Why do bike tires suffer from frequent punctures whereas car tires don't?

The main reason is that bicycle tyres are much, much thinner than car tyres. A little tetrahedron of broken glass or a drawing pin that would puncture both tyre and tube on a bicycle won't trouble a car's tyre in the slightest.
A secondary reason is that bicycle tyres with tubes have additional ways to suffer punctures: an under-inflated tyre is susceptible to pinch flats.
It's pretty much as simple as that.


How can I gauge what angle I can safely ride at on a downhill curve?

Focusing on the strava bit - its a screwed up strava track.  The track shows they flew, and strava's point-grabbing routines have gone wonky.  Short answer they did not do it in 11 seconds.

They are bike rides though - just a fortuitous error on the GPS signal makes it look like they were faster, and much more direct.  I suspect there's some obstructions in the way (like a big `merkin freeway bridge thing) that are capable of interrupting and limiting GPS positional signals.  So when they get around the corner and get a better fix, it looks like they've gone really fast.   Its happened to me elsewhere.

There are no easy fixes.

You can flag the whole ride, which is somewhat draconian.
You can go out and ride faster again (you've tried, its really hard)
They can crop that piece off the end of their rides (but its in the middle for both top riders)
They can use something like SNAP (strava needs a polish) at http://strava-tools.raceshape.com/snap/  to generate a "polished" file to re-upload and delete the original.  (image below)
You can tell strava to only show your own results in the preferences, and stop caring so much about KOMs.   Remember you're only competing with yourself, despite what strava imply, so its your own results you want to beat. I've got some KOMs, and they're not that special.  Seeing my own improvement over time, that's special.

Here's a pic of SNAP showing the sugested tweaks for the KOM holder's ride


Are tubeless mountain bike tire systems appropriate for winter riding?

All of my winter rides are tubeless now.  I have successfully used tubeless setups with Stan's at -40F.  Many other riders in my area have used them extensively and without issue at temperatures well below zero.  Stan's happens to be the fluid used by my LBS, but I am sure there are others that work as well.

The hard part is getting the initial seal to work properly on fat tires.  If they don't fail on the initial ride, they are just as reliable as in warmer temperatures.


Is it normal for seat stays on new CAAD12 frame to be slightly warped/not straight?

You are concerned that something is wrong with the frame.  You can check the alignment by getting the Park FAG-2 alignment tool or, and it comes to the same thing, measuring to see if the distance to the seat tube is the same on both sides using a string - a string test.  If you feel uncomfortable running a string from the rear dropouts around the head tube and measuring the distance from the string to the seat tube on both sides, then get the Park tool.  Otherwise, run a string and measure.   If the measurements are identical, then the seat stay "warping" is purely cosmetic - the frame is properly aligned.  If the frame is off, then you are warned not to try cold setting thin aluminum tubes.  I have to admit here that, if I got a really good deal on the frame and it was only off a little, I would be tempted to correct it.  See the Park FAG-2 link for other ways of dealing with it in case you find that the frame is off a little.


If you were going to only add one set of cyclo/interrupter brakes to your drops, I'd add them to your front brakes:

Front  brakes are more powerful and provide almost all of the braking force in emergency stops (i.e., you apply so much braking force you are almost in an endover situation).
Rear brakes skid out more

So assuming your hands are on the tops of the bars when that car pulls out in front of you, you want the set of brakes that actually work to work when you squeeze them.

The cons are that if you're a newbie, the front brake is harder to modulate. The easy solution is to gain more skills in that area.

The other con is that Americans inexplicably have the front brake on their left hand. You can easily (on many bikes) flip the handedness so that your dominant hand (usually right) controls the front brake. I flip all my brakes (right-rear) because I'm used to riding a motorcycle.

p.s. This photo shows an interrupter on the right hand side going to the rear brakes.


Custom/modified Drivetrain 2x/3x Considerations and Planning

In my reading of your question, the big limiting factor is the 29x3. Your question isn't just about what FD/chainring jump hacks function and how well, but also of those which will also work with your clearance needs. The answer to that question is generally not very many, but it's going to depend on the chainstay length of the frame in question, whether the cranks are boost, etc.
Contemporary double MTB FDs of the dainty, short variety that are made to give as much clearance as possible do not play nice with hacking the jump that much. I don't have a ton of experience doing it, which admittedly is what your question is driving at, but if you look at one you'll see that their total top-to-bottom cage space is limited and the contact points for the chain are not large. Maybe you can get it to function okay with 2t extra jump, maybe not.
What always works is just going with a larger cassette range than the total capacity of the RD can handle and accept having a slack chain in some small-small gears. This has been the standby approach to cheating the range on derailleur systems forever and it applies here just the same. Then you're not forever playing games trying to make a front derailleur make a shift it wasn't designed to.
Don't discount just going Rohloff. At 526% the range isn't quite what you're looking for, but obliterating all clearance problems forever is huge.


120 mm fork with a frame designed for 100 mm fork?

Before starting, your fork looks pretty nice. Are you sure you can't send it to FOX and rebuild it? Why do you say it is ruined?
About the fork size, please check the cube FAQ:

CAN I INSTALL FORKS WITH MORE TRAVEL AS PROVIDED IN THE STANDARD EQUIPMENT?
NO. The installation of a fork with more travel will void the warranty. The bike geometry will be changed in a negative way, which leads to a different handling of the bike and can damage the frame permanently.
It is also not approved to install double bridge forks into CUBE bikes.

If your bike is still under warranty, I don't think it is worth it. If it isn't, it will for sure put more stress on the frame but I don't think it will brake. This depends a lot of your weight and ride style, and keep in mind Cube says not to do it, so it is your entire responsibility. I wouldn't do it.
I am pretty sure you can change your suspension between 80, 100 and 120mm of travel. Please check here. Rock Shox has really good manuals so you might even be able to do it yourself, otherwise take it to your bike shop.
Changing a suspension is simple, if you have the patience and the time to learn, and you just need one or two allen tools for most of it. However, sometimes taking the bottom part of the headset from the old fork is a pain. Search on youtube for fork replacement. If you feel like it, I think you can try and if something goes wrong take it to a shop in pieces. They will figure it out :)
Before buying, confirm with the seller the fork will fit the frame, specially if it is an used fork he might have shorten the part of it that goes into the headset and it's shorter size might not fit your frame or your favorite stem position.
IMPORTANT: Please see @mikes comment below.


Why are my pedals not in the correct position

Because they are installed wrong. You can remove one crank using crank puller and install it in correct position, or take it back to shop.


Can I do brevets (long distance rides) on my hybrid bike? If yes, how to start?

This question gets asked quite often. The short answer is that you can do long distance rides on basically any bicycle as long as it’s comfortable for you.

There are a few things you can do to your bicycle to make it more efficient and easier:

Make sure your seating position is good. Especially that your saddle is high enough. This will improve power output and reduce risk of knee pain/injuries.
Reduce air resistance by lowering the handlebar.
If you have front suspension, lock it (or get a rigid fork).
Wear tight fitting bicycle clothes.
Keep it well maintained.
Get road bike tires with low rolling resistance.
Get clipless pedals and shoes.

In the end the most important part will still be training. Training for long distance rides basically boils down to riding a lot. During long rides nutrition (and of course hydration) is also very important.


Lock related

Have a better lock than the bike next to yours.
At the very least get a lock such as this one: http://www.bicycleworkshop.co.uk/products.php?plid=m2b1s93p186 they are relatively difficult to break and are easy to operate meaning you'll lock your bike as a matter of course.
Don't use a cable lock. Bolt cutters snip them in like 5 seconds.

Location

Use a U-lock or solid chain lock (links thicker than 12mm) to attach your bike to something, but (and this is important) never lock your bike to something that would make it inconvenient for someone else.
Lock the bike to something solid.
Never leave your nice bike outside overnight or for extended periods of time during the day (but you're already doing this because you don't want to leave your precious bike out in the rain right?).
it should be in a reasonably populated, busy area
if you park in one area frequently, try to move around a bit - thieves might notice a decent bike often in the same place

Bike Tips

Get a cheap, ugly secondhand bike for city use.
Get allen key skewers as opposed to quick release
Keep your lights and/or cycle computers with you, not on the bike


Others have mentioned good tips about position, but I thought I'd add a few things other than that which I find helpful to reduce lower back pain:

I stopped carrying any sort of bag on my back (no matter how seemingly light!) and switched a rack with panniers
I stretch after riding, focusing particularly on my lower back (obviously), but also my buttocks and hamstrings, since having these tight can lead to lower back pain.
When I'm getting back into commuting after not riding for a while, I give myself more recovery time between rides to gain strength. In other words, don't start from zero biking days to biking every day and expect to not be in pain.

I've found that these steps have largely eliminated the problem for me.


If its unopened you might be able to take it back to the shop and swap for the right size, but the difference between 2.125" and 2.175" is 0.05" which is only 2.3 % smaller so it would probably work fine.

There may be a bit more tube than you strictly need, and this could make pinching the tube easier when fitting it, so do take care.

Otherwise, a tube is probably one of the cheapest parts on a bike, and buying another won't break your wallet.


Keeping the bottom of your legs warm in very-cold-weather biking

I would suggest shoe covers, which look like a boot and cover the ankle.

Or wear mid-calf or knee length socks and roll the upper part down for double or triple coverage on the ankles.

Or, mini ankle warmers :-).

Pics of my Pearl Izumi MTB overboots. The sole is exposed so walking is possible. (Not a product recommendation, just what I happen to own.)


Single wall rims on disc brake wheels aren't especially any more problematic than with a rim brake. It's a pretty cynical way for bike manufacturers to allocate parts dollars, so thankfully it's not super common.
Putting a single wall rim on a cargo bike is a bad idea though. Single wall rims are far less structurally efficient than double wall, typically manifesting as being less rigid and able to support less spoke tension. (Specimens do exist that go the other direction and are strong but very heavy.) Typical singlewall aluminum ATB/hybrid rims can't really be built to more than about 70 kgf before buckling in the stand or having major fatigue problems, compared to 100 minimum for even a basic double wall. That's a massive difference in strength. Also, 25mm external is very marginal for a 60mm tire.
A Rhynolite or Rhynolite XL is an okay choice, but the world has moved on from the days when they were a great choice for something like this. They're not disc-specific, and you do get extra strength for the weight out of a proper disc-specific rim.


Should I rather treats single spots to conserve the original paint or go for a repaint with a restoration project?

Answering your numbered questions first:

Will the rusty/blank spots be a functional problem down the line?
A: Bare steel will rust. It needs to be covered in some way to prevent corrosion.

Will power coating work well with the steel frame?
A: Powder coating is an option that will work well on a steel frame. Here is a Sheldon Brown article that talks about the work involved in a full paint job and the different methods.

Is it possible to treat all the small spots where the paint came independently to preserve "the original"?
A: Yes, it is possible to touch up problem spots, protect the bare steel and look nice. Here is a link to a professional bicycle frame touch up expert (not a recommendation) to illustrate what is possible in the world of touch up.

Full repaint or touch up? It depends on your preferences.
When making this decision keep in mind that no matter what you do a bike that is ridden will get scratched - it's inevitable.
Here are two ends of the decision spectrum...

I'm trying to maintain the originality of the bicycle as much as possible - touch up.
I don't care about originality and I'm willing to do what it takes to get a fresh paint job - full repaint.

In my mind a full repaint is a last resort.

It's time consuming and difficult to do right on your own.
It's expensive to have someone else do it for you.

Looking at your pictures my evaluation is that you can do some touch up / spot paint work and remediate most of your issues.

I would not repaint the fork end. The paint will be scratched again when you put the front wheel on. At most a clear coat.
the brake bridge is bare steel so it needs to be protected but it is also hidden so a clear coat would do the trick.
Drive side chain stay is a candidate for touch up. Or, possibly a chain stay protector.


What is a good way to mount / secure a regular backpack, while commuting?

Option 1

Your bike has a parcel rack on the rear - I'd suggest exploring modifications to that rack to hold your existing backpack more securely.

Bungee cords are good because they have tension, holding the hooks on.  And the length will somewhat adjust for bigger or smaller loads.

Downside - they do slip and move under vibration.

Answer - either make or buy a mesh of bungees to hold your existing bag on top of your rack.  Something like this:

I'd secure the rear edge and one side to your rack and organise the hooks so they secure to your seatpost, and to the other side of your rack, forming a nice mesh.  Each hole should be too small for your bag to slip through even at full stretch.

The shoulder straps on your bag may hang off the side.  Just position it so they don't.  If the straps hang through the structure of your rack then line the underside of the rack with some firm PVC scrap plastic (also, that's a decent mudguard too.  Or you might want to drape the shoulder straps over your seatpost before securing the mesh down.

Perhaps use carabiners instead of bent wire hooks, for added security.

Option 2

You have a rear rack, but its not good enough.  Use the rack to carry a cage like this:

Picture shows two, but you could easily just ahve one rack on whatever side you prefer.  The pictured bags aren't required either - they're more for grocery shopping.

Advantage is that it takes a heck of a bump to throw something up and out of the cage.   They will also "concertina" when empty and take up much less space.  Also good for keeping long skirts out of the rear wheel!

Downsides are added weight and they're not rated for heavy loads.

Option 3

You have a rear rack, why not add a matching front rack too ?

This shows a front basket on a rigid MTB.  These work well and can carry a lot more weight because of the bottom struts.  A bike with front suspension can't carry as much cos the struts would change length.

Advantage, your stuff is right there in sight at all times, its not going to jump out of the basket, and also you can access it easier.

Downside, the handling of the bike might change - it depends how close you can get it to your head tube and how long your stem is.  Plus the brake cables can sometimes foul the basket.


Is it possible to buy a frameset from Trek that isn't listed separately?

No, Trek will not sell you just the frame if they don't offer it in their product lineup. And a bike shop wouldn't either, given that they have to buy the whole bike anyway. It's just a massive headache to allow things like that for manufacturers. And many manufacturers generally aren't all too keen on letting people sell their bikes online (accessories are fine to some extent).

Moreover, why would you put Di2 on a crossrip? It's frame isn't designed for it (e.g. mounting the battery), and its quite low end compared to what people would run Di2 on (a Di2 groupset costs more than most of the crossrip models out there, as complete bikes!)


How does waterproof rating translate into rain intensity?

This isn't really cycling specific, but I'm not sure it's worth migrating to Outdoors.

  What does pressure have to do with rain intensity?

The rating is indeed from the hydrostatic head test, and doesn't translate directly into rainfall, but there are approximate conversions like this. The conversion is indeed related to the average peak impact force, but it's probably a fairly rough heuristic rather than a formula, and it doesn't directly address issues like whether the seams are taped.

  Are we talking about about the pressure the rain hits the fabric? But even then it doesn't add up because light rain shouldn't be expected to hit a lower pressure than a storm.

The impact force is probably correlated with droplet size, and light rain will tend to have smaller raindrops. Strong winds can obviously also drive raindrops harder into the fabric. Finally, peak force isn't reached until the surface layer is completely wetted, which will happen more slowly if at all in light rain.

Most waterproof fabrics have water-repellent surface treatments which will encourage droplets to simply roll off - this is the system that breaks down when the surface layer is completely wetted: if incoming drops hit a stationary layer of water they impart most of their momentum (creating an effective hydrostatic head on the underlying membrane), instead of beading off the fine surface structures and rolling away.

Footnotes:

as Criggie says, the water-repellent surface treatment (or DWR = Durable Water Repellency or whatever) needs maintenance. Some are refreshed by cool ironing, and some need chemical re-application.

After-market treatments by Nikwax or Granger are also useful, and do note that washing with detergent (rather than soap or Nikwax TechWash or whatever) can further impair proper function.
I mentioned the effect of surface wetting on the hydrostatic head, but it also impedes evaporation through the membrane. They're only breathable while there is air outside the pores to absorb vapour.
Breathable membranes are anyway unable to keep up with hard efforts, at least in high-humidity rain conditions.

IMO for low effort activity like walking or slow cycling, you don't need an expensive breathable fabric anyway, as mechanical ventilation is sufficient (ie, wear a poncho or use an umbrella).

For high-effort activity, you're just choosing between being drenched in sweat and drenched in rain. A water-repellent windproof and anything underneath that stays warm when wet, without getting heavy or uncomfortable (ie, not cotton) is generally lighter and cheaper.

The conditions where breathable waterproofs are actually beneficial are roughly

when you don't want to carry an umbrella or mechanical venting is for some reason unsuitable (maybe high winds)
low external humidity conditions such as snow rather than rain


You can use the Strava website to find categorised segments. You'll have to register for an account and I'm not sure how "official" the categories are.

Go to Strava.com
Register or sign in Click on "Explore" menu
Find the region you're interested in using the search box.
The map will then show all segments registered in Strava.
There is a slider along the top that allows you to filter out various categories, so you can see just categorised climbs.


You mention Strava: they do that for you. If you register components and parts of your bike like a chain it will show the mileage from the registering date. It might a bit problematic if you have two sets of wheels (like one for rain and another for sunny days)that you use alternatively.


Is it possible to control two brakes from a single lever?

Glad to see you're back!

You can use a Problem Solvers Cable Doubler 1:2 to pull 2 brakes with 1 lever. Its a little device which you hook up the two brakes to (assuming they have the same cable pull) with 2 sets of brake cables, then run something to the levers. This works for essentially any pair of cable operated brakes with the same cable pull.

For hydraulic brakes, there are some lever mounting strategies here, but I'm pretty sure the obvious solution (using a Y-splitter in the hydraulic line) won't work.

You also might want to look at this question for general one armed cycling stuff.

As for shifting, a bar end shifter is probably easiest, or shimming a thumb shifter. Depending on how your strength is distributed, an interrupter lever might be useful as well.


Chain slips to lower gear when pedaling backwards

This sounds like a stiff or separated link in your chain.  There are other options, but this would be easy to eliminate, and a likely cause.

Get off the bike, and very slowly pedal backwards while looking at the chain as it passes through the rear derailleur.

A stiff or broken link should jump as it goes through the derailleur.

If the chain starts to come off the gears, check the chain at the point where is is coming off.

Most likely, you will need to replace the chain. If the chain is new, the link where it was joined may be the issue. In that case gently flex the chain side to side (against the link plates, not in the direction they pivot) at that point and it may free the stiff link.

If not, replace the chain, taking care to join the links more carefully this time.


How durable are road or hybrid tyre tubes compared to mountain bike tyre tubes?

Having ridden both mountain and road bikes, I don't think tire/tubes designed for paved surfaces are actually any more puncture prone than tires designed for dirt or gravel, if used within their intended limits.

If you are getting frequent holes and tears in your tubes but not your tires, and you are not getting pinch flats, inspect the inside surfaces of your tires carefully for debris or small sharp objects that may be buried in the tire surface. if you run your fingers over the inside surface you can sometimes feel embedded objects that are not visible.

It's impossible to say how much faster you will be on different bike types on your commute. Also, speed is only one consideration, you may be more comfortable and happier on a hybrid with relatively wide tires and a riding position that allows better control than a slightly faster but more uncomfortable road bike.


What bicycle design factors affect stopping power?

The biggest factor in bike stopping distance is the mass transfer towards the front of the vehicle when braking. On an upright bicycle, the limiting factor in how hard you can brake is the point at which the front wheel goes from slowing you to simply throwing you over the handlebars. As you brake, your center of mass shifts forward, lifting the rear wheel.  Shifting your weight backwards and down while you brake dramatically increases your braking capability.  A human-powered vehicle with a lower center of gravity such as a recumbent trike or recumbent low-racer can also typically stop more quickly.

A bicycle's braking limit is approximately 0.67g, while the limit for a typical passenger automobile is somewhere between 0.8g and 1.0g. Legal requirements in the US are even less stringent than these limits - typically a passenger automobile must be able to brake at 0.53g, while a bicycle is only required to demonstrate the ability to skid the rear wheel, providing at most 0.2g of braking capability!  It's certainly the case that there are automobiles driving around with less braking capability than many bicycles.

The factors you mention aren't really significant in the limiting case - friction is related to the normal force over the size of the contact patch, so larger surface area doesn't really help, and even if you did increase friction (sticky tires) you'd still hit pitchover before the front wheel skidded. The bike's weight is usually a tiny fraction of the total system weight.  Disc brakes help in the average case since the discs typically have a better interface between the rotor and brake, but clamping a dry and clean rim brake can easily pitch a rider over the front wheel.


This question may be what you are looking for: How to get a bike from one city to another in the U.S

Besides the obvious UPS, USPS, and FedEx, there is train shipping as Daniel suggests. Some bike shops and outdoors stores will pack and ship for you (good if you are not mechanically inclined). Bike shops are a good place to get free bike-sized cardboard boxes for some odd reason...


The part you've circled is called the axle, even if it is not solid, and if it's bent you need to replace the axle, or the hub, or the whole wheel, whatever is cheapest. It can likely cause minor damage to your fork, but more importantly, if it's bent then it can fail- potentially in a catastrophic manner. Get it fixed, cheap insurance.


Chain falls between the chainrings of the front derailleur when shifting from the big ring to the small one

This is not normal. Modern bikes should not throw the chain off the rings, either off the outside, inside or between the rings when changing gear.

The front derailleur is probably set up wrong. Don’t let the bike store staff tell you it’s normal. You have a choice here so just buy a bike that works right from the beginning.

It's true that you don't want to be cross-chained: on largest chainring and inboard half of cassette or smallest chainring and outboard half of cassette. That puts extra strain and wear on the chain, but the chain should not come off if you forget to follow this rule.


MTB Wheel Building (asymmetrical vs symmetrical)

I have built MTB rear wheels with both asymmetric and symmetric rims. As long as you do a reasonable job and pick the right components, both will stand up well over time. I am not sure of the axle dimensions of that era MTB, but generally MTB have a wider rear axle which reduces the dish and thus the need for an asymmetric rim.

Asymmetric rims are at best a marginal gain. However the heavier the load and the lighter and narrower you're building your rear wheel, the more that marginal gain helps extend the life of the wheel. Dyads are already pretty durable rims, with the appropriate spoke choice and count they should build up to very reliable wheels.

Unless you have a history of breaking spokes on non-drive side of the back wheel, I would not focus much on asymmetric rims for a general purpose rear wheel build. They do make getting the dish correct during the build easier, ( especially for narrower road wheels), but like a lot of bike things they only matter when you are pushing the edge of performance.


Should I be continually weighting the handlebars?

Yes, the arms should support some of a rider's weight.

However, outside of a hard effort, the hands should be light on the bars and the arms should be relaxed. I'm reminded of a brief quote from Wheelmen,

  "[Eddie] Borysewicz adjusted the [American] riders' bikes, taught them proper positioning, and described how to use their abdominal muscles to keep themselves steady on the bike and their hands light on the handlebars."

Making sure your hands and arms are loose helps to not only take pressure off your hands, but it also can help keep your shoulders and breathing more relaxed as well. Try riding with a tense upper body for a long period of time and you will see the difference.

Therefore, while it probably isn't feasible to do for long periods of time, you should be able to remove your hands from the bars while continuing in the same position you just were (leaning forward, but not sitting up).


Is there a route-planning tool that clearly indicates tunnels?

None of the bike routing services I have tried or asked about know about tunnels.  They don't even mention them on route/cue sheets (unless presumably the road name has "tunnel" in it) so a text-search fails too. When it comes to scanning the route for tunnels, OpenStreetMap (standard or humanitarian layer) is clearer when zoomed out to a reasonable scale than Google maps or OpenTopoMap.

If you like watching video and your route is on Google Streetview, this video player for Streetview (link is a section of my route) will indicate tunnels, but it takes more patience than scrolling through the route.


Crank axle cracked on 1972 Centurion, looking for guidance on how to replace

The crack is in the bottom bracket(BB) axle. This will at least need to be replaced. If the crank arm(silver part) is not damaged this can be reused.

There are many types of bottom bracket standards but it is most likely this frame has a 68mm English thread square taper bottom bracket which are the most common in pre year 2000 bikes.

Something like a Shimano UN26. Any bike shop should be able to supply and fit a new bottom(price in my local area would be $30-50 supply+fit). You do need specific tools to remove and fit bottom brackets so unless you plan on investing in some tools I suggest get a shop to replace it.


How to find a bell that works well in the rain?

I agree with Daniel R Hicks, my bell also gets a lot dampened in the rain, and this will happen with any bell.

But even so, some bell properties might influence:

Steel is denser than aluminum, so a similar-sized steel bell could have more mass and ring longer;
Bigger rings might also ring longer, because of the relation among size, mass, wall-thickness, and frequency pitch.

But, to be honest, I cannot say any of the above for sure, because I didn't test it.

If it is of any help, I use my ring upside down, and raindrops get inside it, but even so it rings just a bit less than dry (not a lot less).

It is a steel ring, the type that has a lever and a spinning mechanism inside (which I strongly recommend over the model you've shown).

Also, I have a set of similar rings on my bikes, and none of them has the same acoustic properties, I think there are some subtle factors involved, most probably the relation between the bell's main frequency and the frequency of natural resonance of the raindrops on the bell (I'm serious!).

Hope it helps


How can I learn to take care of an old (70s era) road bike/get it back to working condition?

It's doable although it doesn't make sense from a cost perspective. Only do it if you have an emotional investment in the bike or want a fun project that will teach you a lot about bike mechanics.

To give you an idea, I bought a 1975 Peugeot UO18 Mixte (a woman's road bike, perhaps similar to your mom's) that had been stored in a barn and turned it into my commuter bike. In order to do this, I had to (in order of simple to complex):

Replaced the brake pads which had oxidized.

Easy. You just need an adjustable wrench or set of open-ended wrenches (maybe a screw-driver). There are different styles of brake pads, it's best to remove the old ones and bring them to your local bike shop so they can give you the right replacement.

Replace all of the brake lines and derailleur lines, which had seized.

Easy-to-moderate. You need to get your brake/shifter housings cut to length which your bike shop will do for you. Replacing brake lines is fairly easy although you need to readjust your brakes after you do this. Rather than cutting the brake line to length (which needs a special tool), you can have the bike shop cut and crimp it after you're done. No special tools needed except screwdrivers, wrenches, and the aforementioned cable-cutter which is optional. Having a brake "third hand" will make your life a bit easier although asking a family member for their physical third hand also works.   Replacing derrailleur lines is a little bit more tricky and not recommended until later on as you'll need to readjust the derailleurs after replacing the cable.

Replaced the old steel front and rear wheels (rims, cassettes, sprockets) with 700c rims with a nice modern cassette in the back and a nice dynamo in front. New tires and tubes too, of course, as the old ones had rotted away.

I could have kept the rims but they were steel and not very "grippy" in the rain; in addition, the old size limited my tire options. I knew that I wanted a dynohub and so it was just cheaper in the long run to just go straight to buying new wheels front and rear. It also allowed me to go from 5 speeds in the rear to 9 speeds.
Easy to moderate. Even if you don't replace the rims, you'll likely need to replace the tires and tubes.  Replacing the front tire is fairly easy. You do have to get a new tire on the bead, which will require tire tools (get the Pedro levers). Replacing the rear is also pretty easy, just watch how to snake the chain around the rear sprockets. You'll also need a pump too, of course.

Replaced the chain with a 8/9 compatible chain

Moderate. You'll need to get a chain-breaker tool and replacement pins.

Replaced the front stem (the old French AVA stem is prone to snapping) and bars with contemporary Velo Orange components.

Easy. Just needed a set of hex wrenches.

These were the "basic" mods. In addition, I also changed out the rear derailleur with a nice Campy one and changed out the shifters to a nicer set of vintage Shimanos.  But these are optional.

Now the overall cost for my bike was much more than if I had bought a decent used bike (I estimate more than ~$300 in parts and several hours of labor) but less than what a new, steel-frame commuter might be (~$800). The advantage in my case is that I live in a high-theft city and this commuter doesn't look too fancy but rides like a dream. And I like fixing things.

If you're a beginner, the only real "essentials" would be to make sure that your tires have air, the cranks work, and that you can brake. After that, everything else can be a slow upgrade as you learn more skills as a mechanic.

In terms of resources, I'd recommend Sheldon Brown's site, the Zinn book on maintenance, and the Park "Blue" book. And of course, a lot of hanging around at your local bike shop.

It might also help if you can find someone to mentor you as a fledgling bike mechanic. I know it's hard as a gal who loves to get my hard hands dirty to find any respect, but it's possible to find community. See if there are any community bike clinics offered at your local bike shops or in the area.

Here is the bill of materials / notes from my repair notebook:

Front wheel
700c  vuelta rim  622x18
Stainless steel spokes 36h
Sanyo 6vac hub dynamo NH27

Rear wheel
SRAM PG950 9-speed Cassette  SR-PG950-34      11X34 $18.39
2012.11.21  Dimension Road Rear Wheel 700c 36h Shimano 2200 Silver / Freedom Ryder 23 (622-17)Black

Front sprocket (original), crankset original, pedals original
52-38

Rear Sprocket
SRAM PG950 9-speed Cassette  SR-PG950-34 (was 14-26) 382g
11-13-15-17-20-23-26-30-34

Derailleur
Campagnolo Mirage (used/vintage)
Chain wrap  = (52-38) + (34-11) = 14 + 23 = 37

Stem and bars
Velo Orange Threadless Stem Adapter ST-0001 $16
VO Porteur Handlebar $32

Upgrade Schedule
2012.09.26: Front Suntour derailler. Put new chain on (7.96mm outside width)
2012.10.09: Replaced front wheel with Dynohub + 700c 622x18 (36h) $85
2012.10.09:  Continental Gator Hardshell Urban Bicycle Tire with Duraskin (700x28, Wire Beaded) $48.79
2012.10.18: Rear Campagnolo (8-9) derailler
2012.10.24: All new brake lines and derailleur lines (Jagwire L3)
2012.10.24: 15.6kg w rack and dynohub and lights, front sun tour derailleur, rear campy derailleur.
2012.11.28 sks mud guards
2012.11.21  SRAM PG950 9-speed Cassette  SR-PG950-34      11X34 $18.39
2012.11.21  Dimension Road Rear Wheel 700c 36h Shimano 2200 Silver / Freedom Ryder 23 (622-17)Black
2012.12.01  Rear wheel => Continental Gatorskin ($49.99)


Chain wedging itself between cassette and gaurd

It is possible that you have damaged something but the most likely is that things need lube and are out of adjustment.

Check that the rear derailleur is vertical - if not go to a bike shop for help.

There are two screws (usually crosshead on the rear derailleur) that prevent the rear derailleur going beyond the ends of the cassette. The one that is for the big cog end needs adjusting so the chain cannot go beyond it into the plastic ring (I can't tell you which screw without looking on the web for the specific derailleur type).

The poor changing (front or rear) is probably due to the cable not moving well in its outer or cable stretch or poor adjustment. Try dripping some light lube into the end (eg thin Teflon, WD40) or if this is tricky undo the cable from the derailleur (note carefully which side of the screw it is on & remember this when replacing) and relube whole cable, checking for free movement when using the changer and pulling the end of the wire.

Re-attach the cable to the derailleur and use the adjustment nut on the derailleur to get the gears to index correctly (lots on the web about this: generally put the handlebar gear changer in the position for the smallest cog, pulling the wire taught manually & tighten the cable bolt. Then use the adjuster to get cable tightness exact for correct indexing).

If the cable condition is bad replace it and if possible the outers.


Replace V-Brakes with Caliper Brakes on a Flat Bar Road bike

Generally, V brakes have much better stopping power than calipers. And I'm guessing that your frame will require calipers with a pretty long reach, which makes it even worse. Forget about caliper brakes - concentrate on making your existing brakes work better.

First thing you should do is to check if anything's malfunctioning: are the cables sliding freely? Are any of the moving parts binding? Are the pads contacting the rim squarely? Next step is to upgrade the brake pads.

If you do switch, then yes, you'll need new levers. Caliper and cantilever brakes: short pull, V brakes: long pull.


What is the advantage of a reverse arch suspension fork?

Looks like nobody has taken the geometry into account yet...

In the image below I have drawn the situation with highly exaggerated proportions.

All not-lowest-end suspension forks (at least the ones I know of) have a rake that is created by shifting the axle in front of the lower tubes. Let's take a wheel of radius r (solid blue circle) and add some clearance for the tire (dashed blue circle). Above that, the upper edge of the lower tubes shall be of equal height with respect to the upper tube's axis.

Here we can already see, that the wheel passes the front side of the lowers at a "higher" position than its back side. As the arches (green rectangles) have to span from one lower tube to the other over the clearance radius, we can see that the arch in the front side (the right one in the image) has to reach higher (higher green rectangle) above the lower tube's body than the one on the back side.

Technically speaking this means, that to build an arch with the same stiffness, less material (i.e. less weight) is needed on a reversed arch or at the same weight, the reversed arch can be built more massive and therefore stiffer. Unfortunately I don't have any measurement values about how much influence that really has. And obviously there are (or at least were, cf. heltonbike's answer) other drawbacks to be taken into account.


What's the foot retention used by pro track cyclists?

It's as you suggest, a combination of a standard road cleat and straps as a 'belt and braces' approach.

A quick google showed some packages of both sold together


How can I prevent bicycle theft while bikepacking?

With multiple bikes, locking them together prevents them being picked up or ridden off. The latter is often the biggest risk when camping - simple opportunism.
A reasonably long cable lock would lock all the bikes together (also outside cafes), and if you use it in an awkward position (down near the chainrings), getting cutters to it would be noisy, and tricky in the dark.  I like my Masterlock Python  for this sort of thing - it can be pulled tight meaning less stray cable at risk of cutting. It could extend into your tent locked to a bag right next to you, if you're worried. In fact even a piece of ground-coloured cord tied to the outermost bike and run through the grass into your tent, where it's tied to your bag or your cooking pots is an effective alarm; you're worried about theft in the dark, so mainly someone quickly picking up a bike and taking it away - if they make a lot of noise they'll run away empty handed.
There are ways to lock bikes to the ground, which I've used while camping. I doubt they're necessary, but I've used this when leaving the bikes on site completely unattended during the day. What I've done is to buy two corkscrew dog stakes, and screw them into the ground as close together as possible. A cable lock run through the triangular handles of both (not the free-spinning leash points) and through the bike(s) is too stiff to allow the stakes to be unscrewed from the ground. If you lean the bikes against each other the right way up, with this arrangement underneath, you can also lock the top tubes together. It can be tricky on rocky ground. Another secure anchor is two sturdy stakes hammered into the ground forming an X, locked together through holes where they cross. This probably means carrying too much weight.
Another suggestion, an additional measure, is to peg down a tarp over the bikes (and any other kit that won't fit into your tents).  This will slow down a potential thief, especially if you bang the pegs right down into the ground.  They either have to pull the pegs or cut the tarp,   before they can even discover how well-locked your bikes are.  In addition it protects your stuff from the elements.


Chain skipping and loud noise when pedalling

If the skipping started happening right after you replaced the chain, I would suspect that the cassette needs to be replaced.  If the chain has excessive wear, it causes a wear pattern on the cassette that will prevent the new chain from engaging properly under heavy pedaling load.  It is hard to discern this wear pattern by visual inspection.

This situation can be avoided by replacing the chain before it's worn excessively. When the chain wears, the wear is on the pins, so the chain gets longer. The chain should be replaced before the increase in length is 1%.

Wear can be checked by measuring the length over a number of links using an accurate scale.  The pitch (distance between the centers of pins) is 1/2 inch, so a new chain should measure 12 inches over 24 links. The chain should be replaced before this measurement reaches 12 + 1/8 inches.

Alternatively, there are special chain wear measurement tools made for this purpose.


How often do you need to grease the crank?

It is likely, unless your bicycle is quite old, that it has sealed bearings in the crankset, so there is no real need to grease them yourself. It is good practice to visually inspect and clean them regularly, but they do not need deep maintenance unless you encounter rough movement or an unusual sound coming from them.

Ciitation: Bicycle industry work experience.


How hard is it to remove a European-style rear-wheel ring lock?

Performed the operation today and it was, as suggested, very easy. Simply unscrewed a bolt on each side affixing the lock to the seat stays. For mine, the lock did not obstruct these bolts. I was then able to twist the ring lock and pull off the wheel, around the fenders, without any more fuss.


How to hold rear derailleur sprocket arm extended

Assuming you've trimmed the chain to the right number of links already...

First, put the gearing in small-small, whatever that is.

Thread the rear first.  Use a short length of old spoke through the end of the chain to stop it pulling through.

Then thread the front.

Pull both ends together at the bottom of the chain-path and use a double hook of old spoke to hold them together with a small bulge of slack chain is upwards at the joint.

Stop here, and check that your rear chain-path is correct.  The little tongue in the middle of the cage is a common culprit.  If not right, rethread.

Do up your master link or pin according to instructions.  Then check for a stiff link at the joint.


Turned out it had nothing to do with changing the tire: the brakes were simply worn out. Solved by replacing the brakes.


Did you take one of the crank arms off at some point?
Did one fall off accidentally?
Or is someone playing a trick on you?

Remove dust cap if its in the crank's axle.
Unscrew the nut of the left side crank, probably a 14mm socket.
Take the pedal crank off - it should be really hard and you need a crank puller, or it will be suspiciously easy.
Put crank arm back on so its the right position compared to the other side.
Reinstall nut/bolt and tighten it up good and tight.
Reinstall dust cap if you had one.

I've been guilty of doing it wrong... mostly because of working later at night when tired.


Are shimano FH-2200 hubs strong enough to use in a tubular wheel for CX racing?

Yes, I would suspect they are just fine. These are relatively inexpensive when new, and require little maintenance if broken down and lubed once in a while.

What really matters in cyclocross is the number of spoke holes and flange geometry of the hub. I just did a quick google and found FH-2200 hubs have beefy flanges and 36 spoke holes. I was not able to find any other configuration.

I've more often than not found wheel failures at the spoke junctions (hub, rim) or the rim itself. I've very rarely seen a hub fail that has been properly maintained.

So, my answer is this: they should be fine. Lace them up in a 3x pattern with a decent rim and enjoy some cyclocross!


Externally routing cables on Trek Allant 7.4

Assuming you have no cable stops on the outside of the frame, you'll need to use full housing all the way from shifter to derailleur.  Simply run it alongside the top tube and down the right seat stay, and secure the housing to the frame with cable ties.
Its not the prettiest solution, but you're strapping on a motor, battery, controller, and wiring on anyway so looks are already going to suffer.
If cable ties aren't your thing, there used to be brackets for the top tube which would hold a rear brake cable on 80s style road bikes, or you could buy pairs of clamp-on cable stops of suitable size.


How to fix handlebars that have virtually turned into a seesaw

Cut a piece from an aluminum can and insert it.  Aluminum is soft and it will (hopefully) clamp in.


You don’t say what size the cassette is but presumably it is a wide range model.
11 speed compatible freehub bodies are 1.8mm longer than 8-10 speed ones. Some wide range 11 speed cassettes can fit on a 10 speed freehub because the the large diameter inner sprockets can overhang the inner end of the freehub body a little and clear the drive side flange and spokes. Such cassettes come with a 1.8mm spacer for installation on a 11 speed freehub.


Better to change rim or tyre size to get lower rolling resistance on trekking tyre?

The tire change would have been the biggest change, the ALLTERRAINasaurus is a knobby tire, while the Lugano is a slick road tire.

Years back I used an ALLTERRAINasaurus and it had to be one of the slowest touring tires I have used in my life. Some earlier versions I later found out also had an incredibly stiff casing making it even less efficient.

I have also ridden on Lugano as well. It is a slower tire too, kind of like a gatorskin, but no where near as slow as the ALLTERRAINasaurus.

Note that  your pressure could be an additional confounded factor, that said from my experience with both tires I would put money on the the tire change being the culprit. The rear wheel also carries the most weight so will be disproportionately affected by rolling resistance.


That doesn't seem to match any Cannondale serial number formats.

https://vintagecannondale.com/info/serial_numbers/ says that there was a non-drive side placement for serial numbers, but they don't start with S.

That said, it seems to be a decent-enough looking road bike.  Simply add yellow paint to cover up the scratches, or perhaps contrast-paint over the damage with a different colour like deep black, or red, or ride it as-is.

The small support for the gear cable, lower on the head tube, is somewhat distinctive, and someone might recognise that.  Its not a cable-stop, it is just holding the cable outer.


Help Identifying Sun Cruiser Tandem Bike

There's been a bike company named Sun making tandems since before WW2.

Brand: Sun
Model: Cruiser tandem
Year: Unknown - probably 1990-2010 range.

The bike looks nice and comfortable to ride, with wide plush tyres, and relatively high handlebars/low saddles it will give an upright ride.
That bike is not built for speed, but for getting out and around in pairs.
The V brakes front and rear, with no third brake suggest its not really for touring, and the timing chain on the right-side with one-piece bottom brackets shows its an entry level bike.
In the Trendy category, it could legitimately be called a 1by because its a single chainring and probably 7 speed derailleur at the rear.

All in all its a loverly bike and would be a pleasure to ride.  Especially in these days of pandemic.
It would also make an excellent platform for a cargo bike conversion, should that be more use to you.
As per Carel's comment, the two cranks are at different positions in their cycle.  A conventional tandem has both cranks in identical parts of their rotation, so that both riders are pressing the same side crank down at the same time.
This makes for a better "feeling" else one rider's cranks push themselves forward at the wrong part of the stroke, and also when cornering.  Though this bike probably doesn't corner aggressively, it is still possible to get pedal strike. To fix this, just unship one end of the sync chain, rotate a crank to match the other, and refit the chain.  There is a chain tensioner under the keel tube which will allow the slack needed for this simple tweak.


The faster you're going the more power you get out of a given amount of force or "push". Ad bsdl says, power = force times speed, so the same force at a higher speed requires or provides more power.

Going slowly up a hill even quite a strong push doesn't cost much power. A 200W "push" at 10kph will take you up most road hills with little to no pedalling, since that's all the power that's required. A 200W push at 70kph on the flat is noticeable but only just, because 200W requires less force and the rider is already having to put out 500W or so to go that fast. The extra 40% power also has a reduced effect since air resistance goes up as the cube of speed. Adding means 1.4x as much power but the speed change is roughly 1.4^1/3 = 1.11, so you'd only go ~8kph faster or 78kph.

You can experiment with this if you are the one giving the push. The relationship between how fast you're going and how much effort your legs have to put in for a given push force is quite perceptible even at relatively low speeds. It's very easy at a moderate speed to push someone and find that you're going backwards relative to them quite dramatically, but without their speed changing much at all. They'll be saying "go on, push" or "that did nothing!" while you're sprinting frantically to catch back up to them.


Should I be concerned about new helmet laws?

Summary: a helmet that meets the new standard is going to protect your head better than one that just barely meets the old standard.

Old Law: AS/NZS 2063:1996 (PDF); unfortunately just the start, the actual full text of the law is behind paywalls.
New Law: AZ/NZS 2063:2008 (PDF); also need to pay to get full text
some stuff about US rules for comparison: CPSC bicycle helmet rules (PDF)

Summary of differences from the preface of the new regulations:

Something about "projection requirements" from the horse-riding helmet regulations added in. This is probably about stuff sticking off the outside of the helmet (such as a visor/peak).
Update to what headform is used for testing to match an international standard
Reduction of maximum allowed force to headform in test from 300g to 250g.  For comparison, 300g is the US requirement for adults, but 250g is the requirement in the US for children. I think it's a similar impact test.
Update to test of retention system (straps)
A new test for "peak deflection" added in, which I believe is another test of the retention system (straps), but measured differently.

Also, from the stuff I saw, a helmet meeting the old standard will still be perfectly legal to own or wear, will still be allowed in organized races for a while, etc.

I think the 300g to 250g change is the big one.  The g forces imparted to your head in a collision directly translate to how much damage your brain is going to take.  They're taking a weight shaped like a human head, strapping it into the helmet and dropping it onto various "anvils" and measuring the impact. This is a laboratory test of what would happen to your head during a collision wearing that helmet.

Note that the tests are simply pass or fail.  It's entirely possible that there's helmets certified to the old standard that would pass the new standard (or parts of the new standard) but those models weren't tested to it.

Personally, I'd be likely to pick up one of the old standard clearance helmets and not worry about it. Maybe get something a little nicer than I'd normally choose to afford. If I was planning some riskier riding I'd probably choose something certified to the new standard. However, I'm opposed to adult mandatory helmet laws, so my personal opinion should be taken with a grain of salt.  My personal opinion is that it's 90% silly bureaucracy and 10% actually making your head safer.


There is danger and there is discomfort...you should accommodate both.
There is a max insertion line on the seat post - do not ride the bike with the seat post extended beyond that line, buy a longer seatpost. Though I would imagine that a standard 17.5 frame would accommodate a 33 in inseam (is that your real inseam...or the length of trousers you prefer? There is a difference).
If the reach to the bars is too short, bringing your hands too close to the hips for your center of gravity, then you will feel that you don't have a lot of steering control.
It sounds like the bike is too small for your comfort - some people like small, whippy bikes and others like to ride much larger, more stable, bicycles. People are usually more comfortable on a larger bike, where they can change position during a longer ride and as the terrain changes.
Good luck, and have fun riding!


Budget advice
Visit/Join a Tri Club and check out what second-hand bikes the members are selling. Aim for the low end, say less than $1000. Make sure you ride a few different bikes so that you can compare.

It needs to be comfortable and fit well.
It must have quick-release wheels.

Also, work out what shoes and pedals you are comfortable using: will you use toe clips or clipless?

Serious Advice
Find a local Tri shop or LBS and talk it over with them. Be firm about your budget, and that it includes clothes, shoes, and pedals. A good shop will let you ride the bike before you buy, provide some free service and fit the bike to you. Shop around as well. Be up front with the staff: tell them that you are starting and are checking out your options.

Good luck!


Can someone help identify my vintage bike frame?

Back in the day, the quick way to tell the road-race style bikes from the road-tour bikes was to look at the wheel clearance.  The race bikes would have very little clearance (~1cm) between the rear wheel and the frame, and the touring bikes tended to have closer to 5cm.

This is why from a distance it looks like a touring frame, but up close you can see that the positioning screws in the rear dropouts are missing, and the wheel settles into a location much further back than it should.  You can see the scratches in the dropout from the original wheel position.  You might want to replace those screws.

In any case, it's not a touring bike.

The Italian BB thread is a big clue.  According to https://www.sheldonbrown.com/cribsheet-bottombrackets.html there were a few French makers that used Italian threads as well.


How do I properly torque a track cog lockring?

A torque specification is not just a torque-spanner setting but a physical property. That is, there are many ways to apply the correct torque.
In this case it means more or less: pull it as tight as you could. One can conclude this from the high torque value and wide torque range.
To illustrate this let's find the force F you need to apply to a tool to get the torque t.
The spanner you used as an example is 30 cm long. Since you need to grip it you cannot use its whole length for leverage. Let's calculate with l = 0.25 m.
t = F l
F = t / l
For the minimum torque 40 Nm we need a force of 160 N and for the maximum 65 Nm it is 260 N. That is the weight force of 16 kg and 26 kg, respectively.
The limit to over-torqing the lock ring is either your strength or pain in your hand as you begin to crush its bones on the narrow handle of the tool.
One more thing: with bike specific quality tools, especially from manufacturers who are long in the market, you can assume the tool was built to fit its purpose. That means also that it has just the right length and shape that a professional mechanic (who tends to be strong) intuitively uses it with the right torque.


I'm guessing your brake nuts look something like this, except they're completely recessed in the frame and all you can see is the hex socket on the back

Good news is there is no threadded part here that connects to the frame.  They will be rusted/stuck in place, or there's some possibility that the installer used some kind of thread-locker product and its come out the front and set onto the frame/fork's metal.

I'd start by removing the wheels for easier access.
Then hang the bike so the nut is vertical - start with the back one cos its shorter, so the seat stays are horizontal.
Get some blue-tack or something similar, and bog around the hex socket to retain the oil. Arrange a rag to catch any drips.
From the brake caliper side, squirt in some penetrating oil, like Liquid Wrench, or another brand.  CRC and WD40 are a poor substitute for the correct stuff.
And then leave it for a couple hours.  Come back periodically and give it another squirt.  (you can also do the front one, but the angles are all wrong so it probably drip straight off)
Next day (or longer, I've done this for a week on some car stuff!)  fit a longer bolt and thread it into the nut from the top.    Tighten till it bottoms out on the inside of the hex socket.  If it pops out the other side fit a nut as a locknut and tighten that against the underside of the stuck nut.
Then try and twist the stuck nut loose.  Don't shear the temporary bolt!  No cheater bars!
If that doesn't move it you're definitely facing some goop.  Some of the thread lock products weaken under heat, so depending on your frame you can try some gentle heat from a hair dryer. Don't exceed "comfortable holding temperature" on anything made of carbon or aluminium - it shouldn't get any hotter than "summer's day sunlight"   If your frame is steel it can take a bit more heat but be careful.
Finally, try a sharp tap on the end of your temporary bolt.  I've had excellent results from using an automatic center punch.  You'll want the brake bridge well supported.

I thought of suggesting an impact gun with a suitable 4/5/6mm hex bit, but there's really nowhere to get that into the back nut.  The front would be easier cos you can turn the bars to increase access.   Risk here is stripping the hex socket.

If you're feeling creative, building a puller from scrap may be a good solution.  It depends if you have the nuts that allow a bolt to match the thread to enter through the hex socket.

Last resort is to know when the bike's beaten you.  There's absolutely no shame in taking it to your LBS and asking for help.

And do keep your mate in the loop as well, let him make the final decision on what to do   - its one thing to damage your own bike, its an entirely different thing to damage someone else's.


Does a seatpost affect the rigidity of the frame?

Seatpost setback is used to get the saddle in the right place to get proper rider fit on the bike. The amount of setback required is dictated by the desired riding position, the seat tube angle and the bottom bracket to saddle distance.

If you switch out a seatpost that has some setback for one without you are either going to mess up your riding position or be forced to mount your saddle to far rearward in the rail clamps.


I am not an expert. It looks like a scratch to me because of the curves and the way it doesn't end at a sharp point. However, it's impossible to really tell from a photograph so you should take it in to a bike shop and get them to have a look at it.


Recommended spoke for enduro/all mtn riding

The best spoke is one that is light enough, strong enough to carry you, stays true through whatever riding you do, and doesn't cost too much.

To that end, the more butting on a spoke the thinner and lighter it is in the middle, but that adds to the expense.

You also need to consider whether you want normal brass nipples or aluminium ones which are lighter and cost more.

Other considerations for your wheel build might include spoke head washers, and whether the rim needs special nipples and/or washers.

Costs blow out quickly - you may only be paying 2 to 3 localdollars per spoke but 32 for the wheel and three for spares gives you $70-$105 just for spokes.  Nipples may or may not be included so check that.   Also see if a box of 50 is cheaper than buying 35 separately.

You can also make choices in colour (chrome/black/coloured+anodised/galvanised) and profile (bladed spokes for more aero)  but realistically it doesn;t matter and weird/unusual choices will cost you more in the long run.

Do buy a new spoke tool if your old one is a bit sloppy.  The right tool helps a lot and prevents rounding off.

We don't normally recommend products by name, but if you go into a LBS and buy spokes you'll probably be offered DT spokes, which are perfectly adequate.  Check their website for comparisons, but notice that they don't have specific spokes for downhill vs uphill vs espatchio vs whatever kind of riding you want.  A good wheel is a good wheel anywhere, and the tyre has more variation on the type of riding.

I'd bet a 29" MTB rim in a road bike, or a 700c road rim in a MTB would work perfectly well for either terrain.


Is possible to mount an existing freewheel on a fixie wheel?

The axle (the object on your picture) does not define which types of cogs can be used. It is the hub that rotates around that axle that determines it.
The flip-flop hub of the wheel you are linking to is designed to take a single speed freewheel (used also on BMX and some single speed city bicycles) on one side and a fixed cog on another side. It is not designed to work with multi-speed freewheels.
A simply longer axle is unlikely to help, as there are many other factors that define the compatibility. Among them are:

The axle itself. Its diameter and bearing types/dimensions must match the hub body (i.e., if the hub has cartridge bearings, loose ball bearings and a cup-and-cone axle will not fit it.)
Hub width. The fixie flip flop hub is 120 mm wide. Some of  multispeed freewheels require 126 or 130 mm widths.
Wheel dish. The multispeed wheel is more asymmetric because it has cogs only on one side, while a flip-flop hub has similar free spaces for cogs on both sides. A wrong wheel dish means the rim and the tire won't sit in the central plane of the bike but more on one side of it; as if that was not bad enough, it may also cause the tire to rub against the chainstay.
Threading pitch of the freewheel must match the hub threads' pitch. That is something to keep in mind even when changing single-speed freewheels.

More about freewheels: https://www.sheldonbrown.com/freewheels.html


I find the v-brake on the front fork, which often times has just one hole for the spring pin, is a smoother install. Idk why.  There is no difference in "front" or "rear" v-brakes except the direction of the pads.

Typically at the rear, the frame's tabs where the brake bosses are threaded or brazed on will have three holes per side drilled in them from which to choose the insertion of the brake arm's spring pin. Each arm's spring pin should be placed in the same relative hole (if the left spring's pin is in the middle hole, the right spring should also be in that side's middle hole).  Spring tension is highest when the upper most hole is used. Typically the middle hole is chosen.

One way to ease getting the pin into the desired hole is loosen the brake pad's nut enough so the pad can be rotated parallel with the arm. In this position the whole side of the brake can freely rotate on its boss without the pad bumping into the seat stay.   This way allows easier access and placement of the spring pin into your desired hole.  This may be the crux of the problem. Is the brake pad blocking the movement of the arm before it's pin is sufficiently lined up with the hole?

Park Tool has a great tutorial on installation of linear pull brakes.  V-brakes is a term coined by Shimano and is a linear pull brake system.


is this cassette and chain ring combination good in terms of number of teeth?

I read that as you already have a bike with this gearing, you're asking if its okay, not whether it will fit and work.

You might want to recount the teeth on the big ring.  42 is not impossible, but 44 would be more common based on the other two.

Assuming this is your 11-23, 11-12-13-15-17-19-21-23, and that you're on a 700 wheel with 23mm tyres, then Saint Sheldon says this at  http://www.sheldonbrown.com/gears/

Little Middle Big chainrings

4.2   5.9   7.3 (metres of forward roll per complete pedal revolution, 11 tooth)

3.8   5.4   6.7

3.3   4.6   5.7

2.9   4.1   5.0

2.5   3.6   4.4

2.2   3.1   3.8

1.9   2.7   3.3

1.6   2.3   2.9  (same, but for the 23 tooth gear)

So its a road bike with a granny gear for steep hill climbs.  The 42 chainring limits your top speed a little, and the 11 tooth rear will have mechanical loss of efficiency compared to a 12 or 13 tooth.

There is nothing wrong with your combination.  Use and learn what you want, and where you struggle. Personally I have a 25 in the rear and a 22 on the front, and I still struggle with steep 20% grades.

Once its a bit more worn and you know what you want, then replace the chain and cassette with a range to suit your riding needs.


I am not sure if I got it wrong, but to me it seems that what you describe as a problem is in fact a solution.

It is expected to get a SUBSTANTIALLY faster bike if you replace a tire, because of tire quality, rubber compound, thread pattern, pressure, etc.
1.5 size, comparing to 2.0, is a specially much more efficient tire measure, which would for sure make the difference you mentioned.

If you are getting "the result" (bicycle is moving) with less effort, and the old gearing seems inadequate, I would suggest you to update the gearing, for example, getting a bigger chainring (not TOO bigger), and keep going faster.

If you don't want to spend, you can just enjoy less effort for the same speed.

Keep in mind wider tires might be more comfortable due to cushion, and more resistant to impact-induced flat tires, because they have larger air volumes. But except if you don't feel the bike right, consider to keep the narrow tire (perhaps exchange also the front one) and enjoy a new level of cruise speed at lower efforts.


Items required in a World travelling bike?

On a very long tour such as this, the cyclist will want to be as self-sufficient as possible. Bike components and accessories are often a trade-off between weight and cost, but touring brings durability and ease of repair to the forefront.

This kind of riding is often called loaded touring, and has the strong implication that the cyclist is carrying everything needed such as food, camping equipment, tools, spare parts, maps, and sometimes more. There are other styles of touring such as supported touring, but I'm guessing the cyclist whose bike you saw wasn't doing this. Features of a bike suitable for extended loaded touring include:

A comfortable saddle may well be the most important component of a diamond-frame touring bike. The cyclist will be spending many long days, weeks, months, or even years sitting on that saddle. The Brooks B-17 is an extremely popular saddle, and is common on touring bikes. Brooks has made leather saddles in England for many years. Leather saddles are comfortable because they conform to the wearer's butt over time, and may not be comfortable until they have several hundred miles on them. If you see a bike with an old, ratty-looking leather saddle, there's a good chance you're looking at a well-loved and well-used bike.
Touring bikes need to be durable. This is a reason that steel frames are favored. Steel is flexible, strong, and can be fixed by welding. Steel frames are sturdy enough for racks to be installed on them. Other frame materials, such as aluminum and carbon fiber, are lighter than steel but aren't as strong. There are touring bikes made from aluminum, some of them good ones, but carbon fiber cannot at present take the weight of 30-60 pounds of panniers and camping equipment. Steel is also inexpensive. Unfortunately, steel is heavier than other frame materials. (This summary is a significant oversimplification.)
Handlebars on a touring bike are a less-critical component, but bars that are a little wider than on a typical road bike are common. Since the posture of the rider on a touring bike will be oriented more towards comfort than on a road bike, riders often favor a more upright posture and handlebars are therefore set higher up. Handlebars may have room for accessories such as computers and lights.
Wheels that are stronger are best, since a bike that is carrying a lot of weight will tend to break more spokes. A high spoke-count usually means a stronger wheel. 700c wheels are common on touring bikes, but 26" rims are more commonly found worldwide simply because of the availability of 26" tires and tubes worldwide.
Tires will be selected for durability rather than speed. A tire that is faster but is prone to flats will slow the rider down more than a tire that is more durable.
Navigation hardware can include a standard bike computer with an odometer paired with maps, a GPS with routing capabilities, or even both.
Sturdy racks are important. Weaker, inexpensive racks will bend and break under a heavy load. Most racks used for touring are sold with a maximum weight capacity figure. Tubus makes an excellent selection of touring racks.
Panniers will be selected based on durability. The question of whether a rack will have many small pockets or one large one (i.e., a simple sack with attachment hooks) is a matter of packing style and personal preference. Ortlieb and Arkel are two higher-end touring pannier manufacturers.
Drivetrain components should be durable and easily fixed on the road. For this reason, internally geared hubs are seldom used, even though they are generally more trouble-free. A traditional derailer can be fixed at the side of the road in many cases. A gear ratio should be selected that allows for hill-climbing, even at the expense of sacrificing speed. Bar-end shifters are often favored, because they're simpler to fix than more complex shifters.
Suspension is often not used on a touring bike, since they are less efficient at translating pedaling into forward motion. However, there are offroad touring bikes. Suspension also makes it difficult to attach racks, particularly rear suspension.
Brakes are usually rim brakes, for similar reasons as drivetrain components: they can be fixed with few tools. However, disc brakes are starting to be more common on touring bikes.

Common touring bikes include the Surly Long-Haul Trucker and the Trek 520. (The Novara Randonee is essentially a clone of these bikes.) Rivendell and Bike Friday also make well-regarded touring bikes; there are no doubt many other manufacturers of sturdy frames. Steel hardtail (non-suspension) mountain bike frames can be converted into touring bikes relatively easily.

There's an old touring adage: You can tour on any bike. Carbon-fiber racing bikes can pull a trailer full of gear. The above outline of what's helpful on a touring bike is what I would consider a best-case scenario, but is by no means mandatory.

I'll close this with a picture of one of my touring bikes.


How to patch glass cuts in a bicycle tire?

I periodically check and pull out the street glass shards

I have been doing the same for as long as I have a bike. Glass shards, small sharp stones, nails, drawing pins... name something I haven't pulled out of my tires!

But I never worried of patching the tire, and never had problems because of that. My tires (even those which weren't puncture resistant) reached end of life because of wear, not because of cuts. I just patched the tube inside, and went on.


The tube you’ve circled is the head tube. Inside the tube, on the top and bottom are the headset bearings which allow your fork to turn smoothly.
The bearing play or preload has to be set correctly with the vertical screw on top of the stem cap.
If there is play in the bearings allowing the fork to rock back and forth you’ll have to adjust the preload. To do that you have to loosen the two screws on the left and right side of the stem which clamp the stem to the steerer tube. Then slightly tighten the vertical screw until the play is gone. You shouldn’t need force, we are talking <2Nm torque here. The fork should still turn freely, if it doesn’t you’ve tightened too much. Afterwards, make sure the stem and handlebar are aligned correctly to the wheel and tighten the two screws to the left and right.
See this tutorial: https://www.pinkbike.com/news/tech-tuesday-headset-adjusting-2010.html
Since you have carbon components you should use a torque wrench to tighten to the specified torque.
If the steering feels rough the bearings are worn and have to be replaced. If you suspect bearing damage it could also be a good idea to completely remove the fork and take a look at the bearings directly and how smoothly they run.


Summary

I have heard of people in the old day mixing in paraffin oil, but I personally have just used straight paraffin with good results. All the original testing done by Friction Facts only used solid food quality paraffin.  I suggest cleaning your chains again (i.e. strip off all oil) and using only straight food quality paraffin.

Detailed

I gave hot waxing a try after seeing how well straight paraffin performed in a series of controlled tests performed by VeloNews and Friction Facts (2013 and 2014; both results are in the linked document).

Those tests used food-grade paraffin (i.e. must be > 99.5 percent pure to be labeled “Food Grade”). I watched Oz Cycle's video and some reason he had been using paraffin from candles, which could have less pure paraffin and other additives (e.g. perfume) that are not ideal for chain performance. So the first potential issues could be that you are using sub-par paraffin. Second, Oz Cycle also claimed, without evidence, that since straight paraffin wax easily flakes away from a candle with his finger nail, it will flake away from your chain leaving metal on metal contact, and hence need for paraffin oil to soften the wax.  I find this claim dubious at best.

Let's look at the evidence. Friction Facts was probably the best source for detailed friction testing available to the public, before being bought out by CeramicSpeed. They had meticulous protocols and very accurate machinery, and didn't have any vested interest in the results outcome.  They were hired by VeloNews to find the best lubricant available, straight paraffin won hands down.  If straight paraffin simply flaked away from inner areas of the chain (e.g. the inner side of the roller) then the original Friction Facts testing would have immediately showed this problem as the 2013 testing also included extensive longevity testing.

From the original 2013 Velonews article:

  We  tested  eight  of  the  lubes  for  longevity,  simulating  a  single  dirty,  wet  ride  and  testing  efficiency before and after.[...]

  Once  again,  the  old  technology  of  paraffin  wax vanquished all comers.  In the longevity test, it was completely  unperturbed  by  water,  sand,  and  dirt; in fact, it was over 0.5 watts faster after being run for an hour in the grime. We believe that the wax needs to bed in a bit for maximum efficiency. And, since nothing really sticks to it, the goop was simply shed before it could slow anything down. The only other lube to increase efficiency after the dousing and dirtying was Park Tool’s CL-1.

and

  The fastest bike lube isn’t designed for your bike at all. In every measure, the most efficient chain lubricant is simple paraffin wax, sold in solid blocks at any hardware store.

After you hot wax a chain, excess paraffin may flake off the outer surfaces, but this doesn't mean it is flaking off on the inside of the chain where 1) space is very restricted and 2) where you need the lubrication to be.  If paraffin wax was flaking off from the inside of the chain, I don't think Friction Facts would have seen the stellar test. Given they were an independent testing body at the time, hired by VeloNews to get answers, I believe their results are credible.

The reason the straight paraffin wax likely does not flake away from the interior are for the following two reasons:

Getting the chain very clean (i.e., bare metal, with no residue) before waxing means the paraffin adheres strongly to the internal surfaces of the chain; and
The restricted space between the rollers and bushings means that wax that does penetrate into that area stays there as it has no where to go, especially in the hardened form!

As such, I suggest you stop using paraffin oil.  Re-strip your chains back to bare metal, and get some fresh food grade paraffin wax. Leave the candles for romantic dinners with your bike.

Bonus

A cheap and easy cleaning protocol I have worked out for dusty/dirty chains, as an alternative to an ultrasonic cleaner, is dumping the chain in boiling water and agitating roughly with a stir stick.  The temperature liquefies the paraffin and the agitation dislodges the old paraffin and dirt.  I then let the chain dry over night, before waxing the following day.  I usually do 2-3 chains in one go. This is a "poor man's" ultrasonic cleaner, without the ultrasound cleaner apparatus nor ultrasonic compatible cleaners.


Need advice for my brakes on vintage Torpado

Those levers are from the days when road bike levers mostly all came in one reach "category," which is quite a bit longer than ideal for probably a good 50-60% of the adult human population.

You may be able to get it a little better without changing components by adjusting either the angle of the bars (where they're clamped into the stem) and/or the position where the levers are clamped to the bars, which involves messing with the tape. It's normal to have to tweak both before one feels the lever ergonomics are as dialed as possible. That said, they may very well still be too far out.

If by tight you mean the brakes are adjusted now so there's little lever travel before the brake firms up, that's pretty easy to adjust by giving the brake cable some more slack, either by screwing in the barrel adjusters if they're out now or by re-clamping the cables, being careful not to leave any overly crimped spots in the system. That might make the brake feel in use a lot better for you even if it doesn't help the initial reach.

There are at least two different modern brake-only levers that you could get that are designated as "compact," for smaller hands. Tektro makes them and a bunch of companies have versions of them with their name on them, like Cane Creek and Origin8.

Current road bikes usually have integrated brake levers/shifters, which these days all have some way of adjusting reach.


How do I stop people blaming me for a crash?

I dispute your claim that the collision was entirely the pedestrian's fault. Of course, the pedestrian shouldn't have stepped into the road without looking. However, you, as a road user in a busy city should have been aware that pedestrians often cross the road carelessly. You shouldn't have been travelling so fast and so close to the bus that you had no time to react if a pedestrian appeared.

Even if you don't feel you have any responsibility towards careless road users, surely this makes sense purely from the self-preservation angle. You need to consider what other users might do, not only what they will do if they obey all rules and guidelines.

Now, I wasn't there so I wont attempt to apportion blame any more precisely than "You were both at fault." But you were both at fault.

In your edit to the question, you point out that the pedestrian appeared so late that you would probably still have hit them at 1–2mph. First, if that is literally true, then you must have been riding extremely close to the buses. If you had been riding a meter away from them, you would have easily avoided the collision at walking pace. Riding very close to stationary vehicles is very dangerous: if they start moving, there's a good chance they'll move towards you; it invites other traffic to overtake, trapping you in a space barely wider than your bike; and it gives you no time to react if a pedestrian appears or a door opens. Second, if you had collided at walking pace, nothing serious would have happened but, for example, colliding at 12mph involves nine times as much energy.


Why do we rarely see recumbents and almost never see velomobiles?

Talked to a guy who had a velomobile at a local charity ride. He said the thing cost $5000. Recumbents, while not as expensive as velomobiles are also quite expensive. Usually over $2000. That could be part of the reason. Sure, with economies of scale, they could be made cheaper, but that's kind of a chicken and an egg problem.  Also, even though recumbents and velomobiles are so much more efficient, they do have quite a few of their own problems.  Because they have so much extra weight, they tend to be quite a bit slower on the hills. Many people also don't like being so close to the ground.  I like being able to stand on my pedals and see over most of the cars when riding in traffic.  Also, regular bikes are pretty efficient these days. For $1000 you can get a pretty good bike. And one last thing. Don't underestimate the "conformity" factor.  Many people don't want to be seen as weird, or outsiders, and want to fit in with social norms. Riding a bike is already going against social norms in many places. For some people, having a recumbent just takes things a bit outside their comfort zone.


Hydraulic disc brakes are now available on Shimano's lowest level MTB/hybrid groupsets (Altus, Acera and Alivio) which opens up the possibility of putting them on inexpensive flat-bar commuter bikes.

Hydraulic discs brakes are obviously more expensive, and they are a little heavier than rim brakes. They are going to give better and less variable performance than rim brakes. They do work better in the wet and are much less affected by mud or dirt on the trail or road,

Hydraulic disc brakes require less maintenance. Once you have them set up they just work and keep working without needing continual adjustment. The pads adjust themselves and there are no cables to stretch or get dirty.

Replacement pads are a little more expensive, but are quite easy to change. You do have to remember to pop them out occasionally to check the wear as they are not as visible as rim brake pads.

One downside is hydraulic discs need bleeding periodically, which is a little expensive. How often and how much is costs depends on the make and model.

Wheel removal/reinstallation is straightforward. You have to be a little careful getting the rotor in the caliper, especially on the rear wheel when you are fighting the derailleur but it's not too difficult. You also have to remember to not pull the lever while there is no disc in the caliper (or insert a special block to keep the pads separated).


Which cleats provide more adjustment freedom?

All brands and type of cleats offer some left/right floating freedom.

Regular Shimano SPD have a lot of freedom.

Shimano and Looks cleats have different cleats to allow different range of left/right floats.

Shimano SPD-SL Pedal Cleats

Red 0° Float
Blue 2° Float (provided with high-end e.g. Dura Ace SPD-SL pedals)
Yellow 6° Float (provided with most Shimano SPD-SL pedals)

Look Pedal Cleats

Black 0° Float
Grey 4.5° Float
Red 9° Float

Have a looksie here for more pedals and cleats info.


Rounding slightly to make the math easier (And all paces taken from the conversion machine at the Cool Running site:

At 20 mph, you are covering 100m every 11 seconds. At 25mph, you are covering 100m every 9 seconds. (And yes, I'm mixing mph and meters). So the one going faster is gaining 2 seconds every 100m, so a 30 second gap will be bridged in 1500m.

Other than either memorizing the differences per 100m, the only other real way to do it is be able to do the math in your head. However, the problem is that you won't always get the speed of the peloton with the time update. The best thing that I've found is to watch the mile markers or other signals on the side of the road, and if they bring the gap from 30 to 20 seconds in a mile, they're gaining 10 seconds a mile.

Conversely, if you can do the math in your head, and you know how much they are gaining per mile, then you can work out the speed of the peloton compared to your speed. Or, you can also calculate it against how far you have to go. If you have a 30 second gap, and they are gaining 5 seconds a mile with 10 miles to go, you're going to get caught if you can't speed up. Then you have to gauge how much you have left against what they are doing, etc etc. It gets complicated fast towards the end of a race. :)


How to properly gear compensate for short crank arms?

Being able to easily compare gearing across bikes with different crank lengths is the main reason why Sheldon Brown advocated switching to the proposed Gain Ratios system for expressing bicycle gearing. Gain Ratios measure gearing in terms of movement of the pedal rather than rotation of the chainring. You can use his popular Gearing Calculator to check it out. The other systems are more or less racer-myopic and force you to do additional math when different length cranks are involved, but yes you've got it as far as how to do so.


Giant Revel 29er 2015 - maximum width of tire I can fit?

The Giant bike specs page says nothing about tire clearance. You can measure it yourself:

Measure mounted tire width at widest point.
Measure distance from wide tire points from #1 to frame/fork.
Considering a (very arbitary) minimum 1cm clearance for 29er, choose a suitable tire.

For example, if current tire is 53mm wide and clearance at each point is 1.5cm, about 1cm wider tire might fit (about 2.3"). Keep in mind that tire width will vary from claimed depending on manufacturer and your rims inner width. You should also factor in riding conditions, especially amount of mud. And make sure that new tire will fit into rim brakes, if that's what the bike has.

You might find it easier to visit a local bike shop and find a suitable wider tire together. Just fit something bigger and see if clearance is good enough.


The critical factors are rolling resistance, wind resistance, gearing, and body posture.

Rolling resistance is minimized with smooth, high-pressure tires.  It's not required that they be super-narrow, but narrower than 2" is probably best for wind resistance.  You should generally run 80-100 PSI.

Wind resistance is minimized by a head-down posture, with arms fairly close to the body.  Changing out the handlebar, or installing bar extensions, may be necessary to optimize this.

Gearing is important if you "max out" your high gear, or you can't find a gear to let you run at optimal cadence.

Body posture (over and above issues of wind resistance) involves having the body "fit" the bike in a way that lets you pedal efficiently at high cadence (and with your head down).  This is more a function of the bike than the other factors, and likely harder to optimize on a mountain bike.

(Remember, maintaining speed on the road is not a matter of putting out maximal force, but rather sustaining power output over a long period of time.  Higher cadence with less force is generally better than maximizing force.  A cadence of 80-100 RPM is generally considered optimal, and a reasonably good first take at balancing force and cadence is to be doing two revs of the crank for every breath you take.)

Oh, and lock out the suspension.


Shimano 170mm FC-TY301 48/38/28 alternative

FC-TY501 is a straight swap according to Shimano's specs https://productinfo.shimano.com/#/lc/tourney/3x7, but you will need to get one the same chainrings you have now (e.g. 48/38/28 or 42/34/24).
Other options will work fine also, preferably those with 47.5mm chainline, but for proper front shifting either matching all three chainrings, or failing that smaller chainrings with the same gap and then move your front derailleur up/down, will be necessary.


Storing bicycle in a shed for the winter

http://velonews.competitor.com/2010/04/bikes-and-tech/technical-faq/technical-faq-carbon-in-cold-conditions_111530 summarises to "No problems"

  CF (carbon fibre) components are used extensively in launch/reentry
  vehicles and satellites where the temperatures range from superheated
  to near absolute zero. The ultra low CTE (Coefficient of Thermal
  Expansion) of carbon fibre make it ideal for these temperature
  extremes. I find it very hard to believe that a bicycle sustained
  damage during winter storage in a cold garage – regardless of the
  earthly location. I have seen “green” (not fully cured) paints and top
  coats crack in extreme temperature conditions but never a CF composite
  structure.

Although if your bike had water in it and that froze, you would have a different problem.   To deal with this, dry your bike, and hang your bike so it drains - often there are two breather/drainholes at the aft end of the chainstays... but do eyeball them first.


Swap Shimano/SRAM freehub for Campagnolo

Swapping hubs to a complete wheel is almost never practical. You would need a hub that matches the exact drilling of the original hub, or has similar spoke counts if you also replace the spokes. Even spoke counts may be difficult if the wheel has different number of spokes on left and right, as the Fulcrum does.

The good thing is that since these are both third party brands[1] that are marketed for both Shimano and Campagnolo users, you can get just the freehub body for different cassette as spare part for about 50€.

[1] Technically Fulcrum is owned by Campagnolo and the products are mostly the same, just marketed for people who haven't figured out that Shimano compatible wheels have been sold under Campagnolo brand for a long time.


What parts do I need to change to convert from flat handle bar to drop bar?

To do it best, You will need the bar (obviously) and the brifter(brake/shifter) and to switch to cantilever brakes. The latter is avoidable if you use what's called a travel agent but if you have the money the canti's are the way to go, as the travel agents are ugly and I have heard a lot of people having issues with them.

The reason for this is that V brakes have a different pull ratio than road brakes and with v brakes and a road lever you don't get proper leverage and the result is poor braking.

Look up 9sp brifter on google and you should have a plethora of choices. You should be able to use your existing stem as long as the clamp diameter is the same.

If I had to guess your looking at a 200 bucks if your were to go through a shop, total guess on my part though, and that number could vary greatly dependent on the components and quality/brands you go with.


Is there a left-sided powermeter that requires less than 8 millimeters of clearance?

The Checkpoint is a gravel frame, and that particular model has a road groupset. Unfortunately, while not all gravel frames have this clearance problem, this does illustrate part of the rational for the slightly wider chainline on gravel-specific groups.
I would strongly urge you not to get a right-sided power meter based on a Shimano crankarm. It's been shown that because of the way the spider is shaped asymmetrically, drive-side meters on the current generation of Shimano cranksets (e.g. R7000, R8000, R9100) are inaccurate. The problem is not present on the non-drive side, but that's the side you don't have space for.
Given that and your cost limitations, it may be difficult to get a new functioning power meter within your budget. The lowest cost pedal-based meter that I know of is IQ2, but they are not yet shipping widely, they had to redesign their product completely once, and they have had numerous production delays. See my comment on your main question. A good crank-based solution would very likely involve a new bottom bracket, since many of these use 30mm spindles, and your Shimano group is based around a 24mm spindle. (An exception: Rotor makes some cranks with 24mm spindles, and Power2Max sells power meters with Rotor cranks, but these tend to be expensive and may be out of your total budget.) You could also try looking for a used power meter; to my knowledge, drive-side power meters based on the last generation of Shimano cranks are still reasonably accurate (see the GP Lama post that I linked earlier).
Used power meters are worth considering, but I would investigage the reliability history of the particular model if possible. To my memory, the second generation of the Stages units and the second generation of Garmin's Vector power meter pedals (neither of which apply to you, unfortunately; the Vectors are Look road pedals) were less reliable than their successors. Quarq spider-based units have generally been very reliable, but DZeros made before about 2018 could, in some cases, get irreparably damaged if they were subjected to a side strike, such as from a dropped chain (I was one of the victims on that thread). Quarq covered those of us under warranty for that failure mode, but you would not have this recourse. I had neglected to mention this earlier, but Powertap appears to have offered a disc brake power meter hub. You would be locked in to the rim it comes with, unless you chose to replace it, and you would want to verify that the hub either has a thru axle fitting or that SRAM (which owns and has now discontinued Powertap) or a dealer is willing to sell you the thru axle endcaps.
Train without power?
One thought is that you could do without a power meter. It's true that structured training with power can enable pretty substantial gains, but it also takes time and effort to select, learn, and adhere to a structured training regimen. Moreover, in the absence of a power meter, you can do unstructured but purposeful training. Ned Overend described this approach in the first part of this Velonews podcast. He tracked his time on various known segments, e.g. climbs, and he just made sure to do a variety of efforts of various durations, plus get enough rest. You can use Strava for tracking segment times, and it will also estimate your power in the absence of a power meter (making a large number of simplifying assumptions, so it's not a substitute for real power, but it is actually reasonably accurate on average). Hence, you'll only need a GPS head unit, which you would have needed for your power meter anyway. The term I used earlier is not a formal term, and I don't believe there's one for it. It's a bit more structured than the advice "ride lots", a quote from Eddy Merckx when asked about what advice he'd give to aspiring riders. This approach is perhaps akin to fartlek workouts in running.
You could also train with heart rate. When you do decide to upgrade to power, many structured programs also incorporate heart rate data to gauge your freshness, so a heart rate monitor purchase wouldn't be wasted. For example, Strava will display freshness information to premium subscribers, and that requires either heart rate or for you to enter perceived exertion on every ride. For heart rate, one thing to know is that it's a lagging indicator of effort. Once you start a hard interval, it takes your heart several seconds to catch up. It's not as good for short hard intervals. And heart rate is also influenced by fatigue, so you still need to listen to your body; if you are having a hard time getting into the prescribed heart rate zone, you may want to take an easy day (but that principle also applies to power-based training). It's likely that heart rate is better for longer duration intervals. However, if you are riding gravel, those are the type of intervals you want to concentrate on. You could supplement longer intervals with shorter, unstructured sprints, or do an occasional day of short hill repeats to get your top end speed built up.