Nipple wrench flat sizes don't correspond to spoke gauge in as clean or universal of a way as you're suggesting.

This depends a little on where you are in the world (and in history), but 2mm aka 14g spokes are by far the most common for bicycles, and there are three different common size nipples associated with them: 0.127", 0.130", and 0.136". (These correspond respectively with the black, green, and red spoke wrenches that several tool companies use.) Of these, the 0.127" wrench flat size is the standard one for 2.0mm spoke nipples by all the modern premium quality spoke makers (DT, Sapim, Wheelsmith, Marwi), and the other two are used seemingly at random by various lower-tier spoke/nipple producers.

Nipples for 1.8mm/15g spokes also almost always have the 0.127" wrench flat size.

2.3mm/13g spoke nipples can have either the 0.136" size or one of the more "oversize" standards like 0.156".

So there is no 1:1 mapping, especially because looking back into history there can be found any number of now-unusual permutations. The gauges listed on ring-type spoke wrenches are arbitrary and outmoded in actual use even if once they were based on some kind of real system.

Also, spoke wrenches in shop use get a lot of reps and do develop slop and eventually wear out.


Do I need a Blackburn bike rack for my CoPilot Limo kids seat, or will the vintage Schwinn rack do?

According to the user manual, the Blackburn rack is required. The seat snaps in to the rack, so the old Schwinn rack won't work.


Welding mounting plates on mountain bike frame

It depends a lot on the fine print of the bike, and how good you are at guessing where forces will go. Broadly, if you make a solid structure and mount it properly the bike will usually be fine, but most parts of a bike are not designed for forces in new directions.

Generally muffler tube is 1.6mm or more and mild steel, where even cheap bikes are 0.9mm or thinner and a harder alloy. If you're confident stick welding muffler pipe you can probably weld the thicker parts of a cheap bike, and if you can somehow magic up some really thin rods it'll be much easier. You want to be down around 30 amps for much of the welding, and most transformer stick welders struggle to maintain an arc at that sort of current. Modern switch mode ones work better, even without HF start, because they can up the voltage to keep the arc active and drop it back when the arc starts, on a millisecond-to-millisecond basis. You can't do that by hand :) If you can get gas a TIG kit for a switch mode welder might be worthwhile, but I suspect you might struggle to do that based on your comments.

Normally I wouldn't spit on a gasless MIG, but for you it might be the least worst option if you get the chance to try one in civilisation on day (FFS don't mail order one sight unseen). Maintaining the flux cored wire is not much more hassle than keeping welding rods dry, but you can weld thinner tubing more easily. Or you just just decide to burn 10 or 20 rods getting the hang of thin wall tubing (or just design so you don't need to weld it very much). Running a bead along something solid so you're just barely melting into the thin tube might be the least awful solution. You can't easily join two thin tubes, but you can still do a lot. Or maybe "pre-set your filler" rod by tying non-galvanised wire along the join before you weld, to bulk it up a bit. I haven't done that with stick, but I do it occasionally with TIG with I have something really tricky to weld (a sudden transition from 6mm dropout to 0.6mm tubing, for example)

Welding a new stand plate on, for example, should be fine as long as you can weld the thin wall bicycle tubing. Look closely at the existing plate, most of them are kind of )o( shaped, with the tapered ends designed to give a gentle transition in the amount of force applied, so that the thin tubing of the bike can better cope with the load. Cheaper bikes sometimes fake this with tack welds, or just don't bother because the cheap tubing is thick enough that it doesn't matter. But then you go and load the bike to twice what it's designed for and it does matter.

Panniers and load platforms can often mount to existing attachment points. The hassle is that welding to the seat tube has to be done very carefully, and if you can back purge with TIG that's even better. If you even roughen the inside surface of the seat tube it can make getting the seatpost in difficult to impossible. Filing that smooth requires a half-round file hand patience (or a rotary tool with a filing bit plus skill and luck). You're trying to file 0.1mm off a tube that's 0.9mm thick at most.

Ideally you'll add vertical loads to or very near the axles. If you're lucky the dropouts will be cut rather than cast, and will take welding well. In that case you can just leave enough space to do up the wheelnuts and weld directly to the dropout. Making a rack out of whatever you have, as one piece, is usually fairly easy. Making it light and strong is the hard part/ So give up on light :)

My limited experience is with chopping up bikes to make prototypes, and they seem to survive that better than I expected. Skim the "I built it" section of my site and you'll see a few hacked-about-with bikes. http://moz.geek.nz/mozbike/  and specifically the "Bin Bike prototype" which was a BMX with extras, including a rack largely made of 10mm reinforcing rod.


Diagnosing and correcting hop on carbon wheel

By 'hop' I assume you mean radial run-out (as opposed to lateral run-out).

A bent axle will have no effect on the rim running radially true or not, because the hub rotates around the static axle. A slightly bent quick release shaft will just conform to the bore through the axle and have no effect.

A rim can be perfectly circular but still have radial run-out - if the hub axis is not at the center of the circle. That may be what is going on here. In any case the solution is to have the wheel re-trued.


In the manuals/parts lists I have seen, Schwinn and Blackburn refer to the part that envelopes the ends of the axle or quick-release skewer as a "cone". Minoura refers to it as a "grommet" at the end of a "coupling".

I don't have a Cyclops manual handy. I also don't think there is an industry standard name for this part, as there is some variation between all manufacturers when it comes to the coupling/mounting mechanism of their trainers.


Adjusting Hozan spoke threading tool for different spoke gauges

I have inadvertently threaded many spokes with my Hozan not properly centered vertically -- so much that the threaded ends were bent slightly. They laced up fine in the wheels. Of course I corrected this after I noticed, but I'd say the difference I got due to my error was much more than the fraction of a mm difference you'd get in height by moving between those spoke sizes.

The vertical centering is so imprecise, were I to move to another size, and if I had mine nicely centered already, I wouldn't bother trying to recenter, because I think I'd be equally likely to make it worse.

But I second the notion of threading a spare(s) of different sizes to see if you even notice a difference.


Is a pad spacer needed when installing disc brake pads?

The pad spacer is intended to prevent you from accidentally closing the brake without the rotor in place.  It is not required, for any part of the adjustment or installation process, as long as you do not need to bleed the brakes, and as long as you refrain from squeezing the lever without a wheel in place.

If you do need to bleed the brake, it is convenient, but not required.


The high spoke-count wheels look nice but are mostly for show rather than increased load capacity.  Notice the front wheel is laced radially and the rear is laced crossed.  As such this front wheel would not suit a brake.

At least one tyre has been replaced because of the colour and tread difference.

Otherwise its a fairly neutral BMX, not intended for stunts or trials.  If you like it, just ride it and maintain it.

Since you've "just picked it up"  try asking the person selling it.  If they're the original owner they will know the most.  Original paperwork is always a selling point for a bike too, and a service history.  I know exactly how many km are in my chain and cassette.


I have a 2013 Diamondback Podium 3. Is it possible to use it as a touring bike?

This bike is a poor choice for any touring where you have to carry things (if you're doing a supported tour, you may be able to pass with it). It doesn't have rack+fender mounts and doesn't have particularly tough wheels.

Depending on the type of touring you're doing, you should look at some touring bikes like the Surly Long Haul Trucker or Trek 520.  Typically, these are made of steel (repairable), have lots of rack and fender mounts (so you can carry stuff and not get wet), bar end shifters (simpler and less prone to failure than brifters), a wide range of gearing (so you can tackle hills efficiently), tough wheels (36 spokes typically, so they don't break), good tire clearance (fat tires = more weight carrying ability and nicer ride) and a relaxed geometry (so you're not in pain after a long day of riding).

The bike you choose (and how you modify it) for touring will depend on the type of tour you plan to do. But generally, you need to pack light.


Why does a loose pedal destroy the crank threads?

Once loose, the pedal spindle will describe a cone as the crank rotates. This concentrates force at certain points in the crank threads, leading to damage.

Top image shows the pedal spindle in the threaded hole in the crank. The threads are fully engaged and tightened, and forces are distributed. Note there is space between the male and female threads (somewhat exaggerated).

Bottom image show what what happens what the thread is loose. The spindle can move around in the threaded hole in response to changing pedaling forces, and forces get concentrated at the red dots.


Winter riding: Is it safe to ride on a BSO/cheap bike at temperatures below -15°C on icy or damp roads?

I can only speak from my experience, as a winter rider in Norway (around the capital).

When the winter sets in I usually just end up putting more clothes on myself, and studded tires on my bike. I avoid hard biking (biking so that I get tired, breathing heavy) when it's below minus 10/15 degrees C, because breathing in such cold air can be damaging for your lungs.

Of course, with all the extra salt (at least in Norway) the bike parts get worn out faster, and I usually end up changing at least the chain after the winter, and maybe also the cassette. I have some friends that usually buy used cheap MTB and throw them away or sell them at the end of the winter season.

Edit: One other thing that is important, is to be visible. Depending on the road you're riding, you may share it with other cars or cyclist/runners/walkers. In Norway it is mandatory to have light (yellow in front, and red in back), plus a bell. In the winter I also use a safety vest (they may look silly, but it's not cool to be hit by a car!), plus a stronger light in front, than in the summer. Just be aware that the light should point down, so you don't blind other people.

I think the best solution is just to try it out, and take it easy. Wider studded tires will help you.

Also, be careful about sharp turns. They are dangerous in the snow/ice/winter.


How to carry a concealed firearm on a bike?

A thread on this subject on Bikeforums ran to pages and pages...   Some expressing utter horror that a bicyclist would feel the need to be armed, others ridiculing the whole idea, others with decent suggestions.
I'm a cop, I know that numbers of cyclists ride in conditions that are less than optimal.
We have had armed robberies and muggings of cyclists here in St. Louis, usually the bad guy is after the high-end bike.
As well, mountain bikers have been attacked by cougars in Western states.  Bicycling magazine detailed several such incidents while I subscribed.   Rare, but possible.

First up.  Having the weapon concealed on the bike is rather a bad idea if the intent of the bad guy is to steal the bike...  Your first indication of anything wrong might simply be a pedestrian knocking you over at an intersection.  Now, he's got your pistol too...

Unfortunately, cycling gear isn't much designed for concealed-carry.  I have a little Taurus 2" 38 special as an "off-duty" weapon.  Drops right into my jersey pocket.
Sure, it "prints" there.  But then, I'm a cop...I don't care.
A reasonable idea is the "fanny pack" (I've just been informed that Aussies call them "bum bags"...).
As far as I know, you can still buy a fanny pack that is designed specifically to carry a firearm....


How do I know if I can replace the 27 inch wheels with 700c wheels on my bike?

You may or may not be able to make that conversion with your existing brake/frame combination. Your brakes will have to reach farther because a 700c wheel is a smidge smaller than a 27 inch wheel. Depending on your setup, that may be possible. I'd recommend borrowing a 700c wheelset from someone to see if you can line it all up. If it all lines up, great. Purchase whatever 700c wheelset strikes your fancy. If not, you may be able to purchase brakes with a longer reach. Some older frames still won't work with 700c wheels even with the longest brakes available. If that's the case for your frame, you're stuck with 27's.

Personally, if it were me and I couldn't get it to work with the existing brakes, I'd stick with 27 inch wheels. If you start having to swap brakes out, it starts to get iffy and frankly, I think it's more hassle than it's worth. It's a lot easier (and maybe cheaper) to just start hunting for a frame that already has 700s on it.


You probably broken something in the fork. Bring back to the shop to have it check!


Further to the above comments:
Your bike size sounds about right - see here:
Evans size guide
Stand over height is that you can stand over the top tube with your feet flat on the floor and raise the front wheel off the ground. When seated on the saddle you should be able to touch the ground with toes and possibly ball of your foot on one side at least. Look also at having your leg only slightly bent when your pedal is at the bottom of its stroke.

Before ordering a new bike visit a few cycle shops and try different frame sizes and wheel sizes. Mountain bike wheel sizes go from 26" to 29". Some riders prefer a frame on the larger size and some on the smaller size. "Feel" although it cannot be measured is a good indicator of a bike that is right.

Having a bike that is too big may not cause any noticeably negative effects, but handling and efficiency may never be as good as you would want.

k


The brake (not break) / fork interface will be standard post mount and is the least of the problems. Adapters are readily availble so you won't have a compatibility problem that cannot be sorted for a few $$.

The other issues to watch for when switching forks from that era would be the steerer - Talon was probably 1/18th straight, but tapered are now far more common. Its possible to get adapters to fit straight forks into frames built for tapered, but not the other way round.

You will also need to match your wheel, or more accurately, axle. Likely the Talon had a 9mmQR, forks now comes in many variations of QR and though axle.

Therefore you want to find a disc compatible fork fork with the same steerer and axle mount as you already have.


I unscrewed the lockring, and *both* BB cups rotated - what's going on?

This a request for clarification rather than an answer (sorry, I don't have enough rep to comment yet).

First thing to assess is the threading of the right cup.

I assume the BB is English threaded, because it's a CB product; if this is correct then when you unscrew the right threaded left cup, the left threaded right cup would rotate in the same direction, hence would unscrew itself. Can you see a gap developing between the frame and the right cup when you unscrew the left cup?

If my assumption were correct, the fact that they do not rotate more than 20 degrees might indicate that there's some sort of connection (intended or not) between the two. By unscrewing both sides simultaneously you are stretching the connection, hence the block at only 20 degrees.

Finally, sorry if the following comments sound offensive. Depending on your experience in bicycle repairing:

are you sure you are not rotating the whole eccentric when you rotate the cups? I can see you have an eccentric in your pictures.
you might be surprised on how much strength one needs to unscrew old BBs, so when you say "won't easily rotate", what do you mean exactly? Are you applying strength with the arm only or are you using your body weight?

Cheers


How to replace a spoke on a rim with no spoke holes?

It looks like a pretty standard threaded nipple with aluminum spokes. Is the spoke broken off right at/in the nipple, by the rim, or is there enough of the broken spoke sticking out of the nipple that you can 'grap' it with a pliers/vice-grip type tool? ...

a). If the spoke broke off right at the nipple, leaving nothing to grasp -- or if the nipple itself is somehow damaged -- then you'll need to remove the rim strip/rim tape from the inside of the rim in order to remove the nipple. Spoke nipples aren't threaded into the rim so it should 'back out'/fall out freely. In this case, you will need a spoke wrench to install the new spoke and you will need to install new rim tape after the new spoke and nipple are installed. You may need an sharp knife to carefully cut/lift the old rim tape.  Otherwise...

b). If you can grab the broken spoke securely, just use a spoke wrench to turn the nipple and un-thread the broken spoke. You shouldn't need to access the nipple from the 'inside' of the rim. In this case, you will need a spoke wrench (to turn the nipple) and a pliers (to grasp onto the broken spoke).


The answer to your questions is not straighforward, as shown below.

The easiest to answer is your first question: are X and Y the same? No, they are not. This follows from the formula for the air-drag power Pa = ½.rho.Cd.V.(V-Vw)² , where rho is air density, Cd is drag coefficient, A is frontal area, V is forward speed, Vw is wind speed.

Suppose that for a certain power input your speed in the absence of wind is V0.
Now if you keep power constant, we have for a tailwind a forward speed Vt : Vt.(Vt - Vw)² = V0³.
For a headwind we have a forward speed Vh : Vh.(Vh + Vw)² = V0³.

For any V0 and Vw, you can calculate Vt and Vf by solving a cubic equation. It is easy to verify by substitution that for a no-wind speed of 20 mph and a wind speed of 10 mph, the headwind speed becomes 13.95 mph and the tailwind speed 27.16 mph (neglecting rolling resitance). So Y>X.

However, I find it more elucidating to consider a return trip along a road heading straight in the direction of the wind first and returning in a tailwind on the same road. Suppose that the trip without wind takes a time T0. It can be shown that the total time Tw is always larger than T0 and that the ratio Tw/T0 does not depend on A, Cd and rho nor the distance : Tw/T0 = (V0/Vh +V0/Vt)/2.

A few years ago I made a graph where the ratio Tw/T0 is plotted against the wind speed,  assuming a wind-free speed of 20 mph, shown below.

The graph shows that a wind always increases the return time. At 10 mph wind speed the return time increases by 8.5%. At 15 mph wind, the increase is about 20%. This calculation assumes that the rolling resistance is small compared to the aerodynamic resistance, which is roughly the case at 20 mph.

Your question about the effect of a side wind is much more difficult to answer, because the wind-exposed area plays a big role. This takes a much more elaborate study. There is a free-access paper on the internet by Osman Isvan that investigates this question in depth.

See research paper Wind speed, wind yaw and the aerodynamic drag acting on a bicycle and rider


What are some good exercises to prevent knee pain?

The problem with diagnosing knee pain is there are multiple possible causes. The original cause may not even be in the knee itself! I have a cyclist friend whose knee seized up. He went to a physiotherapist, who explained that the real problem was an extremely tight lower back. The tightening back was tugging at his gluteal muscle (buttock), which in turn was tightening his hamstring - which was pulling his knee out of alignment! His body was actually acting against itself, as each muscle struggled to retain its preferred position. The physio pummelled out his back and glutes, he did back stretches for a few weeks, and everything relaxed.

I've had ITBS for almost a year, caused by a combination of incorrect seat height and an over-aggressive cycling schedule. The iliotibial band is a tendon-like bit of muscle which runs down the outside of the thigh and connects the hip and knee. When it tightens, it pulls at your knee-joint and rubs painfully against the bone, becoming inflamed.

For this problem, stretching has been surprisingly effective. I stretch the IT band itself, my hamstrings, and my lower back and glutes. The stretches I do are:

IT band - Standing stretch. Stand upright and cross one foot behind the other. Then lean towards the foot that is behind the other. Hold this stretch for about 15 to 20 seconds, and then repeat it 3 to 4 times on each leg.

Hamstring - Standing stretch. Basically, try and touch your toes, although I do this with legs crossed one behind the other. With this one, if you let your upper body just hang loose, you will feel the stretch increase naturally after a few seconds.

Glutes/lower back - Seated twist. This is an effective stretch for the big muscles in your buttocks.

Glutes/lower back - Supine spinal twist. Great for the lower back, and your hips.

Obviously, these exercises may or may not be helpful for you, depending on the exact cause of your problem. Only a doctor will be able to correctly diagnose your issue. But they're easy to do, safe, free, and may be helpful.


Well I thought we needed an answer to this, so I just phoned the shop. He's a nice fellow (as you can tell from the vid) and said that his mechanic is convinced that this method works to free-up seized and corroded mechs. Apparently dousing it in something like GT85 and lighting it for a very short time boils in the lube, and works.

I assume that the combination of a penetrating lube, some heat, and vapour would achieve this as a last resort for badly seized metal components. I've done something similar on bearings when trying to get them out of BMX cups in the past.


Bicycle chains are heavily standardized. They all use the same 1/2 inch pitch. All derailleur systems use chains with 2.4 mm internal spacing between the plates.

As manufacturers increased the number of sprockets in the rear cluster the sprockets had to be spaced closer together, which necessitated use of chains with an correspondingly narrower outside profile. You'll see that chains are specified for '6/7/8 speed', '9 speed', '10 speed' etc. 'Speed' here means number of sprockets in the rear cluster.

A 1977 bike presumably has 5 sprockets in the rear. Any chain good for a 6 speed will work.

Chains come with more links than you need and are cut down to size and joined. Instructions on how to do this are easy to find on the internet.


How to reinstall a tension screw of a V - brake that been fully unscrewed

Yeah loosen the brakes ,hold them with your hands such that the brakes just does not touch the rim of the wheel then tighten it .

If you find it a bit loose the adjust the secondary screw for more accuracy .


Shimano SL-RS47 SIS handlebar shifter reassembly

Shimano calls this a "REVOSHIFT Shifter (3x8/7-speed)"  and since its the left one, its only a three position shifter.

This model line is called Tourney and is the lowest named groupset.  Its made down to a price and all the design decisions are about being cheaper and faster/easier to assemble.  Downside of this is once its damaged they're generally a write-off.

You could spend ages and still not fix it.   Instead I'd suggest you replace both rotary shifters with an equivalent pod or trigger shifter like the Tourney SL-TX50 left and right.

They will have a thumb lever to drive the chain up to the larger sprocket and a push button that drops the chain to a smaller sprocket.  The left one is 2 or 3 positions, and the right one could be 6 or 7 or 8, so do make sure to get the same number as whatever's on your bike now.

I'd also suggest taking the opportunity to replace the two gear inner cables for a few dollars.   And optionally treat yourself to a new pair of handgrips because the old ones will have to come off anyway.

Left shifter as documented at https://bike.shimano.com/en-US/product/component/tourney/SL-TX50-L.html


Strategy for removing a bottom bracket with plastic retainers?

Based on my experience with such cups I suggest a rather robust approach:

cut off the external parts of the plastic cups with a hot knife
chisel away material from one side to expose the outer edge of the cartridge
apply penetrating oil to all areas
heat the bottom bracket with a heat gun (bear in mind the heat may damage the frame's paint @Argenti Apparatus)
drive out the bottom bracket by whacking the bottom bracket spindle with a mallet

if that doesn't work
* remove the bearings and the spindle
* uncover the other side of the bottom bracket
* drive out the cartridge with an improvised punch (eg steel tube, hex socket) and a press, apply penetrating oil and heat as before

I'm confident I should be able to remove such a bottom bracket in less than two hours now, if I must. I also shall not ever put myself in a situation where this may happen.


Are there any things to avoid when being given a free bike?

It's probably worth riding, if you don't have another bike.

First, of course, simply wipe off the dust (or hose it down and wipe dry).  Then examine for bad rust.  If it's an inexpensive bike that was stored where it wasn't completely dry there's apt to be some rust spots here and there, which is OK.  But gobs of rust around the bearings is a bad sign.  If the chain is badly rusted that's not fatal, but not a great sign.

Air up the tires.  (Once you decide you'll be a bike rider you'll want to get a bike pump of the full-sized "floor" variety.)  Then pick up the bike and spin each tire -- they should spin freely, with no gritty feel in the bearings.  Note that the brakes may drag, but that's not a serious problem.

Pick up the rear wheel (or hang the whole thing from ropes or some such) and then turn the pedals with your hand.  The chain will likely clatter quite a bit, but by adjusting the shifters (and maybe "helping" the chain with your hand a bit) you should be able to get squarely onto gears front and rear and then turn the crank at a fair pace.  There may still be clatter, but you shouldn't feel a gritty feeling in the bearings of the crank.  (Note that if the chain is badly rusted with "frozen links" you won't be able to get beyond this point.)

Next, try the brakes.  If the bike has been exposed to the weather the brake cables are apt to be badly rusted, but that not a big ticket item.  But for a test ride you want at least one working brake.

If you get this far, try to adjust the seat to about your height (this may require an Allen wrench of the appropriate metric size, or a regular adjustable wrench for a bolt head).  (Keep in mind that if anything on the bike is rusted it's apt to be the seat height adjustment, though.)

But if you can get the seat semi-adjusted, get on the bike and try riding a short distance.  If you're brave you can try the shifters, but you're more feeling for a grinding feeling anywhere, in the pedals, wheels, or steering.  And somewhere along the way examine the condition of the tires, looking in particular for cracks in the sidewalls.

At this point you may have no problems at all with the bike, in which case you can just ride it, though you should probably take it to a shop to be tuned up within a few weeks (or buy a good book on the topic and do it yourself).

Or you may have found something (rusted brake cables, bad shifting, rotten tires, etc) that isn't "fatal" but demands more immediate service.  Almost certainly worth paying a shop to fix.

Or you may have found crunchy bearings, severe overall rust, or some other problem that makes the bike at best a "fixer upper".  Only spend money on this one if you've got a "thing" for "lonely" machines.

One thing to note:  If you decide, for whatever reason, that the bike is not for you, ask around for an organization that "recycles" them.  In our area Christmas Anonymous and the Kiwanis Club will take bikes in any condition to be rehabbed for kids and needy adults.  Bikes that are in too bad of shape to be rehabbed are stripped for spare parts and the rest is recycled.


Can Shimano Rear Derailleur Lever Be Fixed?

Those are "stem shifters"

Problem is its not just a simple bolt.  There are washers in there that do the actual gripping and it sounds like they may be dirty or worn to not be holding so well.

If you're handy, take it apart completely, clean with solvent or citrus cleaner, and then reassemble in the reverse order.  Take lots of photos to assist with rebuilding.

If you're after a quick fix, take out the screw/bolt, squirt some "locktite" on the threads and reinstall.  Leave it a day to harden and then ride like normal.   Superglue (cyanoacrilate) can be used instead in a pinch.


How quickly can the body restore energy reserves mid-ride/post-bonk, and how do we optimise this?

I'm interested in how we can maximise restoring energy stores (mainly glycogen, but I'm deliberately being vague) either between closely spaced rides or on long rides.

On a ride

Here your ability to actually rebuild glycogen stores are compromised as your body is trying to fuel the activity not rebuild your stores.

Exercise actually alters your physiology, for example the blood flow to the gut is restricted. As such, severe or exhaustive exercise actually inhibits gastric emptying and interferes with gastrointestinal absorption. This makes it difficult to absorb food, why easily digestible  foods such as gels were invented.

Your insulin response is also greatly reduced during exercise as your body is trying to keep your blood sugars elevated so it can create high energy molecules (e.g., ATP) through glycolysis which in-turn are used to power your muscle contractions.

As long as you continue to exercise your body will prioritize creating energy over rebuilding stores, so rebuilding or recovering from a bonk while riding will always be severely compromised. The short answer is on a ride DO NOT let your glycogen stores get depleted. The general rule of thumb is eat something easily digestible carbohydrates at least every 45 minutes. The idea is you want use ingested carbohydrates to elevate blood glucose levels, rather than relying on your glycogen stores, which can be depleted relatively quickly (e.g., within 2 hours)

In-between Rides

Here refueling within the first 4 hours post-ride can be critical:

  Finally, take advantage of the glycogen repletion window that facilitates muscle glycogen repletion in the 4 hours immediately following vigorous exercise. During this time, any carbohydrates you eat are converted into muscle glycogen at up to 3 times the normal rate. And this window of opportunity closes fairly quickly as some data suggests there is a 50% fall in this super charged repletion rate by 2 hours with a return to the normal repletion rate by 4 hours post exercise. (Ivy JL et al,J Appl Physiol 1988 Apr;64(4):1480-5).

  [...]

  After this initial 4 hours surge, muscle glycogen stores are replenished at a rate of approximately 5% per hour. And while it may require up to 48 hours for complete muscle glycogen replacement following a 2 hour ride, for all practical purposes glycogen stores are almost completely rebuilt in the first 24 hours post event.

  [...]

  The rate of glycogen repletion is highest in the first 2 hours and then begins to fall off.
  Is more better? Although the rate of CHO incorporation into muscle glycogen storage begins to fall at 2 hours, there is a maximum repletion rate in the range of 1.5 grams of CHO per kg body weight during the first 2 hours post exercise. Thus a strategy of taking all your CHO replacement in the first few hours is not going to work.

  http://www.cptips.com/recvry.htm

Summary

There are physical limitations to how fast we can rebuild stores. The optimal strategy is not to let your glycogen stores get depleted if you are planning on completing back-to-back endurance bouts.

A lot of this comes down to strategies:

Nutrition, before, during and after;
Not digging too deep on earlier rides, or too early in the final ride (i.e., pacing);
Minimizing your effort where ever possible:

Skipping pulls in the group;
Never letting gaps form between you and your daft; and
Not running a pannier (these are essentially parachutes), instead try a frame bag or a larger saddle bag, as the latter has very little drag.


What are the advantage of the different gear shifters

This is based on my experience with the following type of shifters, but is limited to Shimano so others may have a different experience.  I haven't tried to split out the different variations of brifters either since I've only used 105's.

Integrated brake/shift levers (aka "brifters")

Pros:

Shifters are always close at hand, so you can always shift when you need to without taking your hands off the handlebar (unless your hands are on the flats).
This means shifting while climbing/descending is a breeze.
Similarly, brakes are always nearby

Cons:

Expensive
Complicated devices, so a mechanical issue can cripple your shifter when on a long ride far from the nearest bike shop.
Brake levers are very likely to take a pounding in a crash (whether major or minor), which is bad news for brifters (see "expensive" and "complicated" above)

Bar-end shifters (mount at the end of drop bars or aero bars)

Pros:

Simple devices, usually indexed for quick gear changes, but can also be switched to "friction" mode which allows you to dial in your gear by feel (handy when your shifting goes out of alignment).
Lower total cost than brifters (including separate brake levers)
Easier to learn than down-tube shifters

Cons:

Shifters are nearby, but you still have to take your hand off the bars.
Inconvenient if you need to shift while out of the saddle.
Possible to hit them with your knees (depends on bike and rider geometry) which can cause an unwanted shift (and can be quite painful)

Down-tube shifters

Pros:

Simple like bar-end shifters (including choices of indexed/friction shifting)
Also inexpensive
Shorter shifter cable runs
Not likely to hit your knees

Cons:

Quite far from the bars, so you'll likely shift less often than with the other styles
Inconvenient for shifting while out of the saddle or during a white-knuckle descent
Takes some getting used to finding the levers without looking
Not all modern frames will have the appropriate braze-ons for mounting (but most should).

My current bike uses bar-end shifters based on some of the reasons above.  Plus for long randonneur rides (over 20 hours) I lose a lot of hand strength and the bar-end shifters are the easiest to work with (can shift using the heel of my palm).


Why do I lose so much power/speed in an aggressive position?

I've heard many cyclist say they can go faster (and are more comfortable) with a large bar drop.

I think this initial assumption is somewhat faulty. Most riders will find they are less comfortable and can make less power in a forward, aggressive position. I certainly find that to be the case myself. (I'm a reasonably fit rider who can hang with the A group on local rides.)

You may just need to accept that your anatomy and strength just don't allow for a aggressive riding position. If you are riding in hilly terrain and are concerned with making your max power, set up your bars in a less aggressive position that is comfortable for you and just ride on the hoods. You can get in the drops on descents where max power output is less important compared to getting more aero.


Weight limits are usually based on what the wheels can take rather than the frame. Also like with most things nowadays the manufacturers build in a margin of error so you can likely ride it safely 10-15 lbs above the actual limit.

Riding on compact gravel should not bother the bike so long as you keep it clean - make sure dust isn't getting into the hinges. To rule out any issues with the hinges clean them thoroughly and apply a light coat of quality lube something like Dumonde or Finishline. Then ride the bike and see if the creak gets any better. If it does, there may be some play in your hinges. A good bike shop should be able to adjust that play for you. If it does not get better the culprit is likely somewhere else. Possible sources could be the saddle mount or bottom bracket area.


I want to convert a 1-piece crank triple chainring to a double

Yes, you need to consider chain line, but that does not mean you cant swap in larger rings on the middle and outer positions.

Sounds like right now you are are using the middle and outer chainrings exclusively on your triple crank. If you put two larger rings on the middle and outer positions, there's no actual difference in how you are treating the chain.

Obviously it would be better to use a double crank as this will put less strain and wear on the chain, but using the two outer triple rings may be acceptable, as it's the lowest cost option, especially if you are careful to always avoid cross-chaining from the large ring.

BTW, you'll want to make sure that there is clearance between the new large rings and the chainstay.


Why is the steering so twitchy? Steel 90's MTB fork

Short answer - your fork is stuffed.  Stop riding it.

Longer answer - Here's your bike with the main lines drawn on top

And compare that with this approximate equivalent Peugeot bike.  Spot the differences and compare with my list below...

Headtube angle is steeper on your bike - closer to vertical
Negative trail -

A line drawn straight down from your front hub hits the ground at a point.  This is where the tyre touches the ground.
A line drawn down your head tube center line hits the ground after the first line.
This difference is called trail, because the tyre's contact patch "trails" behind the head tube's axis.  Normally, the larger the trail, the more stable your ride is and the more effort it takes to turn. The trail is what helps a bike go straight by default.
Your bike doesn't have positive trail... it has negative trail, or "lead" if you like.  Your bike's head tube angle is continuously pushing the front wheel to a side and you have to actively correct this.

Additionally, notice the top tube slopes down.  That was not done on MTBs where the top tube was horizontal or sloped up to the head tube.  Since the fork is stepped forward at the end, the front is now lower.  As a compromise, someone has fitted a small A bar from a kid's bike into the quill stem.  This weird set of angles will also compromise handling - you've effectively got 20+ centimetres of stem and the handlebars are noticeably higher than your saddle.

Upshot - you're riding a clown bike that is trying to murder you and may fail at any moment with little to no warning.

The fork is your problem - it needs replacing outright.  Once that's done, the existing wheel and brakes should fit up normally.  I'd strongly suggest getting a flat bar not that double-stack - once the fork's fixed then the extra height will be more of a hinderance and you won't want to be sitting up like a dutch bike with your arms straight forward.

Do check the headset bearings too - there's a chance they've been damaged.

There appears to be too much bend there for a safe un-bending.  Steel is nicely flexible but it has bend limits, and you've likely exceeded them with that level of distortion.   If you continue to ride this, the fork is being extra-stressed in the back under the headtube, and this is where it will fail first.

Please ride safe bikes.  Right now, this is not a safe bike.   This bike can be safe again, with work.


For any given speed, you can either spin at a higher cadence in a lower gear, or a lower cadence in a higher gear.  The high cadence + low gear combination should reduce the strain on your joints since you don't have to push as hard.  You just have to do it more often.

I like to ride around 90rpm and sometimes drift up to 100-110 especially if I'm trying to catch up to or overtake someone.  I'll drop down to 80 for long, steep climbs (seated -- no idea what my cadence is standing).

Lance Armstrong apparently maintains 110rpm for efficiency.  It took me a while to get used to 90 so I'd suggest building up to it slowly.  Let us know when you can do 110 comfortably!


Will magnetic pedals interfere with ebike batteries or motors?

They won't interfere with the batteries (which aren't sensitive to magnets) or the motor (which contains stronger moving magnetic fields). Anyway even in the worst case both are a good few cm away and magnetic fields reduce quickly with distance.
Even wiring run along the downtube is reasonably well separated from the pedals, and it takes a lot to induce a measurable current in a straight wire with even a strong permanent magnet (I've tried - even a coil has trouble picking up much unless far closer than your setup would suggest). A problematic current would be even harder to induce.
There's a slim chance they might interfere with a magnetic cadence sensor in the cranks, which some electric bikes use to sense pedalling to know when to assist. You may be able to whether a particular model uses that sort of sensor.


Do my Shimano 7900 Dura Ace chainrings need replacing?

You should be ok for training, but when the time comes to replace the chain the worn chain rings will speed up the degradation of the new chain. You should try to replace the drivetrain components all at once or you won't get maximum value for money. But this can be expensive and overkill if you're not cycling competitively.


What should I look for in a cyclo cross bike

Not much to go on.  Disc brakes for wet.  2x set up if you are going to use is on the road.  You probably want clincher wheels.  Aluminum frame.

Not technically a CX but a bike like this http://www.trekbikes.com/us/en/bikes/city/fitness/crossrip/


Which kind of bicycles is better and comfortable for shorter communtes, 4-5 km daily

My priorities:

Right size for you. A must.
Light weight as possible/desired
Low price - it needs to be do a simple job without being a thief magnet (at least here)


What tactics other than 'setting an example' successfully encourage friends/family/others to become cyclists?

Sex.

Convert them one at a time, starting with the attractive ones. Only date potential cyclists, and slowly convert them while you date them. This tends to produce a solid conversion, because you have the opportunity to reinforce the positives and address the negatives over an extended period.

I've been doing this for a while now but it's a slow process, usually taking more than five years. The benefit is that I have a partner who cycles, but it isn't very good at producing a great mass of cyclists unless you import thousands of Dutch singles. In my case people have asked whether I only date cycling activists. The answer is no, the people I date become cycling activists (well, two out of two in the last 10 years have).


A perfectly reasonable question.

Cycling is gererally thought of as being an excellent way of keeping fit. It is seen as beneficial for cardio- health and for leg muscles (not so much for arms), and is low-impact on joints. On top of that I would add that the benefits are proportional to the amount of effort you put into it.

Of course, how safe this exercise is for the individual would depend on the individual themselves, their existing fitness etc. and any pre-existing medical conditions. An individual should discuss any proposed fitness regime with their doctor. So where your question becomes impossible to answer is how reasonable your fitness regime is for you, and any improvements you could make. But that holds true across the board.


Can I install/convert a Giant Quick-e+ 2019 to use an Alfine 11 speed IGH?

Seems like a perfectly reasonable project, but there is possibly a technical implementation issue.

The SG-S7051-11 hub is part of Shimano e-bike series that includes a motor, and as you pointed out Shimano says the hub is designed for an e-bike, so it obviously is fine to use it on your Giant.

The dropout spacing offered 135mm only, I would expect the Giant to have that spacing as it has a disc brake. You will need to run a chain tensioner obviously, but that's no big deal.

The difficulty I see is the compatibility of the anti-turn washers with your dropouts. The installation manual here shows quite deep vertical dropouts which the Giant does not look like it has. I believe that is why you were told you need a torque arm. Finding one compatible with the Alfine hub may be a problem, as I believe Shimano does not make such a thing for that hub.


To weaken the wheel you really want to remove a multiple of 4 spokes, so you balance leading, trailing, left and right. Six would be tricky. If the rim is reasonably strong you should be able to remove 12 as 3 groups of four to give that Shimano-style gapped spoke pattern. You'll have a gap, obviously, but the wheel will still be somewhat evenly tensioned.

Ideally you'd rebuild the wheel with the missing spokes distributed as a missing pair from every 6 spoke positions, but that would probably be more work than you want to do. If the wheel isn't fairly new the chance of stuck spokes is high, and disturbing it makes it more likely you'll damage something.

If you're reasonably familiar with truing wheels I suggest backing everything off a turn, removing the spokes, then tightening it all up again. That will let you work the spokes into a reasonably even tension while keeping the wheel straight. Removing groups of spokes when everything is tight will cause odd stressing mid-process and the risk of pulling a nipple through the rim or taco'ing are higher.

But... you're only going to save 20-30 grams, when a lighter wheel will save more. I'd stick with the strong wheel and save/scrounge a light one.

Also, per the comments from Criggie and Daniel R Hicks, if you are cutting spokes remember that they are under tension and the cut parts can exit the wheel with some force. If you want to keep the wheel it's better to back the spokes off rather than cutting them when tight.


Which clothes to use in wet weather for long distances?

Short answer: you won't stay dry.  Your best option is to maintain comfortable body temperature.

Longer answer: What to wear depends how cold it is, how hard it's raining, and whether your bike is equipped with fenders.  In the Pacific Northwe't, we have a lot of light rain and a moderate temperature band.  I keep the fenders on year-round (which makes me stick out a lot when I attend events in eastern Oregon ;-) and assume that I'll get wet one way or another.  How I dress depends on the anticipated temperature band:

Above 70 F (21 °C): dress as I would if it were dry, namely wicky polyester jersey & socks, spandex shorts.  These things air out pretty quickly.  I'm usually working hard enough that staying warm is not a problem.
50 - 70 F (10 - 21 °C): A Merino (non-itchy) wool jersey works very well in this band.  It holds water, but it'll keep you warm.  If it's especially windy or approaching the lower temperature range, I'll add a layer, wear wool/poly socks, a beanie, and a polyester light fleece set of tights.  The main purpose of these is to stay warm, especially if I stop (e.g., to change a flat).
Below 50 F (10 °C), it's cool enough that I'll definitely be wearing tights and a rain jacket.  I'll also have the closed-finger gloves.  For my feet, I'll cover the shoes with a neoprene bootie.

Shoes: The neoprene booties don't ward off water as much as you'd think they would, but they do keep my feet warm.  They go on sale for ~$20 at various places.  I've been very tempted to wear sandals and wool socks.

Leg wear - the polyester fleece tights tend to go on sale at Costco for ~$20 in the September timeframe.  They're great for this temperature range.

Rain jacket: I have a nice Showers Pass jacket with lots of zippered vents and pockets.  I find that I tend to keep the underarm zippers open to regulate heat except when it's really cold.  When I get warm enough, I'll roll it up and stuff it in the handlebar bag.

Head beanie: is a polyester, light fleece cap that I picked up at REI (though many other places have them).


Does rebuilding a hub increase efficiency?

For a typical rebuild the increase in efficiency is negligible. Think about the leverage you have over the bearings on a rotating wheel- it's pretty substantial compared to the friction of the bearings, even if they're not in perfect shape. The bearings would have to be destroyed for it to make a significant difference, and if the bearings are destroyed it's likely that the hub would be too, at which point a rebuild is moot.


Dynamo cutting out after a couple of seconds

You could try measuring the voltage the dynamo outputs when spinning the wheel. Strip two thin wires on both ends , insert them into the dynamo plug (plug which is usually present on the hub to which the wire going to the light Is attached), attach a multimeter and spin the wheel. If the voltage drops to zero/drops considerably after a few seconds whilst still spinning the wheel the problem is not with the dynamo and it's probably a short circuit/ground or bad electrical connection somewhere.

Example of what a dynamo plug/ connector might look like:
https://i.stack.imgur.com/fQyr8.png


How much easier is cycling compared to walking or running?

I know calorie counts vary quite a bit, but a rough ballpark for cycling at a 20 mph pace is 450 calories per 15 minutes according to this calorie calculator.

Running a 6 minute mile is expected to burn a similar 450 calorie count on the same calculator with the same settings.

So, if you do the math, and the calculator is assumed to be reasonably accurate, then 5 miles on a bike at 20mph, is roughly equivalent to 1 mile run at a very fast pace.

Running a half marathon, which is 13 miles, and ignoring any difference due to endurance of effort, 13 miles at full pace running could be assumed to be a similar effort to 65 miles on a bike, in a very general sense.

This is dependent on fitness, body weight, and many other factors.

The best method to work it out would be to measure power expended, but I don't know how to do that for running, and to be accurate, you'd need to do it yourself, and for the full distance of the half marathon.


For this you will need to know the gearing ratio from front to back (or number of teeth on each gear), the wheel diameter, and the rate at which you are pedaling.

1) RPM to rad/s:
Firstly determine how fast the front gear is turning, assuming that you are pedaling at one complete revolution per 2 seconds: 30 RPM / 60 (convert from minutes to seconds) * 2pi rad/rev:

pedalSpeedRPM = 30
speedRadPerSec = pedalSpeedRPM * 2 * pi / 60

2) Next determine how fast the rear wheel is spinning by using the gear ratio; the ratio of the number of teeth on the front ring to the number of teeth on the back ring. For example, if the front ring has 53 teeth and the rear ring has 13 teeth, then the ratio is 4.08. That means that the rear wheel is spinning 5.2 times faster than the pedals. Thus:

gearRatio = 4.08
speedRearWheel = speedRadPerSec * gearRatio

3) Rotational to linear motion: If you know the diameter of your wheel, you can determine how far it moves with one revolution, for example, a 26" wheel (in metric because that's what I know) has a radius of approximately 0.33m. Using the formula velocity = radius x angular velocity gives

wheelRadius = 0.33
velocity = wheelRadius * speedRearWheel
velocityKPH = velocity * 3.6

So to bring it all together, you need to know the following variables:

pedalSpeedRPM = 30
gearRatio = 4.08
wheelRadius = 0.33

Calculations:
speedRadPerSec = pedalSpeedRPM* 2 * pi / 60
speedRearWheel = speedRadPerSec * gearRatio
velocity = wheelRadius * speedRearWheel
velocityKPH = velocity * 3.6

Running this on MATLAB gives the result:

velocityKPH =

   15.2274

Which isn't a bad estimate for middle gear, non-frantic pedaling.

Another example, with (maybe) more realistic numbers:

pedalSpeedRPM = 60; % Faster pedalling
gearRatio = 4.2; % Abitrary
wheelRadius = 0.37; % 29"

velocityKPH =

   35.1507

So I guess to (finally) answer your question, yes, you can determine it, but you need to know the gearing ratio, your wheel size, and an estimate of your pedaling rate.


For a complete knowledge base on fitting tires for different rim-sizes, see here: http://sheldonbrown.com/tire-sizing.html
and scroll down to 'Width Considerations'.
30 or 33mm tires will fit your rims but they'll probably need a lot of pressure which might just be counter-productive on snow. On the other hand you should consider another possible issue: 30 or 33mm tires might not fit into the front fork or between the rear stays.
If they do, you might want to buy a second pair of wider wheels and use the wider tires on these. It will keep your 'Summer' wheels nice and shiny.


Cannondale Synapse 105 chain dropping on the last gear

The problem was that some ring teethes were a little bit bent. There have to be some impact somewhere between manufacturer and delivery service (the box was not damaged).

I took it to a bike service and they flatten these teethes and everything is now perfect.


Look for downhill MTB goggles.  These will be made to fit with a standard bike helmet and will have sticky plastic on the straps so that they will stay in place on your helmet.  I rode with a pair last winter and was very happy with them.  Kept my eyes warm and didn't fog even under heavy riding.  Many also come standard with clear lens so visibility won't be an issue.

Link - Note these arn't the pair I have - just did a quick search and posted the first pair I found.  I am not endorsing these goggles or the company selling them.


Biologic now makes an iPhone 4 specific mount. I have the 3 version that I use an iPhone 4 in.  It's pretty decent, but this looks like they've made some good improvements.


Bottom bracket bearings grinding only when installed into frame

Bearings are never as buttery once they've been installed, they all feel rougher after they're put under pressure. I put GXP BB90's in my carbon 29er frame and it was the same, though not too bad. It looks like you've installed them properly, it may just be that the frame could be a bit on the tighter side. Riding the bike will loosen things up a bit though, take it for a ride then check the bearings again to see if there's any difference. Unfortunately there's really nothing else you can do about it except hope that it smooths out a little from breaking it in. Those bearings are a closed system, you can't adjust them. The only other solution is to try a different bottom bracket.


Can I shrink my steel rear dropouts to fit a smaller hub?

One solution might be to add a larger 5mm spacer on the axle, between the outside of the cone-nut and the inside of the locknut.

The risks here are that your axle may suffer from bending easier because its now supporting the bike's weight further out.  Also, you'll probably need a longer axle too because the track wheels are unlikely to have much spare.  Get the strongest axle you can, and I'd suspect a solid axle with nuts will be better than a hollow QR axle.

You could also do both, slightly compress the frame and have 2~3mm of spacers rather than the full 5mm a side, to minimise parallelism changes in the rear dropouts.

Spacers are marked on this image of a replacement rear axle.


What do you do to make positive you remember your water bottle?

I'm not a commuter, but I believe in putting something that must not be forgotten next to something that might be forgotten.

For instance, I would put my bike gloves on top of my water bottles.

(I do the same thing when I have people over to visit. If there's something in the fridge that I want them to take home, I put their car keys in the fridge on top of the container.)


How can I inflate Presta valve tires using a Presta compatible pump without bending the valve stem?

I've never had this problem.  It would take considerable force to bend the stem.

First be sure you have the nut on the Presta stem, and that it is screwed down firmly against the rim (though it shouldn't be wrenched tight).  This will keep the stem from wobbling around in the rim hole, and makes the whole job easier.

Then make sure that the wheel is rotated around to where the stem is easy to reach, and the pump is pre-positioned so you won't have to fight the hose to get the chuck on.

With most chucks you press the chuck on, the raise the lever on the chuck, but a few you raise the lever first, install the chuck, then flip the lever down.  Be sure which style you have.

Prepare the chuck for installation, press it on squarely, then, while holding the chuck with one hand raise/lower the lever with the other.

Note that on some chucks there is an adjustable collar on the end of the chuck which you can screw in for a tighter fit, out for a less tight fit.  You want the collar (if present) adjusted to allow the chuck to slide on with only mild resistance, then grip firmly when the lever is raised/lowered.


Can a regular diamond frame bike be packed to fit as standard airline carry-on luggage?

You are correct that bike wheels are the dealbreaker—even if you could get the frame down to carry-on size, you won't get the wheels that small (although people have tried making collapsible bike wheels too).
There are full-sized bikes made with couplers, which can be taken apart and packed in a case with the same footprint as the wheels, and there are a few "full-sized folders" that look nearly identical to a conventional bike as well. But these will always be bigger than carry-on size. Attempting to bring one on board would require the indulgence of the cabin crew, and is not something you could count on.


Can Shimano Tiagra 9 speed levers (ST-4500) be used with 105 brakes (BR-5700)?

As long as you use a Shimano brake caliper designed for a road STI lever, which is any Tiagra, 105, Ultegra, or Dura-Ace, they will work not just well, but perfectly. There may be a performance difference, but there will not be a compatibility difference.

Even most 3rd party brake calipers will work just fine.

New additional information: Starting with the Dura-Ace 9000 and Ultegra 6800 groups, there are differences in the brake caliper design which require levers which match the design. They also recommend, but do not require, a specific type of cable to get full benefit from the new brake design.


How can I tilt up a stem of my bike's handlebar which is held by two bolts?

Adjustable stems follow a couple different design schemes, all of which involve some interlocking toothy bits that hold the angle in place. If the angle isn't changing, the toothy bits are still locked together.

There's probably a bolt on the underside of the stem extension. If so, that's what locks the angle adjustment in place. So you loosen the side bolts, loosen and adjust the underside one, re-tighten underside, re-tighten sides, in that order.

There's another type of adjustable stem without the underside bolt, where the side bolts are tightening down a pair of toothed plates that hold it all together. That doesn't appear to be what you have, but in the case of a recalcitrant one of those, you would just need to gently pry the plates free.


Are electric bike speed limitations set in stone?

The limit is set by law depending on the country. There's nothing to prevent you from going faster if you can pedal harder. The limiter just cuts off the electric assistance above 25km/h, so you'll have to rely on pedal power alone above that speed!


How to transport an unusable bike AND a set of wheels without a car?

"Ghost ride": Borrow a good bike (if needed). Ride on the good bike, while pulling the incomplete one alongside you by holding its stem. Your secondary hand sits on the second bike's stem and pulls it along as you ride slowly.
It may sound silly, but I had to do it once and I was impressed with how well it worked. One way to look at it: it's not much harder than riding one bike in the first place.

I don't have a clear understanding of what the condition of your bike is and whether this will work for you.
For my solution to work, your incomplete bike needs to be complete enough for you to roll/push it as you walk alongside it, so stem and both wheels need to be on and capable of spinning. But you don't need a seat, chain, gears, brakes, pedals etc.
Some notes from Criggie - he posted a very similar answer minutes after me and he kindly suggested I merge his into mine.

The towed bike should be slightly behind your bike, by perhaps 100mm
or 4 inches, to help limit handlebar interference.
If you have a choice, ride the smaller/lower bike or the one with
the most upright body position.
Obviously you need your prime braking hand ready to brake your bike.
If that means you can't change gear, so be it. Score one for
right-hand front brake and right hand rear shifter setups.
Turning can be a tricky process too - you need the inside bike to
turn more sharply, and to not get the handlebars or pedals hung up
on each other. And if it does go badly you need to be able to
recover without falling off. So pick a quiet route with no big
intersections, no climbs/descents, etc.
It is possible to lift the towed bike to get it back on track, but
avoid leaning on it while riding. However you can do an awesome
trackstand at a red light this way!
This is nothing to do with Ghost Bikes, the white-painted memorials,
and also nothing to do with "ghost riding a whip" a trendy bike
trick where the bike rolls all by itself with no rider.

EDIT: someone already wrote a good guide for this.
Please also note I have no idea whether this is legal, so only do it on your private land:-)


Saddle for long rail trails, streets and dirt paths

The kind of biking you do is exactly the kind of biking I do. I was once a devotee of the Cult of Saddle Cushioning as well.

I was wrong. Painfully, chafingly so. Ow.

You don't want the gel. You don't want lots of cushioning. What you probably do want is springs (saddle suspension) and perhaps something a bit wider in back than your typical Lycra Laddish roadie thing. You may also want to invest in bike shorts with a good chamois. You definitely want to invest in a decent skin-lubricating cream (hunt around here; several posts on that).

I splurged on a Brooks leather saddle for my tourer, and while I'm still breaking it in, I can already tell it's a much better ride than the cushion-packed saddle I replaced. If Brooks is too pricey, but you still want leather, Velo-Orange has some less-expensive ones (though caveat emptor: I've seen some poor reviews).


Do more expensive bib shorts make a difference when sat on a turbo trainer for hours on end?

The big difference between rollers and the outside is that your position is much more static inside. If you are good enough on rollers to stand every once in a while that might help. ( I'm not ). Maybe just take a 5 minute break every hour.

If your shorts/saddle are comfortable outside for 2+ hrs, I doubt expensive shorts will really make much of a difference. However, when it comes to saddle comfort everything works for somebody and nothing works for everybody.

I'd try the expensive Assos cream to start with, it's only a $30 experiment vs a $300 one.


Shimano GRX front derailleur compatibility

The 11sp derailleur cage is designed for the externally narrower 11sp chain. therefore the shifting will be less precise using an 11sp chain with a 10sp front derailleur


What is the advantage of a "compact crankset" vs changing a chainring?

Getting though all the hype and testosterone - Compact cranks allow a smaller small chain ring as they have a smaller BCD. Modern tech means you can have a wider gap between chain rings, giving larger spread.

This means modern compact cranks with wide range 11 or 12 speed cassettes can get the same gear range and stepping as a triple 7 or 8 speed with just a double.

Where you would switch to a compact is if you have decided you need a smaller chairing than will fit on a standard crank. However, you may still need a new Front derailleur and possibly a shifter.


I'd suggest starting with enamel paints from a model shop.  They come in small tins, and you will need one tin of each colour your design requires.
Enamel paints used to mean oil-based, but now there are "acrylic enamels" that can wash up in water, but still have oil based qualities.
Additionally you will need multiple small brushes, on a size to suit your design.  Fine pointed brushes for fine lines and details, and some wider brushes (10-12mm) to fill in larger parts.
Preparation is key - literally.  You need to prepare the surface so it will have a key, or tooth, to hold the paint.  That means sanding, and you might require an etching primer too.
Lastly once your design is done, you will need multiple layers of clearcoat on top to protect the paint from impacts, dirt, weather, and fading from UV light.
Another significant issue is vibration and cracking - a bike is ridden and the mudguards/fenders will flex.  This could crack the paint and make it fall off over time.   I suggest you try a small test before investing a lot of time in something that may look awful after a few rides.

Sadly one pottle of paint is around $4 USD so your budget won't go far.  I'd suggest you buy some 220 grit sandpaper $3, one colour of paint $4, one spray can of clearcoat $12, and a paintbrush $2.  There will be leftovers of course, but you're in for at least $20, or 1500 rupee.  You might be able to source things cheaper, or perhaps you already have some items.
Either way, if you just slap paint on an un-prepared surface, it won't last very long.  In that case, might be better to not do it at all.


Are there two Raleigh bicycle companies?

There are license branding.
For example Raleigh is sold in Japan through a Japanese bicycle wholesaler that design Raleigh bicycles to be adapted to Japan local trend.
The "Japanese" Raleigh are made in Taiwan and China and have not much to do with the original brand except the name and vintage design inspired by the original models of the 60's and 70's.
Many brands do this.

Your bike is probably of better quality than lower priced model.
You have to compare specification to be able to determinate if your bike is "lower" quality bike or not.


What is the "3 foot law" and which US states have it?

The 3 foot law is an example of a law that exists mostly to create awareness rather than having some direct practical function.

This law is rarely enforced by itself. Can anyone cite an instance where a motorist was ticketed for passing in under three feet (and not ticketed for anything else)? The 3-foot law is, AFAIK, typically enforced as a supplement to some other violation such as failure to yield or reckless driving.

But more than anything else, the intent is to create some level of awareness in motorists about how to deal with cyclists. If motorists know it is a law, most will make an effort to abide by the law.

A quick google search reveals that, as of this year, 20 states in the USA have this law.  You can view a map depicting the status of this law in the United States here: http://www.3feetplease.com/important-stuff

It seems to me that in the last 10 years or so, motorists have been getting much better than in the past about getting along with bikes. It could be the marked lanes/signage, or perhaps things like the 3-foot law, but I have noticed a LOT LESS "entitlement-to-the-road" behavior from motorists than in the 1990's and earlier.


Cutting cables and housing is a bit of a pain in the ass (especially regular spiral housing for brakes). A Dremel with cutting disc or something like the Park Tool CN-10 is useful to cut the housing, along with a small file / punch to make sure that the hole is clear and smooth.

The rules for running cables are here and here, along with some directions for cutting. Even if you do get a kit (e.g. this), you will still need to do some cutting, since bikes are of different sizes. Assuming your housings were sized appropriately before though, you just need to use them to size the new ones.

Note that bad cable installation can drastically degrade performance / be dangerous if its on your brake systems.

The cable cutting tools may not be a worthy investment if you don't use them often enough, so you may want to borrow them from a bike co-op or just get a shop to do it for you.


Pointing it forward or downwards would be problematic as the lever might get caught somewhere and therefore get opened.

Remains pointing it backwards and upwards parallel to the fork. When pointing it parallel to the fork blade, it might touch the fork and therefore not fully close. This might cause the quick release to open by itself unintendedly. One can easily mitigate this if one knows about it and orients the lever a bit different, however, one has to be aware of it. Pointing the lever backwards does not suffer from this problem and therefore is the most safe version (also from a legal point of view) for the manufacturer, as one does not have to be aware of any implications.


Pretty sure this is the frame in question, maybe different color, but the reason this won't generally work applies to most designs.

The chainstay link is connecting its dots in 3 dimensions, not just 2. In other words, it's not flat; the distance from the pivot to the frame centerline is a different, larger number in back then in front. So even if the way the hardware interfaces wasn't an issue, which for most frames it would be, you can't just flip it upside down because it won't connect the dots right anymore.
Say you were asking a similar question but more from a fabrication standpoint; i.e. you were thinking about making a new chainstay link that did connect the dots but took a little different path for clearance reasons or whatever. Generally that's fine if you make it strong enough, design it right, etc. There are various full squish frames with very different looking pieces left and right.


Litespeed frame has clear film all over it

If it’s polished Ti (bright silver) it’s most likely the protective clear coat finish. A picture would help confirm that.

If the bike is relatively new contact Litespeed and see if they will cover it under warrantee.


Easiest thing to do is just cut off the old hood then take the new hood and thread it on over the bottom of the brake lever. Some are 'ergo' and have a right and left hood so make sure that you watch for right and left hoods.


Shimano Altus 9x3 speed shifter leaver is soft

If there are any problems with a bike after a week you should take it back to the store where you bought it.

If that's not possible or you bought online etc., it sounds like there is no tension on the shift cable, or possibly the shifter is broken.

The cable may have become detached from the rear derailleur, or pulled through the pinch bolt. A section of housing may have come out of a frame stop, or the cable may have broken (unlikely on a brand new bike). Possibly the derailleur is jammed on a low gear (large sprocket) so the spring is not pulling the cable.

Inspect the cable run from the shifter to the derailleur, making sure the housing is in the frame stops and is attached to the derailleur.

If that does not reveal a problem, detach the cable from the derailleur by undoing the pinch bolt.

Inspect the derailleur, can you force it to change gears by pushing the parallelogram while manually turning the cranks? Be very careful to not get fingers stuck in the chain while doing this!

Grab the cable (pliers may be needed) and put tension on it. Work the shifter. If the shifter is not working and releasing and pulling cable as you shift up and down then the shifter may be broken.


This question I remember was about fitting rear racks to disc brake bikes, using quick release (QR) skewers. Seemingly, good ones are supplied with an extra long QR skewer to mount the rack: Which holes to use for mounting rear rack?


How do I put a lower seat clamp on my Alinker walking aid?

OK, now I see what you're talking about.  I suspect the piece you have should go beneath the seat rails, with the cylindrical section pointing down and nesting in a matching half-cylinder depression in the base of the assembly.  The two ends of the piece have grooves (on the opposite side from the cylindrical face) that should accept the rails from the seat.

Then the top piece is bolted down over the rails (with bolts from the bottom).

The purpose of the cylindrical side of the piece you're wondering about is so that that piece can "rock" in the "cradle" created by the base, allowing forward/backward tilt of the seat to be adjusted.


How can I charge my phone while cycling?

Three options that I know of:

AA cell phone charger (which you're already using) -- uses 2 or 4 AA's to recharge your gadgets.  I use an Energizer model to charge my GPS for rides over 12 hours.  Of course you need to carry enough batteries for the length of your ride.
Solar charger -- can be mounted on a handlebar bag, a rear rack or hanging from your pack and typically has mini-USB connections for cell phones etc.  No batteries required but won't help much on a rainy day.  I've seen a variety of these at local outdoors shops.
Dynamo hub charger -- this is probably the most expensive option, especially if you don't already have a dynamo hub.  I'd like one of these (already have the hub) but the AA charger has been fine so far.


Replacing the bike seat on my mid-1990s Trek mountain bike

tl;dr: Yes, you can pretty much buy any seat except some rare/expensive racing or classic leather seats.

Explanation: As long as your seat attaches by two parallel rails that are 44mm apart (which is 95% of seats), then you can replace it with another seat that also attaches by the rails. In case you don't do metric, 44mm is just under 1.75 inches measured between the center of the rails.  Here's a photo of a seat with standard rails from wikimedia commons:

For example, even bizarre noseless seats use the two parallel rail design, visible here (for the record, these noseless designs make it hard to control your bike, so they aren't advisable, also see comment by Criggie):

If you're keeping the same seatpost, then you would normally keep the old seatpost adapter as that's what changes between different bike models (seatposts vary in diameter and some seatposts are tapered at the top). A slight complication is that some rails are 7mm in diameter, some are 8mm in diameter and so forth. Usually the clamps are flexible enough to accommodate that variation. I think your bike is bog standard so you shouldn't encounter any problem.

The 5% of seats that don't use the 44mm rails include some keirin racing bikes (that use 30mm rails), classic leather seats (like older Brooks) that use four rails, banana seats, children's bike seats, and a few others.


The website has drawings that show roadbike cable ends.


Suggested tire pressure for an "overloaded" bike

Generally, the tire pressure range marked on the tire is somewhat loose - the marketing department wants a big range since it will sell better, the legal department wants a small range so liability is lower and the engineers have something probably bigger than whats marked on the tire as safe. Your tire pressure should be high enough that you don't get pinch flats but not give a harsh ride. The links in the recommendations show roughly what tire deflection should look like. Note that lower pressures are generally more comfortable.

150 kg on a bike is a lot - most companies will mark this as higher than the max weight for their non-touring/cargo bike models (so you're on your own legally). That being said, I have carried a lot more on bikes marked significantly less, you're on your own with that.

As for tire pressures which are best, you have to find this out on your own - its dependent on terrain you're riding over, your daughter's stomach, etc (and the best tire pressure (which is largely subjective, hence why I'm voting to close the question) will depend on the load on the bike so if you wanted one pressure, you'd have to trade off between the no daughter and daughter rides).

There are some recommendation charts and manufacturer recommendations to start with - tweak your tire pressures to your liking.


Can't figure out the correct wheelset size for my Raleigh Rush Hour to replace the stock wheelset

It's rare for a manufacturer to have different wheel sizes for the same model, but it does happen sometimes. Fortunately, it's easy to check the wheel size, it's always printed or embossed somewhere on the tires. Yours will probably say 700c or 622mm or 28 inch - these are all equivalent.

One other thing you'll have to consider is the rear dropout spacing. If you can't find the manufacturer specs, you'll have to measure it. Most road bikes use 130 mm, and most track bikes use 120 mm, I have no idea what yours is. (The front dropouts are almost certainly 100 mm).


The problem is that you have to start considering the failure modes of the failure detection system. You're quite likely to end up with a less robust system or a lot of false alarms if you have a system designed to warn you of failure.

You also have to consider what faults would be detected:

a dead battery? You'd need another power source to feed your warning
a briefly open contact causing the light to switch off (I've had a proper brand light do this every pothole on a road bike)? Can this be distinguished from a deliberate switching off?
accidental switching (e.g. bumped by a pannier)? How is that different from switching it off?
unlikely failure modes like LED burnout? These shouldn't happen in a well-designed system, and I wouldn't trust failure detection in any other system.
the light falling off? Quite a likely failure mode but an extra fixing would be more reliable and less effort - and your failure warning service could fall off too.
Damage (which could be things like a failed connection or loss of focussing optics) due to vibration/fatigue/impact. My helmet-mounted rear light has lost an LED to this, and another flickers, so it happens.  With series-connected LEDs (common on e-bike rear lights) or a failure in a common electrical path, you could easily lose the whole output.

So instead we consider a system designed to confirm that the light is on. If the confirmation fails you stop and check. This could be a design or mounting that deliberately directs a little of the light to where you can see it. Simply mounting your rear light on your seat tube and having a silver-coloured pannier rack is an easy solution to this. A light with some front-facing white/yellow lights that shine between your legs would cost battery power but might increase visibility.

There are big advantages to multiple independent lights:

you're more visible from more angles (and further away if you add lights up high)
approaching vehicles can get an idea of how fast they're gaining on you (this really needs multiple constant lights to work well)
they indicate your size better - important if you're wider than a driver might expect (trailer for example)
and of course the big one here: if one dies you've still got some minimum level of lighting at the back.

I take this approach with two steady rear lights and a flashing one on my helmet (also with yellow LEDs on the sides). Sometimes I have a third rear light as I have one on the top of my daughter's seat and one on my spare pannier.

Another consideration is what you'd do if you detected a failure and it wasn't easy to fix at the side of the road, an hour from home, in complete darkness.  With a backup light or two, just ride on.  Of course this does mean you should check your lights at home - this is just a matter of looking at them as you switch them off and not doing it by feel.


How can I upgrade a Shimano FC-TX70 crankset?

You can nominally replace the TX70 crank with any 3x7 speed, square taper axle crank with the same chainring sizes (or different sizes if you want a different gear ratio range).

However, you need to make sure the new crank maintains the same chainline as the TX70. (Chainline is the distance from the centerline of the frame to the middle chainring, 47.5-50 mm for a MTB triple.) Different model cranks require a different axle length for a given chainline, so the challenge is finding the crank and bottom bracket specifications and matching them up. It's often easier to replace both the crank and bottom bracket as you can select a pair that give the correct chainline.

Shimano provides an extensive archive of specifications. I found the FC-TX70 in the 2004-2005 document. It says the FC-TX80 provides a 47.5mm chainline with a BB-UN25 D-NL bottom bracket. This is the only option given so we can assume your bike has a 47.5mm chainline. Finding the specifications for the BB-UN25 we see the D-NL version has an axle length of 122.5mm. The archive specification documents are very long, but you can easily use search to find the FC-TX70 and BB-UN25 product codes.

Looking at the current crank specifications and taking the FC-TY501 crank for example (again, use search to find the specs for that crank model), that crank provides 47.5mm chainline with a BB-UN100 or BB-UN26 bottom bracket, D-NL version. Looking up the BB-UN26, the D-NL version has a axle length of 122mm.

Bingo!

You can obviously go through the same process with the other current Shimano cranks, figure out which ones will replace the TX70 directly or will require a new BB.


SRAM BB30 cranks - how to remove crankarm from spindle?

The left arm has no threads because that side is designed never to be separated from the spindle...
From what I can find, that's an M18 thread, pitch unknown but probably M18x2.0mm or M18x1.5mm.
Remove the right arm, put the spindle down through a sturdy surface with a hole no larger than 31mm so the metal part of the left arm has maximum support. Screw a steel rod of the correct M18 threads into the good threads you still have in the spindle. Hammer the end of the rod. The longer the rod the easier it will be to keep it perpendicular to the surface that's supporting the crank.
You can use a deadblow hammer if you have one, or go find an auto mechanic's workshop since they are very likely to have a hydraulic press they use to press bearings into car spindles.


Help please - Dent in top tube of double butted aluminium frame

Yes it's safe to ride. That "line" it's just a crack on the paint surface, I would suggest painting it with something like clear nail poslish jusft in case. A dent on a commuter bike is nothing to worry about.


Is it worth buying carbon fiber road bike for short commutes?

Comfort isn't really an issue for a 30-minute ride, as long as the bike fits. Also, for any given price point, an aluminium bike will have better components than a carbon bike, so will probably be more enjoyable to ride.

For a commuter bike, I'd be much more worried about theft and damage, unless you have somewhere secure to park the bike at work.  If you are worried that aluminium will be too harsh, you're probably wrong but I'd consider steel instead, rather than carbon. Or just put wider tyres on it. I've ridden rigid aluminium hybrids with 28mm tyres and had no comfort issues at all.

Any good bike shop should be happy to let you take a test ride of at least half an hour on any bike you're thinking of buying.


Front brake won't respond until fully engaged

Work the lever and check that that the caliper is moving - that will tell you that the cable is attached and has not broken.
Make sure the little lever on the caliper that spreads the pads to let the wheel come out of the bike isn't engaged
Inspect the cable run from lever to caliper, make sure the housing is properly inserted into the lever and all frame stops.
If that all checks out the cable may have slipped through the pinch bolt on the caliper. Undo the pinch bolt to free the cable, verify the lever is pulling cable by pulling on the cable and and working the lever, reattach the cable. You can refer to this Park Tool video for installing and adjusting calipers.


my bike pedals but the back tire will not move

One possibility is that the hub's freewheel mechanism has broken. Maybe it's fixable with some spare parts or you may need a new freewheel hub body or a new hub altogether. Your LBS will be able to assess the situation.

It looks like this: https://www.google.gr/search?q=mtb+freewheel+hub+body&tbm=isch


Rear derailleur speed number interchangability

You're right, indexing is handled by the shifters.  So if you replace the 8 speed to cassette with a 9-speed cassette you should be able to use the same derailleur.  But you will have to upgrade your shifters.  The only caveat with the derailleur is that it has to be long enough to accommodate the amount of chain slack generated by going from the largest gear to the smallest gear. This becomes a problem when trying to use a road derailleur with a mountain bike, which usually has a much bigger range of gears.


If the Shimano freewheel didn't fit, it means that your bike uses French threading for the freewheel (which isn't surprising given that it has a Maillard freewheel; the other non-bmx standards are interchangable). You're basically out of luck and need a new wheel (or at least new hub).

Depending on the hub, you may have to re-space the frame(*), since 6 speed likely means 126 mm rear spacing, where a newer hub would be 130 or 135 mm. This isn't difficult, and a shop that has a decent amount of clients with older bikes should be able to do this easily. You can also still find 126 mm wheels on the market if you look (Velo Orange still sells them, for example), so you wouldn't need to respace the frame. Or, you can respace it yourself. But this is the way I'd go.

(*) Assuming its steel, which given the age, it probably is.


Carbon assembly paste increases friction and can be used for metals as well.
Make sure to use a torque wrench and tighten to the torque printed on the seatpost clamp.
From the photos of the Fizik seatposts it almost looks like only the back screw is actually clamping the rails and only with 8Nm tightening torque? If nothing helps I’d get a seatpost with two side-by-side screws and ≥10Nm torque.

I put the saddle forward because the break in the rails happens at the
back, and I want to minimize flex.

Don’t compromise seating position just to avoid breakage.


What causes my chain to derail at the rear when I accelerate?

It sounds like the combination of your chain and cassette / sprocket are at the end of their lives. Examine them for signs of wear.

To check a cassette for wear, look for pointy teeth. A non-worn cassette will have teeth with a fairly flat ends.

A worn cassette will have teeth that have become pointier.

To check your chain for wear, ideally you'd use a chain wear tool to check how much your bushings have been worn away. If you don't have one of these tools, you can kindof tell when a chain is worn out because it will feel like the bushings are a bit loose.

Alternately, a drivetrain generally wears out at around 10000 kms (~6000 miles). You can rack this amount up pretty quickly as a regular commuter.


How can I stop my toes from going numb on long rides?

There is probably a combination of things that can help.  Periodically getting your weight off can help as can making sure your pedaling stroke includes ankle flexion.  In my experience, that helps a lot with circulation in my feet.  Obviously, you'll want to make sure your shoes are not laced or velcro-ed too tight.  I will often stand in the pedals and do calf stretches by flexing my ankles up and down (still clipped in) to help with foot circulation.


How deep does a quill stem need to be inserted?

I measured five quill stems that I have, three steel and two aluminum. The overall lengths vary from 5 1/2 to 6 1/4" (about 14 to 16 cm). The minimum insertion length was 2.5 to 3.0 inches (about 6.5 to 7.5 cm). There was not a consistant ratio of length to minimum insertion. It is possible that the insertion length increased on newer bikes due to safety/liability concerns. If you haven't got at least 2.5" (6.5cm) I would shop around for a longer quill or one that has an angled stem that will give you the height you need. An alternative is an adapter that inserts like a quilled stem but allows the use of threadless stems. The availability  and variety of lengths and angles on modern stems will give you more options.


Is there a cable-stop variant for the screw-in internal routing ports?

They aren't universal in any way. Depending on the bike/brand, there may be some out there that fit the same frame hole and do what you suggest in the case of a manufacturer trying to employ the tactic of re-using the same small parts, but that's not how it usually is.
Some frames are set up to allow a straight shot of cable like you suggest, but usually it would have that sort of housing stop if so. Running bare cables in a frame set up for continuous housing is generally not something that can work.


It depends a lot on the ambition of the trail and the local conditions. Are you trimming branches in a forest or creating a safe path down a rock face?

Other dirt-working tools will probably be helpful, a pick and wheelbarrow are the obvious ones I can think of. Knowlege of how to safely prune trees and plants, plus some knowlege of trail construction, and some skill at dealing with people might be handy (I'm not sure whether skills count as tools in the same way knowlege does).

Consumables like tree repair paint and gravel will be useful and possibly necessary.

If you have significant embankments you can definitely move concrete embankment bracing segments by hand, but a motor vehicle would make that easier. If you're using concrete a trowel would be good. If you're driving stakes a sledgehammer is essential (and if you're not, what holds your anti-erosion material in place?)

The limited MTB trail making I have done has all just required a spade, hammer and supply of pegs (I have used a small axe for the latter two but it's not a good idea). Stuff that I could carry on my bike, in other words.


I can't find a clearly written spec page for this bike, but based on the picture your easiest change will be to swap out the cassette/freewheel for a 7 speed with a larger number of teeth.

The question is whether the rear derailleur can fit a larger gear.

You'll also need a new chain to add more links.

Your other option is to replace the whole front chainring assembly with a smaller one.   At this price point there's a good chance its a common square taper fitment, so you might even be able to rescue a smaller crank off a donor-bike.

You could even use a triple crank off a MTB but only hook the chain onto the middle or little ring.   This would be the most economical option, the only bike-specific tool you need is a crank puller.


Attaching a stem to a carbon steerer: how much torque?

Assuming the stem was chosen by the manufacturer, it's  required torque as printed on the stem should be within the ability of the fork steerer to support.

If the stem says,"Max Torque 10Nm" as opposed to just "10Nm" then start with a lower setting around 6Nm and work up slowly until the stem clamp will not slip on the steerer. If only the number is printed, it must be exactly that number.

It is a good idea to check the torque compatibility of parts purchased for your bike. If you buy a stem that requires 12Nm, but your handlebar won't support more than 10Nm, you are destined for trouble.

Usually, 6-8Nm is enough for that purpose. You can lower the required torque by adding a carbon friction compound, sometimes called carbon grease. It increases the friction between the steerer and the stem clamp and will therefore require less clamping force to stay solid.

I assume you've dealt with this issue long since, but in this case 10Nm would be correct.


How can I undo the locknut on this Shimano 105 hub

OK, I eventually worked out the easier way.

The locknut has a hole in the end which, in addition to taking the skewer when fitted, has a hex socket for a 5mm allen key. Turn the hex/allen key anti-clockwise relative to the cone spanner to undo.


What others are saying is right.  If you have a 48/11 and are only going 20 mph (32 km/h) then you aren't spinning fast enough. You also won't be able to find a cassette with smaller than an 11 tooth cog.  You'll have to get bigger chain rings.  That being said, it might be difficult to spin fast on a hybrid with platform pedals. Personally I find it easier to spin fast when I have clipless pedals. Also, make sure the bike is fit correctly to your body. If your seat isn't high enough and your legs are bent too much, it can be hard to get a high cadence.


What are some key road flat pedal bicycle adjustments that affect neck strain?

If a rider is suffering neck pain, one of the first things to try is removing any visor from the helmet.  MTB helmets frequently come with some kind of sunshade/peak/bill horizontally over the eyes, and when on a road style bike, that means craning the neck up more to see underneat.  So unclip it.
Rider can also try to ride with a straighter back.  Its easy to hunch over so one's spine is curved.  That also puts strain on the neck.  At least try and straighten the back periodically while riding.
After that, it becomes a bike fit process, which is getting a bit much for an answer here.


I am a big guy who wants to buy a race bike

Fact: True pro-level road racing bikes from all eras, including but not limited to the current iteratons, prioritize being light as possible while durable enough, and the right kind of durable, for a pro racer.

Fact: A heavy non-racer riding for fitness and pleasure doesn't really get any utilitarian benefit from the extra bit of weight reduction that distinguishes really high-end bikes, at all, other than potentially the psychologically driven kind of utility, i.e. you have a light, sexy bike and that motivates you to ride more.

Fact: There's a whole ton of ways the durability factor could bite you. That said, none of them are individually super likely. A related thing is that really high end bikes cost more to maintain and replace components on, especially if you care about keeping everything high end.

Fact: Wheels are going to tend to be the biggest and/or most immediate trouble spot if you do go for it.

Fact: Pro race bikes tend towards offering position choices that work for pros, and it's very common for this to create difficulties or impasses for non-pros doing long-distance recreational riding. The "endurance road" category was basicaly invented to address this.

Fact, but more contentious one: There can be some nice things about having a really stiff bike as a large, strong rider. That said, the importance of this as it relates to what modern humongous-tubed carbon frames actually give you over the competing options, like say a nice steel frame with 31.8 downtube and 28.6 seat and top tubes, is often overstated.

Opinion: Do it if it's what you need to do. Meeting your goals and having fun while making emotionally driven equipment choices is a lot better than nothing. You won't be the only one. Do make sure your fit on the bike is uncompromised, which you may find to be a criteria that other decisions have to flow from. All that said, many of us find there's another kind of emotional satisfaction in having bikes that actually make sense for who we are and the kind of riding we do.


Where is the proper location to measure the tube size?

Look at the tire.  It will have the size embossed on the sidewall -- either inches diameter & width (like 26x1.5) or metric sizes (like 700C-32).  Use a tube that says it's for that size.

Tubes generally are made to fit a range of sizes.  Eg, a single tube may fit both 27" and 700C tires, and 1.25-1.5 inches or 32-38 mm wide.


Yes, it will work fine. For road cassettes, the freehub body length had to be increased for 11 to fit more cogs, but for mountain there was no such change because the largest cog slightly overhangs the hub flange.