease with optimized properties for the application/operation temperature is always best. Automotive brake grease, while not ideal, won't cause any damage to your bicycle.

Naturally one uses MUCH less grease on a bicycle compared to on a car, therefore the cost of grease is negligible compared to other consumables for private repairs.


How do you ride on a road that doesn't have a bicycle lane?

I'd ride in the road before riding on the sidewalk just for the reasons you mentioned -- cars pulling out of driveways, pedestrians, etc. Note that sidewalk laws for bikes are generally up to local towns, so while one town may allow bikes on sidewalks, the next town may not.

I'm not sure what you mean about not wanting to be on the far right side by the cub, as riding as far to the right as safe is required under Washington State Law:

http://apps.leg.wa.gov/RCW/default.aspx?cite=46.61.770

  Every person operating a bicycle upon a roadway at a rate of speed
  less than the normal flow of traffic at the particular time and place
  shall ride as near to the right side of the right through lane as is
  safe except as may be appropriate while preparing to make or while
  making turning movements, or while overtaking and passing another
  bicycle or vehicle proceeding in the same direction. A person
  operating a bicycle upon a roadway or highway other than a
  limited-access highway, which roadway or highway carries traffic in
  one direction only and has two or more marked traffic lanes, may ride
  as near to the left side of the left through lane as is safe. A person
  operating a bicycle upon a roadway may use the shoulder of the roadway
  or any specially designated bicycle lane if such exists.

But sometimes being "safe" means taking the lane and it doesn't mean that you need to ride in the "gutter" by the curb. Use your judgement to find the safest place to ride. Regularly hopping from the sidewalk to the road and back again is likely less safe than just staying on the sidewalk or the road, so pick one.

In any case you should definitely ride like a car - use the appropriate lane for turning (i.e. don't make a left-turn from the right side of the road), follow all of the same traffic signals (stop signs, stop lights, etc), signal your intentions, etc.


I posed a similar question (or at least a question which raises similar issues) on here a few months ago: Moving tfrom Shimano 9- to Shimano 10- speed

The issue is not the different Shimano ranges per se, its going from 9 to 10 speed.

You can imagine that the 10-speed shifters will be expecting a 10-speed cassette at the other end of the wire - these things are indexed after all.

The other complication in going from a 9- to 10-speed cassette is the chain. You'd need a new, slimmer one. And unfortunately this means a new real derailleur too. Strictly speaking, this again knocks on to the front derailleur. And the chainrings. But as regards the front setup, I was advised that I should be able to get by with my existing setup.

Unless you specifically want to go to 10-speed, you may have some luck doing what I did - jump over 105 altogether and head for the old Ultegra 6500 range.....which was 9-speed. I suspect if you could find shifters from this range, it would do the trick. Alternatively you could go not quite as far and upgrade to Tiagra - I believe the current Tiagra range is now 10-speed, but its not so long ago that it was 9-speed. (The bike I raised my question about was a 2011 model.) Obviously Ultegra will give you better quality but you'll still find Tiagra shifters a noticeable step up from Soras.

If you really do want to go to a 10-speed 105 setup, well I think I costed it as something like GBP400 or more...not a lot less than buying the whole 105 groupset (which can be bought as a single product). But I seem to remember the biggest single cost was the shifters, so take that as an indication.


Finding a replacement for "Schwalbe No.19 40/62-584/635" tube

40/62-584/635

Means the tube will fit ETRTO 584 to 635 rims, and 40 to 62mm wide tires.

Inner tubes don't have an exact ETRTO code because they fit a range of rim diameters and tire widths. Tubes from different manufacturers (and single manufacturers at different times) will have different ranges, so buying an exact replacement model can be difficult.

As ojs said, find the ETRTO size of the tire then buy a tube that accommodates that size in its acceptable range.


Should I use cheap or expensive lubricant?

There are actually some organizations that have tested various chain lubricants against each other. However, some caveats. The easiest thing to test in the laboratory is drivetrain friction. The chain's durability to contamination is harder to test, although one person has done this.

The research is described in this Cyclingtips article. One caveat is that it's aimed mainly at performance-oriented cyclists. Friction Facts did the drivetrain friction test, and found that the worst tested lubricant (White Lightning Epic Ride) cost you about 3 watts of drivetrain friction versus a good lubricant, e.g. NFS, Rock-n-Roll Absolute Dry, two Finish Line products, or even Mobil1 5W-20 motor oil.

3 watts is not a lot of power, though. It is unlikely to cost you a significant placing in an amateur race. I suspect that the minimum difference an average cyclist can perceive is bigger than 3W (albeit I know of no studies of this question).

You also might want to consider durability. For example, some lubricants attract less dirt than others. White Lightning claims that some of its lubricants are self-cleaning, and I got suckered by this when I was a newer rider, but it's very likely untrue in White Lightning's case. Dirt on a chain works like a grinding paste, which is why it's better to keep your chain clean (which, admittedly, a lot of cyclists don't do). Zero Friction Cycling's test reported the estimated running costs of each lube under the test protocol, which involved contaminating the chain gradually and replacing it once it hit a specified amount of wear.

Your question as asked in the title can't be answered exactly. It's more complicated than that. Also, I don't know that the inexpensive oil you report using on your other question was tested for wear; the friction test does report Mobil motor oil, but I'm not sure how your oil compares to this. I guess we can definitely say that people should not use White Lightning Epic, unless White Lightning is giving you chains and cassettes for free. Most people should probably also stay away from Muc Off Nanotube or Hydrodynamic lubricants, since they seem to wear fast and are very expensive. That said, it's probably safe to assume that they're very low friction lubricants (they don't appear to have been specifically tested for friction); if you compete in the Tour de France, then I believe your equipment sponsor will take care of the chains, so you could and maybe you even should use those lubricants. (Alternatively, if you are a competitive road racer, you could also just leave this question to the directeur sportif and the mechanics.)

The article did report that one of the testers recommended not using oil-based lubricants. They generally seem to have higher friction, and their viscosity attracts grit, which damages the chain (but note that the same person said this might not apply in harsh off-road conditions). So, you may be better served by going to a dry lubricant. They recommended one particular lube, which I also use. But other good ones are probably more widely available. We don't discuss product recommendations here, and discussing specific products (aside from the ones above!) isn't necessary to answer the question, so I must recommend you read the article and do your own research. If you have two bikes, you could try out a dry lube on one and see if you can keep the chain cleaner with it.

Aside from that, I have to wonder if most lubricants (aside from White Lightning Epic) would perform adequately if you kept the chain clean. The method you described in your other question doesn't really clean inside the rollers very much. On-bike chain cleaning devices aren't very expensive, and they will brush inside the chain. This should help you get the chain cleaner.


Are Shimano saint pedals suitable for trail / xc use?

In the shortest way of answering this, yes, they will be suitable for trail/xc use.

All flat pedals are relatively the same. They only differ in the amount of pins, contact area, weight and their thickness.

You'll want something on the thin side for trail use, as you'll be pedaling quite a bit more than if you were on a downhill bike. This will help to reduce the amount of pedal strikes.

The weight is probably the biggest difference between all of the flat pedals. It is totally up to you as to what you find acceptable. For everyday trail use, the Saints should be fine and they should last quite a long while.


Aero bars are a pain in the neck - are there strengthening exercises?

There are a number of things you can try.

Firstly the aero position on the bike and holding that position is often related to how flexible your hips and lower back are as well as the strength of your core, so yoga, stretches of those areas, and core exercises will make it easier to hold an aero position in turn taking strain off your neck.

There are some neck specific exercises that will improve neck strength specifically those similar to what f1 drivers use to handle the G forces through fast corners.

Take an exercise band and tie the two ends to a pole or bar at height so that if you were sat down it would be at approximately head height. This will essentially give you a loop. Sit down at distance away such that when you put the exercise band on to your forehead it is tight and offering resistance.

You can then pull your forehead forward to engage the muscles. There's a link to video if my description is terrible.


Shimano STI does not shift up/to lower cogs

Sounds like the shift cable have become contaminated by grit or mud and are hanging up or there is excess friction, which stops the derailleur pulling the shifter onto the next highest gear position.

When you give the cable a little extra tension it overcomes the friction allowing the shifter to shift properly.

You can try removing the shift cable from the housing, cleaning and lubing it. If that does not fix the problem you can replace the housing. Start with the section at the derailleur end as it is closest to the ground an has the highest chance of getting something in it.


How to stabilise the bicycle seatpost and saddle when it is all the way up?

Your seat post is not all the way up, it's too far up.

If you need the saddle at that height you need a longer seat post. As mentioned in comments there is usually a 'minumum insertion' point marked on the post.

Don't ride the bike with the seat post too far out of the seat tube. It's dangerous as the seat post may collapse under you and you risk damaging the top of the seat tube even is that does not happen.


SPD PD-M520 Pedals, replacing the Body Cover

I remember doing this last year. You need a way to keep the spring-loaded part (on the left in your pictures) out of the way while you move the other part into the correct position where you can attach the screw. If I remember correctly, I did this by sticking a long screwdriver between the axle and the spring-loaded part and holding it with one hand while using the other hand to position the loose part and putting at least one screw in to hold it.


Difference between 22x635 and 40x635 wheels/inner tubes?

The 22x635 is the rim telling you its own ISO designation, which is internal rim width x bead seat diameter in millimeters. The 28x1-1/2 in parentheses is an attempt to help make it a little bit clearer what tire goes on it, or maybe help out in the case of a tire, presumably an old one, that only has that size printed on it. (28x1-1/2 and similar numbers are nominal sizes, and they make tire sizing confusing in a number of ways.)

Presuming your tire has an inflated width of around 40mm (say 37-43mm), and also presuming the valve type is correct, the tube you are looking at is the right one. I'm pretty sure virtually all 635mm tires are around that width.


Will the topeak FX & RX mudguards fit a Carerra kraken?

From the Topeak website, the front one attaches like this:

and the rear one like this (onto the seatpost):

so it's likely they'll both fit.

A search for the Topeak FX Mudguard on Google Shopping gives me various ones at less than £9 as does the Topeak RX Mudguard. This place allterraincycles.co.uk appears to have both the front and rear in stock and will charge you 2 quid less including delivery, than the ebay one you're looking at.


Replace Nexus 3 with rollerbrake with Alfine 11

I think your next point of call will be to speak with a framebuilder local to you.  The chainstay has the big tab for your roller brake, so the chainstay is beefy enough for that.  Whether that translates to being enough for a disk brake, I can't say.

What you need is a pair of brake mounts brazed onto the bare metal, and perhaps a brace up to the seat stay to spread the load.  Once welded in it needs painting too.

If you go this route, consider what else you might want done to the bare frame.  Do you need additional mounts for racks, bottle cages, brake lines, etc?  If so, get them all done by the frame builder in one visit.  You generally have to strip your frame completely for work like this.

Does your fork have a disk brake mount?  If your bike has front suspension, its even more work to weld/braze because of the suspension.  If you have a rigid front fork, see what your frame builder says. but often the front tines are too weak to take a disk brake and you have to buy a stronger fork anyway.   However if the frame builder's got a painter, you might want them to paint your welds and the new fork so they all match.


With any number of brake puller solutions such as this: http://www.amazon.com/Problem-Solvers-Cable-Doubler-Levers/dp/B001CK0R64 you can have as many levers as you want. Installing an additional lever and cabling isn't hard but if you don't want to do it your LBS will have no problem.


Whilst I come from a mountain bike background so my advice might be different from someone with a road background, I've found the following tips work well when I've been on a road bike in the mountains.

Keep your weight centered - don't be tempted to lean back. You want to keep a good amount of weight over the front wheel to help it grip.
Look through the corner, not at the corner, focusing on the exit.
On dry roads with a good surface you can probably lean the bike a lot further than you realise.
Brake before the corner, not in the corner. Braking in the corner will cause the bike to "stand up".
If you have to brake through the corner, only use the back brake.
If you can clearly see through the corner, use the full width of the road (but ONLY if you have good visibility of what is coming up the hill).

On wet roads, go slower :-) The same advice applies, but it's even more important to not use the front brake in the corner. And in gravel, take it slow - it's just not worth taking risks because you can lose the front wheel without any warning.

The best way to lean to descend mountain roads is to follow someone who knows the road and has carbon rims. You'll be able to hear them braking and you'll be surprised how much faster you can go!


Are mountain bikes good for urban riding?

For the past few years, I have commuted on a road bike for most of the year and on a mountain bike for late fall through early spring. My commute also involves both classic road-riding and more urban-style riding.

What I've Found

I've found that I prefer the road bike by a significant degree. Living in a hilly area, it is always a pleasure to drop the excess weight of the shock system, the efficiency loss due to bouncing and flexing, and the wide tired of my mountain bike come spring.

I can finally take my backpack off and put on panniers, which keeps my back from getting as sweaty and is generally more comfortable. My fenders work better to keep the mud off me. It is an altogether more enjoyable experience.

If I could ride my road bike in the winter, I would. Hard to do in the snow, unfortunately, especially when it comes to the turning bit.

What I Lose

However, when I switch to the road bike, I feel I lose some peace of mind. On my road bike, whenever I see a patch of sand at a corner I've got to take, whenever I ride in the rain over fallen leaves, I worry that I will lose traction and fall.

Furthermore, I've been run off the road before and gotten close to it several times and I feel much safer and more comfortable on my mountain bike knowing I can ditch the road and jump into the rough easily if necessary.

On my mountain bike, I don't fear to hop up or down the curb to, for example, avoid a runner in traffic. I can take shortcuts over uneven terrain, hop a few stairs, and be on my way.

Conclusion

In conclusion, I recommend finding a bike that fits your specific needs. If you can only have one bike, find the bike that allows you to do everything. If you live somewhere that gets significant snow, if you live in a place with terrible roads and worse drivers, you may need that mountain bike. If you live in a city with as many shortcuts and stairs as potholes, you'll love the "Go Anywhere" ability. If you live in a very hilly environment, you'll love the climbing gear on your MB. If you have any interest in actually mountain biking, keep in mind that a mountain bike can do both while a road bike has to stay out of the trails.

If you live in a more suburban area, or somewhere as flat as Kansas or The Netherlands, or if you live somewhere with nice weather year round, a road bike is the way to go. The ride quality will be higher; you will feel light as a feather, fast as a Ferrari, and much more efficient than on your MB.

TL;DR:

Mountain Bike: true go-anywhere ability, safety sdvantage
Road Bike: better riding experience, faster, more efficient.


lacing Alfine wheel, trailing spokes inside or outside hub flange

If I remember correctly Shimano recommends lacing with trailing spoke heads in (flat part out) for rear drive-side whereas Sheldon Brown recommends the opposite, so take the reasoning that sounds best to you and run with it. Ultimately it probably doesn't matter much, especially if your chain doesn't fall off to the inside which it shouldn't if everything is in proper adjustment. I just looked at two sets of wheels that I have built which are nearly identical. On the older set I have drive-side trailing spokes with heads facing out, on the other set they are facing in. I have no recollection of why I made the change. I do not notice a difference and I haven't had problems out of either set. If I were going to build another set right now I would probably do trailing heads facing out, but as Sheldon Brown pointed out:

  Note: This is not an important issue! There is a sizable minority of good wheelbuilders who prefer to go the other way around, and good wheels can be built either way.


Common for spoke nipple head to rust but not nipple body?

That's an unusual rust pattern but not impossible.  Your wheel has a cloth rim strip? Those hold moisture from rain and road dampness.

There's a chance your rim is not particularly waterproof, so moisture enters through the bead, possibly the spoke holes around the nipples, and maybe even through the tyre carcass.  Plus there's sweating/condensation when warm and cool things meet.

Plus black tyres are great at warming up due to sunlight.  So warm and wet, plus possible salt can corrode even stainless steel.

Spoke nipples are normally brass which doesn't corrode, but the nickel/chrome coating on the outside makes them look different.  Sometimes race bikes have aluminium nipples but these are fragile and oversized and expensive.

You might have plain old chromed steel nipples too, if the wheel is old enough.

Grab some sandpaper and see how deep the rust is - it looks like purely surface rust in your photo.

Fresh nylon rim tape sounds like a good idea, and remove the fabric or paper tape.   You don't have to replace the nipples, but they're cheap.


Feasability of repairing '70s-era welded-steel luggage rack

That looks as though it was chrome plated after it was welded together, which means cleaning it up so you can safely weld it again is going to be tedious. You'll need to clean the chrome off anything that will get hot, and afterwards painting it will not look that great. It would probably be cheaper to build a new rack.

One repair option that occurs to me is to cut a T shaped piece of steel to fit on the bike side of the bracket, bending the bottom of the T out to support the lower part of the rack. Then make a second piece of steel for the other wide, probably rectangular, to actually hold everything in place. Drill holes in both parts to allow the mounting bolt to go through.

If you made that out of ~2mm thick steel, then painted it, you should get another year or so out of the rack. Assuming to can resist the urge to overload it.

A rack like that with one bolt really isn't designed to take much more than a journal and a baguette.


How do I inflate this bicycle tire valve?

This is what's known as a Presta valve. It doesn't look broken, it looks like it is all there and the valve is in the open position because the captive nut at the very tip of it has been unscrewed.

You can test if it is working by just nudging the end of it upwards briefly, some air should escape. This is good to do before inflating anyway to see that the valve has not become stuck before you pump.

You need a Presta compatible pump (some have a double head and some can be converted), or a small brass 'Presta valve adapter' to convert from a normal car valve (Schrader) type pump.

A 'track pump' is a bicycle specific pump that typically has a head that suits both type of valve and is available from all good bike shops.

Here is an image showing operation of my preferred style of pump head, that I found online on multiple sites with no attribution (but probably Topeak themselves):


For a road bike the quill / threadless adapter size it is almost certain to be 22.2 mm (0.874"). When people talk about a 1" steering tube 1" is the OD, the ID which is the actual size of the stem is usually 22.2 mm.

The description of the adapter will call it a 1" to 1 1/8" or a 22.2 mm to 28.6 mm adapter.

When you install it you don't need the spacers under the stem that would be used in a normal threadless setup. To me the look took some getting used to, but I loved being able to swap handlebars without having to strip everything off one side.


I did a ride of this length solo in March this year. I designed a route to suit me (not flat, not steep), and intended to be quick (I was aiming for under 21 hours). At 400km it was a tough day, but I never doubted I'd finish. I have seen people (tougher then me) go from a solid base of centuries/200km rides to this distance without anything in between, so it's possible.

A few things that helped me get round (an hour faster than my target).

all the riding I'd been doing. Prior to this I'd ridden at least one 200km (125mi) ride a month (often more) for over a year, of which several were 320+km (double centuries) in tougher conditions, though none for a few months before the 400km. When training for endurance, even commuting counts, especially if you've got stretches you can push hard.
fasted training. Until I injured myself recently I was going out once a week for 90 minutes before breakfast. For endurance rides this is really beneficial - you don't bonk as easily or as hard, and you learn what it feels like to be out of carbs. Once a week is ideal, twice as an absolute maximum. This seemed to help after only a handful of training rides.
a feeding schedule on the day. I set an alarm on my phone to remind me to eat, drink and stretch out of the saddle every half hour. I tried to remember to drink in between as well. This really helps when pushing a personal distance record.
aim to cruise round. Hard efforts only on climbs and if you're riding in a group take turns at the front especially into a headwind. You don't have to be right on each other's wheels to get some benefit.

A ride of this length is never going to be easy, and by going for it so suddenly you're doing it the hard way - so plan the actual ride carefully. Know where you can get a meal - you'll need real food - and where you can stock up on snacks and drinks. You might need to carry more water than you think. Know where the bike shops are in case you run out of tubes. Know how you can get home if things go more wrong than you can fix (it happens; it's happened to me twice this year).

Apart from fasted training, I suggest you try to pack all your training time into long sessions, rather then hard efforts. You need the saddle time. But don't push yourself for a few days before the event.


Cheap alternatives to avoid tire punctures

Puncture resistant tires and liners are hard to DIY since they are made from kevlar and other specialty materials which are not easy to come by on the consumer market.

Flat protection opions:
Puncture resistant tires $35 to $80 a tire - most expensive, best protection, only good for the life of the tire. My favorite lightweight ones are panaracer t-serve, most protection panaracer ribmo.
Tire Liners - $15-$25 a set- cheaper, reusable when you get new tires, adds a bit to rotating weight.  Mr Tuffy and Slime brands are available. I haven't used these personally.
Tubes with sealant - $10-$15 per tire - will seal small punctures with a liquid sealant. This is pretty much the same liquid in tubeless tire setups. This can have mixed results. Slime can get messy and clog valves. I don't think these are worth it.

Really, none of these will prevent pinch flats either. Your best bet is to use one of the first two options and keep tires inflated to the proper PSI regularly. Always carry a patch kit and tools to fix a flat and a spare tube is nice to have as well, it pays to be prepared.


My rear derailleur won't shift after up after 3rd cog

From your description it's likely that the pawl responsible for upshifting is seized and not engaging properly. The reason it would be able to shift the first two gears is because for the 1-2 shift the pawl face engages with an edge of the ratchet wheel instead of a tooth and since the trigger moves far enough that you can shift over two gears at once the 2-3 shift is possible using the same mechanism.

To fix this you would need to remove the cover and clean out the old grease using a solvent or degreaser, or even something like PB Blaster or WD40. You'll probably need to move the pawl back and forth to work the old grease out from around the shaft the pawl rotates on. Once the pawl is moving freely (ie, it snaps back against the teeth without hesitation) apply some fresh grease and put the cover back on.

This video describes the problem and fix, at about 1:08 you get a clearer shot of the upshift pawl and ratchet wheel. Most shimano rapidfire plus shifters use a variation of this design, even if you have a different model than depicted in the video you should still be able to clean and regrease the mechanism the same way.


Advantages and Disadvantages of Bibs vs Shorts?

Bibs

Don't move.
Looks more pro.

Shorts

Easier to put on.
Easier when the you hear the call of nature.


Can anyone tell me the specific year and model of this Benotto bike?

It is an early 90's steel rigid MTB.

That model of BIOPACE chainring dates it to 1989-1993, as does the Shimano Exage groupset was released first in 1988/9 with a last year of 1993.  These parts can be replaced, but given the bike's lack of wear they're probably original

The plastic spoke protector isn't broken so it has not had a hard life.

The only oddities are the aluminium(?) fitment under the downtube (kinda like a bottle cage but not and the rear brake location, down on the chainstay is unusual.

Nice bike! You should enjoy riding it... but first check the tyres - I see lots of cracking on the sidewalls. They may be OK for now. Also check the brake pads, cos they can harden and not brake you effectively.

I'd totally ride your bike (no hidden message there, it looks sweet.)

Sheldon Brown says "An Italian company that moved to Mexico. Some of the Italian examples are exquisite"  which is quite a compliment.


Do I need a spacer on my crankset? (2x11 SLX, BB shell width 92mm)

The literal answer to how to figure it out is pull up the exploded view diagram and/or manuals from si.shimano.com of your crankset model.

Most Shimano 2-piece cranks (until very recently all of them, but new XTR is a departure) handle preload via the cap on the left side and crank attachment via the pinch bolts on the left crank. This sort of design has no use for the sorts of spacers you sometimes have to add and take away from the other main design, where one bolt does everything and you may need to mess with spacers to make sure bearing preload "just happens" in the manner intended.

All BB92 is doing is putting the outside bearing surfaces in the same planes as they'd be in with a 68mm or 73mm shell plus a regular outboard Shimano mountain BB.

Tldr, worrying about whether Shimano cranks need spacers isn't really a thing unless you're doing something unorthodox, at least not yet.

Note that a number of Shimano cranks do have little spacer-like rings that go on the left side and are more part of the crank, there as part of the sealing and/or bearing contact design. They live in a groove on the bearing side of the spindle attachment area of the left crank, and in some instances it may be helpful to know that if your crank has that groove, it's supposed to be occupied by that ring.