How many miles of riding require the same effort as one mile of running?

The short answer to your question is "probably between 2.5 and 3.5 miles; the faster the runner the closer to 2.5 while the slower the runner the closer to 3.5." The long answer is quite long.

As you already noted in your question, the full answer depends on pace; but it also depends on the surface being run or ridden on, whether it is up hill, down hill, or flat, whether it is windy or calm, and how "aero" the cyclist is. That said, if we are talking about a road bike on a firm flat surface under calm conditions, it is possible to make some estimates of the “equivalent” distance. The simple answer is given in the chart below, which relates the distance one must cycle in a given amount of time to equal the effort in running a mile at a given pace.

In this chart, the x-axis is the run pace for a mile and the y-axis shows the distance one must cycle in the same amount of time. For example, if you can run a mile in 4 minutes, an equivalent cycling distance if you were riding "in the drops" would be to ride about 2 miles in the same 4 minutes (that is, to average 30 mph). If you ran a mile at a 10 minute/mile pace, it would take you 10 minutes to run a mile and an equivalent cycling distance would be to ride about 3.5 miles in the same 10 minutes (that is, to average about 21 mph).

How was the chart calculated? In running, the power needed to run X meters/second is approximately X watts/kg of body weight (cf. Hall, Figueroa, Fernhall, and Kanaley, 2004 or McArdle, Katch & Katch, 2007), while the power needed to ride at Y meters/second varies with Y^3 (cf. Wilson and Papadopoulos, 2007). Thus, if we know the amount of time it takes to run a mile, the weight of the individual and the bike, and some other simplifying assumptions we can make the conversion. An exact estimate of running power will depend on the individual's gross metabolic efficiency, the runner's energetic economy (that is, how economical in an energy sense is the individual's running style), and the runner's resting metabolic rate, but it is commonly observed that for a normal-sized individual without unusual abilities or disabilities, energy expenditure while running on a firm flat surface will range between about 0.8 to 1.1 kcal/kg/km. Thus, a common rule of thumb is that running requires about 1 kcal/kg/km. There are 4.2 joules per kilocalorie but gross metabolic efficiency usually lies in the range of 19-25%; if we assume a value of 23.8% for GME, we can derive the happy simplification that (running speed in meters per second)*(body weight in kg) is a reasonable estimate of power in watts; or speed in meters/second ~ watts/kg.

For this chart, I first calculated the speed in meters per second for various running paces along the x-axis, from a 4 minute mile (= ~6.7 m/s) to a 10 minute mile (= ~2.7 m/s). By the running rule of thumb, this requires roughly 6.7 watts/kg down to about 2.7 watts/kg. I then presumed “average” values for the coefficient of rolling resistance (Crr) of .005, flat ground, no wind, and a CdA (drag area) of the cyclist of 0.25, 0.33, and 0.42 sq. meters (typical of a road bike rider "on aerobars", "in the drops", and "on the hoods") and calculated the cycling speed for a cyclist able to produce between 6.7 watts/kg and 2.7 watts/kg. The running pace defines a total amount of time needed to run a mile so the question becomes "how far must a cyclist producing this much power ride in the same amount of elapsed time?" Knowing the speed and the elapsed time lets us calculate the distance. That is what is shown on the y-axis. Note that for the fastest runners, the equivalent cycling distance approaches 2 miles while for the slowest runners competing against the most aerodynamic cyclists, the equivalent cycling distance approaches 4 miles. Thus, for a friendly race between you and your co-worker, if neither of you is a world-class athlete, a reasonable range is 2.5x - 3.5x the running distance to handicap a race so that you both finish in approximately the same time.

If the cyclist were a bit more aerodynamic (for example, if the cyclist used aerobar extensions and subsequent CdA was below 0.25 m^2) the curve would move upward and the rider would have to ride farther in the same amount of time (that is, faster) to match the runner's energy expenditure. If the cyclist were a bit less aerodynamic (for example, if the cyclist's position was more upright, or was wearing loose and flappy clothing) the rider would be expending energy at a faster rate so the curve would move down.

A rough validation of this approximation is that, anecdotally, people who both run and cycle say that running 10 km in about 42 minutes is roughly about as hard as riding 40 km in an hour. That's a running pace of about 6:45 per mile, and the chart equates that to cycling about 2.75 miles in 6:45, or about 24.5 mph -- which is 39 km/h. Our rule of thumb for equivalence is "between 2.5 and 3.5 times as far; closer to 2.5 times if the runner is fast and closer to 3.5 for a slower runner." Running a mile at a 6:45 pace is moderately fast, so we would expect the equivalent multiplier for cycling distance to be closer to 2.5 than to 3.5 -- as you can see, the predicted multiplier is 2.75 so the rule of thumb appears to work. Further evidence can be gathered from duathlons or triathlons. Below you can see data from the 2010 Ironman World Championship in Kailua-Kona, Hawaii. The Ironman comprises a 2.3-mile ocean swim, a 112-mile bike ride, and a 26.2-mile marathon. The scatterplot matrix below shows the swim, bike, and run times (in hours) for each of the finishers.

If we ignore the swim leg and concentrate only on the relationship between the run and the bike, we can prorate them to equivalent 10k run times and 40k bike times, as is done here:

What these latter two charts clearly show is that equivalent bike distance will depend heavily on run pace but also on the individual. There is a great deal of "scatter" in the scatterplot, which indicates that while the rule of thumb is reasonable it is not precise.


Avalanche upgrade cartridge for Boxxer, or tune existing?

I'm not too familiar with the Boxxer line, but it looks like they come in both a coil and air versions. If yours is a coil one, have you considered trying a stiffer spring? It is likely the cheapest option, and should help with the bottoming out, and will quicken the rebound for the 'packing down' on small bumps. Replacing the spring is probably the cheapest option too, so it might be worth a try.


Is it better to get an entry-level carbon bike or a similarly priced aluminum bike?

Essentially this is about low end carbon versus high end alloy. Carbon is typically lighter and less harsh (more vibration absorption) than alloy, but is not as robust. I doubt that the alloy is much heavier. I think it will come down to the difference in component quality and your budget.

Personally for a training bike I would probably go for the alloy, but that is driven by my financial situation. If the bikes are of similar price and the components are of the same quality, I would consider the carbon.  However I would not trade component quality for a carbon frame.

Edit : Seven years after the answer was give.
Many of the tecniques learn laying up carboon, and with advances in hydroforming alloy, have lead to allow alloy frames that are significantly cheaper to fabricate yet nearly as light (if not lighter) than low ebd carbon frames, while having teh characteristics of stiffness and complance where wanted. You can no longer discuss 'Carbon' and 'Non-Carbon' frames as most major manufacturers have 2, 3 or more variations of carbon from 'cheap and cheerful' to 'insanely light and expensive'. The cost saving in Alloy frames put into better compenets leads to a better bike for the same build cost. As carbon is consdidered more desireable by many, it fetches a higher price for the bike.

TD;DNR when buying a bike, look at the whole bike, not just the frame.


How do I put grips on mountain bike handlebars?

Two solutions I've used:

Spray the inside of the grip with hair spray. Slide it on immediately, and then when the hair spray dries, it will glue the grip in place.
Use rubbing alcohol. It does not do as good of a job at locking the grip in place, but it does evaporate quickly and doesn't leave any lubricant inside the grip.


Lacing wheels Hope Wheels one a enduro synthesis alloy rims

If I measured the rim to be an actual ERD of 564 (the published number) with the nipples I was using, this is what my calculation would look like using the raw formula via Spocalc:

From there I would choose 271 for my right length or 270 if that wasn't available, and 272 for my left or 271 if that wasn't available. The rouding down by those amounts is to compensate for spoke stretch and rim compression. Never round up.
Your problem could be occuring because published ERDs usually are based on 12mm nipples. Longer nipples typically have longer threaded sections, so they can make a spoke that would be perfect for 12mm instead bottom out on the threads with a longer nipple. This issue is real but a detail that gets left out of too much written work about wheelbuilding.
Cut to the chase and measure the ERD yourself. Take 2 spokes of known length, poke them into the rim 180 degrees apart, then take 2 of the nipples you're using and screw on the nipples until they're at the point you want to define as ideal thread engagement. With 12mm nipples, that usually means the tip of the spoke flush with the top of the nipple, but with longer ones you have to choose how you're going to define it yourself. Usually what I do is screw the spoke all the way in and then back it off two rotations or 1mm, which for most spokes is 9mm of thread engagement out of 10mm of thread on the spoke, or thereabouts. Take your vernier caliper and pull the J-bends tight together with the jaws, then take the measurement of the caliper and add it to two times the spoke length. That is a method for measuring ERD that is superior to all commercial systems because it automatically accounts for any quirks of the nipple you're using, which is done virtually or not at all with other systems such as the Wheelsmith tool.
This measurement will likely give you a number that accounts for your long nipples in a way the published number isn't. You will probably plug it in to a spoke calculator and see what's going on immediately.


Can I convert my v-brakes to cartridges?

There are plenty of cartridge pads for MTB v-brakes.
For example http://www.ebay.com/itm/Cartridge-V-Brake-Pads-with-Titanium-Finish-for-Shimano-XTR-XT-SRAM-9-0-Avid-/200719390579?hash=item2ebbced773:g:auQAAOSwJSJXGDxZ .


Carbon taperd road fork - use crown race or not?

That looks like an integrated crown race for sure. Does the rest of the headset use integrated bearings as well? If so, that would also reinforce my suspicion. It's certainly safe because you've been riding for years already without issue.


Tips for a novice cyclist wanting to get fit with a turbo trainer before summer

A lot of cyclists find they need motivation to train on a static trainer. It can be unrelentingly tedious to sit spinning on you bike staring at the same wall when you are used to nice scenery going by. If you are used to running on a treadmill or a similar exercise this may not be such a problem for you.

As you have a smart trainer that will work with Zwift, I'd recommend getting a subscription and taking advantage of the structured workouts they offer, and the motivation of virtual cycling courses and competition. You only really need a laptop or tablet to create a workable set up.

If you are not going to do Zwift, there are structured training videos for 30-60 min workouts on you tube that you can use. The Global Cycling Network has some pretty good ones.

You'll want to figure out what your goal is for when you transition to outdoor riding and pick appropriate workouts. E.g. if you live in a hilly area you would want to train for hill climbing, or if you want to do long rides select workouts that build endurance.


Bike is slightly too large, shorten the stem?

A relatively cheap way to make the reach shorter without compromising handling is to move grips little closer to you. Applicable on most drop bar handles. Most bicycles have grips set far forward and moving them back 2 centimeters is safe and won't move them up too much. Expenses - new duct tape to fix cables onto place if they are not internal and a screwdriver if you don't have one.


I checked several from a variety of years. If they weren't symmetrical the thicker side was toward the wheel.


Power meter upgrade on 2015 Surly Long Haul Trucker

Power meters for square taper BBs are hard to come by, and usually custom made and expensive.
However, fortunately the Surly LHT has an ordinary English threaded bottom bracket. Just swap out the UN-55 for any Hollowtech 2 compatible external BB, such as the Shimano Tiagra BB-RS500 or 105 SM-BBR60. Then, get any hollowtech 2 crank, replace the left side with a power meter, and you're good to go.
In fact, more recent models of the LHT use hollowtech-2-type crankset systems out of the factory.
I know Stages only sells power meters for 105 and above for road, so it might make sense to get a 105 BB and a 105 crankset, coupled with a 105 power meter such as the stages Gen 3 Power L, or 4iiii equivelant.
If you want more gearing range than a 105 crankset provides, you can mix and match with other cranksets that use the Hollowtech 2 interface, of which there are plenty.


Are the Shimano BR650 brakes really Ultegra spec?

No, these brakes have nothing to do with Ultegra.

A lot of unscrupulous Ebay sellers put unrelated keywords into the title to get more search hits. It's against Ebay rules, but it's pretty widespread, unfortunately.


According to my research, which consists of a couple of web searches and looking at a few photos, the failure mechanism that causes pits in bearing cones is spalling. It is the result of metal fatigue from balls repeatedly rolling over the same part of the cone, and it can be recognized by the irregular shape of the pits. This is different from mechanical wear, which produces a smooth groove and brinelling, which produces smooth indentations at even intervals.
The reason why cone is affected first is that the load is concentrated on smaller surface. The inner diameter of the bearing is smaller than the outer bearing, so the surface is smaller to begin with, and in bicycle wheels the cone does not rotate so the load is concentrated on a small part at the lower side of the cone. Because the outer race rotates, the load is spread to the entire bearing track. The quality of materials has also some effect here: I have seen this damage only on two Alivio hubs. The cheap no-brand cup and cone hubs that I have seen had a worn groove at the bottom side of the cone, and I have not had cone failures in higher tier hubs.


Is my interval training routine effective for mountain bike training?

Whether an interval training is effective or not depends mostly on your particulars relative to the interval. Heart rate is only a very inexact measure of effort, but you seem to be roughly in the ballpark. However, such quick switching between on/off interval state does not generally produce interval-like results and should be viewed as a single 30-minute interval at the average power of this period.

A better gauge of interval quality would be this: how long can you keep up the effort? A more typical interval training might be e.g. 6-7 times 3-8 minute efforts, with 2-5 minute rests, at such intensity that you simply cannot complete another interval round.

A goal of "strength and speed" on the mountain is unspecific enough that you can be sure it's being helped somewhat, and in some way, by the intervals. However, it's counterproductive to do interval training and weight training both in one session. If you are still in shape to do weight training after your intervals, it means the intervals weren't done hard enough. Do intervals and weights on alternate days.


Can I use tubeless tires on Araya DM-27.5 Black 32 hole Rims?

A quick google search for that rim suggests they aren't marketed as being tubeless ready (normally, this is a point of advertisement for a manufacturer). So, you're stuck with running tubes unless you try a Stan's no-tube kit (video; or similar) or  ghetto tubeless (or the alternative method), but this is highly YMMV/at your own risk, and highly dependent on your rim+tire combo (not all rims and tires will work). Or get wheels which are tubeless compatible. Tubeless isn't cheap, but the advantages/disadvantages have been extolled extensively elsewhere on this SE and on the internet.

As for punctures, you can make sure your tires are properly inflated, buy thicker/tougher inner tubes (thin tubes you buy may be under 1 mm thick; thicker tubes may be 4 mm or more, for thorn-proof tubes), run a sealant like Slime, and pick a tougher tire.


Derailleur play between cage and knuckle

How worn are the cassette and chains? How old is the shifter cable.

In my experience the order of things that cause shifting issues are chain wear, cassette wear, cables first. In my mind these are all considered consumables and replaced regularly. Derailleur hanger, especially if unknown history, is a likely suspect

Last is derailleur itself.  At 10000km on a Claris it past its 'economic life', so I would not be worried about replacing it.  The play in the video is a bit more than I would like, but I hesitate to say it is definitely the cause of your shifting issues.


Motobecome Mirage (I think) made in France

There are fixed gear bicycles don't freewheel. Presumably you have multiple gears, so its not fixed gear bicycle (or you know it used to freewheel).

That being said, if it is really a French Motobecane (the Motobecane brand is now used for bikes sold directly from some Chinese factory), it probably predates the common use of a freehub and almost surely uses a freewheel.

The solution in this case is to put on a new freewheel. You can try blasting it with WD-40 or whatever to see if it loosens up, but at the end of the day you will need to replace it. Assuming this bike was sold in an export market (i.e. not in France), it almost surely uses a regular old freewheel (ISO threading, 1.375 x 24 TPI). If it was sold in France, it may require a French threaded freewheel (1.366" x 25.4 tpi; in which case, you're best off buying a new wheel and possibly spreading the frame to accommodate it).

See these directions on how to remove a freewheel (and if you can't find the appropriate tool quickly or cheaply, use the destructive method).


I hacked the seat in our burley trailer to recline by decoupling the seat top from the frame tube it ran through (required disassembling the trailer), and suspending the seat top instead from some climbing webbing which could be tightened or loosened with a typical adjustable nylon clip. I did that so the kid could recline a bit more and sleep more easily. I also ran some pool noodle down the sides of the interior to act as bumpers. The first thing made the kid more comfortable. The second thing made me more comfortable. She'd still fall asleep and her head would sink or flop, and I couldn't believe her neck didn't hurt, or that she wasn't choking herself with her head that far forward. (I eventually tried that position and realized it does the opposite with the chinstrap.)

Finally, I learned to chill.

The same thing happens to kids in cars. And on airplanes. And in the jogging stroller. And when you walk a baby around in a snugly. Are you aware of actual injuries resulting from this? I'm not. And I looked. I couldn't find anything on this (or in car seats) on pubmed.

Don't get me wrong, I used to worry about this with my kid in the trailer as well. (And I took mine on 50-80-mile days beginning when she was 9 months old.) However, before I did that, I created a baby test dummy (a large doll, weighted, with a 3d accelerometer on its head. Yeah, I was crazy.) I ran the numbers from the bouncing in the trailer against numbers from bouncing walking around the house, down the stairs, on the trail nearby, and the peak Gs were all comparable, and very low. When she was older, she never reported a sore neck from sleepflopping in either a car or bike trailer.

There are gadgets designed to support kids heads by wrapping around their foreheads, but frankly, I'd worry more about a choking risk from that than I would a neck injury from a floppy head.


Why so few mountain bikers with spandex?

As already said, aerodynamics are less important to MTB's, but otherwise its largely convention and fashion that dictate what people wear.

A vast majority of MTB'r are not wearing basic shorts - they are usually wearing shorts made for riding, including padding just like Lycra road shorts, flat seams and materials designed to withstand the rigour of riding. Many MTB shorts consist of removable lycra under shorts with the baggy outer designed for cycling.

For me personally, I wear baggies MTBing because we often spend time "in public" - around cafes or pubs after the ride, socialising and I feel like a fashion mistake (and I am not fashion concious) walking into a cafe in lycra. I will wear lycra if doing long distances, or I know I won't be more than 10 feet from the bike for the whole time I am out, but feel more comfortable wearing shorts.


Is this for a group of riders or just one rider?

I'll share the experience I had from a big group cross-roads biking event I was part of as a Cyclist, so you can take ideas and maybe create a better plan for yourself.

We were going to cycle across country from north coast to south coast. So first we departed from the country's capital city towards the ride starting point. Two busses for the riders and support personnel, two trucks for the bikes and other items (advertising banners, podium structure, etc). Also a couple of small vehicles.

Once we got to the starting point, the busses served as logistics vehicles, carrying everyone's luggage, and support personnel with food, drinks and tools. The busses departed before us and parked a few kilometres ahead in a previously selected point. (Each bus in a different spot). After a while the busses departed again, overtaking the cycling group and repeating this a few more times. The stops where somewhere like 15-20km (10-15 miles) apart.

The smaller vehicles were also carrying food and tools, but they where going back and forth, sweeping the whole span of the cycling group. And a police officer was riding a motorcycle behind the last rider. The smaller vehicles would drive forward up to a certain point, then go back until they find the motorcycle behind the last rider and then drive forward again, sweeping for stranded cyclists who could not get to the next support point (bus) by themselves. If necessary the vehicle would pick up the rider and bike and take them to the bus. If possible, mechanical or medical support would be delivered by this smaller vehicles.

The whole ride spanned seven days over nine cities. Every stage was from one city to another, (except one stage in which we visited one city just for a few hours ant then continued to a second city). Each day every rider would unload his/her luggage from the busses for the sleep over and load it again the next day.

All the vehicles would be driven at normal road speed and stopped either on planned spots or to help a stopped cyclist, but wouldn't be driven at cyclist speed. The only exception would be the cop's motorcycle at the back of the group.

Each cyclist would ride a his/her own pace, except the pros, who would form peloton. The exception would be that the arrival departure points where a few kilometres outside the city. To go from/to these points to/from downtown, the whole group would form a tight peloton lead by a police car and would travel at around 20km/hr taking the hole lane.

I think this form of logistics worked very well for a group of near 100 riders.

If I was to plan a vehicle supported long ride for a single rider (or a very small group), I would set the car to depart some minutes behind me, calculating to meet me on the road near the mid point of the distance towards a next planned stop point, and repeat.

The distance between the stop points would be what the average of the group would ride in one hour. That means that the car would depart so they meet the group in 30 minutes after the riders started, would drive past us and wait nearly 30 minutes for us in the next stop point.

I hope these ideas serve your purpose and that you are abe to adapt some to your needs.

EDIT: As noted in one of the comments, the support car itself may suffer a failure. It may be obvious to say that the support vehicle shall be in the best operating condition, and must pass a mechanical revision prior to the ride, as with any car-travel activity.

However, I think there are at least two possible alternatives:
1) Is to let the riders depart first and the car attempts to get to the next stop almost at the same time as the cyclists, thus remaining behind the riders all the time.

2) Let the car go first, and the riders would catch up at the next stop. If any rider suffers an accident or a failure for which she/he can't get over, then the support car shall be asked to go back to pick them up.

The planner of the ride must adapt the strategy according to the probability of bike/rider/car failure and to the capability of the riders to fix common issues, or known rider health issues. For example, if no rider carries flat fixing tools, then it is better for the car to reamin behind the riders at all times. But if the riders carry tools and food, then for a little more of a thrill the car can be let ahead of the riders.


Are there any reasons not to build road bikes with through axels, even if they are not disc brake equipped? Is this a trend we might see as manufactures produce more pairs of very similar road disc/non-disc models?

It makes very little sense to produce a rim brake bike with thu-axels.  What wheel set would it run?  Custom? Almost all thu-axel wheel sets on the market now come with disc specific rims that cannot be used with rim brakes.

I would ask what is the advantage to non-racers of having a rim brake frame with thru-axels over a disc frame with thru-axels?

Brake modulation? A good hydraulic disc brake has much better modulation than rim brakes.
All weather braking - this one is no contest, disc brakes.
Wheel compatibility? - you will need to stick with QR then as this is the most common road wheel interface.
Familiarity? - If they want to keep with a brake format they are already familiar with I doubt that they would suddenly want to switch wheel interfaces and have any extra wheels they already have rendered useless.
Weight - QR interface wins again.

The only "advantage" to the rim + thru-axel seems to be steering response (although some would argue that this is a myth), with the main disadvantages of brake performance and basically no compatible wheel sets.

If the industry produced such a bike, even more people would be lining up complaining that they are producing a completely unnecessary bike configuration.


How exactly to clean it depends on the type of dirt, so try to figure that out first.

If it's just regular dust, possibly mixed with moisture and some grease/oil to make it sticky, regular household cleaners should work well. Try to get something mildly (!) abrasive, such as a metal cleaner (used for cleaning stainless steel metal sinks) with a mild abrasive component.

The dirt could also actually be a different paint (maybe someone tried to repaint the frame at some point?). That will be a lot more tricky. Solvents would likely remove the original paint too; here your only option is probably to gently work with sandpaper.

Finally, there are special erasers for cleaning hard surfaces. They look and work similarly to pencil erasers, but are harder, to clean away stuff that is difficult to remove. They should be available at stores for household goods, or at hardware stores.

Note: Do not use oven cleaner - it is meant to be used on enameled surfaces, and will strip off paint (it is actually a fairly decent paint remover).
Thanks to andy256 for this warning.


Disc brake rotor scraping against mounting bracket

A few things can cause this:

In theory it could be a problem with the alignment of the mounting posts on the fork. This isn't likely for a few reasons. One is that the problem would have been pretty egregious if the bike was doing it from day one, i.e. the wheel wouldn't have turned and someone would have noticed. Another is that suspension forks rarely have such problems because the brake mount is usually part of the same casting as the dropout, and in that case you're not going to have random one-off problems with bad positioning of the mounts due to fixturing errors at the factory, which does sometimes happen with frames.
A sufficiently out of true rotor could do this.
If the wheel were installed out of alignment in the fork and ridden it could cause this.
If the hub parts were put together wrong, after service for example, it could do this by creating an incorrect distance between the rotor surface and the left locknut service. Between the plane of the back shoulder area of the centerlock mount and the plane of the left dropout should be about 19.5mm. If this happened, it would also throw off the wheel dish unless that was corrected afterward to compensate.


Are there any good reasons not to remove cantilever brake bosses in order to fit calliper brakes?

A framebuilder could do this in a sound way. The best approach is to do as much as possible cold, i.e. cut off the bulk of the posts and work the area back down to smooth with files and then sanding.
For the most part, it sounds like a giant hassle that accomplishes little and is founded on the misconception that cantis aren't good brakes.
One exception to that could be if there's something about the frame/fork design that made cantis a bad choice. For example, if overly flexy stays or blades were used, performance with cantis can be lacking. If this is the problem you're trying to address and you're willing to go to this length to do it, going to direct mount centerpulls like Mafac, Herse, or Paul would be far superior to a caliper in terms of braking power, assuming this bike has the kind of clearances that usually go along with cantilevers in the first place.
You haven't mentioned reach measurements, but in the more normal case that this is some kind of typical hybrid/touring/cx bike, it would probably need very long reach calipers to use the existing bridge and fork, although the bridge could in theory be moved. Those kinds of calipers are pretty mediocre brakes compared to a well set up cantilever. You'd be giving up a lot of function.
If you want the bike set up to not have any use for long reach, and again assuming it's a clearance-heavy bike now, then probably the best path would be replace the fork entirely rather than rework it, and move the bridge. That way you can use any reach-appropriate off the shelf modern caliper with a recessed nut front and rear without having to screw around with either adapting modern brakes to non-recessed nuts or working with the few extant options for stock non-recessed nut calipers.
I wonder if you're using basic smooth post low profile cantis and making the assumption that other types are equally hard to live with, or if the bike is set up to create excess shutter off the front brake. These problems are all solvable with less extreme measures and certainly with better results than an ultra long reach caliper.


Which Shimano pedals have reverse threaded bearing adjustments?

I found the answer in this document: https://si.shimano.com/pdfs/dm/DM-PD0002-07-ENG.pdf#page27

NOTE:

Right-hand thread: Black-colored (without slit)
If the fitted lock nut is black-colored (without slit), the cone and the lock nut have a right-hand thread.
Left-hand thread: Black-colored (with slit)
Silver-colored If the fitted lock nut is silver-colored or black-colored (with slit), the cone and the lock nut have a left-hand thread.”

I pulled both pedals apart again, and lo and behold, the left pedal’s locknut is a brown color, while the right pedal’s is plain silver.


To make suspension effective, it must decouple light-weight moving parts from heavy stable parts. For this reason it is most effective to suspend the wheels - they will move fast up and down, while the frame and the rider will not move vertically. A suspension stem is not very effective because it does not carry much vertical load. A suspension seat post is better but will never work as well as wheel suspension.

You can observe the same principle in cars: light-weight aluminium rims are better for suspension than heavier steel rims.

In sort: suspension stems are ineffective for suspension, add weight and complexity, and potentially dangerous failure modes.


Looking for help identifying/fixing a bike

Fortunately, bicycle chains are standardized. You do not need to know the model of the bike in order to buy a chain for it.
There are two types of chains: narrow derailleur chains and wide non-derailleur (single speed) chains. Your bike does not seem to have a derailleur, so it is probably using a wide non-derailleur chain.
The non-derailleur chains are 1/2" x 1/8" in size. You also need another spec, i.e. how many links there are in the chain. You can count them in the old chain.
However, if the chain keeps popping off, you don't necessarily need a new chain. You may need to adjust the chain tension. Looking at the bike, I don't know how easy it is to adjust the chain tension if it is at all possible. Most good single speed / hub geared bikes have horizontal dropouts, allowing you to loosen the wheel, move it back, and tighten it to get more chain tension.
If there's no way to increase chain tension, then you need a new chain. In any case, a new chain might be a good idea even on single speed bikes even though they are not as likely to cause expensive damage to rear sprocket with an elongated worn-out chain.


Valve loses orthogonality in a tubular rim

I've glued a lot of tubular tyres and never seen this issue with any of mine, so it's certainly not normal. I've also raced on them in temperatures exceeding 40°c, so I don't think that heat should have caused that either. I also leave the base coat on the rim if it's in good condition, so as long as the glue on the rim is still in a good state, that should be fine.

When you mount the tyre, is it a very tight fit onto the rim, making it a real struggle to get the tyre on? If the tyre isn't a tight fit onto your rim, then you need to make it a tighter fit before putting it on. You can do this by applying more layers of glue onto the tyre and the rim before mounting. You can also install a tubular rim tape on top of the base layer of glue to add height to the rim, then install the tyre on top of that using more glue again. If you don't make a bit of a mess wrestling to get the tyre onto the rim before the glue dries, then it isn't a tight enough fit.

Many people suggest leaving a small area of the rim unglued on either side of the valve to make it easier to remove the tyre when it eventually needs replacing. If you're following this advice, then stop. You should be gluing the whole rim for safety (not rolling tyres) and to prevent issues like you're having now.

After mounting the tyre, what do you do? Do you inflate it and then ride it immediately or leave it deflated for a while until you need to ride it? Immediately after mounting a tyre on a rim, I inflate it to 50 psi to make it easier to check that it's on straight and has no hump. If it's not on perfectly straight, I'll let out a little pressure, straighten, reinflate, then repeat until I'm satisfied. Once I'm happy with how the tyre sits on the rim, I inflate to 130+psi. Refer to your tyre for max pressure and put it to that, if it's not listed then just pump to 130. Leave the wheel like that for 24 hours then you shouldn't need to adjust it until you replace it.

When you remove a tyre, how easily does it come off? I glue my tyres on well enough that I prefer to cut them off when they need replacing. It otherwise takes me over half an hour to get it off, with my fingertips being very sore by the end. If yours are quite easy to remove by hand, then they are not glued on nearly heavily enough and will have issues like you're asking about or more concerningly, will lead to the tyre rolling off in a turn while riding. The answer is more glue, both in terms of how many layers you put on and how much you put in each layer.


How do I know when it is time to replace the brake pads for caliper brakes?

More expensive brake pads will have a wear line. Replace these when you hit the line. Not so expensive ones should be replaced when the protrusions from the main block have been worn away.

Another decent way to tell is by how far you're rolled out your barrel adjuster. If it's out more than 5mm or so, it's probably time to replace the pad.

More importantly than any of these indicators, if you see any metal showing through the pad, it's time to replace.


It seems like it could be:

Loose Hub
Loose Headset
Untrue Wheel
Tire messed up one way or another

From your description, it's hard to believe that the source is in the rear half of the bike (I'm assuming it also happens when you're not pedaling, correct me if I'm wrong).

It seems to be a fairly minor problem (for now at least), that could be very hard to pinpoint.

If you can't find the problem after a technical inspection, I would just keep riding. If you notice the problem getting worse, inspect it again (it'll be easier to find).


Rear derailleur mounting bolt or hanger thread stripped?

If the bolt spins in the hanger the threads are indeed stripped. The threads on the bolt don't look too badly damaged, so the hanger is where the threads are properly stripped out.

The tops of the threads on teh bolt look a bit worn to me - possible from spinning around inside the damaged hanger threads. I'd replace both the hanger and bolt as a precaution.


Questions about shifting from a new road cyclist

Sounds like an issue with bike-fit. Try the following:

While on the bike and stationary, lean on the wall with elbow (of one arm). The other arm/hand reaches the hood, your body should be as close as possible to the normal riding position (on hood).
two feet on the pedal
Use your back muscle and gradually reduce the load on the hood. Is this possible?

If the answer is no, which is what I suspect, try:

invert the stem, if you have threadless headset. Keyword: 'stem threadless adjustment' for further details on the internet.
increase the (quill) stem height, if you have threaded headset. You often seen this type on older bicycle (1980s and older), which is likely to be your case. Keyword: 'quill stem adjustment' for further details on the internet.
change the seat angle: change the angle so that the seat prevent you from sliding forward
change the seat position: slide the seat forward and have a more up right riding position. However, your centre of mass also shifts forward and your body is more likely to slide forward. Thus there should be a balance between seat angle and seat position (and stem length/angle).


Can't find a helmet that's large enough please help!

Helmets.org is a nonprofit organization that compiles lists of helmets that fit specific needs, including a list of helmets that fit particularly large heads. Their website ToS bars verbatim copying (even though data like that is probably not protectable), so all I can do here is link.


How to pick correct front derailleur replacement

I would suggest you return the bike to Walmart. If the derailleur doesn't move it is not a spring that is too tight. There is something either out of adjustment or broken. The problem with buying a bike at Walmart or other department stores is the skill of the person assembling the bike varies from competent to no idea what they are doing. The bikes they sell are at the lowest possible point. They generally don't work well right out of the box. If you replace the derailleur yourself you have potentially voided the warranty for any other issues that show up.


Will running an LED designed for batteries on a NEXUS dynamo hub damage the LED?

Reverse pulses at low voltage probably won't damage the LED, but the COB (chip on board) that gives the flashing modes might not be able to cope with the full reverse voltage.
The problem is that the hub dynamo is more accurately a constant current source, and will supply about 500mA. One common trick is to run two 6V lights in series off a hub dynamo, and most dynamos will give full brightness from both... they put out 12V. The actual voltage you get out of it might be clamped by a zener, but it's unlikely to be a 5W zener that can take the full power of the hub forever. Not that you want that anyway, it's extra drag.
I have run bare 5W star LEDs straight off a SON hub dynamo (well, with a diode and capacitor to reduce flickering) because they're designed to take 500mA and that's what the dynamo supplies. It worked really well, just using a chunk of aluminium channel as a heat sink/weather sheild/reflector. I don't really know about longevity, after ~10,000km/a year or so I got a proper light cheap so switched to that.
So if your 6V LED is actually a 1W light it might be getting 12V or more. Whether it survives that is anyone's guess. Worse, even a 5W light is likely to be getting +6V on that half of the wave, then -12V on the other half when it's not drawing any power. I suggest a basic diode or bridge rectifier in series, capacitor in parallel to give you DC.


Would a MTB frame be too long if fitted with drop handlebars to build an adventure bike?

How long is a piece of string?

Any bicycle is possible, which is the beauty of a bicycle in general. Bicycles can be anything really - roadies, MTB, single-speed, recumbents, even giant A-frame types that have steps to get to the saddle!
Your question is very theoretical and will require a proper re-write because you're not being specific to a particular bicycle or size that we could say ok.. here's what you need.

As an "answer", all I can say now is that you take your frame and your new build to a competent bike fitter and get fitted for the bike! You may find all that geometry might have to be thrown out the window for the sake of your posture, back and skeletal health.

Good luck!


Changing wheels on Scott 960 - will 29" 12 x 142 fit

I think you are out of luck and have ordered the wrong size rear wheel.

Looking at the page you provided a link for, the bike has a quick-release rear hub. (I had to open the picture in a separate tab and zoom in to determine this, the text does not appear to specify the hub width or type).

The wheelset you have ordered has a 12mm thru-axle, so regardless of the hub width it will not work.

Have a look at the Terminology Index and search for 'quick release' and through axle' if you are not familiar with the difference.

It's very easy to determine the hub width you need. Just get the rear wheel out and measure the distance between the inside faces of the drop outs with a ruler.


Are there research graphs for the Rotor Q Ring system?

Yes. If you want to know about independent research, a good place to start looking is PubMed. If you do, you'll find this: The influence of elliptical chainrings on 10 km cycling time trial performance, which is a comparison of Rotor Q rings at two different orientations (100 and 110 deg) against round conventional cranks. The riders were "blinded" to the cranks (the cranks were housed in a guard or shroud so the riders couldn't see which ones they were using). The experimental design was randomly counterbalanced. The result was that no statistically significant difference was detected in power or RPE (rating of perceived exertion) between the Q rings and the round ring. Heart rate was higher to a statistically significant degree with the Q rings. The "4%" improvement in power was not observed.

As an aside, if you are testing round vs. eccentric chainrings, you must account for the difference in cadence within the pedal stroke for eccentric rings. This means, for example, that you should either test power differences with a Power Tap or on a rear wheel driven ergometer -- crank-based power meters assume that cadence is constant within each pedal stroke so they can simplify power calculations. If crank angular velocity does vary within the stroke (and high force corresponds with the lower velocity) the estimated power will be biased high. The degree of bias will depend, of course, on the individual rider's exact mix of angular velocity and force application but 3% bias is not unexpected.


How do you keep from coasting too much on a bicycle?

You are correct - keeping the bike in the appropriate gear is important. Generally, you should have a preferred pedaling rpm, or cadence that you try to keep constant. Change to lower gears on uphill gradients, higher gears on downhill gradients.

If you find yourself going downhill at a speed that even your highest gear makes you pedal too fast, feel free to coast. There is no rule that says you have to spin your legs madly to keep pedaling. Hybrid bikes tend to have fairly low gearing so coasting on faster downhill sections is normal.


What supplies do riders carry on century sportives and how do they carry it?

I've ridden many sportives at this distance in the UK and here is my experience.

Food/Drink
Looking at the route map there are 3 food stops and 11 water stops so you don't need to carry loads with you. I'd say a 750ml bottle will do. If you find you drink a lot on your training rides then take a second bottle.

Food will be available at the stops but you should take some food with you. Find out what's going to be on offer (its usually bananas, jaffa cakes and cereal bars) and bring something different. I tend to buy a tub/box of bite-size flapjack pieces from the supermarket and stuff about a dozen or so in a jersey pocket (can have unpleasant effects if its really wet).

Tools
A basic multi tool for adjustments while riding is useful.

Spares
Two inner tubes and a set of tyre levers. Small pump. If you get a puncture then just swap the tubes and pump with enough air to get you to the next service spot, where there will be a floor pump for you to attain proper pressure. I never bother with a puncture repair kit.

Clothes
Unless you are confident about the weather I'd take a small waterproof. It needs to be one of the small, lightweight ones so it can fit in a jersey pocket.

Other stuff

keys (if you have a huge keyring with lots of keys, take off the ones you need)
mobile phone
a £20 note
I generally don't take a wallet
I definitely wouldn't be carrying my passport
small tube of sun cream
tools, keys and spares go in a little bag under the saddle, like this; other stuff in jersey pockets

Finally

Use at least one or two food stops or you'll run out of energy
if its sunny, reapply sun cream when you stop
have fun, I'm envious as I didn't get through the ballot


The Quoc Pham shoes are nice: they do recessed-cleat "touring" ones, but also plain leather shoes with thin, fairly rigid soles, suitable for flat pedals or toe clips & straps.  They seem to have a US distributor, Mission Workshop.

I've seen the Dromarti ones advertised as well, but don't know about their distribution.

These Exustar ones are apparently useable if you just leave the cleat cover in place.

Finally, Vittoria have the 1976, and seem to have a few US distributors, so they might be worth a look.


timing chain keeps dropping/derailing only with partner

This answer has been significantly changed since being accepted because the accepted answer cannot be deleted.

Based on the new photo, your timing chain needs checking. Its quite uncommon to see both chains on the right side of the bike, but not impossible.

Do both timing chainrings have the same number of teeth, or do pedals go out of phase over distance ?

Are the chainrings in line? You might need a keeper on the front chainring - essentially a front derailleur mech that doesn't move.

Check for timing chain and chainring wear too - if its worn/elongated then fit a new 1/8" timing chain. Leave it too long and the chainrings will wear out as well.

1/8" chain will last much longer too, and will slip less because it doesn't flex left and right as much as normal 3/32" chain.


What to pay attention to when buying a used race bike

There are lots of bikes with skinny tires that aren't necessarily racing bikes.
As with any bike, new or used, you want to make sure the bike fits you. A bike that can be made to fit with new handlebars/stem/saddle might be worth it, but that's a decision you'll need to make.
Has the bike been well-maintained? Is there rust or corrosion on the frame or parts? Is everything tight that should be tight? Do all the rotating parts turn smoothly?
Has the bike been crashed? Is the paint basically intact? Is anything bent?
Possibly harder to determine unless you're knowledgeable about bikes, but does the bike have parts that will be difficult to replace if/when that becomes necessary? Sometimes there are evolutionary dead-ends in bike technology (although I can't think of many in recent history).
Most importantly, do you enjoy riding it? It's a good idea to test-ride as many bikes as you can to get an idea of what you like and dislike.

Even if the bike isn't perfect for you as-is, it may be close enough that with some replacement parts, it'll be a good bike for you. You'll need to decide how much extra you're willing to spend to bring it up to that level.


Shimano 3 Speed Internal Hub Gear on child bike popping chain on 3rd speed

Put the hub in each of it's gear selections ( esp the one where the chain falls off ).  Attempt to twist and push the cog.  If there is any play in either regard, that is probably your issue.  Could be adjustment of the shifter, but....


How to get housing seated into shifter barrel adjuster

I think that bit of plastic on the end of the housing is called the "ferrule".

If you have a spare and want to replace it you have to get the inner cable out which means cutting the cap off the far end of it (down by the derailleur) and pulling the cable out. Then you put another cap on the far end after replacing the ferrule.

The shifter end of the cable has a lump of metal permanently attached to it so it can't be unthreaded from that end.

I think it would also probably work fine to just clean it up as best you can and put a couple of drops of superglue between the housing and the ferrule. That way you don't need to take the inner out.


Do I need a bike bag / box to put my bike on the Eurostar?

That page actually lays it out pretty well. You have three options: box/bag your bike, pay £30 for a reserved bike space, or pay £22 to ship your bike such that it will arrive within 24 hours of you.

The reserved bike spaces and shipping don't require you to box or bag your bike.

When I traveled on EuroStar and on French trains, I had a friend handy with a sewing machine make me a housse out of lightweight ripstop nylon. By turning the handlebars sideways and removing the pedals and wheels I was able to get it mostly within the size restrictions - it was bulky but fit in the luggage area, which is all that matters. It was slightly longer and wider than allowed but no one checked.


You could do this with off-the-shelf reacharound brackets. You can also make them out of leftover rack upper stays or other flat strip metal stock.
The idea with them is you take a fender set and cut them where the fork crown and seatstay bridge are, so the fenders don't have to go under them or the brakes. Then you drill holes in the cut off pieces and bolt the brackets on.


Using non-Shimano link with Shimano chain?

In general a SRAM or KMC link for an 8 or 9 speed chain will work fine with a similar Shimano 8 or 9 speed chain.

If you are dealing with a 10 speed chain I believe you will run into a compatibility problem as one brand is sightly narrower than the other (I can't remember which way and I only deal personally with 9 speed or lower).

I've used a SRAM power link on a Shimano HG-40 for a while now with no problems.


The main limiting factor is chainstay clearance.  If your chainrings touch the chainstay it will wear and weaken and eventually fail.  So the first thing is google your bike frame and see what maximum size chainring its rated for.  Do this first.

Once you have that info, get onto Sheldon's gear calculator https://www.sheldonbrown.com/gear-calc.html  and play about with the numbers.    Will changing from 42 tooth to your maximum tooth give enough difference to notice?

Finally, print this PDF https://cdn.shopify.com/s/files/1/0230/9291/files/BCD_finder_tool_v2.pdf in 1:1 scaling, then put your chainring directly on it and see which BCD matches.
Note that 102 and 104 are very close as are 94 and 96.

Armed with those numbers then you can go shopping.  Make sure you fit a new chain (it needs more links anyway) and a new cassette.


How seriously should I take Fulcrum Racing 6DB tubeless tire compatibility warning?

I'll attempt to offer a bit more nuance than the other answers. On road bikes, the downside of a poor tubeless fit is that the tire could burp, i.e. you hit something and the bead comes loose from the rim momentarily, while you're at high speed. Given the high pressures involved, a burp could mean that you lose a lot of pressure instantly. This would mean a loss of control. On a gravel or cyclocross bike, a burp is never a good thing, but you shouldn't lose all your pressure, and moreover you're probably traveling slower and on loose (and softer) terrain. The lower pressures may mean that wider tires are inherently harder to burp as well.
Normally, I'd take a manufacturer compatibility list very seriously. Some examples follow. Note that this paragraph refers to hookless rims, which the OP does not have. Enve tested a wide range of tires on its current hookless rims, and they produced an explicit list, including tires that are specifically not approved, and another list that are specifically recommended for its wheels. Zipp instead says that tires must be compatible with hookless rims, and encourages riders to check with the tire manufacturer. They say that these tire manufacturers explicitly said to them that their tires are compatible with hookless rims. Continental, on the other hand, has explicitly said that the Grand Prix 5000 is not compatible with hookless rims in general, and thus Continental tires appear on Enve's not approved list. Cadex merely has a short list of tires that are known to have failed their testing (NB: they also have transitioned to hookless rims).
However, at least Zipp and Cadex appear to have tested a range of tires. Fulcrum's compatibility information is a lot more terse, and it's unclear if they even tested any manufacturers apart from Schwalbe. (NB: see @gschenk's answer; Campagnolo Germany may have told some German forum posters they only tested with Schwalbe.) Thus, I would assume that more tires than just Schwalbe are tubeless compatible on Fulcrum wheels. The problem is that we don't know which ones might fail. Riders should remember the very considerable downside to a poor tubeless fit on road wheels. Additionally, I personally use tires with latex tubes on the road. They provide similar rolling resistance benefits to tubeless setups, and they are actually more puncture resistant than butyl tubes. They are trickier to mount than butyl tubes and they do require daily inflation, but they enable you to forego the hassle of tubeless initial setup (albeit that's a once and done deal unless you change tires). Because I don't face frequent punctures, I don't see the benefits of changing to tubeless. If the OP does need that puncture protection, then at least Schwalbe is known to make good tires as well.
In contrast, you can sometimes ignore manufacturer compatibility warnings entirely. Campagnolo's (which is Fulcrum's parent company) component instructions frequently warn that mixing and matching with other company components can result in mechanical failures, and possibly even injury or death as a result. That warning is meaningless; I've used third party chains, chain quick links, chainrings, and cranksets, and even a competitor crankset, on a Campagnolo drivetrain. I've exceeded the stated rear derailer capacity for both Shimano and Campagnolo. Fulcrum's tire compatibility warning has to be taken much more seriously than Campagnolo's component compatibility warnings. The issue is that we don't know precisely how much more seriously, and it is difficult for consumers to find out which tires may be incompatible.


As recumbents are low to the ground and hard to see, how to you use one safely on a normal road?

Getting a high safety flag is common on recumbents (and trailers), at least in the US.

Photo credit


Loud cracking noise after installing new chain

My guess is you have some tight links that are making noise as they go over the sprocket. Those can probably be fixed easily.

See this Park Tool video. Tight links are addressed at about 10:35.

It might be that you did not join the chain links properly. What method was used to join the chain? A master link or rivet?

You can also see the chain tensioning advice in the Park video to check if that is the cause.


Do Left handed bikes feel different to ride?

Pretty much yes. Depending on quality and material of the cranks you might feel the slightest difference when engaging because the stiffness of left crank+sprocket isn't exactly the same as just right crank. But practically: yes, the same. And, pretty much the main reason left hand drive exists on bmx in the first place: with the advantage that if your prefferred grinding side is right there's less chance of ruining the sprocket and chain.

With regard to pricing/options: the vast majority of BMX brands today sell both RHD/LHD parts and do so for the same price. At least I checked the major brands on a couple of websites and found none which had different pricing and none which didn't offer both options.

Hubs usually are available as either LHD or RHD for the same price; in the production process there isn't anything intrinsically different apart from e.g. thread direction, and LHD doesn't seem uncommon enough to be more expensive due to lower demand. The so-called flip-flop hubs work both for LHD and RHD and are more expensive due to needing more manufacturing/material. Hubguards these days are non-threaded so the exact same for left and right, idem for sprockets and chains.

Most of the cranks sold today are symmetric with the threaded slot for the sprocket bolt available on both cranks. Which also makes sense because that means apart from the different threading for the pedals the production process for both cranks is the same.


Will 20 inch BMX wheels fit a folding bike (with 20 inch wheels)?

Thanks, guys, like you say "it depends". But those pointers allowed we to find the answer for my own case which is:
"Yes, if I get 3/8 inch BMX axles and bend (cold set) the rear frame or add spacers."
Axle Diameter
Cheap store-bought bikes like mine have 3/8" or sometimes 10mm axles, which are practically the same. BMX ones are either 3/8", or are 14mm, which is a good bit larger.
It's not quite game-over for the 14mm BMX axles though because some have flats on them so they fit 3/8 dropouts as well. If the axles are solid you can file the flats yourself - but a lot are not.
Opinion was pretty unanimous - do NOT file-out the dropouts to take he larger axle.
Front Wheel
The width of the road and the BMX axles are both generally 100mm so the 3/8" BMX front wheel often drops straight in.
Rear Wheel
The rear axle is significantly wider on a road bike - 130mm on the road vs 110mm on a BMX. The BMX axles might be over-length enough to fit if you put in a 10mm spacer each side. Or you can bend-in the rear frame if it is steel to take the narrower axle (cold setting).
Just want to reinforce that the full answer is indeed "it depends", and this answer is specific to for cheap store-bought bikes with steel frames.


With respect to riding in a group, or with more numerous riders closer to you than you are used to.

Be aware of the space around you
Maintain a safe distance from riders in front
Look sideways and over your shoulders before overtaking or maneuvering
When cornering be aware of riders to you sides and give them space
When slowing down, hold up a hand palm forward, or call out 'slowing' or 'stopping'

Common sense stuff really.


Can you run a standard tyre on a tubeless rim?

I've been waiting until I had enough time to give this a proper answer, because the answer to the question in the title is "it depends" and it's a very important "it depends." It runs the gamut from yes to absolutely not. I want to cover road bike tires here as well, as I don't want folks making the jump from "it's ok for mountain bikes" to "it's ok for road bikes." Cyclocross bikes sit right about in the middle depending on the pressure you like to run

For mountain bikes you can run just about any tire you want on a tubeless rim as long as you use sealant. There are some exceptions, as I covered in my answer here. It's also important to note that when you go tubeless you cannot run the high end of your tires' pressure range anymore. The wider the tire, the more this is true. Most folks have no intention of switching to tubeless and pumping their tires up tight, but then again you'd be surprised.

For cyclocross tires, pretty much everything above holds true, especially the bit above pressure. If you're considering running anything above 50psi you need to get a dedicated tubeless cyclocross tire. It's just not worth the risk otherwise.

For road, the answer is an emphatic, unequivocal no. You cannot run road tires made for tubes on a tubeless setup. Ever. They will blow off the rim, hopefully before you even get them up to pressure, and you will get hurt or killed. You can convert a normal rim to a tubeless setup with a kit, but you cannot run a normal road tire on any tubeless road setup. If you want to know why, keep reading...

The whole reason pneumatic tires work is because they're pushing outward on the wall of the tube or tire. PSI stands for pounds per square inch. I assume everyone already knows that but what some haven't thought about is that the term is pretty literal. For every 1 PSI you pump up your tire the air pressure inside is literally exerting a pound of force per square inch on the inside relative to outside atmospheric pressure. That's why if you're a 150lb rider, bike and all, and you have your tires pumped up to 100psi, you've got a grand total of 1.5 square inches of rubber making contact with the road (there are other circumstances to take into account here like casing and compound, but we wont nitpick material physics here). That also means that you've got enormous amounts of pressure trying to tear your tire off the rim in every direction. The bead on wire (non-folding) and kevlar (folding) beaded tires is ever so slightly stretchy. Not very stretchy, but just enough that neither type of bead will stay seated on the rim under the amount of force which the air inside of a pumped up road tire is exerting outward on the tire. Think about what a tube does when you over-inflate it outside the tire- it expands to a much larger diameter than your wheel. Your tire is doing the same thing on a much smaller scale. It's doing this just enough that a standard bead without a tube in place can climb out of the channel where it sits and over the edge of your rim, causing catastrophic results if you're rolling.

With a tube in place inside a rim, the air pressure pushes against the tube first which in turn pushes against the tire which binds the bead in place against the rim. The interaction between the tube pushing against the tire vs just air pressure pushing against the tire is a little different. The tube helps reinforce the pressure against the bead and lock it in place whereas air pressure alone is not enough to fight against the tire's need to expand in diameter.

So how do tubeless road (and "official" tubeless cyclocross) tires fix this problem? Instead of a kevlar or wire bead- both of which have a little bit of stretch to them- tubeless road tires use a carbon fiber bead which has virtually no stretch to it at all. Since they don't stretch, carbon fiber beads are not susceptible to the pressure inside the tire tearing them off the rim like a standard bead (I'll mention that road tubeless tires typically have a little differently shaped bead as well, but this is more to prevent burping when matched with an official road tubeless rim). This is why you can convert a standard road rim to tubeless but you cannot cannot cannot run a standard road tire on a tubeless setup, official tubeless rim or not.

The same problem described for road tubeless can apply to cyclocross or mountain bike setups if the pressure is high enough. That's why carbon fiber beaded tires are available for cyclocross but you can run a standard cross tire tubeless at lower pressure. For mountain bikes non-elastic beads just aren't necessary because no one in their right mind pumps a mtb tire up that tight to begin with- tubeless or not.


What's the best way to fix carbon to titanium?

There are many companies today producing "lugged" frames out of aluminum/steel/titanium with carbon fiber tubes.  Seven Cycles is one example, but there are others.  Additionally, some people are independently making carbon frames with lugs that have been created using 3D printer madness.  Reading various forums and the last link, 3M, Loctite and West System all make epoxies that would work for such an application.  Your best bet would likely be to contact the company and have them recommend which product would be appropriate.

All of this assumes that you are trying to lug a piece that will be under compression.  Lugged bicycle frames work because the triangle largely experiences compression forces which actually force the tubes into the lugs.  Forces acting to pull the tube out of the lug are more rare and the epoxy acts mainly to hold the setup together and isn't as "structural" (bad use of the term) as the lugs or tubes.  If this is not what you are trying to accomplish, you may look for a different solution since gluing/epoxying together two pieces that will be under tension will rely on the strength of the epoxy to hold them together and likely not be appropriate for the forces generated cycling.


Should I get a 18/25 tube or a 25/32 tube?

It doesn't matter.

The difference in weight is practically non-existent, and puncture resistance is a property of the tire.

You may be able to pack an 18/25 in your spare parts kit a little easier than the 25/32, but that still isn't much of a big difference.

Just get whichever is cheaper.


Doesn't look anything special - theres a one-piece crank, indicates a cheap low-grade bike.

The brakes are cantilevers which would be 90s at best.

The tyres will have been replaced at some time, so brand means nothing to the bike's model

The whole front wheel looks like its been swapped out for one of those hilltopper electric kits, which are not bad for a simple-fit kit.  Batteries tend to be expensive.

The whole bike looks like an overgrown BMX with a derailleur and rider bars with a reinforcement strut.


Safety guidelines when using MTB clipless pedals on a road bike

This answer is for SPD pedals, which are the most common MTB pedals. Other systems do not have multi release cleat, and some don't even have adjustable springs.

First: make sure you do not have multi-release cleats. They are designed to release when pulled up hard enough, and can be distinguished by letter "M" stamped to them. If the cleats are too worn to tell whether they have the marking, it's probably best to replace them anyway.

Second: Adjust the release spring tension so that the pedals are easy to unclip but not any looser. Too loose pedals may release unintentionally.

Third: If these do not help, it's probably time for new pedals.


Remote rising seat posts and heavier rider

Both seatposts you mention use an air spring, with a hydraulic release. There is no maximum weight listed for either one.

They are designed to use your body weight to drop the saddle when the remote lever is pressed, and to use an air spring to return it to full height the next time it is pressed. You need to be off the seat when the lever is pressed to return the seat to its normal position, regardless of your body weight.

In addition, I'm a big dude, and I have no issues with mine that are weight based. I wouldn't be worried about it.

The Rock Shox Reverb is a solid unit, and the crank brothers design looks to be as well, although I've only ridden the Reverb. The one issue I've seen is that the remote levers are exposed, and sensitive to impact. I've damaged mine by resting the bike on the handlebar to cha nge a flat, even done carefully.

Bright side is, parts are cheap and easy to find, and the bleed process is easy.

I do recommend the Reverb.


Have rollerbrakes a longer stopping distance than drum brakes?

In my experience roller brakes can be set up to lock up a front wheel, but it takes more lever force to do that than most other brakes. Many riders consider that a useful feature, but it's disconcerting if you're used to other types, which generally fall into the "lots of force and it still doesn't work" or "a bit too much force will lock the wheel"... roller brakes feel like the former but are actually the latter.

But most bike shops don't do that, and Shimano ship them from the factory requiring a very large force to lock the wheel. It's possible to adjust the brakes to require less force, if you find a bike shop that's confident working on those exact brakes. It is likely to require some asking around on your part to find that shop (realistically, the one mechanic who likes these brakes).

I'm a fairly strong guy with good grip strength and it feels as though I'm more likely to break the lever than lock up the front wheel. In reality though, actually testing this is hard because I had to sprint up to speed, then grab the brake lever as hard as I could, squeezing quickly before the bike stopped, to get the front wheel to lock.

I think that's actually a useful way for a brake to work - it's very hard to lock the front wheel even in a panic stop, because the bike normally comes to a halt before the wheel locks up. The problem is that not everyone has "big strong man" grip strength, so may find that the brake just doesn't work for them.

(full disclosure: I had one of these brakes on the rear wheel and did not like it. I wouldn't have one again if I could avoid it)


The squeaking is caused metal parts rubbing against one another, not by the spring 'jumping'. Maybe you mean the spring is rotating on the shock body as it is compressed and uncompressed?

Adjusting the suspension is not the answer to getting rid of the noise, if you did the noise would probably still be there.

BTW, the adjustment you are talking about is the preload of the suspension spring. Here is a question about that (for forks, but the principle is the same).


Why are tubeless tyres popular in mountain biking?

Although this is purely anecdotal, I know from my own experience mountain biking that most of my flats were from so-called "pinch flats" (where the tube is pierced by pinching or friction with the tire/rim rather than piercing by an external object). This was highly annoying. After having switched to tubeless some years ago, I've not yet had a single flat. And, obviously, without a tube to get pinched, there's no way to get a "pinch flat".


Gear Inches Optimal For Steep Hill Climbs

There are many factors involved in working this out, which is why many people would say this is opinion based, and others say

  What's "optimal" is whatever works for you. – Daniel R Hicks Sep 21 at 1:43

The main factors are

your strength
your weight
your muscular endurance
your aerobic capacity
how fast you are trying to go
what gear you're using
how steep is the hill
how long is the hill

With so many factors Daniel's comment is not surprising, and is actually pretty accurate.

Looking at various online sources, in general the cadence to aim for is at least 70 rpm. This probably higher than you're using; many of us climb at 50 to 60 rpm, which is hard on the knees.

To follow this advice you need to measure your cadence. You'll need a bike computer with a cadence sensor. Then climb the same hill multiple times in different gears, keeping track of your cadence and the time taken. Do the experiment at least twice to reduce the effect of random variations and the effect on your performance of training. An app such as Strava can do some of the record keeping for you.

Next make a plot of the times. Such a plot can show surprising things, but it will give you some knowledge about yourself. It may answer your question about gearing. If, for example, your times keep getting better as you go to lower gears, then you could benefit from having gears that are even lower.

The next experiment is to ride hills that have different gradients, in the same gear for all of the hills. Keep track of the time and cadence again, and make another graph. It may seem that this will give the same results as the first experiment, but in practice it does not; it gives you more information. An important point here is to include hills with a lower gradient (even as low as 3.5 to 4%), they give you a greater range of gears you can use, and are good for training on.

What to do with this information?

If your cadence is below 70, work to improve it. You can do this by riding less steep hills, faster. Also look into interval training to improve your strength. These approaches can avoid spending money on components that will only give benefit in the short term.
If your times keep getting better in lower gears,  then spend the money on getting a cluster with bigger gears at the low end. Make sure your derailleur can handle the extra range before you do this. If it can't handle the range then you'll have to decide whether the extra cost is worth it to you.

If you look back at the variables listed at the top of this post, you'll see that every one of them can be changed. You can choose a different hill, with a different gradient. You can build up your strength, reduce your weight, build up endurance and aerobic capacity, choose a different pace, and choose a different gear.

By keeping track of your performance, you'll get feedback on how you're going. How it feels is not generally a good indicator of performance; I only ride by feel these days: sometimes I think wow, I destroyed that hill only to check the time and find I was way off my PB. Other times I've thought Uff, that was a struggle and found that I was minutes inside my PB.

In general, we get better power, and hence speed up the hill, with a higher cadence. But this is not true for everyone, as at least one of the linked articles will show.

As you develop, you will need to use different approaches to get improvements. Professional coaches frequently seek to introduce novelty into the training they give their athletes, so that the athlete has a new challenge, or training stress. It's when your training provides a new stress that your body responds with new growth. So when your improvement plot reaches a plateau, make a change. Instead of cadence, work on strength, or a different gradient, or shorter climbs.

Happy climbing.

Ps. I left out one important way of getting stronger and faster: ride with someone who's a bit faster, or chase someone who started a little before you. A little competition does wonders :-)


Does the valve have to be straight when replacing a tube?

It should be straight out, perpendicular to the rim. Otherwise you risk damaging the tube.

When the valve stem is at an angle the valve isn't free in the hole – it is trapped by the edges of the hole where they bind the stem. The edges of the hole may cut the stem which will be moving a little bit as the tire and tube flex over bumps and the like.

There will also be an area of the tube that isn't supported by the rim (or that is stretched more than the rest of the tube) near the valve stem. That area is likely to be a weak point in the tube.

And one more thing! As pointed out in the comments below, there are conditions – such as the tire moving on the rim – that are likely to further stress the tube as it passes through the valve hole. If the valve is initially straight any angle of the valve is an immediate sign that something is happening.


Possible issues (probably not a complete list - things I've seen)

Dirty rims - if the rim does not provide a consistent friction surface (there is dirt that makes one part too sticky or too slick - brake pad residue etc.) you will not get smooth braking.
Dents or blips in the rim - if the rim is wider or dented in some places it will affect braking smoothness.
Dirty brake pads - may not affect smooth braking but clean pads will improve general braking.

I'm sure others will have suggestions.


Bike Rack from Apartment's Underground Carpark Removed - Is building management liable?

If you are insured make an insurance claim and they will follow up on any legal liability someone else might have, but you get a replacement bike quickly.

If you are not insured, you are in a lose/lose and maybe lose some more situation. You can accept that your bike got stolen and get on with life. Or you could sue a large property investment company and spend the next few years in a legal battle you cannot afford to lose digging a deep hole that is only getting deeper. Regardless of legal liability, the cost means they will laugh at you with the response "My pockets for legal fees are deeper than yours, see you in court and raise you costs". Given the risk they will win, and seek costs against you, they don't really care about how much they spend winning because you pull out - and when you do, they will seek costs anyway.

The only realistic option is ask nicely, or if your country has the concept of a small claims tribunal where you can bring a claim without paying lawyers.

As far as answering your question - apart from the fact that would be providing legal advise, its not answerable without seeing your contract and knowing what part of the world you live in.


What are the most important things to bring on a ride?

A mobile phone. These days, irrespective of where you're riding, what you're riding and over what terrain or distance, there's no excuse for being deliberately out of contact. We can't guarantee being in an area of reception, but if you haven't got a phone you'll never know.

Additionally, a huge benefit of smart phones are the apps that can do more than just call for assistance. e.g. I have an app which lists all bike shops in London, with maps, reviews and opening hours. A couple of times I've been stuck in the middle of somewhere unfamiliar and in need (after the second puncture of the day without a second spare tube): fire up the app, where's the nearest open shop and then it can lead you there.


The hub likely needs normal maintenance. The kind of noise and drag you're getting is fairly normal when these need lubrication. Hopefully it hasn't gone so long it's been damaged. Play developing also implies needing overhaul.

Shimano 7 and 8 hubs come apart in layers. The first one is pulling the core of the hub from the shell, which allows you to tank it in an oil bath and grease the bearings as indicated in the product manuals available at si.shimano.com. This constitutes normal maintenance and needs to be done for the hub to last. It's not super technical, maybe approximately on the level of overhauling a cup and cone hub. In some regard it's easier because all the small stuff stays together as a unit.

The second layer is taking apart the hub core into what you could call its subassemblies. You can grease some things that would normally be oiled by doing this, and some are advocates of doing that for weatherization/local climate resistance purposes. The other reason to do it is to find and replace broken things that can't be seen or accessed otherwise. The second layer is more technical than the first. You mostly just need to go slow and keep things in order; it's not fidgety or difficult to figure out, and it only really goes together one way. Shimano does publish procedures for this.

I can't see the wobble you mention. If it's looseness coming from the hub bearings being loose, you'll be able to adjust that out at any time as a regular hub adjustment. If it's coming from elsewhere, that would imply something being broken as well as I can figure, and you might need second layer type service to figure out what and whether there's a replacement available.

The dealer manual files for your model will let you know what special tools are needed, cone wrench sizes etc. Substitutions for the proper Nexus/Alfine disassembly tools and how prudent it is to go there is a whole other conversation. Same with substitutions for the Shimano hub bath oil and Nexus grease. My station in life has me always and only using the Shimano products so I don't have a ton of opinions there. The oil is expensive and intended to last many, many hub dunks. Many on the internet report success using gear oil instead.


Are Merino cycling boxers/cycling pants worth the cost?

Those merino boxers you linked to aren't cycling nicks, they're just
  underwear. You'd still have to wear somethign over the top of them. If
  you're spending any time in the saddle I'd suggest a proper pair of
  cycling nicks - with a chamois. That said, I got some cheap merino
  thermals at Aldi, and they're great. Warm in the wet, but not sweaty
  like lycra. You can even machine wash them.

I accept this comment, to get this question away from unanswered list. I will remove this if the original commenter makes the comment as answer. I think the comment/answer is good because it cuts the marketing facade into issues such as proper pair of cycling nicks (with a chamois) and machine-washing -- and needless to get some XYZ -branded merino [wf]-ools, even discounters offer proper ones.


Barrel adjuster cable housing sticking out, why?

Should the cable be able to come out of the adjuster like this?

No, definitely not. It's a dangerous situation as the brake lever now cannot pull the cable inside the housing - the housing will just be pulled back with the cable and teh brake will not be engaged.
Either the cable is much too loose which has allowed the housing to slide along it, or the housing has come out of a stop on the fork (or the frame for a rear brake). Check the run of the cable and make sure it is inserted into any stops or the brake caliper itself properly.
Mechanical disc brakes can be tricky to adjust if you are used to rim brakes. The barrel adjusters are not used to adjust the position of the pads, adjustments must be made on the caliper to do that. Using the barrel adjusters can lead to a dangerous situation.
This Park Tool video shows how to properly set up and align mechanical calipers. The cable set up starts at about 3:39.


Can we use Shimano XTR 2x11 speed shifter with Shimano 2x11 Dura-Ace RD and FD?

Shimano 11 speed MTB and road derailleurs and shifters are not compatible. The cable pull per shift and derailleur actuation ratios are different. See this Art's Cyclery page](https://www.artscyclery.com/science-behind-the-magic/science-behind-the-magic-drivetrain-compatibility/).

The MTB groups use a longer cable pull to be more reliable in dirty conditions.

While rear derailleur cable pull/actuation ratios are well documented, front ones are not, but I have to assume 11 speed MTB and road groups use different pulls and are not compatible.

MTB double cranks typically have a 10 tooth difference between rings whereas roads cranks have a 16 tooth difference. Cages on MTB front derailleurs are therefore smaller and will not work with road cranks.


What is the weight limit for a Cube Aim Pro 2021?

From personal experience: The #1 thing you're going to 'destroy in like a month of riding trails' as a heavier rider is the rear wheel.  As soon as one spoke gets a bit out of tolerance the whole thing starts to come apart and go wildly out of true very quickly.
The frame might only last 7 years instead of 10, maybe crank arms and spindle will wear out in 3 years instead of 4 etc etc. but it's almost certainly the 32H rear wheel that is driving the uniform 115kg stated rider+bike limit across the entire product line of different types of frames.
A mid-range Cube would seem to be in the range where it's "worth" upgrading with a sturdier 36H wheel and would still come out cheaper than a specialty bike like a Surly that comes with them standard.  (and one assumes decent wheel builders aren't that hard to find in the Netherlands...)
(You may also just get the stock wheel re-laced with sturdier spokes, but if you're paying all that labor to have it re-laced anyway, the hub and rim aren't super expensive...)


Can I replace an inner tube with a Dunlop valve with one with a Schrader valve?

Answer: Yes you can.  Woods/Dunlop valves have a nominal hole size of 8mm, identical to a Schrader/Auto valve.

For completeness, a presta valve uses a 6mm hole.

Reasons not to - authenticity of an antique bike, or maybe having to carry a second pump head/fitting if both tubes have different valves.


Late 90s mtb with shimano ig chain, trouble buying cassette

Every currently produced 7-speed cassette you can buy, which all have Hyperglide-style ramping, will be fine with your KMC Z8.1 and all the other currently produced Shimano, SRAM, and KMC 7/8-speed chains. You should buy whatever appropriate range 7-speed cassette you can get your hands on.
Shimano called out various incompatibilities involving HG vs IG chains. The third-party makers just say their chains work with both. (You can probably find some exception to this if you look back far enough). I've never had an issue dealing with the HG vs IG question by just putting a SRAM or KMC chain on.


General Principles. If you have too much weight in back, the front wheel's contact on steep uphills can be a little bit light, and your odds of pinch-flatting the rear tire can increase (especially if you are running skinnier tires relative to the load), or breaking spokes, because it already carries more of your body weight than the front. If you put too much up front, low-speed maneuvering can get a little more tricky because the handlebars have so much mass/inertia, and also it will alter the handing even at other speeds in a way that may take some getting used to. For typical riding, I doubt it is going to make much difference unless the load is really uneven. Maybe 70/30 or 60/40 weight bias towards the rear is what I've done.

Ease of Access Also A Consideration. I've found it to be more important to arrange things primarily by ease of access, with weight balance the secondary consideration.  Gear that you use only at camp goes in my front duffel or at the bottom of the panniers or seat bag. I end up using my tangle bag as a buffer space for food, an extra layer, paper maps, or whatever other stuff I need to access frequently while riding. Top of panniers for occasionally-during-the-day-access items.


Between BMX and mountain bikes I've fallen quite a bit over the years.  If you're getting bad speed wobbles then there is something not right with your bike.  I've never seen anyone get speed wobbles on a rocky course.  If you're going fast enough on a rocky course that this is a risk you should be wearing at a bare minimum a full-face helmet.  Shoulder guards wouldn't be a bad idea either as would shin/knee combos and elbow pads.  Get a helmet, get safety gear.

The worst crashes I've seen have always been when the person doesn't see it coming, and you're probably not going to see it coming.  Popping a wheelie and landing on your back is known as looping out.  Even if you land on your feet, at speed you're going to mess yourself up anyway.  Don't do it.  I might try locking up my back brakes and skidding sideways, but that's still really sketchy and a desperate measure.

When it comes to crashing there really isn't definitive answer, and you really must use your best judgement.  You want to stay loose and judge the situation in that split second before impact.  Screw the bike, save yourself.  It's better to get road rash than to hit a semi/boulder/tree.  Be aware of the worst hazards and TRY to choose the lesser of two injuries.  Remember that if you're going fast enough that speed wobble is an issue, then losing control of your bike is one of the worst things that could happen.


How do I choose a replacement Derailleur?

Let's say that your new derailleur is dependent on the number of gears you have on the back and sometimes brand dependent. SRAM and Shimano, have (they used to have at least) different pull ratios and/or inverted numbers (which is not a problem, only a funny fact), so this are the first thing to check out.

Then as you said you do DH, so you need in my opinion a short, or medium length derailleur; so it doesn't bounce that much and also to have a little more clearance for obstacles.

That said there are some derailleurs that have clutch systems so the cage won't move as you hit bumps and obstacles, for a more consistent pedaling.

If you have the money go for a Shimano Saint, Hone or SLX. Then again if you don't have it, go for a Shimano XT 98. If you have a small ratio transmission in the back (tooth count doesn't differ that much from gear to gear) you can get a away with a derailleur made for road bike, small and light.

PS: You can get your old derailleur straight with the use of two french-wrenches (crescent wrench), one to set the direction to bend and the other to apply force to the first one.

Cheers.


Can I replace my mountain bike's back wheel quick release?

Yes. There are many, many products exactly as you describe, with mechanisms ranging from simple hex keys to actual locks. A web search for "theft proof quick release", "anti theft skewer" or something like that should find some of them.


If you are building your own kit, you can do whatever the heck you want. The reason pre-built ones have them is both safety and convenience -- you want to know when the e-assist is on for safety reasons, what power mode you're in, and how much power you have left so you're not stuck on the road.

Without blinkenlights, it can be hard to diagnose problems, especially on the road. Is your e-assist not working because the battery is low or dead? A bad main power connection? Maybe the brake-cutoff switch is broken, etc. etc.

If you are aesthetically against the blinkenlights, you can design your own enclosure that is more modest, use dimmer LEDS or tape over them, or relocate them to make them more discrete -- perhaps under the saddle where you can still check them when problems arise.


Is it worth getting a suspension seat post as a cheap alternative to full suspension bike?

You might find a suspension seatpost to be comfortable, but a suspension seatpost is not a substitute for a full suspension bike.  The purpose of a suspension seatpost is purely comfort (though as mikes mentions, not everyone agrees that they achieve this goal), where as the purpose of a full suspension bike is first and foremost control.  Suspension on the wheels helps them stay on the ground over rough terrain, which a suspension seatpost will not do.  Any extra "comfort" is simply a side benefit.

If you're looking to smooth out your ride, the #1 thing you can do is lower your tire pressure.  You will lose some efficiency when the ground is smooth, but if you're already riding 145 on a bike with a front suspension, I suspect efficiency isn't your top concern to begin with.


Tyre popped when going from 26 x 1.95 to 26 x 2.125

I would say, you just didn't put the tire on well. When you inflate the tire to half its recommended pressure you should check that the tire seats well for the whole diameter around the rim on both sides. If it came out even a little, push it back in (may require some deflating). Otherwise the pressure may push the tire out like you had, and then the tube can explode.

For your questions: both the tire and the tube can be used again. But check accurately that the tire's bead is not damaged.


Why did my valve pin bend? Is there anything that I can do to help it without any specialized tools?

You have a Schrader valve. The pin on the valve core has been bent or the core is cross threaded in the stem - the picture is a little blurry.
You can remove the core by unscrewing it from the stem. There is a special tool for that, sometimes skinny needle nose pliers can be used.
Here are the options I can think of:

If the pin is bent or the threads on the valve core are ruined you'll need a new valve core. The shops I've worked at would replace it for you for free.
If the core is cross threaded you may be able to remove it and thread it back in straight.
If the threads inside the valve stem are ruined you'll need a new tube.

Hard to say what caused the damage but it's probably related to something getting cross wise during inflation. A bent valve core pin is unrelated to road types or number of miles.


I don't read French, but it is clear that the Mavic Aksium wheel you linked to has thru axle fittings: it stated that it took a 12x100mm front axle and a 12x142mm rear.
The Surly Straggler fork you linked to is for quick releases only. I believe this line:

Système d'axe : réglage rapide (9 x 100 mm)

Was saying that the fork used quick releases. For sure, 9x100mm refers to quick releases. There are no thru axles with 9mm diameter. Also, the dropouts in the fork have openings at the bottom, to let you drop a quick release wheel out. TAs need to screw into a hole on one side of the fork, so TA forks have closed dropouts.
On Surly's website at least, one easy way to tell if the fork is for thru axles is that they picture it with a thru axle screwed in, e.g. this pic of the Trucker fork: (note, link goes to the US website)

It's also worth mentioning that the Straggler fork you linked to was for International Standard (IS, usually called post mount) disc brakes. Current drop bar bikes use the flat mount standard, although some older ones (around 2014-2016, I think) may have been for post mount brakes. Just make sure the brake system is correct for the rest of your components.


What are the most important accessories for a new biker to get?

bike
helmet
lock
puncture repair kit or spare tube and a mini pump
multi-tool
lights
first-aid kit


I would use the same techniques as used on rusted hardware. Liberally apply a penetrating oil (liquid wrench, PB Blaster, CRC Knocker Loose). Use a penetrating oil not a lubricant to break them loose. With the nuts being so small you can soak them in a small container for several days. Then hold the flange with pliers while turning the nut with a wrench.  Once it is freed up I would apply either Never-Seize or a dab of grease that will keep the water out and rust from forming.


It's safer and way easier just to buy another MissingLink (KMC's name for their master link design) of the same type (pin length) the chain came with, leaving you with an inner link that has one on either end. They're around $2US.

In addition to saving the trouble of getting the pin back in there, there's also the question of the integrity of modern outer chain links once they've had a pin pushed back through, even in the more normal circumstance of pushing a link halfway out for chain removal. Every current major manufacturer of derailer chains except KMC says not to do this, due to the risk of the fit not being as tight after re-insertion as it's supposed to be. I've long wondered whether there's actually anything different about KMC in this regard, but I know that modern chains in general are prone to breaking, usually during hard or fumbled front shifts, when they've been reconnected the "traditional" way. I wouldn't venture to guess what the odds are of it happening, probably quite low, but putting in another MissingLink eliminates the risk. They're very trouble-free. Having a couple close together may seem goofy but doesn't cause any issues in practice.


Aesthetically, it's just a case of keeping it clean. Use a toothbrush to clear accumulated dirt out of the little nooks and crannies, like the joints between tubes (especially around the bottom bracket). Waxing the frame can help keep that brand-new lustre.

The back of the chainring and spider, sprockets, rear hub, and dropouts, can get grotty pretty quickly, so use a gentle degreaser to keep on top of it. Same for the chain. Use a brush to get all the little bits of road dirt out of the links, then, with a clean brush, apply oil liberally. Brush it right in there. Wipe off any excess afterwards. As far as the feeling of mechanical "newness" goes, a clean, well-oiled drivetrain is the biggest contributor IMO.

Edit: Bike cleanliness pr0n