Signalling before braking is a defensive riding skill, to be used when you think there are riders close behind. In my answer to one of the linked questions, I wrote

  If you think there are bikes behind you, signal with your hand (palm facing backwards) to show you're slowing and they should too, or call "SLOWING!".

The idea here is that while bikes crashing into you from behind can cause you to crash also, it's more likely to cause them to crash.

As you say, in time critical situations, you may not have time for signalling, in which case I recommend calling "SLOWING!".

You can argue, as many do, that cyclists should not be so close behind you. The conventions I have described originate in group riding situations, where a bunch of riders are in close proximity. They may be social riders, club riders, commuters, or organised ride participants. I have experienced these signal conventions in Australia and Europe.

The biggest danger is when random commuters ride close behind one another, since the rider behind doesn't know anything about the skills or experience level of the rider ahead. So, to answer your question, in the context of commuting

  Is this considered safe/advisable?

No riding close behind a commuter in traffic is not considered safe or advisable.

Two cyclists should only ride in close proximity when they both know each other's skills, and are both comfortable to trade the benefits and the risks. In a commuting situation that is not the case.

Edit in response to David Richerby (thanks David for heads up)

Is braking one handed safe?

How safe it is depends on whether you can maintain control braking while steering one handed. It's certainly an advanced skill. When the situation is too urgent then focus on braking and control. If you're worried about following bikes, then call out as I suggested.

If you have time, I do recommend signalling first.

Second edit

The answer by muphblu led me to investigate what international standards for hand signals exist. I'm not going to reference what I found here, because it's a complete mish-mash.

To summarize, many places still allow riders to follow outdated rules adapted from the rules for motor vehicle drivers (and they were probably adapted from horse cavalry, but I digress). These require

for a near side turn (left turn in Australia, NZ, UK, et al, and right turn in US, Canada, Europe, Russia) to be indicated by holding the other arm out horizontally, with the forearm vertical from the elbow and hand facing forward.
for an offside turn (right turn in Australia, NZ, UK, et al, and left turn in US, Canada, Europe, Russia) to be indicated by holding the same arm out horizontally. I.e. you point in the direction you're turning.
for stop, it's a mess. It can be the same as the nearside turn, or with the arm strait up, or in some parts of the US, the arm horizontal with the forearm vertically down and the palm facing back. I think of this as "holding those behind back".

In additional, many places allow point in the direction you're turning for turns in either direction.

I have not seen any updates to the cavalry-style stop sign.

What is a cyclist to do?

Any time you suspect there are riders behind, you need to take extra care, because you are the one who can see ahead, and they cannot.

So when approaching the kind of situation described in the linked question, if you can see the situation developing before you arrive, it's time to start signalling (with the palm vertically down and facing back) to those behind so that they can be ready to stop. In this case you're already using your brakes lightly with the other hand if you can.

If you don't get any warning, there's no time to be gentle. Call out loudly that you're braking / stopping, and get on the brakes asap. Try to feather the brakes if you have room, so that those behind have a better chance of avoiding you.

An advantage of calling out is that with a loud enough call even the motorist can hear you. (I swear I've moved whole cars sideways this way).

Why palm vertically down, facing backwards?

Cyclists who ride close together tend to be road cyclists, and because of the position they tend to ride in, they will more easily see a low signal than a high one. And to make the high cavalry-style signal, you need to sit up, which is the opposite of what's needed for braking. And we can get our hand back on the brakes more easily from the low position too.

So, is it a thing?

Well, yes. But not an officially or universally accepted thing.


Which brake should I use, on a full suspension bike, if I broke my brake lever

If it's to get you home or to the bike shop, use the one that works and ride cautiously.  You may have to walk down some things. Trying to fiddle with it at the side of the road or trail is risky - you don't want to lose a screw. If you're considering long term use it's a bad idea to run only one brake in most situations, especially as you know the ones you've got are prone to failure.

As you're taking about full suspension I assume you mainly use it off road. I'm not a mountain biking expert by any means, but on loose surfaces you don't have much stopping power from the back as a side is both easy and ineffective. On the other hand a light touch on the back brake is very useful, and overheating can be an issue on a single brake. On road you have the same effect to a lesser extent but the consequences of your second brake failing can be more severe (an uncontrolled meeting with fast-moving traffic).


Why do some people leave the chain sitting on the smaller sprocket when the bike is not used for a while?

The cable that moves a mechanical derailleur is counteracted by a spring. To the best of my knowledge the "leave it on the smallest sprocket" theory suggests that the spring is sitting with the least amount of tension on it. The same is true for the cables. Because they have the least tension they are more likely to maintain adjustment over periods of storage.


Why does my bike crank creak and come loose?

Square taper cranks are easily damaged if they a ridden loose. You may find that the only fix is to replace the crank. If after tightening to the correct torque they continue to loosen, they must be replaced. Over tightening, while tempting, is not the correct solution and will lead to maintenace problems down the track. (Essentially someone will have to remove the crank for some reason, it will keep coming loose after that and eventually be replaced. The process of fixing will take several attempts as the presumption will be the crank is in good condition when it is not)

Take the bike back to the the shop. As the crank has come loose again, ask them to replace it. If they refuse, be prepared to take your bike back every two weeks until they install new ones. Do not "fix" the bike yourself. The LBS might claim it was something you did that caused the problem.


Crank and Bottom Brackets Compatibility for Shimano GRX

From what I can see on the Token page, you need to select a BB that matches the crank axle diameter (24mm for Shimano) and the frame bearing cup standard your frame has. The Token web site has a nice filter that lets you select crank and BB cup types so I'd let that guide you initially.

This is about the most informative page I've found on the myriad of BB standards.

By the way, the TF24 appears to be natively designed for 24mm axles but the TF37 uses adapters for different axle diameters. Go with the 24mm axle specific design if you can. I think that if you have a frame designed for a BB for 30mm axles you may have to get a TF37 and use the adapters.


Trouble getting the right cup and cone hub adjustment

Getting the adjustment right is sometimes difficult and is as much art as science.   I rebuild lots of old bikes, and frequently have to rebuild wheels. Here's what I do...

First, be sure to work from one side.  Normally the non-drivetrain side; that way your axle will stay centered.  Clean everything up and inspect carefully.   Since you've already bought new cones... Should be no problem.
The difficulty, as you note, is making the final adjustment.  You can get everything all set up so that it's apparently perfect.   Then you apply the cone wrench to hold everything in place and tighten the locknut....And it's too tight.
The problem is that the axle itself will tend to move when you tighten the locknut.  So...When I get everything set to tighten down, I then clamp a big pair of vise-grips on the other side of the wheel, and hold the thing in my lap so that the vise-grips are held in place by my knee.
Then, you can hold the cone in place and tighten the locknut with little chance of the axle moving.
As to the exact adjustment.... It's always been the paradigm that if you have QR skewers, you leave the adjustment so that there's just a tiny, barely perceptible amount of play so that when the skewers are tightened they take up that slack.
I've never done it.  I always set mine so that the axle rotates freely and there is no perceptible play.  I also don't tighten my skewers nearly as tight as all the "industry" guys recommend.  Don't think it's necessary.


2 speed (double) shimano road shifter on triple chainring crankset?

Yes, but....

If your shifter is a 2 position brifter (ie an STI lever) then it will only be in the right place on one chainring.   The second position may be acceptable, or it may be off enough to create clatter.   The third chainring will be unavailable to you completely.

If your shifter is a friction shifter, then the entire set of chainrings will be reachable and tuneable assuming you have sufficient range in the front derailleur.

I successfully shifted on a quad chainring using a thumb friction shifter on a custom bike.   You could also look at using a bar-end shifter in friction mode.

Since you mention road bike, its going on drop bars, and STI / brifters is where its at for roadies.  You'd be best off getting a triple-position left brifter (used shouldn't be too expensive)

The other option is to look into a compact double crankset, which will let you use a smaller inner chainring, paired with a wider range cassette at the back could approach or even equal a 1:1 ratio with an 11-32 cassette and a 32+48 chainring setup.

Depending on the age of your shifter, it may have a pseudo third position which is the trim setting.  This lets you do a sub-shift on the front mech so to avoid the chain clattering away on the cage as you ride in a sub-optimal gearing like big-big, or less often in small-small.   This Trim position should not be confused with a triple shifter.... when in doubt check the web for the part number.

Generally speaking a triple anything ends in a 3 in the Shimano world.


Protecting beater bicycle from scratches and rust

Even though it's a "beater bike", I'm guessing you really want to keep it around for a while.  If that's the case, I believe the best protection for it would be to paint it.

Strip the frame down (take all the components off) and thoroughly wash it.

If you want to do the job yourself, sand the frame down to remove any rust spots.  If you have too much rust and you think epoxy might be in order, you can do that - but I suggest being extremely cautious at that point.  If the rust incursion is that bad, you may very well have structural damage that could cause a nasty crash - or worse.

Use "Frame Saver" and spray the inside surfaces of the frame down with a liberal coating while it has been disassembled.  Clean the surfaces again, Use rubbing alcohol to remove any oily deposits.

Use a quality exterior paint.

Alternatively - almost any autobody shop that has a paint booth can paint the bike for your fairly cheaply.  They might even have sand blasting facilities/capabilities to make cleaning the metal easier.  If you don't care about the color - just have them paint it when they do a regular paint job - and it'll be even cheaper since they don't have to clean their paint guns for a tiny batch color job for the bike.

Smaller/independent shops will tend to be a lot more willing to work with you on a project like this.  The big shops tend to not be too friendly to "side jobs" like this.

I've had steel frames completely stripped via sandblasting, and professionally painted with powder coating, including two layers of protective clear finish, then baked in an oven for 2 hours.  The cost was $130.


You need to be moving (and pedalling) to change gears on a bike with derailleurs. So you should try to change down before stopping, to a small gear at the front and a big gear at the back.  The front gear are often labelled L...H for low to high, while the back gears are 1...8 (or anywhere between 5 and 11 depending on how many cogs you have) -- again low to high.

If you try to select a different gear and then backpedal before it engages the drive train can lock up; this is probably why you can't backpedal if you changed down without pedalling forwards.  You can lift the back wheel and spin the pedals in the normal forward direction (by foot or hand, whatever's easier) to change gear while stationary.


Bicycle Trailer pulls back wheel sideways

It is possible that you put not enough torque on axle nuts. The axle moves in the fork.
 If there is enough space, add some extra, broad spacers and then screw it back to the frame.

Use this kind of spacer (it's from Sram I-3, might require some drilling)


Increasing speed and reducing effort on steel MTB on the road

Free stuff - start with your bike fit.  Make sure your saddle height is high enough, but not so high your hips wiggle while pedalling.

Check brakes for rub - adjust brakes or true wheel if required.

Carry less stuff - wear fewer clothes when riding.  Roadies tend to avoid big flapping jackets, and their clothes are more close-fitting.

Carry the right stuff - Water and some fuel is useful.  A small thing like a lolly or a square of chocolate or a gel per hour of riding works for me for up to 3 hour rides, after that I need a more solid snack like a muesli bar or bliss balls.

Lock out any suspension on the road.  Bobbing along slowly saps your power.  If there is no lockout, then some bikes have tuneable suspension, so you can make them more firmer and loose less power.  Downside is you still have to drag the useless suspension parts around with you, as excess weight.

Technique - look closely at others and see if you can observe differences between your technique and theirs.

Ride straight, but defensively - I see a lot of slower riders wiggling in and out of parked cars in the stationary lane.   Turning reduces your forward speed, and ducking in between cars for a few metres is dangerous.  So take a position on the road and ride in a straight line.  Wear high vis colours and so on, but be perceptive to your surroundings in front and behind.  I found the faster I go the further away from the kerb/curb I want to be.  Be a door's width from parked cars.  Ride with lights, even DRLs in the daytime.

Then a service - clean/lube your chain, clean your cassette, check wheel and BB axles for play/wobble.   If you can do this yourself its free, otherwise its a service cost at the LBS.

Next options cost money, sorry.

New commuter tyres is your first and easiest gain.    Inflate towards the higher end of the pressure range.   Store your old tyres in case you want to take the bike on something offroad and gnarly someday.

Long term free things:

Carry less weight - Develop and implement a weight loss plan.  I started at 105 kilos and have dropped to 95 over two years.  This has certainly helped.  However a lot of the weight loss has been offset with muscle mass.

Ride more/train more  -  Developing both fast and slow twitch muscle fibres will help with your raw burst power and your endurance respectively.  This is not an overnight process, but better legs will totally help you go faster for longer.

Ride with others - Some of my best times have been gained while in pursuit of other riders.  Organised rides help keep the motivation up, and show you routes or methods that could help you.  Plus draughting/drafting can be a good 30% saving on your power input.

After that, you can look at getting more aerodynamic, but at some point you have to stop spending money to "put makeup on the swine" and start saving for a road bike.

As motivation, consider a lot of lighter road bikes have a maximum rider weight of 90 or 95 kilos, so consider setting this as a target weight before buying a new bike.


Liability Insurance - What if you break the law?

Note that 'liability insurance' is for damage you do to others, and 'personal insurance' is for damage you sustain. So your title suggests you want cover for, eg, running into a Rolls Royce when jumping a red light, while your question body suggests 'what happens to me if I go round the barriers and ride under a train?'

It's almost impossible to find insurance for illegal activities in general, and often even for non-causal/incidental minor infringements. That makes sense if you start from the extreme cases "I want to insure my house before I set it on fire" or "I want to buy life insurance before I kill myself" and work backwards until you find a nice easily-defended place to draw the line... "it's illegal so you're not insured".

Your normal cover on just about anything (per Matt) should give you some liability insurance and it may well pay out if your infringements are not considered relevant. But if it goes to court you will almost certainly lose because the other side will be very keen to point out the law-breaking.

For personal cover it's harder. There's are lots of UK articles about how to invalidate your car insurance by breaking trivial laws, like this one but they are all very careful to say "might invalidate" or "may cause insurer to deny". So if you, say, are on the wrong side of the road, hit a pot-hole and go over the handlebars you could well be covered because you would probably have been hurt even if you were obeying the law. But if you hit that Roller above and wreck your bike you're unlikely to be covered for anything and Murphy's Law says the Roller will have a QC behind the wheel.


Carbon fiber crank arm with scratches--how much damage is a concern?

The thing with CF components is that you can't really tell much about structural integrity without specialized tools and knowledge unless it's obvious from the first glance.

Anyway, SRAM carbon fiber cranks have a healthy dose of paint and clearcoat, any damage to those aren't structural. Source: I own a set of S2200 that survived a bunch of pedal strikes, coming out deeply scratched in pedal insert area. The coating has been sanded away for a cleaner look and the crankset in question has been performing just fine over years. Take this with a grain of salt, I'm just a guy from the Internet.

If your crankset does not exhibit signs of loose pedal insert, I'd just ride it and check from time to time. If it's loose, a repair is still possible, but the price might be more than a replacement Red.

To protect from scratches in the future you can use silicon crank arm boots.


Is it worth upgrading my wheels on a commuter?

Yes, I think it's totally worth it.  It depends on if you have a budget to spend on extra parts of course.

I have a specialized secteur as my commuter and after a year or so of owning it I replaced the stock wheels with some mavic aksium wheels.  Now, the decision was made as part of a groupset upgrade.  The bike was equipped with a low end shimano 8 speed and I got the wheels as part of an upgrade to an 11 speed groupset.  That said, the wheels are on the low end of an aftermarket wheel and they still make a huge difference.  They ride much better than the stock wheels, are lighter (but still heavy by road/race standards), more responsive, and brake better.

I also bought some locking skewers with them and don't ever worry about carrying an extra cable or anything besides a good lock.  The downside is that you need to carry your skewer key around everywhere, but I usually just keep mine in my bag.

Of course, they might get stolen, or your whole bike might get stolen because it draws more attention, but if it's something you want to do and aren't going to be upset if it happens, don't think twice about it.  Make the upgrade.  I'd recommend getting a used wheelset.


b) is most correct, except that you don't need anyone else by your side.

Taking the lane is riding pretty much right in the middle of the lane, and asserting control of the entire lane. Riding in the middle makes it obvious to motorists that they'll have to change lanes, or wait for a safe opportunity, in order to pass you.


Before you ride, give your bike a safety check.  Its been sitting about for a while, and there could be problems you're not aware of.

The Sustrans website covers this at https://www.sustrans.org.uk/what-you-can-do/cycling/your-bike/bicycle-maintenance-made-easy/m-check-your-bike-11-steps

For things to buy/find:

Wet weather gear - You mention Halfords so its likely you're in the UK, which seems to be enjoying a riding renaissance.  But the weather's going to be wet someday.  You'll need a coat that works for wet riding.  Later you can add overtrousers or overshoes.  Personally I ride in gumboots (wellingtons) in the wet.
Helmet - Not mandatory in the UK, but still a very good idea.
Lights - again if your job hours mean riding after dark, lights are probably mandatory for you.
Spare clothes, towel, deodorant.  Either carry them with you in a waterproof bag/rack, or store them at work for a change on arrival.  Consider using your non-bike days to carry that bag to/from work for starters.
Bike security.  Its no good coming out of work and finding your bike's missing.  Even though its a cheap BSO bike, a lock will help prevent it from vanishing.  I've got access to a bike room at work - check with your MAMIL about where to park it safely.
Water bottle and bottle cage on the bike.  On a hot day you can go through a lot of water, so its easier to carry that on the bike and not on your person.   Your bike should have a couple of screw holes on the downtube, and a cheap plastic bottle cage will bolt in there with M5 screws.  Use grease.  Any convenient sized bottle will do, but poptops work best if you drink on the go.  Screw tops require you to stop for a sip.

Those are all I'd call immediate needs, and its likely you have a lot of it already (how many people in the UK don't have a waterproof jacket already ?)

If you're handy you would consider carrying pump/spare tube/levers and whatever you need to get the wheel off, for changing a flat.  You will get a puncture eventually.  Its just a part of cycling.

Depending on how old your bike is, it might benefit from new brake pads.  They dry and harden with age, and braking suffers.

If your bike has knobbly MTB tyres, consider replacing them with smoother ones when they wear thin and punctures start getting frequent, or you see canvas.

Otherwise simply keep riding.  Aim to wear your bike out and then reward yourself with a better one in a couple years.

Related - recording your rides can be of massive value over time, to see how you're getting faster.  Personally I use strava to record my commutes and rides for future comparison.   Downside of this, your MAMIL might do so as well, and it may become competitive.  Don't be put off if this happens, just use strava to record your own progress and don't compare with other people.

Seeing improvement over time is an awesome ego boost, because it never feels faster at the time.


What are cheap options for an extra set of brake levers for mechanical disk brakes?

Presumably you have drop bars. Inline brake levers are your only choice. The only places to mount extra levers on drop bars are tops. With inline levers installed you can reach levers from the drops, hoods and tops, so you really don't need levers anywhere else.


Shifter clicks in but chain stays on the largest cog, when riding

Given its only a month old - return to the shop for the first "tune-up" which is standard in most parts of the world.

If you bought the bike on line, you can either learn to do it yourself or take it a bike shop and pay for a tuneup.  Depends on your mechanical aptitude.

Sounds like your bike mechanic visit missed something.


Is it cheaper to mass produce a carbon frame than an aluminium frame?

Given that alloy framed bikes are generally cheaper than CF framed bikes, it's reasonable to conclude that an alloy frame is cheaper to produce than a CF one.

There are some videos on YouTube that show the basics of the process of making a CF frame. There hundreds of individually cut sections sections of CF cloth that need to be combined together in multiple steps to give the frame strength where it is needed. All the sections of CF cloth need to be combined together in moulds by hand. This is where a lot of the cost comes from.


What is the max weight an MTB bicycle with a freewheel can handle until it starts putting high stress on the rear axle?

Axles break for various reasons - weight is only one of them. Miss aligned dropouts, flexing in the frame, tension of the QR all play a big part. Different axles with slightly different materials will also have an effect - some are stronger overall, some more brittle, some more prone to fatigue.
As you identified, riding style also affects the axle loading.
While the manufacturers probably put a number on this for their axles, I suspect its very conservatives and more reflective of there policy around warranty and brand value.
As far as regularly breaking freewheel axles, they are known to be weak compared to other options. A freehub wheel will probably solve your problem, but also check your frame dropout alignment.


Sachs- Huret derailleur (re)installation

Here's an image of your derailleur showing the return spring attached to the slot furthest from the top of the cage
https://c1.staticflickr.com/9/8111/8602860708_0e4e4a50ef_b.jpg

To answer your second question, seems reasonable to replace the double nut on the outside of the fork end with a single nut.


What does A/V mean on an inner tube package?

Schrader valve/Schrader tube
aka "American valve" or "Automotive valve"

The Schrader valve consists of a valve stem into which a valve core is threaded, and is used on virtually all automobile tires and most wider rimmed bicycle tires. The valve core is a poppet valve assisted by a spring.


11-42t cassette with a 9 speed derailleur, will it work?

A 9 speed Deore groupset is presumably a 590, 530 or 510 series. Assume you have a 590 series which was made up to 2009 (the Shimano Wikipedia page has a nice table of group series and years), you can pull the Shimano 2009-2010 specifications from this page

Search in the PDF doc for 'RD-M59' and you'll find the RD-M592 model has a max sprocket size of 32 teeth and the RD-M591 model max sprocket of 28.

So technically no, your derailleur will not work with a 42 tooth cassette, however, many people seem to have had success with a derailleur hanger extension that drops the derailleur down so it clears the largest sprockets. The derailleur has enough total capacity (45 teeth difference for both models) to take up the chain slack if you will be running this with a single front ring.


Praxis Works M30 crankset to FSA BB30 fitted in a BB386EVO shell

Looking at the Praxis web site it looks like M30 is a proprietary BB and you need a specific Praxis M30 to BB386 adapter.

Strange that you tried PF30 BB units in a BB386, but I think maybe the cups and bearings are the same. According to https://www.bikeradar.com/advice/buyers-guides/the-complete-guide-to-bottom-bracket-standards/ they both use 6806 bearings and a frame shell diameter of 46mm.


In addition to the points noted in other answers, there is a significant technical difference: bearings.  Traditionally, Dura-Ace equipment with bearings has had much better quality bearings/races/cups/seals/etc. That appears to be true here as well. Look at the parts breakdown documents from shimano and you'll see a significant difference in the axle/bearing setup:

PD-6800 - 12 ball bearings inboard, 12 outboard with bushing between
PD-9000 - 17 ball bearings inboard, 9 outboard with needle bearing between

The bearings in the 9000 will live much longer and deal with intense loads better than the 6800. That said, the 6800 is a fine pedal.


Which country has the cheapest top-end mountain bikes?

The factories that make these bikes are mostly in China and Taiwan, I've been told (by my boss when I worked in a bicycle shop).

If you're going there, maybe you can find a nearby retail outlet.


Answer Looks like a straight swap (but the proof is always in the doing.)

Neither link say what size the wheels are, so assuming the most common 700c size for both and the wheels will fit under the brake bridge.

Neither link says anything about spacing, but we can expect the front is 100mm over-locknut because that's standard, and the rear will also be 130mm (check this) which is the standard for 9-11 speed.

The cassette should swap over okay, yours is 9 speed and the new wheel is 9/10/11 speed.

Rim brakes will need some adjustment, but both rims are alloy so the brake pads shouldn't need to change type.  You may choose to replace brake pads anyway so there's a fresh surface to work with.

Observations:

The new wheels say "Recommended rider weight limit is 109kg (240lb)" so that should be noted.

You're going from a 28 spoke front to a 24 spoke front wheel.

Have you considered investigating why your current wheels are loosing spokes?  Could be a badly machine-assembled wheel, or budget spokes.  A bike that has been left out in the weather for years can suffer, but that's probably not the cause here.

Are your spokes all breaking on the rear or the front or a mixture ?

Freedom isn't exactly a high quality brand, so rebuilding the old wheel on new spokes may not be worth doing, unless you will try it yourself.

I see there's a 32 hole version of the wheel as well.  Could be your norco bike is rated for a lighter rider ?


SLA batteries are all the same, 2V/cell nominal, mostly 6V and 12V batteries. In this case you have a standard 6-DZM-9 6V, 9AH battery. All you need to do is find a replacement 6-DZM-9. The best solution would be find a battery specialist (not just you corner car/truck and motorcyles battereis seller) and see what they have in their catalogue.  Ideally you want a Deep cycle battery desoigned for electric scooters, bikes carts etc, not a Standby power battery. The latter is designed for UPS with the very occational deep discharge and won't last quite as long as one designed for regular discharge/recharge cycles.

With lead acid batteries, do not replace just one battery out of a bank, you will need to replace all the batteries - at 6 years old theyare at the end of there economic life anyway, and replacing just one battery will mean the life of the new battery is significantly reduced.


Rear Cassette worn + needs replacing - what other components to replace?

From the drive train, Chain/Cluster/Chain ring(s) would normally be enough and should be done together, or the old components would wear out the new one quickly. Although you can get by not changing the chain ring if you replace the chain often, if the chain is badly worn, a new chain ring is strongly recommended.

Check the pulleys on the derailleur for wear, and replace if needed. The derailleur itself may or may not be worn out - Unless obviously sloppy, I would leave buying a new one till the new drive train was in place, I had replaced the cable and checked hanger alignment and still could not get it to shift well.

Based on the wear on the drive train, I would presume the bike has been somewhat neglected. Check the BB and pedals  while the chain is off. Check the headset and wheel bearings, ideally clean and repack.

Unless in obviously new condition, I would replace shifter and brake cables as they are cheap, although if you don't have cable cutters and they are working well its possibly more effort than it worth.


I had a similar problem until recently, initially thought it may be the BB, but after cleaning, greasing, and eventually replacing the problem was still there.

Turns out it was the freewheel hub on the wheel, and fairly quick to fix, if that is your problem, open up the freewheel hub, I needed 2 5mm allen keys for this, but various wheels have different methods of opening up.  Don't force anything, these are easy to destroy, and expensive to replace.

Once you have the freewheel open, make sure that the little pins stay in place, most new hubs will have springs keeping them in place.

Apply grease, I used the Park Tool one (personal preference), and close everything up again.


Aluminum fork dropout potentially compromised - advice?

Fork is toast, dropout cannot be trusted or reasonably repaired. Carbon forks with steel dropouts basically don't exist. Probably best for everyone is get comped for a fork plus install labor. Shouldn't be a difficult fork to get a suitable replacement for.


Remember a dynamo hub has a small electric generator inside of it. What you are feeling when you turn the shaft is the interaction between the magnets and wires in the the generator creating peaks of torque on the shaft.


What air attachment screws onto a Presta valve with the core removed? High volume for seating bead?

Inflator heads with Presta fittings let you do this because they tend to (always?) seal down around the stem, not the core. I don't know any other way. I suppose you could also take a spare Presta core from a dead tube, break the plunger out of it to get more airflow, then temporarily install it in your tubeless valves and put your adapter on that. This is conjecture.

If you haven't already, one thing you might try if seating the beads with your inflator head plus an adapter just isn't working is first install the tire with a tube, seat the bead that way, then break just one of the beads free and try to do the tubeless seating. This can make obstinate ones go pretty smooth.


Can this bent (after crash) rigid steel fork get repaired?

The quick answer is NO, you can't bend back the fork. Or at least not at a reasonable price.

Your bike looks right knackered. You could maybe find a used fork off a donor bike for free or cheap at a bike coop - but you might put said fork on and find your frame is bent.

I'd say your bike is what we kindly refer to as a said "donor bike." It's brain dead and its best use is to give up its vital organs to a bike that might be able to use them. Given that it looks BSO quality, the parts aren't that valuable but if your next bike is a BSO, you might want a spare drive set, seat, brakes, or rear wheel.


I think that it is definitely worthwhile to patch a tube for many reasons:

five patches go for about $5, lower than the price of a single tube (~$7).
a patch kit can be taped under the seat whereas a tube must be carried in a bag or pocket (and if in a pocket, remembered).
Given the ability to avoid flats almost entirely (e.g. using puncture-resistant tires, riding mindfully / carefully), I have never had to wait for a patch to 'dry', even the minute or two for the glue to set passes pretty quickly. Except when in a rush (e.g. a mountain bike race), it takes this much time to change a tube.
Tubes deteriorate more quickly and are more likely not to work when needed than a patch. For example, improperly folded tubes often crack where folded or at the base of the stem.

Despite my own advice, in practice I carry a spare tube in my pocket if one is handy.

On a side note, if you have neither a tube nor a patch kit you can

tie a knot in the tire where the hole is and stretch
ride home on a flat and risk damaging your rim
stuff the tire with grass or something else handy
hitch hike
call a friend/ family member


What is this valve and how do I fill it?

This is a Dunlop valve, also known as Woods. These valves always let air in but not out. The nut holds the valve in place, and you are supposed to unscrew it only if you want to deflate the tube.

There are adapters from Dunlop to Schrader, but the most common way to inflate these is a simple hand pump that has just a rubber gasket instead of chuck like shown in your picture.


Looks like a standard 1-1/8in headset to me? The gold standard is the Chris King NoThreadSet. Sealed cartridge bearings, lasts damn near forever.


What's the point of removing the excess oil after lubing the chain?

The excess oil collects grit from the road, which acts as an abrasive that will wear out the chain.


I need to change my bike from UK to US Spec

Kind of what Daniel said, brakes are easy. Sit down and think about it for a minute, all you have to do is switch the cables. Run the front cable to the left and run the rear cable to the right.

If you want to switch the shifters you will probably run into some trouble. You won't be able to just switch the cables, you would have to get shifters that work on the opposite side. I would just forego that goal if I were you.


What is the working mechanism of Shimano Power Modulator?

There appears to be a couple of things that Shimano calls 'Power Modulator'. I think the I think the basic idea of both is to prevent inexperienced riders from over-braking and losing control.

If you are talking about coaster brakes, it's basically a clutch which limits braking force. https://bike.shimano.com/en-EU/technologies/component/details/power-modulator.html

There is a mechanical disc brake version too which changes the lever ratio as the brakes are applied.  https://bike.shimano.com/en-EU/technologies/component/details/power-modulator-unit.html


What is Speed Lockout on a SUNTOUR fork?

Remote lockout means that the fork has a "remote" lever that is installed in the handlebar.

My fork is a XCR RL from 2011 as well and pressing the blue lever locks the fork, pressing the black lever on top of the blue unlocks it. This is a XCR from 2011 as well.

You can see the remote in the following picture:

If you have a knob with speed lockout you should have a fork similar to SF11 XCR LO 26". If your fork has rebound adjustment then it's a XCR LOD. You'll have to look that up in Suntour's site since I can't post more than one link.

Browsing Suntour's Tuning Base may give you additional information.


Can you recommend a fixed LED headlight for a bike with a hub dynamo?

Peter White has done a lot of testing of dynamo headlights and has even put together comparisons of luminance.  I have the Schmidt Edelux and love it.


Childrens' bike if I want to put my feet down?

The seat-to-bottom bracket height is important for comfortable riding and efficient power transfer.

The seat-above-road height is what you're trying to minimise in your question.  This means a lower bottom bracket, which means an increased risk of pedals hitting the ground.

The size of the wheels is utterly irrelevant to the bb-road distance.

Instead of sliding forward and standing over the bike's top tube, consider attempting to lean the bike and put a foot to the road and the other ready to take-off.

Leftmost police cyclist here is leaning to her right, the other is leaning left.  Both are seated on their saddles with one leg ready for the first power stroke.  I'd suspect female police rider is left-handed.

From left to right: Purple bag is leaning left, but has a foot on the curb/kerb.  Jeans Man is leaning left.  Can't see Red Jacket too well.  Red Bag Folder is track-standing (staying on bike without rolling)  NoHelmet appears to be drifting slowly forward while being off the saddle (prepared for a big power push when the light changes.  Other Folder seems to be right foot down.

My point is, none of these riders are standing over their top tubes with both feet on the ground.    Its really hard to find a picture of anyone even doing it that way.

Generally speaking that is only done when fully relaxed with no need to get up and ride again immediately so you'd rarely see it in traffic.

Another option if something is available.

Amusing video about how to stand with your bike:


The Dura-Ace BB-7800 is designed to be replaced as a cartridge unit. Replacing the bearing in the cup, without replacing the cup, would be difficult, if not impossible without damaging the cup.

These bottom brackets are exceptionally cheap, and really don't have much to them beyond the bearing, and the threaded cup to hold it in the frame.

Why spend the time and effort to replace only the bearing?

If you want to replace the whole cup cartridge, you need a 5mm allen key, a 3/8" drive torque wrench capable of 40Nm, a 1/4" drive torque wrench capable of 12Nm, The Shimano Hollowtech 2 BB cup tool, and the Hollowtech 2 BB bearing adjustment tool.

Procedure here from Shimano on PDF.

Video of general procedure here.


It could be anything. Submerging the wheel in water will be useful. You might need a new valve, new rim tape or a new tyre. The air may be leaking around the spokes, around the valve, through a hole that is not properly sealed or just through the tyre material (least likely).
Be aware that a hole that is not properly sealed might be leaking air only during the ride when the tyre material is being deformed.
I do not thing you can get a definite answer without testing the real physical wheel.


All chains are the same link length, but there are different widths. Some single speed components require a 1/8 inch chain, while the chain that come with your bike is probably 3/32. You will have to get a new chain or exchange the chaining for one that fits your chain.


Properly locking on a floor mount rack with a U-lock

In a situation like this, I usually don't fit any of the wheels in the support; instead I park the bike over the rack and just to the left or right of a loop, so that the lowest part of the frame is in close proximity with the loop. I then lock the frame and a wheel with a single cable (a U-lock might not work). Alternatively, you can place the rear wheel next to the loop (with the loop on the left side so it doesn't clash with the derailleur), and pass the U-lock through the wheel, straddling the chainstay and thus locking the frame as well.

In short, just forget about the fact that the rack is designed to accommodate a wheel in a certain way. Use it as a piece of metal you can lock your bike to.

Keep in mind though, that by parking your bike next to a loop, instead of in it, you're taking a bit more space and making it a bit more difficult for others to park. Something to bear in mind if the rack is often full.

Also, as others pointed out, that doesn't look like a very secure rack. That doesn't necessarily mean you shouldn't use it; you choose how well you want to lock your bike depending mostly on how common bike theft is in your area, how attractive a target your bike is (especially in comparison to other bikes similarly locked), and how much risk of having to replace it are you willing to accept. I lock my bike on a rack just like this every night, but it's on a communal yard, not right on the street, and the bike is cheap.


Why the small difference between common sizes of handlebars (31.8mm) and MTB seatposts (31.6mm)?

Frame tubing is generally standardized by external diameter to imperial dimensions in increments of 1/8 inch, which makes it a lot easier to standardize things like front derailleur clamps.  Seat tubes therefore tend to have external diameters of 1 1/8” (28.6 mm), 1 1/4” (31.8) or 1 3/8” (34.9 mm).
Handlebars are similar. Though there has been more variation historically (eg 26.0 and 26.4 mm in addition to the imperial sizes), modern bikes tend to use handlebars with imperial sizes for the clamped diameter.
The problem, however, is that the internal diameter is not standardized, because it depends on the thickness of the tubing wall, which varies quite a bit. High quality lightweight frames can have very thin-walled tubing, while lower quality frames might need thicker walled tubing to get the same strength. So two seat tubes that are both 28.6 outer diameter could have different inner diameters.
Since the seatpost diameter has to closely match the inside diameter of the seat tube, variation in inner diameter of seat tubes has resulted in a large number of different seatpost diameters. Makers of more expensive bikes have largely converged on 27.2 and 31.6, but there are still many others, especially on lower end bikes.


Trying to repair avon roadster 2000 circa

You do not need a special manual and there probably isn't any. You have to identify the kind of parts that are used on the bike. Like: quill stem, coaster brake rear hub, the type of bottom bracket (square taper) and so on.
Most skills you need for this bike are the same as on any other similar bike from older times so you need to get generc knowledge about bike maintenance - directed to older bikes specfically.
There are many resources you can use, books, vdeo tutorials, the Sheldon Brown's website. There are specific questions and answers here that list such resources.


Is there a All-In-One Bike that I can use for several types of riding?

In general you can get an very good all-around road bike, or a very good all-around mountain bike.  To get a single bike for everything there will always be trade-offs in areas like weight/durability; speed/traction; etc.

That said - many people own one bike and use it for everything.  If I had to drop to one bike I would buy a 29"-wheel based front suspension mountain bike with the following:

suspension front fork with lockout
disk brakes
rack and fender mounts (and a rack and fenders)
a spare wheelset

In my mind the spare wheelset is key - that way you can run a high pressure slick on one set, and then switch to a knobbie without the hassle of swapping out the tires on each wheel.


How often should I refresh the sealant in tubeless tires?

At minimum, you should replace the sealant every 6 months or so.  As you have found, a good tubeless setup will stay inflated well beyond that time, as the latex in the sealant has already sealed any small holes.  However, the sealant does dry over time, so the systems ability to self-repair when you run over a thorn or sharp rock is greatly reduced.

There is no need to clean and remove the old sealant.  However, some brands tend to leave clumps that you can pick out.

If you're valve cores are removable, the easiest way to add sealant is through the valve.  Otherwise, you'll have to break the tire bead off the rim (just a small section) to add sealant.  This can sometimes take a few tries to get sealed again (helpful to have a compressor or large CO2 cartridge to "slam" the tire into the rim).


Play in the suntour front suspension of my raleigh hybrid bike, what exactly is the problem? can i repair on my own?

A play of the inner (upper) legs inside the outer (lower) legs is typical for cheap suspensions.

Repairs would mean exchange of the outer legs (if you can find the parts, which is rare for this pricepoint), but it is not uncommon for these entry level parts to come with some play already from the factory as my local retailer assured me when I complained about it. I asked for a replacement and they said I could get an even worse one.

If it bothers you I recommend an upgrade, if you are just concerned, I'd say ride it till it gets unusable. Remember, bike shops sell them like that, and many customers never see an issue.

Suntour offers many of the current entry-level forks and some argue you'd be better off with a stiff fork instead.

If you want to upgrade a-la-cheap, a used Rockshox, Fox or Manitou suspension fork would work fine (I would just stay clear of very old ones, as they are not service-able anymore due to lack of service parts). With some patience you can find them in 700c size.


If it's a mountain bike, you could use a chain guide like this one. The rollers keep the chain aligned on the chain ring at all times and the rear provides tension as it normally would.

NB: I'm not necessarily recommending this one in particular, just it or something like it. I have no experience with this particular model.

I'm not sure if they make anything comparable for road setups. I wasn't able to find anything with a quick Googling.


Can I use a Brompton bike with a trailer like the Thule Chariot Cougar?

I'm going to say yes based on this photo.  It looks that the hole is big enough to pass over just about any axle, quick release or nutted.  I think what is throwing you off is that it comes with a quick release skewer that is longer than what is typically used for wheels.  You may not need that provided skewer.  Burley uses a similar one and I was able to put the hitch on a Jamis bike using the skewers that came with the bike.

If your bike has the internal gear hub, it probably has anti rotation washer (special washers to keep the axle from turning).  This hitch would mount to the outside of that washer.


As it says on the top tube, it's a Bianchi Main Street.

Looks like an older hybrid (probably early 90s).

Would do fine for riding around town possibly after a bit of a tune up.


How to handle motorists' dangerous behaviour with an impassable group?

Don't create the situation in the first place. Every large event I've ever been on would either have the roads closed down, or send the riders out in waves so as not to create a situation where a car would have to pass so many cyclists at once.

Obviously the guy in the car was in the wrong, but there are still things that can be done to prevent the situation in the first place. Forming a defacto blockade on the road isn't really in anybody's best interest.


What kinds of brake designs exist, and what are their general pros and cons?

Here's a more complete list, arranged roughly in increasing TYPICAL stopping power, with pictures:

Rod

Largely outdated
Very low stopping power
Imprecise and heavy
For more information: http://www.bikejuju.com/2010/how-do-rod-brakes-work-a-visual-primer/

Coaster/Drum/Hub

Include 'Back-Pedal' Brake
Generally not very powerful
Very low heat produced for extended periods of braking, used in freight bicycles for example
Isolated from the external environment (rain, mud, etc.)
Very low maintenance
Braking force transferred through spokes like disc brakes (Can't use radial spoking)

Side Pull Caliper

One of the weaker brakes out there for Mountain/BMX use
Somewhat common on older cheap bikes
Note the single pivot point
Sometimes used on road
Light weight
Cheap
Simple

Dual-Pivot Side-Pull Caliper

Common on road bikes
Easily centered so they don't drag against the rim
Note the second pivot point on the right arm
Light weight
Aerodynamic
Slightly more powerful than the cheaper calliper brakes

Center-Pull Caliper

Somewhat common on road bikes
Light weight
Protrude less from frame/fork
Pose a cable pull design challenge for suspension designs (both front and rear)

Center-Pull Cantilever

Better braking power than calliper brakes
Require Cantilever/V-Brake mounts on fork/frame (below rim)
Inexpensive
Protrude from frame/fork very extensively, so not used much in BMX / Trials bikes
Pose a cable pull design challenge for suspension designs (both front and rear)
Center better than Caliper brakes

Delta Brakes

Found on some older road bikes, now uncommon
Aerodynamic
While they look like center pull calipers, they have a few mechanical linkages internally that change mechanical advantage and other qualities
Heavy
Variable Mechanical Advantage (not desirable)

Side Pull U-Brakes

Common on some BMX Bikes, older mountain bikes
Common for trick bikes that route the front brake cable through the steerer tube
Require U-Brake mounts on fork/frame (above rim)
Somewhere between caliper and V-Brakes for stopping power*
Very little protrusion from the sides, so very little to catch your leg/pants on

Center/Dual Pull U-Brakes

Common on some BMX Bikes, older mountain bikes
Require U-Brake mounts on fork/frame (above rim)
Even less protrusion than side pulls
Again, between caliper and V-Brakes for stopping power*

Note on U-Brake power: I have a type of center pull U-Brake that uses a wedge that forces the pads into the rim and stops with more force than any V-Brake I've ever used, and has crushed rims for me. The TYPICAL U-Brake design would be between TYPICAL caliper and TYPICAL V-Brakes.

Roller Cam Brakes

Shown here on U-Brake Mounts
Smooth feel
Somewhat rare

Direct-Pull Cantilever Brakes / "V-Brakes"

Most common brake for Mountain bike use
Require Cantilever/V-brake mounts on fork/frame (below rim)
Generally more powerful than non-disc brakes due to the mechanical advantage
Require different levers than the other rim brakes (the levers pull more cable and have less mechanical advantage than the others)

Hydraulic Cantilever Brakes

Relatively New
Increased stopping power over non-hydraulic cantilevers, but lighter and more aerodynamic than disc brakes

Cable Disc Brakes

Don't heat the rim or use it as a braking surface
Will run fine on bent/cracked rims
Aren't as affected by mud/water as rim brakes
Increase load on hub/spokes/rim eyelets because the braking force is transferred through them. Shouldn't use Radial spoking with them.
All this is true of other hub/coaster/drum brakes as well.

Hydraulic Disc Brakes

Same as cable disk, but...
Stronger braking than cable disks.
Better feel / less input force
More expensive

Hydraulic Rim Brakes

Common on rear brake of trials bikes and somewhat in Europe, also used extensively for unicycles.
Most stopping power of any brake type
Provide the most 'lockout' - a stiffened disc brake will still allow flex from the hub and spokes, where this will not
Can easily crush most single walled rims


Is it possible to reattach the v-brake spring/pin arm?

I'd start by unhooking the inner cable, like you're about to take the wheel out.

Then unscrew the big silver bolt that goes into the brake boss on the chainstay(rear) or fork(front)

Slide the brake arm off and inspect the spring.  If spring is in more than one piece, you'll need new ones.  Replace both springs to keep the tension close to even.

If everything looks okay, undo the good brake arm carefully and inspect how it goes together.  Reassemble the bad one repeatedly till you get it working right.

Don't forget to use blue locktite/thread locker on the two big bolts.


What does "2×4" refer when talking about food?


I would round to 294, since that would keep difference from theoretical less than 1 mm, and as bonus left and right would be of same length which means you have to stock only one size for replacements.


What should I use, VeloPlugs, Rim Tape, or Rubber Rim Strips in new wheels?

There are advantages to all of them, but tape has always been my preference.

I've used velo plugs, but in my wheels the incidence of loss was too high. They lasted me less than a year, before I lost all the extras, and went back to tape.

I don't use rubber rim strips because the rubber degrades, and they move around too easily.

I prefer Schwalbe high pressure rim tape, because it gives a good seal, stays put, and sticks better than cloth tape like Velox, but still removes clean and easy when the time comes.

I hope that helps.


I'm a novice not sure where to get a bike education?

I would inquire at your local bike shop or look on the internet for a local bike advocacy group in your area.  These are generally a fantastic resource.
Some of the education my local group offers are below, additionally they also have regular rides, both adult and family oriented. I have heard of other groups offering comparable resources all over the US and Canada. If you happen to be in the US, The League of American Bicyclists has a search tool to find local groups.

Youth Education
Confident City Cycling
Basic Maintenance Skills
Safe Routes to Schools
Resources for Employers


Flat bars
The simplest kind of handlebar, these are a straight bar with grips on the end. Flat bars were traditionally only used by cross-country riders but now you see them in more general application.

Flat bars (image credit)

Flat bars offer more space to mount lights and computers than drop bars. These bars have  bar ends attached for additional hand positions. (image credit)


Durability of Seat and Chain Stays on steel frame touring bike

Situations when the weight of whole bike + cargo (+ maybe a rider?) is concentrated on a small patch of kickstand's clamp and when a small dynamo clamps the same seatstay are really incomparable. In the first case it's a thousand Newtons of stress applied to a piece that was not supposed to be pressed in that direction, and for dynamo it's about five Newtons and the clamping force.

I would say just clamp your dynamo mount with a reasonable torque, or, if you are really paranoid, use a torque-measuring wrench and clamp according to manufacturer specifications. If it turns out to be loose at some point, simply re-tighten it.

Steel and aluminum alloy frames could sustain quite a lot of abuse of excessive clamping torque (but there is no need for it in the first place). If you make a mistake and instead of 4 N×m would crank it up to 20 N×m, it will still be OK. But I doubt that you will be able to achieve such huge torque with a typical size 3-6 mm allen key that is most likely used for the operation.

If your frame is carbon fiber, then a more accurate approach is recommended, as this material is more sensitive to clamping. However, I am not sure that there are many touring carbon bikes around.


Need to know the wrench size for 10.9 screw

10.9 is the type of steel alloy used, not the size of the hex key (aka allen key) you need.

Get a set of hex keys (almost surely a metric set is needed, given that its on a bicycle) and then try them out to see which one fits. I'd guess its something in a 3mm, 4mm, 5mm or 6mm range.


Does Enduro make a ceramic hybrid wheel bearing kit for WTB Laser Disc Lite hubs?

http://wtb.com/pdf/manuals/ServiceLDLiteV6.pdf

This service .pdf indicates that you need 15x26x7 bearings. I did a quick search on Enduros website and they don't appear to make this size in ceramic.

A quick web search came up with one option that I could (quickly) find.

http://www.vxb.com/page/bearings/PROD/Kit7872

Typically, in my experience, the bearing manufacturers are not going to say that they have a kit for a WTB LaserDisc Lite hub. They simply make bearings of a given size and if they are what you need, great.

What the .pdf doesn't specify is what size the freehub body bearings are. It gives a part number for replacement as a UNIT but does not break it down into its finer parts. Read further along in the .pdf and they do indicate that you can replace the bearings from the freehub quite easily. My recommendation is taking them out, measuring them w/ a vernier caliper and then doing a quick search to see if you can acquire a ceramic version.

Hopefully this helps a bit.


Will these new wheels be able to replace the old ones?

The frame will take any 700c 135mm hybrid wheel, which can be either freewheel or cassette. You likely have a freewheel hub, which means you have a freewheel, which means if you buy a cassette wheel like you are talking about you will need a 7-speed cassette plus a 4.5mm spacer to go with it. And then you're putting a new cassette on a worn chain and chainrings, which could turn into needing to replace at least the chain and perhaps all of it, depending on how worn it is, which may seem cautionary but we're also talking about a bike that was heavily used enough to be riding around with a broken axle.
You could look for a used hybrid freewheel wheel, but without knowing what you're looking at, it would be easy to come up with one that's in poor shape. And, it sounds like you have no particular reason to replace the front anyway. The 18 vs 19 internal width doesn't matter.
7-speed cassette hubs almost never break axles, but if you did have one and the wheelset you're looking at was a good deal, then yes it would be fine.
Unless a project is what you want, there is a lot to be said for just having the shop install a new freewheel wheel and adjust everything for you.
If spending as little as possible is the goal and you're trying to do it all yourself, it is possible you could spend the least by replacing the axle. It's common for broken axles to result in the cups and cones getting too damaged for a shop to want to mess around with, but cheap axles are cheap and you may be able to get it rolling. If it wasn't ridden too much after breaking, it may even be fine, and it's falling apart anyway so it's easy to look at the condition of the cones. You would need a cone wrench and freewheel tool plus grease and bearings to do this.


2200 is the Shimano Claris line from 2009, so not 'unbranded', but at the bottom end of Shimano hierarchy.

Firstly, the derailleur itself is probably not causing shifting issues. Replacing the shift housing and cable will very likely fix the shifting and keep the indexing properly adjusted. Check chain and cassette wear as well.

A 9 speed Sora derailleur with a 8 speed cassette and Claris 8 speed shifter should in fact work. The reason is that all Shimano road rear derailleurs and shifters at 10 speed and below generally use the same cable pull ratios. You can also consider the Claris RD-R2000, which will work a little better than the RD-2200.

The RD-R3000 and RD-R2000 will work with a cassette with a large sprocket up to 34 teeth.

The 48/38 crankset is a bit weird. Fitting a smaller ring depends on the bolt circle diameter (BCD) of the crank. What has probably happened is that a previous owner has fitted a smaller big ring to a 130mm BCD crank which limits the small ring size to (usually) 39 teeth. If the BCD is 110mm, you'll be able to go to a 34 tooth small ring at least.

Remember that if you do change the cassette you'll need to replace the chain as well.

Edited to add: There is another route to a drivetrain with a spread of ratios - buy a different used bike that has what you want (and re-sell the current bike). This is my standard advice in these situations as upgrades can easily cost a significant fraction of the original cost of the bike, and entail headaches and frustration.


Help Me Identify My Bike Serial No. : HZ100202418

tl;dr its a modern bike inspired by workman bikes of the 1950s.

Mayam is/was a bicycle company in Nagoya Japan, and was related to "Nittei Industry Co"  They were known for their "heavy duty carrier bicycles" which is where the double top-tube comes from.

 1970s advert.

Older advert reproduced in a calendar.

 Japanese "Guarantee Medal"  associating the names Mayam and Nittei

More info  http://chikutakurinrin.cocolog-nifty.com/blog/2011/08/index.html

Your bike appears to be a modern reproduction "inspired-by" the older models.  Reasons:

The fork has nowhere near as much rake as the old bikes.
Dual pivot front rim brake
No rear brake - loaded bikes take some stopping, though a coaster brake might work.
No carrier, nor lugs to fit a carrier
No mudguard mounts either.  A workman's bike gets used in the rain and wet.
Super short head tube.  Back then head tubes were longer - short ones increased stresses on the head tube/top/downtube weld areas.  Also related to load carrying limits
Deeper section wheels - these bikes would have had steel box section rims for strength while carrying loads.

Other - Not sure whats up with that bottle cage - might be some special modern thing that interfaces with a special bottle.


It is 2020, and we have had heart rate monitors for quite some time. Additionally, we have had the Bluetooth and ANT+ communication protocols for some time.
Note that this answer is primarily based on reasoned opinion - we tend to prefer more objective answers on Stack Exchange, but we have no basis for such an answer. My instinct is that by now, reliable enough HRM straps with wireless transmitters should be a commodity product, i.e. they're easily mass produced. I'd expect consumers to be able to get an HRM strap of any price point from any reputable brand and not worry about its reliability. You shouldn't need to pay for a premium HRM to increase reliability. If you are getting a low-cost monitor from an off brand, e.g. something generic from eBay or Aliexpress, I would be more concerned about reliability - but note that all our electronics are made in China anyway, so I'm not calling out Aliexpress solely on its national affiliation. Your experience does suggest that Wahoo might be having some design issues with its devices or that you are, for some reason, unusually harsh on your HRMs, which will be briefly discussed later.
If you ask about brand specific information on the web, it can be hard to parse out the noise from the actual signal. It is probably impossible for us to objectively point to reliable brands based on actual data. I could point you towards review sites like Cyclingtips, DC Rainmaker, Bike Radar, Velonews, probably some triathlon sites, the list goes on. The issue is that those reviewers will often not have a review device for long enough to surface many durability-related problems, and moreover they will only have one device at a time. I would expect that even for a low-reliability brand, the proportion of HRMs failing in the first year should be low in absolute terms.
You could, if you deem the effort worth it, continue to pursue a warranty claim with Wahoo. They should warranty the strap. They have generally made reliable products in the past, so I am surprised to hear of your continued issues - albeit I have had one Tickr X warrantied for a similar fault as yours (mine either reported a heart rate of 122-124 BPM regardless of effort even though it looked like reasonably random data, or else it appeared to work for a few minutes then reported a constant 225 BPM). If you don't want to stick with Wahoo, then obviously you should not. Per our FAQ, we don't do specific product recommendations, so I will not recommend a specific brand here.
You did not indicate if you have a chest strap that reads electrical signals or an optical HRM. Electric signal-based HRMs are considered to be more accurate than optical HRMs. However, the durability of the straps on electric HRMs might be a limiting factor, and some people might be unusually hard on their straps - do note that with electric HRMs, the strap contains part of the sensor assembly. One of these might be your sweat composition. If you are one of these people, you might consider an optical HRM, where all of the necessary sensors are in the HRM unit and the strap is just a strap. Be aware that skin tone, hair, and other factors can affect the accuracy of optical HRMs. Also, I believe optical HRMs draw more power than the electrode-based ones; the former have to generate enough power to shine a light through your skin. Thus, they typically rely on rechargeable batteries, which require recharging more frequently than the coin cell ones used by electric HRMs.


If someone wants to write an answer that really runs everything down, I would applaud that. But it would probably be out of date the following week.
What I will say is this: for the most part, every current big crank manufacturer has their own direct mount standard, for which one can buy either a direct mount chainring or a spider adapter. Shimano, SRAM, Race Face, FSA, and Cannondale are all examples I can think of off the top, and there's more. You can get in the weeds quickly these days if you get a direct mount ring or spider that's made for anything else but the specific crank and specific rear end spacing you're working with.
For the most part, there is no cross-compatibility. There are a couple cases where two different manufacturers use the same physical interface. Cannondale and FSA are like that. The spline pattern and the lockrings are the same. But what's important to understand is that even if the interface is the same, chainring offset considerations will sometimes dash any hope of cross-compatibility with using a ring or spider intended for one crank on a different one. Whether that's true and why gets into a larger discussion of the decisions manufacturers now make in making their cranks and attempting, or not, to create arm compatibility among the different rear end spacings and drivetrain types.
Wolf Tooth and OneUp both make third party rings for these sorts of cranks, and you can often figure out what you need to know from studying their sites.


I don't have experience riding at moderate altitude (1000-2500m), but do have experience mountaineering in the French Alps (>3000m) and Himalaya (up to about 5000m).

Going to over 2000m altitude is not trivial, even for people in good shape, and can have some adverse effects. It's not something you can totally ignore. Although if you are fit and have experience hiking at similar altitude you will definitely notice the relative lack of oxygen but avoid any serious issues.

The most important thing is to drink tons of water, which helps with some of the immediate physiological effects of working at altitude.

As your accommodation is relatively low you will have a chance to recover each night. The mountaineering mantra for acclimatizing is 'climb high, sleep low'.


How to lace a 36 hole 4x9 grouped spokes?

I know this is an old thread but there's isn't much out there in terms of a solution for calculating spoke lengths for "quad" rims. I have a pair of hoops that are 4x8 (32h). The space between the quartets is exactly the distance that four additional holes would occupy, so it's essentially a "64h" rim in which we're skipping every other quartet of spoke holes and lacing it to a 32h hub.
Spocalc only calculates for up to 4X and DT Swiss' spoke length calculator only go up to 40 spokes. Sapim's calculates for any number of crosses and spokes.
How to measure
I think in the majority of cases people just aren't measuring correctly to begin with so they don't know what they're working with. The way to properly determine the spacing pattern is to measure on-center the distance between a quartet of four holes. Measuring it from leading edge to leading edge will give you the same distance and is easier to measure than trying to guess where the center of the hole is. Divide that by 3 to get the distance between two holes at the center. It's more accurate to measure across 4 holes and dividing by 3 over such a small distance so that you're not multiplying your measurement error. You're actually measuring the span of 3 holes, not 4.
The blank space between the quartets should be equivalent to the span of 5 holes, measured on-center between holes on either end of that blank section. Again, while there are supposed to be four holes in that space, you're actually measuring 5 holes, not 4.
To simplify, the formula is g = h ÷ 3 x 5 where g is the distance you expect the gap to be and h is the distance between 4 holes on-center. It's simple math but the concept that 4 holes across is only 3 spaces and that the gap is 5 spaces isn't entirely obvious until you think about it.

A quartet of holes measured 91.5mm on-center on the outside of my 700c rim (presumably drilled as 64h in a 4/4 pattern). 91.5mm ÷ 3 x 5 = 152.5mm. I measured the gap to be 152.0mm on-center. Close enough. The 0.5mm discrepancy was within the ±0.5mm error of my tape measure.
Even if the rim wasn't made in a 4 holes drilled, 4 holes skipped pattern, you should be able to calculate how many holes were skipped using the same method. I'm pretty certain it's almost always going to be a multiple of the space between two holes and the real and missing holes will be evenly spaced.
I did some tinkering in photoshop and it seems like those 4x9 rims were built in a 4 drilled, 3 skipped pattern. That works out to 7 x 9 = 63h. Not exactly a neat number but it's definitely a solvable lacing pattern with calculable spoke lengths.

To calculate the ERD of a rim with an odd number of holes, take the outside circumference and divide by π. In the event it's double walled, no problem, just subtract twice the distance between inner and outer wall. If those 4x9 hoops are skipping 3 holes between quads, we should be able to satisfy an equation like g = h ÷ 3 x 4.
I worked out the solution for 4x9 so if you want, you can skip down to the second section below.
4x8 laced as a 64h
Using the ÷9 method to calculate max crosses to get as close to a tangential angle for 64h, we get 7. So I mocked it up at 7X which ends up being a combination of 4X and 3X with the missing spokes.
This diagram is of one side of the wheel. Note that when you're lacing it, there will be a hole (from the other side) next to each of the real holes on this side (illustrated in red at the top of the wheel). Be sure to skip those as you normally would.
After lacing the first half of spokes from the outside-in (leading blue spokes), you flip it over and lace outside-in again with the spokes pointing the other direction (counter clockwise). The first spoke on the second side will start on the flange in the hole offset just to the left of the key spoke on the first side (#2 in the diagram) and will, likewise, run to the hole on the rim just to the left of the key spoke. It will be the first spoke in the quartet.
The holes in my rims are drilled perfectly centered, not alternatingly offset slightly as most symmetrical wheels are. If yours are, indeed, offset and your hole offsets are wrong, you'll have to move your key spoke to the right by one hole and start lacing the second side just the right of the key spoke.

Then do the inside-out trailing spokes on both sides (green). When cutting the spokes, you'll have to correct for the fact that there are no imaginary holes between the 16 actually drilled "real" holes on each side of the hub flange that the trailing green spokes use in the mockup. Conveniently, the adjacent real hole is unused since the hole on the rim that that blue leading spoke would've gone to doesn't exist.
The distance between the imaginary hole and the real one is less than 1/32 the circumference of the flange, so we'll use that as an approximation. It's a double walled rim so overshooting the spoke length by a little isn't a big deal.
The circumference is 2πr or πd where d is the diameter of the hub flange (which we already know for spoke length calculations), so we add πd ÷ 32, which in my case is π x 38mm ÷ 32 = 3.73mm. Since I'm adding, I'll round up to 4mm. If I were subtracting (which might be required in less symmetrical cases) I'd round down.

Spocalc only goes to 4-cross so I'll have to do the math manually or find another calculator. Whatever spoke length I get for each side, I'll add 4mm to half of them. I'll probably thread an extra 2mm onto those longer trailing inside-out spokes to make up for the rounding and any error so there's no chance of the spoke threads bottoming out on the nipple. I'll probably also use nipple washers since I'm expecting a little extra tension on the spokes to straighten the spokeless sections of the rim, so I'll add 1mm to the spoke lengths for that.
4x9 laced as a 63h
Now for the answer to the OP's original question. The solution I worked out for the 4x9 assumes that the rim is a 63h rim in a 4/3 (drilled/skipped) pattern laced 3X with a 36h hub.
When i was initially working it out as 4X, the corrections ended up being quite large, meaning that we would've deviated farther from a near tangential angle on half the spokes. So even though 3X also gives up a bit of angle, it's more even and overall marginally stronger.
The blue leading spokes are laced to the last hole on the right of a given quartet. Easy enough.
Every 7 "holes" (drilled and missing) on the rim and every other hole on the hub, the holes on the rim and hub line up (the purple lines). This gives us a baseline to calculate how far we're moving the trailing spokes and how much we need to fudge the spoke lengths for those spokes.
The yellow line represents where a trailing spoke would normally be when laced to a standard 36h rim. We know that it's exactly 1/18 the circumference of the rim away from the leading spokes.

We need to move the trailing spoke clockwise so that it lines up with the correct hole on the rim. We know that that hole is 2/63 away from the leading spoke, so we're moving the whole thing over by 1/42 the circumference of the rim (1/8 - 2/63 = 1/42). The new position of the trailing spoke is represented in light green.

Note that the trailing spoke doesn't line up with the hole on the hub now. It has also moved 1/42 the circumference along the hub flange. We'll use that as an approximation for how much shorter the trailing spokes needs to be.
For example, if your hub flange diameter is 48mm, that's π x 48mm ÷ 42 = 3.59mm, you'll round down to 3mm. Once you calculate your spoke lengths for each side, you'll subtract 3mm from half of the spokes on each side. If you end up with a number with a decimal that's less than 0.5, say 3.1mm, you'll probably want to round down to 2mm so that you're not short at the nipple due to the error of our approximation as well as any measurement error if you measured the rim and hub yourself. There's also going to be some error in the how accurately the spoke was cut. As with the 4x8 example, it may be a good idea to thread a few extra millimeters onto the end of the spoke, too.

When you flip it over, start lacing the hub at the hole offset just to the right of a leading spoke on the other side and run it to the hole on the rim adjacent to the other leading spoke.
If your rim holes are alternatingly offset and they're pointing the wrong way, you have to shift the leading spokes on the first side to the second hole from the right. Pay attention to this when you start with the very first spoke. If you shifted over, you'll start lacing the second side with the flange hole that's offset just to the left of the key spoke on the first side and run the spoke to the first hole on the left of the quartet adjacent to the leading spoke on the other side.
As far as disc brakes are concerned, a wheel built like this should be able to handle that torque just like any 36h 3X wheel would. If you wanted to, I'm sure you could lace it with fewer crosses if you work out the pattern and the corrections as I did. The only issue might be extreme corrections and, therefore, suboptimal spoke angles.
And there you have it! You should be able to use the same method for calculating spoke lengths for rims that group their holes into quartets in nearly any configuration, so long as the quartets are spaced by a multiple of the hole spacing.
In retrospect, I realize I could've done the 4x8 simply as 32h 3X using the same approach I used for the 4x9, but I was trying to get as many crosses as possible in order to make it a bit stronger. With 64h 7X (4X,3X) I get 4 additional crosses on each side and an ever so slightly more ideal spoke angle compared to 6X (3X). I think I would've arrived at the same correction for trailing spokes (1/32 the circumference of the hub flange). The difference would've been in the base spoke length calculation. 7X spokes are fractionally longer than 6X.


Shimano integrated shifter/brake, model ST-2200

Yes, plastic. All the levers on all the ST-2x00 STIs are plastic.


Strangely your wife's proportions are very close to mine, except I am a little taller. Speaking from experience, in terms of mainstream bicycle fit curves, this  a somewhat long inseam for height, which means

You need a relatively taller stack
You need a relatively shorter reach (a relatively taller inseam means a shorter torso).

This is essentially the worst combination for fitting, which means ordering sight unseen will be difficult to guarantee the best fit. Being marketed with the words "race" makes me concern that the frames may not have enough stack, but looking at the geo chart suggests the stack is decent.

All that said, I think either the 17" or 18" could work, the 19" is too big.  Both the 17 and 18" have nearly identical stack heights, but differ in front-center dimensions (and reach) due to differences in seat tube angles (the top tube length is also nearly identical between the two).

The two sizes also use different wheel sizes.  The 17" uses 29er wheels (larger), a slacker seat tube angle and therefore as has a shorter front to center measurement and a 1 cm shorter reach, while the 18" uses smaller wheels (27.5) and a longer front to center measurement. Perhaps this is to offset handling characteristics of the different wheel sizes?  I would almost phone to confirm the geometries.

Choosing between the two may mean picking a wheel size.  The larger wheel size will be a bit more stable, which could be good for leisure riding. It also has a shorter reach which is good for a shorter torso. Therefore if I had to hazard a guess (danger) I would suggest the 17". Depending on how your legs are proportioned (i.e., femur to tibia) you may need to move the saddle forward if you have long tibias/short femurs, as a shallow seat tube angle is better suited to someone with longer femurs.

Given that you haven't tried the bike, also be prepared to have to change the stem.  Given the long legs, there is a good chance of long arms which could mean a longer stem. Also given that long inseams effectively shorten the stack height relative to someone with shorter inseams, you may need to use a riser stem and possibly a riser handle bars to get the position high enough. A quick check of arm length would be to measure your wing span (an outward facing wall corner can be good for this) and compare it to your height.  Most bikes are proportioned as if the two match.  If you have a proportionately longer wingspan you will likely need a longer stem so that you don't feel cramped, if you have a shorter wingspan you may need a shorter stem so you don't feel stretched out.  Finally, realize that when you flip a stem up (aka riser) you loose reach, so with more aggressive stem rise you may need to find extend the stem length as well.

Geom Charts


8-speed MICROSHIFT shifters and ultegra RD-R8000-SS derailleur

No, Microshift is usually compatible with Shimano (As far as I know, all except Advent 9 speed), but Shimano 8 speed is not compatible with Shimano 11 speed as the derailleurs have different pull ratios.


Effect of BMX bike geometry on manualing

As far as I'm aware, it's all about the rider's location vs. that of the rear wheel.

A short chain stay helps, because it tucks the rear wheel up closer under your center of gravity.

What really makes a big difference is the tilt of the handlebars: When the handlebars are rocked backwards, it lets you get your center of gravity way back past the rear wheel, making it really easy to lift the front wheel. In the same manner, tilting the bars forwards makes it hard to manual.


Identify a replacement shimano rear derailleur

As the picture shows the shifter, the derailleur is the bit at the other end, I presume its the shifter that has broken.
Any 7 speed shifter will work. this is a combined shifter so you will need a combined (with brake lever) shifter or you could choose to install a seperate shifter and brake lever.
You will almost certainly need (and be a lot easier) to get new brake and shifter inner cables to install the new levers. The cable installed though the shifter and brake lever then threads back to the derailleur or brakes. Reusing an old cable, is almost always an exercise in frustration followed by installing a new cable anyway.  I would install new outers as well when doing a job like this just to be sure they are not a problem.   Levers themselves are incredibly reliable, so its possible that the rear derailleur is part of the problem.
Brakes have two cable pull lengths, make sure the lever you purchase matches the brakes on the bike. In this case as the lever says V Brake so any V Brake compatible lever will work.
We don't do product recommendations, but something like ST-EF500-7R2A would be good.  If cost is a consideration have a look to see if you have a local bike coop.


MTB rims branded 26" measure 559mm to the bead seat, which converts to... 22 inches.

You already have 26" wheels.

They're called 26" because when you put an ordinary 2" wide tyre on them, the outside diameter is about 26".


Will a road brake lever work with a v-brake?

Not typically.  They have different pull ratios.  However, you can get a device called a travel agent to make this work.

Some companies such as Paul's make a cyclocross specific v brake such as the Mini Moto which have the same pull ratio as road brake levers.

If you're not using brifters and have separate brake levers and shifters, you can buy linear pull drop bar levers like Tektro RL 520 that will work with your v-brakes without buying separate travel agents.


Is it OK to bunnyhop on a Kona/Fastrax AF2 while in Lockout Mode?

See my answer to this question for a similar answer:

Does ProPedal on FOX RP2 rear shock wear out when on during downhill?

Basically, you could cause damage to the shock by supplying pressure to either the oil or a part that wasn't meant to handle that much force. Now, do I think it'll break after 10 bunnyhops? Probably not, but it could cause much faster wear on the parts involved inside the shock. Also, are you bunnyhopping like a trials rider going 5 or 6 ft in the air? That's a lot more abuse than hopping 4" over that pothole in the road.

So, the bottom line is no, but probably someday. But then again, that's how you'll break anything...repeated abuse!


Mass - resists denting and damage.  Some are steel, some are aluminium.
Single-speed - a lot of city bikes only have one gear, and those that have more are often euro-IGH (internally geared hub) with 3 speed, no more.  Either way they have 1/8" singlespeed chains.
Chainguards - to keep the chain and pants clean.
Robust lubricants - intended to not wash out.
Tyres - fairly hefty, large, and puncture resistant means fewer flats.

And the big one:

Ongoing maintenance  You may not see it, but the company will do ongoing maint of their bike fleet.  Most of the apps support some kind of "report a problem" so that the fleet staff know where to go to find and fix the bike.  Those that don't have etiquette

Cultural factors will come into it as well - suspect there are more vandalistic yobs in the west than in China.


Can I use a 7 speed shifter on an 8 speed cassette

The 7 and 8 speed cassettes have slightly different spacing (see http://sheldonbrown.com/cribsheet-spacing.html), so the derailleur will be slightly, almost unnoticeably, out of adjustment at largest and smallest cogs. And of course you won't be able to shift to one of the cogs.

If you can't change the shifter to 8-speed, you can install a 7-speed cassette on 8-speed hub with a spacer.

The 8-speed hub is wider than 7-speed, so you will also need to bend the rear fork slightly to install the wheel.


Problems with spoke threads, and stressing the wheel

There is one major cause of this problem and it is putting a 1.8mm aka 15ga spoke in a 2.0mm/14ga nipple.
This mismatch will screw together and hold under some tension, but then slip.
It is easy to test. Obtain a known 15ga nipple. If it can screw on to your spokes at all, it confirms the problem.
The same thing could happen with a 2mm spoke in a 2.3mm nipple presumably. Those are visually chunky though, whereas 1.8 and 2.0mm nipples look identical except for the hole.
I can imagine a fringe outlier situation where poor part quality alone causes this, but it seems really unlikely.
If the spokes were way too short, like with a bunch of thread showing, that may be able to cause it too, but you'd probably notice that.
Your prep choice is not the issue here. Linseed oil does take a while to fully set up, but it's not what's mechanically holding the wheel together. Ideally you complete the wheel before it sets up and gets gummy because it's easier to make small adjustments then.


If by "rounded" you mean stripped, then you can follow the next steps:

Get a hold on a dremel with a cutting wheel, and Draw a line from side to side(Over the center, like a Diametre line) about the same depth of the hex tool that was supposed to loose the bolt.
If possible, rotate 90 degrees and do the same a point 1
Dip the the part in "Light Coke"(this thing works wonders on siezed bolts, not so much on your health tho) for about two hours. If you can do it overnight, that's ok too.
Optional to (3.), pour some wd-40 on the bolts and threads. If it's has threadlocker then you will need a solvent, like Isopropil alcohol, acetone, or just a plain soldering iron to heat the bolt and soften the thing.
Use a Slot ScrewDriver on the lines you made with your dremmel.

This is by far the safest way to remove stripped bolts.

Other method i've used include to drill a hole on the bolt, and then screw a special tool with counterclock thread to unscrew the bolt out of place, while you screw in the tool. Also you could just drill the bolt out, but you might get to damage the threads on your dereaullier.

The last method, only works on a couple of situations where the thread are not seized, is to take the head of the bolt out. This will take tre preasure off the thread and you can fiddle with it until unscrewd. Did this on a KTM Duke 390.

Cheers


I went riding almost immediately after applying Squirt Lube (wax-based) on a brand new chain, should I degrease my chain and reapply?

Just re-apply it and let it dry. Stripping the old lube is done to get oils off that will keep the wax lube from bonding, but that shouldn't be a problem now.


shimano fc4400 double chainring replacement

BCD is the key, Shimano 9 and 10 speed chainrings are interchangable. Dropping a couple of teeth is not a problem, just adjust the front derailleur and check the chain length. Really focus on the BCD, as Shimano road has standard and compact chainsets and they can both take 50 tooth chainrings. You probably have a 130 BCD, if you are running the usual 52/39, the 110 BCD compact chainsets are usually 50/34.


How do I tell the difference between bike brands

You can try to find a serial number engraved somewhere on the bike. For road bike it is sometime under the bottom bracket, so you can try to look there first. Manufacturers might have different serial number pattern so you can start your search there.

Other than that, posting a picture on a forum or here might be a good idea since some people might recognize which  bike it is.


Are Tubeless Continental GP5000s harder to mount than non-tubeless (normal clincher tyres)?

They are marginally harder to mount (slightly tighter fit).
If you struggle with the non-TL, you will struggle with the TL more, whether this extra struggle means you won't be able to mount it, depends on you and your rim.
If you get enough practice you will learn little tips and tricks for mounting tubless tyres.
Such as:

Make sure it's seating in the rim well
Coat with soapy water
Use straps to hold seated part of tire onto the rim whilst you manoeuvre the rest
Start at the opposite end of the valve and finish at the valve

There are many more, but we can't really comment on whether you would struggle or not as we don't know you experience on this.


The reason is historical.  Fixed gear bikes have been traditionally used for track racing, long after most other bikes had switched to using freewheels.  In the high-speed velodrome environment, it would be dangerous if the rider in front of you could brake suddenly:  you would crash into them, and likely most of the group behind you would join in the fun (this is also true in a paceline or peloton on normal roads).  So brakes have always been banned, and aren't really needed on the track anyway.

But track bikes sometimes get retired to road use.  And as fixed gear has gotten more popular, many frame makers are building similar bikes for the road.  Some of them are closer to track bikes (no brakes), others might include front brakes or both front and rear.


While stationary trainers are used primarily to train for raw strength and power, rollers provide training for form and balance.
Because the bike is free to move and weave on the rollers, the rider must keep the bicycle centered while riding. You can't just space out like you can on a regular trainer. Imbalance between right and left legs will often cause you to drift one way or the other, so it provides some feedback to work on that. Pedaling at high cadence also tends to make people start to rock the bike, which will be amplified on the rollers, thus requiring the rider to focus and learn to keep their balance and form.
Regular rollers do provide some resistance training, approximately proportional to wheel speed, but not as much as a stationary trainer. They also don't appreciate sudden bursts of power in sprints, if you blast too hard you can come right off the rollers.
There are 'smart rollers' i.e. computer controlled resistance rollers, but just like dumb rollers, they are limited in how much resistance they can provide. Example is the Nero Elites, which I understand to be the best offering, can only provide 830 watts of resistance. Comparatively, I would expect even the cheapest smart stationary trainer to be well above that. 830 watts is plenty of resistance for just about everyone for steady-state training, but it's not going to work for all-out sprints.
When you are riding around on the street, try to ride right on a line, e.g. the white shoulder line, without moving off of it. See how far you can go. If you can't, riding rollers can be good training for that. It's a surprisingly difficult skills to ride in a perfectly straight line on a bicycle, especially under hard power. That's an important skill if you are riding in a peloton where constantly weaving back and forth, even a small amount, will both slow you down, and make the others around you nervous. With a few hundred hours practice on rollers, you should be able to keep both wheels right on that line virtually indefinitely.
Lastly, they are also a great source for comedic videos of people falling off of them. It happens to us all.


Most likely they are standard bolts having a metric thread. To be sure, use caliper to measure the thread width (you measure the major diameter from a "hill" to a "hill", not the minor diameter from a "valley" to a "valley") and thread pitch (pick 10 threads, measure the distance between these, divide by 10).
If the thread matches the coarse threads at https://en.wikipedia.org/wiki/ISO_metric_screw_thread (for example if the width is 5mm and pitch is 0.8mm), you will very easily find a replacement. If the thread is a fine thread, finding a replacement will be slightly harder but not impossible.
It's also possible it's an imperial thread measured in inches: https://en.wikipedia.org/wiki/Unified_Thread_Standard
Also you need to be sure to replace the bolt with one having equal strength. If there's a marking such as 8.8 or 12.9 in the old bolt, be sure to select at least this strength. If the seller of a bolt doesn't specifically state the strength grade, most likely the bolt is junk -- don't buy such a bolt. If unsure, pick preferably 12.9 or at least 8.8.
You also need to select stainless vs ordinary steel. Stainless bolts usually can't be made to the highest grades, so ordinary steel bolts have a higher tensile strength and thus you can find bolt grades such as 12.9. However, in environments such as riding in salted roads without fenders where the bolts are subject to corrosion, stainless may be preferable.
Lastly, don't forget to select the correct length (measure the length of the bolt and pick a similar length), and don't forget to grease the bolt threads when installing the new bolt.


My bike suspension is very stiff how can I make it looser

This is a bso.

The suspension is there just for looks, not for actually doing anything useful, and you don't really have adjustment on it, or the ability to lock it out. That is, you can't do anything. In your case, you want to make the suspension stiffer not looser to reduce the bouncy-ness. That is, if the suspension was fixed, it wouldn't bounce so much.

In general, suspension costs money to do well. You're looking at ~400-500 USD for bicycles with basic servicable suspension forks, and ~1500+ USD for bikes with acceptable full supsension.

Decent suspension forks will have some adjustability, and possibly the ability to lock out (i.e. act like a rigid fork). Rear suspension systems of the coil type need a different coil (with a larger spring constant for more rigidity) to adjust significantly. Other types have other adjustments.

Note that for riding on the road, you don't really need suspension (for comfort, larger tires are often a better choice). And the suspension on your BSO won't really cope with any non-trivial rough stuff off road (note that these bikes are sold typically with stickers saying not to use them off road).


Pick up the shuddering wheel(s) and spin them to make they are "free", i.e., no brake contact when the lever is not depressed.
Check that your wheel axle is securely seated in the dropouts.
Check that your hub is tight -- pick up the end of the bike with the shuddering brake, push side-to-side on the top of the wheel. You should feel no play or a minuscule amount.
Check the brake rotor for trueness. Spin the wheel, looking in where the rotor goes between the pads. Is the rotor staying in pretty much the same point between the pads, or going from side to side? Alternatively, or additionally, you can spin the wheel and slowly depress the brake, to see if the pad-rotor contact happens first at just one "high" spot or if it happens more or less evenly.
Center the caliper. Loosen the caliper position bolts, grab the brake lever, and then tighten the position bolts.

That's what I'd do to start. With more information I (or someone else) might be able to help more.


Have I incorrectly fed chain into the rear mech hanger

Your chain is set up correctly in the second picture. It should go over the metal tab.

The reason your chain is skipping is probably because your cogs are worn out. If this is the case, you should replace your freewheel/cassette to avoid destroying your new chain.


Installing gear cable guide on 80s Holdsworth

The little hole looks a similar size to the one in my early 90's steel frame BB. Mine is threaded, perhaps yours is too. Maybe it didn't get masked off by the painter and the thread is under the paint. You could ask the painter if they remember taping it or not. You could check for threading and possibly tap the hole yourself if if isn't already.

You can also get cable guides which have a little solid plastic nub which goes into the hole and there is no screw, it is held in place by cable tension. I'll have a look for an image or something but might be a needle in a haystack. Chances are an LBS or framebuilder/painters will have some miscellaneous ones, you could ask around in person and see if you can find one to suit your frame, designs vary.

Other suggestions, from here include glue (!) and double sided tape to position the guide before cable tension takes over. I don't know how they would affect the paint long term.