What's the approximate stack and reach for a 5'10" 178cm man

The lack of definitive answers you've noticed is due to the amount of (often unknown) variables at play here. Body height and inseam are indeed good starting points, but people around the internet won't be able to estimate just how flexible you happen to be. Arm length, discipline and your personal preference on how 'aggressive' of a riding position you want also play a major role.
In this light, the advice you've received is reasonably good. After riding a certain bicycle long enough to get a feel of it, you'll be able compare the S&R of that bike to another one and make a somewhat educated guess on how that other bike would feel for you. The perk of going to a bike shop is the opportunity to throw your leg over bikes of your choosing, which likewise will give you some sort of an idea of which size would fit you.
Of course, your question is valid in a sense that for most people, there exists a ballpark of S&R measurements where they should probably start looking at. However, bike manufacturers often got your back on this. Along with the geometry charts, most of them provide you with a model-specific rider height recommendation. While it's not technically a S&R recommendation for your specific dimensions, it's the starting point you should be looking at instead of any arbitrary stack and reach that you haven't tried yourself.


The frame is 100% trash.  Do not attempt to use it at all.

What you can do is to carefully remove everything from the frame.  Discard the frame, and now you have a whole bunch of valuable parts.  You can either buy a new (possibly second hand) frame, or just sell the parts to finance the purchase of another bike.

There are a few parts you won't be able to easily remove, such as the headset and the bottom bracket, but these are not very valuable anyway, so don't worry about buying the special tools for those.


Interesting and personal topic.  I'll ignore your budget for now...

Ok i make use of a Garmin Edge 1000 with a HR monitor.  I like to monitor my HR by % of max rather than beats.  Makes it easier when looking at zones thinking of it in %.

For a indoor training on Zwift i use the Wahoo Kickr you refer to above.  Now here it records in beats since thats what Zwift shows but whats good here is it supports Bluetooth and ANT+

Different tools for different applications.

On the bike Polar works fine easy enough to upload and you can see tour zones, HR in beats or %.  Garment n provides a few more options like routing, HR graph even these days on the edge 1000 and 520s.

Coming back to your budget... The Wahoo kickr is a simple cheap option to use with your phone if you only using Strava.  If your using other apps like Garmin connect, Polar etc a dedicated monitor and strap has more advantages.

But you pay for those advantages.  I guess flexibility and compatibility are the major things to consider.


Yes, these should be compatible.

Sheldon Brown's glossary indicates that the FC-3301 used Octalink V2 (see this reference page: https://www.sheldonbrown.com/gloss_n-o.html#octalink).


If you're willing to accept 5 gears, it's really not that difficult. The main issue is finding a hub that's narrow enough to fit the dropouts.

Sturmey Archer make a wide-range 5-speed geared hub, with or without coaster brake, with 120mm OLD spacing. There used to be a 5-speed SRAM hub with 122mm (?) OLD, but it might be a job to track one down. If it's a steel frame with thin stays, you have a couple more mm of leeway. But most hub gears are 135mm OLD. Depending on the hub, it may be possible to remove axle spacers, but don't bet on it... anti-rotation washers don't count; they mustn't be removed!

Unless your current frame is a conversion, you may have a few cable-routing headaches too (although clamp-on cable guides aren't difficult to find).

It only really makes sense if you love the frame. Part exchange would probably be your best bet, but if you have a good reason to keep the bike then I say go for it.

My partner is very short (5'), and standover height is an issue, so she rides a kids' Fuji track. The cost of the Fuji, plus that of building a new wheel around the SA hub, was significantly lower than any WSD we could find.

Afterthought: A cheap and good way (albeit one that requires some tinkering, swearing, and an awful lot of luck):

5-speeds from the 50s tended to be 120mm OLD, so you might be able to swap out the SS freewheel for an old-fashioned thread-on 5-speed model. There are quite a few caveats, however. For starters you'll need a fairly narrow hub shell. Then you'll need enough free threads on the axle to shuffle the cones and locknuts off to one side, so there's enough axle showing to fit the wheel securely. Then you'll need to re-dish the wheel.

Then you'll just need a rear mech with a bolt-on hanger claw (assuming the frame doesn't have a threaded hanger on the dropout). If you're friendly with a local bike shop / junkyard, you might be able to blag these bits and pieces for free.


Should I buy a mountain bike, what size should it be?

We can't really say what kind of bike you should buy, you should buy the bike you will ride, that is the most important thing. Many (most?) people will want to have both, a road (or gravel) bike and a mountain bike. Some people will want to hove both a hardtail mountain bike and a full suspension mountains bikes. They are different machines for different purposes.

If you want to have one universal bike, a hardtail mountain bike is good for that. So is a gravel bike. The preference is really individual. No-one can make that decision for you. I have both (not at the same place) and the are of use largely overlaps.

Mountain bikes with suspension require the maintanence of the suspension system. That is the job for a bike shop for most people, it is more complex than the maintenance of bikes without suspension. It should be done regularly. There are tutorials available, but even with that most people won't want to do it themselves.

The size can really only be selected after you chose the bike model you want. Follow the manufacturer recommendation, try it if you can, ask the bike shop if you can. But when buying online I would follow the manufacturer,  you probably do not have enough free money for a bike fit. Your size will probably be medium for many bike frames (for MTB 19" or 20"). But surely not for all.


Does new chainring require change of other parts?

It would be wise to check the chain wear with a chain "stretch" gauge and replace it if the chain is beyond 0.75 or 0.8.  Re the rear sprockets, they're only likely to be a problem if the current chain is worn beyond 1.0 stretch.

The other thing to worry about is whether the derailers can simply handle the difference.  The rear derailer has a "tooth range" in terms of the greatest difference between the sum of tooth counts of the largest sprocket pair and the smallest, and if that range is exceeded then the chain will either go slack on the smallest combo or become over-stretched on the largest.

Further, the front derailer has a limit to how great a tooth difference it can handle, and too much difference could result in the chain rubbing the derailer or iffy shifting.

But these problems are only likely if the difference in old and new ring diameters is substantial.


Nexus 7 speed will not go into 6. and 7. gear

have you checked that your shifter cables is in any way rusted or damaged? I had the same problem and i just got a new cable which fixed it quite nicely


First verify these assumptions:  The chain rings are not bent (causing unintentional shifting), the chain ring teeth are not badly worn or the chain itself is not worn and stretched (causing the chain to jump teeth and perhaps feel like shifting), the bottom bracket is correctly adjusted and not wobbling (causing contact with the cage and unintentional shifting), and the leading edge of the large, inner Front Derailleur (FD) arm is not bent away from the bike (forcing a shift completely off the large chain ring).

How your FD works: As the FD cage moves in and out, one or the other of two arms of the FD cage puts sideways pressure that shifts (de-rails) the traveling chain from chain ring to chain ring.  The FD should be securely attached in the correct position on the Seat Tube so that at no point in its travel does either cage arm contact any part of a chain ring and at no gear combination does the chain itself drag on the rear spacer that holds the two FD arms together to form the cage.  The arms should be smooth (not worn), parallel with each other, and parallel with the chain rings (and therefore in line with the chain that is traveling through the cage.) The FD spring typically forces the cage towards the IN position.  Pulling on the FD shifter cable forces the cage towards the OUT position. The inner cage arm is typically wider and longer than the outer cage arm because it requires more pressure over that larger surface area to lift the chain up to a higher gear than it needs to simply drop the chain down to a lower gear. The two adjusting screws are used to limit how far in each direction (IN or OUT) the cage can move.

Now let’s do a complete FD adjustment with the bike suspended in your work stand:  While hand pedaling the chain through the FD cage, carefully shift and center the FD cage over the small inner chain ring.  Shift the Rear Derailleur (RD) into the largest freewheel sprocket (closest to the wheel).  At this point, there should be only very slight tension (and no looseness) on the FD shifter cable.  Loosen the cable clamp at the FD and adjust the inner limit screw until the cage is exactly centered above the small inner chain ring.  Remove any slack in the FD cable at the FD cable clamp and tighten in place.  Shift the RD into the smallest freewheel sprocket (furthest from the wheel).  With the chain moving through the FD cage, shift and center the FD cage over the large outer chain ring, and verify the chain is not touching either cage arm and the cage is clearing the large outer chain ring.  Now tighten the outer limit screw.  Test all possible shifting combinations several times while hand pedaling on your work stand―first slowly then faster and faster.


Can I build a wheel with two different spoke types?

In Roger Musson's book Professional Guide to Wheel Building 7th Edition, https://www.wheelpro.co.uk/wheelbuilding/book.php this is covered in brief (for a dished rear wheel):

The wheel can support more load before the left spokes go slack by making the right side spokes stiffer than the left and this is accomplished by using thicker (stiffer) spokes on the right and thinner (less stiff) spokes on the left.

But he also says any benefit is difficult to quantify and it's unproven if it makes a better wheel, before concluding:

I always use the same gauge spokes either side on dished rear wheels for the simple reason that the wheels work and I have no reason to look for a solution to a problem that does not exist.

It's a tiny section of a very thorough book, so not something to do routinely, but if you are looking to do this purely for spoke availability then yes you can if you were using the thicker spokes on the side with more tension.
In any other year I'd say don't bother, just persevere and find matching spokes from whichever seller (lots of online sellers can cut spokes down to length for you if you contact them) but 2020 is no ordinary year!


I removed the drop-out adjusters... Do I need to adjust my derailleur or add chain or both?

So you might be about two links short, or you could move the wheel forward. The purpose of the adjusters is to make it easy to position the wheel. The tension on the quick release skewer is what actually keeps the wheel in place. From what you describe it sounds like the skewer wasn't generating enough tension.

Try this:

Locate the wheel where you want it – I'd put it where the old wheel was.
Adust the quick release handle so that it is pointing strait out, parallel to the axle (perpendicular to the wheel).
Tighten the adjusting nut on the skewer until all of the gap is taken up.
Press the lever home into the closed position – it should take some force. If you can't get it to go parallel to the chain stay, then back off the adjusting nut. Just a little bit, maybe a quarter turn, and check again. Don't be afraid to push reasonably hard, the lever should leave a bit of a mark in your palm.

If you do that, the wheel should hold where you put it. You might want to put the adjusters back in. They will help get the wheel in the right place, so you won't need so many hands to install it.


Brakes for a mountain bike frame (26'r) with 27" road wheels

I have not tried, but at Paul Components say these Moto BMX brakes might work with 700c rims on 26" frames. But they might turn out to be too expensive for your purpose.


The difference is whether the spoke is butted or straight gauge.

A butted spoke is thinner in the middle, which allows more flexibility without damaging the wheel, which usually makes it the stronger, as well as the lighter choice. The choice is purely personal, though, and either will function as long as the lengths are correct. Note that not every spoke in a wheel set is the same length.


Is there a free speedometer app for Android phones which beeps if I am deviating from a pre-set speed?

The bike computer app I use will do almost all of this: IpBike. It's not free long-term, but you can try it for free for long enough to know whether you like it.  Its "Workout" mode allows you to set a target speed (or cadence, heart rate, power) specified as a range, and have feedback when you're out of range.  This could be as an interval in interval training, or could be for an arbitrarily long time.
I've never used it myself, so don't know what the feedback is like, but you can configure beeps and speech.  I'll have a play, and the author of the app has been known to visit here.
Edit after testing:
In the few minutes since I answered I configured a workout with a speed target of 21--27km/h for 8 repeats of 5 minutes after a 1-minute warmup, and went for a ride.  Below 21 km/h I got a falling tone every 10s (configurable) with an on-screen notification; above 27km/h I got a rising tone.  It lacks the more urgent tone for being further from the target that you'd like, but you can always glance at the speed.
I had text-to-speech disabled in IpBike (couldn't hear it well enough, and couldn't quite get the output I wanted), but testing at my desk in GPS-only mode, I get "Below Target". You can use GPS or ANT+/Bluetooth sensors; it sounds like you'd use GPS as I do.


How to prevent loose brake cables with a single pivot side-pull mechanism?

It's because you have a combination of brake levers designed for V-brakes and side pull brakes. V-brakes need more cable pull for the same effect, so your levers pull the cable too fast.

The solution is to get levers designed for caliper brakes, something like for example this (note "Caliper or Canti Brake Lever System"): http://www.tektro.com/_english/01_products/01_prodetail.php?pid=69&sortname=Lever&sort=1&fid=3. There are also adapters for cable pull issues, but they are made to solve the problem other way round and cost as much as simple brake levers.


Help choosing between two frame sizes based on my dimensions

When in doubt, the best is to try the bike.

Dimensions are important from an anthropometric point of vue especially to prevent injuries and such. So in that perspective if you're kind of in-between sizes the choice will be guided by your sensations.

I know cyclists that prefer oversize and others that prefer undersize, it depends on how much you lean on the bike and that kind of factors.

So the best way to do it is to spot the extremities on your size spectrum and try bikes that match, you will feel what is natural for you.

I personnaly ride an old steelframe oversized roadbike and it's feels awesome.


You can cut an aluminum soda can into a small strip and wrap that around and fold it like a tiny burrito into the end. Crimp with pliers.

Picture lovingly misappropriated from http://billgrady.com/wp/2002/11/14/how-to-wrap-a-burrito/


The bike goes where your eyes are looking. I have no idea why this works, but it is amazing when applied.

The key is to always be looking as far ahead through the corner as possible, when you start turning in you should be looking at the apex, once you have reached the apex you should already be looking past the exit. I've passed cars and motorcycles and taken many downhill KOMs using this technique, while on 23c tires!

If you watch any motorcycle race or go to any motorcycle class/school, their eyes are always ahead of the curve their on. This takes a lot practice to get down especially when your cornering confidence isn't very high.

I have a very similar cornering technique to what you described and I have the same problem you described, where I can make it to the apex just fine, but need to bail out when I get there, this is because I haven't properly sighted through the corner, almost every time. (I watched someone crash in front of me just last week doing this, they saw gravel on the outside of the apex and went right for it, instead of looking at the exit)

I find that slick tires (assuming you're cornering on asphalt) offer much more surface area and therefore grip than semi knobs. The knobs decrease rubber contact with the ground and tend to deform when cornering. (I learned this both the hard way and easy way).

I prefer to decrease my tire pressure when cornering in order allow the tire to deform to the road surface and therefore have more contact with the ground.  I use this to determine tire pressure. This also allows more absorption of small bumps. A very hard tire will bounce over everything and when you're bouncing, you are no longer in contact with the road surface.

You can also utilize different lines through a corner in order to achieve a different exit through the corner. The fastest line through a symmetrical corner will always be a symmetrical line, but it won't always be the safest. A late apex works great also

As someone quoted in the "rules," practice is the best way to increase cornering confidence, well...and maybe a little bit of fearlessness.


It sounds like you are having trouble downshifting from any larger gear to a smaller one.
If a rear derailleur won't go from a larger gear to a smaller gear it's because:

The cable is binding preventing the derailleur from getting enough slack
The derailleur spring is too weak

Starting from a smaller gear on a 105 rear derailleur and moving to a larger gear happens because of tension on the cable. You move the lever and it pulls the cable which moves the derailleur. As the derailleur moves a spring in the derailleur is compressed storing energy.
When you move the lever to shift from a larger gear to a smaller gear the cable is given slack. The rear derailleur spring takes up the slack and moves to the smaller gear.
Get the bike on the rack or into a position where you can pedal and make the rear wheel move.
You can test to see if the cable is binding by:

Disconnecting the cable from the derailleur
Hold the just disconnected end in one hand and move the shift lever with the other. The cable should move easily in both directions.

If you feel any binding you'll need to hunt down the source and fix it.
It could be due to dirt/rust in the housing, a kink in the housing, a kink or hard bend in the cable etc.
With the cable disconnected you can test the derailleur spring by:

Turning the pedals with the rear wheel spinning
With the rear wheel moving use your hand to move the derailleur to shift into the larger gear.
Release the derailleur - keep pedaling - the spring in the derailleur should crisply shift back into the smaller gear.

If the derailleur won't move the chain from the larger gear to the smaller gear the spring may be weak or broken.


What do you wish someone had told you before your first commute?

My suggestion would be:

Scout and rehearse your route before you start.

This is really an exercise in two parts:

First part is to determine what your initial routes from home to work and from work to home (not necessarily the same, certainly not in detail) are going to be. And to work out where you're going to secure your bike for the day.
Second part is to ride the route with no time pressure "off peak" (ideal is probably on a Sunday) so that you know where you're going and you don't get surprised (lost!) when you're riding to arrive on time - it should also enable you clear up any grey areas on your planned route. As importantly, this will give you an indication of how long you should allow for the journey. If you know where you're going and how long its going to take you're going to be more able to focus your attention on riding safely and less distracted by navigation and time concerns.

Once your commute is established I'd suggest that fairly regularly you allow yourself a bit more time (much easier going home!) to explore alternative routes - especially for urban commuters. The most obvious routes are not always the best, you may find shortcuts that are faster or routes that are prettier or have less traffic or smoother surfaces or that you simply like better (or that are not really very different but allow you to vary your route from time to time "just because").


chain jumping when puilling away in a higher gear

When you replace the cluster (rear cogs) you almost always need to replace the chain too because they wear together.  If you put an old chain on a new cluster, you often experience that kind of because the length* of the links in the chain is slightly longer than the spaces between the teeth on a new cluster.

*Note the links don't actually get longer, it's just that the rollers wear out and allow a little play and the links sit a little further apart.  This is known as "stretch" though it's different to the way something like elastic stretches.


Difference between wet and dry chain lube

Wet and Dry lube are pretty much universal terms, they're not constrained to one manufacturer.

Wet lube is suitable for wet conditions, dry lube is suitable for dry conditions.

Wet lube is quite sticky. It will stick to your mech and is less likely to get washed off by rain. The downside, because it is sticky, it can pick up crap from the road, as those guys said.

Dry lube is a much lighter lube. It should keep your mech quite clean, the downside is that because it is that much lighter, it'll get washed off in wet conditions.

As regards use, it really depends on where you live and your climate. Where I am (UK) I tend to use dry lube in the summer and wet lube in the winter. If I think I can get away with it, I'll lean toward dry lube (although I won't put dry lube on top of wet lube, I'm more likely to clean the chain first).

Incidentally if you look at a given manufacturer, they will likely have both wet and dry products, possibly others too. All are optimised for certain conditions. For example, the manufacturer White Lightning makes four lubes (described here). I use Epic (which is a dry-ish lube) and Wet.


Flat handlebar caliper brake compatibility

The product you are looking for is interrupter levers. regular flat bar brake levers aren't designed to work in conjunction with STI levers.  The ones I linked to specifically say they are compatible with caliper/cantilever brakes.  I'm pretty sure most interrupter levers would be compatible with caliper/cantilever brakes because v-brakes don't tend to be found on bike with drop bars, which is where one would normally need interrupter levers.


Your local bike shop might (see comments on the might) buy chain in bulk and can cut it off at precisely the length you need. Get a quick link at the same time so you can easily put the chain on or remove it.

They may have limited selection, though, especially as you’re looking at a speciality chain- a 10 speed chain designed for ebike torques. So they may not have this as a bulk item. Bike shops that specialize in cargo bikes and recumbents are your best bet.

Otherwise, you’ll have to break and conjoin two shorter chains. Be sure to get the same brand and model chain as slight differences in chain width or profile can cause shifting issues. You’ll need a 10-speed compatible chain tool to break one of the chains to length. There’s generally no problem using the quick links to put the chains back together again as long as they’re the links provided in the box.

But back to the speciality chain issue. Many of us think there’s a great deal of “marketing” and much less “engineering” around ebike parts. Given that a top sprinter can easily put out 1500 watts, a high quality 10-speed chain should be able to handle many mid-drive motors which are 750-1000 Watts. My main caution would be to make sure your motor controller has a shift sensor so it de-torques during derailleur shifts as shifting under max epower can snap even the strongest chain.


The debate of Presta or Schrader is mostly religious and often based on poorly misunderstood facts or historical differences.

Rim Width. In the 21st century, the problem is less about the strength of the rim and more to do with fitting the tire beads and valve into a narrow rim. If the rim is wide enough to accept a Schrader and mount the tire, its strong enough.  As we are discussing MTB's – the last time I ran a rim too narrow for Schrader on a MTB was 1993. In the last decade, MTB rim widths are getting wider so it makes no difference what valve you run.

Weight. Presta are marginally lighter; only you know why you care so much.

Length. Although long Schrader valves are available, if you have deep rims you are more likely to find Presta in long valves.

Pressure. It's commonly stated that Presta is better at pressure – Schrader are used to contain pressures of over 600bar. They are used in MTB shocks (up to 250 PSI ) and your car's air conditioning unit (200PSI, expected no gas loss for a decade), so I think that myth is busted.

Inflation. Presta had the edge way back before the days of plastic heads and computer engineering. In 2017, if your pump does not have a head that successfully inflates Schrader every time, buy  a pump worth more than $1.

Robustness. From personal experience and anecdotally from internet discussions, Presta is prone to having the end broken off by some combination of one or more of clumsy novice and cheap pump. I have not done in the last couple of decades...  Schrader really do require the caps to keep rubbish out of the core (although plenty don't and seem to last OK).

Reliability. Schrader are used in every car tire in the world. Presta are probably at least as reliable, nuf said.

Valve Length. Although tubes with long Schrader valves are now available, it's more common for rims requiring long valves to be Presta.

So why use one or other? I mostly run Presta because many people still think  Schrader is a mark of a BSO, and although I ride a 10 year bike, I would not be seen dead on a BSO.

For tubeless though, I think the balance swings to Schrader – bigger hole for putting the slime into the tire and for initial fast inflation to seat the bead.


Are bicycle serial numbers no longer stamped into the frame?

Barcoded labels like the one you’ve pictured are common and usually the most visible version of the serial number, especially on a carbon frame.

However, there are usually stamped/molded serial numbers on the inside of the head tube and bottom brackets.


Is a long, high angle stem safe to use with a carbon steerer?

Within "normal" standards of long and high angle, yes it is safe.

While there are some stems which use clamping styles which are not carbon safe, or other restrictions, these are usually clearly stated.

No restrictions are based on length or angle of the stem, that I am aware of.  I have been a certified professional bicycle mechanic for 20 years, so I would think I'd have seen it by now, if it were an issue. :)


Are two different tires marked with the same dimensions (700 x 25c) the same size?

I'd check if the wheel was in properly and is in good condition (true) along with the tire being mounted properly on the rim.

There is some variation in tires true sizes despite being marked the same size, though half a cm would be a lot larger variation than one could reasonably expect, especially with older tires. Features like studs, knobs can also affect this. If you have reasonable clearance for a given size of tire, one should reasonably expect a similar tire from another manufacturer to also give reasonable clearance, though this is not always the case.


Bicycle maintenance is well within the scope of most people with basic tools. Your task is made easier because the bike had not been ridden many miles before being stored, so it should not have any significant wear and should still be adjusted correctly. Bicycles don't wear out or go out of adjustment when they are just sitting in a garage.

You can go through a basic list of checks then if you find a problem look further guidance here or from other resources.

I always recommend cleaning the bike thoroughly including the sprockets and chain as it makes maintenance more pleasant and is a chance to visually inspect the bike.
Inflate tires to recommended pressure. A puncture will be readily evident (although check the next day for slow leak). Tires or tubes may be dried out and cracked. If so you can replace them.
Check that both brakes are working properly.
With the rear wheel off the ground manually spin the cranks and change through the gears (getting someone to help you makes this much easier). Spin the wheels, cranks and pedals and make sure they rotate freely with no looseness or play in the bearings.
Make sure shift and brake cable housings are inserted properly into shifters and derailleurs, levers and calipers, and attachments points on the frame.
Go over the whole bike making sure everything is attached properly and not loose. Seatpost, seat, handlebars, stem, pedals, brake levers and calipers, shifters, derailleurs etc,
Make sure wheel quick releases are done up properly.
Re-lubricate the chain.

Update, some links to Park Tool Company pages on the most likely adjustments you may need to make:

Front derailleur adjustment

Rear derailleur adjustment

V-Brake setup


Can I use friction shifters with a clutch style rear derailleur?

This is a good question. I speculated about this over the weekend and came to two conclusions.

Friction shifters were designed for narrow(er) rear cassettes. The largest cluster I've ever seen a friction shifter work on is 8 speed. I don't think it will pull enough cable for you to access all the speeds in your ten speed cluster. EDIT: As an insiteful commenter noted, the cluster is only 1.8 mm wider for a 10 speed than an 8 speed so it should pull enough cable for your needs.
Trimming will be more difficult than with index shifting. The industry has added several gears and not much space to the rear triangle. The result is thinner gears and chains, so dialing in the rear trim will be more difficult.

So, will it work? Probably. Is it ideal? Probably not, but it's worth continuing research about the topic. Just my 2 cents.


Tools needed to perform groupset overhaul

A road groupset usually consists of a number of parts.

There are not many tools, and they are generally not that expensive.

With all the resources out there (youtube, sheldon brown website, etc) and basic mechanical aptitude it isn't a difficult task.

You need basic hand/bike tools, (hammer, metric allen keys/drivers, screwdrivers, pliers, socket set, torque wrench, etc)

In terms of specific tools for those components:

Bottom Bracket (BB)

  If Pressfit:
   A BB press, a BB punch/remover.

  If Threaded: A BB Wrench

Cassette : Chain Whip, Cassette lockring socket tool.
Chain : Chain breaker, Chain tool or missing link pliers depending on chain
Brakes
Crankset : Pedal wrench or allen keys depending on the pedals.

  Modern Shimano specific (like the 105 group): Hollowtech II crank arm installation tool
  Front derailleur
  Rear derailleur
  STI levers (Shifters/Brakes)

  You will probably need to replace the cables, so a cable puller might come in handy.

An optional extra that would come in handy and for future work on the bike would be a bike workshop stand I spent 100$ on mine and it has been excellent for regular maintenance and upgrading parts.


Are faceplates for different shimano brifters compatible?

Short answer:

No they are not. Each model, and usually each year requires a specific face plate.


How worrying is damage to a carbon fiber frame near the bottom bracket?

I would be concerned. The bottom bracket is the most heavily stressed part of any bike, and carbon has a catastrophic failure mode--that is, you don't get any warning. One minute it seems fine, the next minute, you've got carbon-fiber shrapnel.

As a first measure, I might clean it up as best as I can, take some pictures, and send them to the manufacturer or the manufacturer's area rep to get their feedback.


This should not be a problem. A decent Al-fork will easily replace a crappy 'suspension' fork. You'll just need to check for the right length and diameter of the stem and maybe replace the direction bearing as well.


Dura Ace 9100 chainring on Ultegra 8000 crank?

The shaped ‘arms’ of Dura Ace 9000 and Ultegra 8000 series cranks that continue from the crank body into the chainrings have different profiles, so the ring from one is not going to match either the crank body of the other.

If you don’t care about the asthetics it’s not a problem.


If the chain/cog no longer drives the wheel, can this be fixed?

There are four main possibilities, depending on the quality and age of bike.

The most likely scenario is that the wheel is a traditional kid's coaster brake wheel - one gear forward, pedal backwards to brake.  In that case it's likely that the clutch is slipping inside the hub. A replacement wheel is probably an easy find, even more so than replacement parts, since kids have a tendency to outgrow their bikes rapidly.  If you're feeling wrenchy however, you can take a look here at an extremely detailed teardown and explanation.  You won't need any particularly special tools other than thin wrenches, preferably real cone wrenches.

If the wheel is on a nicer bike with hand brakes you'll be looking at either a freewheel or freehub design.  If it's a freewheel then you've got two possible culprits: you've stripped all the threads off (unlikely) or the pawls are frozen or broken.  In the former case, you'll need to replace the whole wheel.  In the latter, you'll probably just want to replace the freewheel outright - repairing them is annoying.  Replacing it will need a special tool that matches the splines/notches on your freewheel.

The freehub design is similar, except the pawls are in the hub body itself.  You could be lucky and simply need to tighten the freehub assembly, but once again it's probably frozen or broken pawls.  Reparable, but a bit tricky and once again needing some specialized tools.

The last option is that it's some kind of internal gearhub. If it's broken they can be fun to take apart, but you're not likely to get it working again.  If you've got a local bike co-op they might want the donation.


Judging from the sound and the video, your chain is getting stuck in the rear derailleur pulleys. Sometimes it’s loose and not engaging on the pulley, and sometimes the chain is routed  over the metal bit between pulleys so that it rubs against the metal. You can also get this if your chain is way too long, but it looks tight on the bottom. If it’s way too short, you can also get this by trying to force a gear that the derailleur can’t fit, so the chain downshifts or slips off the pulley.


Been there and not done that. The only option I found was to go used, but even then, its hard to get a reasonably prices upgrade. A better option for me was replace the bike. For the price of upgrading the shock (at least $400) I sold my old bike ($300) and got an 'as new' bike that was much better all round.

Accept that you are choosing to ride her cheap bike. Even if you upgrade the shocks, you will be still be riding a cheap bike..... before you know it it will be Grandfathers Axe (3 new heads and 4 new handles, but its the same axe my grandad used).


How to measure the correct belt drive tension?

As to measuring belt tension, the tool is your best option. If you own the bike, then you should own the tool.

Without it, however, place an S-bent spoke or similar wire in a hook over the center of the top of the belt. Add weight to the bottom hook. 10 pounds is the spec. Yes, this is a lot of weight for a bent spoke. Be creative. Or buy the tool.

Place a ruler next to the belt, at the point of the weight's pull. Write down the measurement.

Remove the weight. Measure again, in the same place. Subtract the first measurement from the second measurement. The difference should be between 5 and 12 millimeters. 10 millimeters is ideal.

The alignment is dependent on the type of dropout.

EDIT 1: The image below is a new tool from Gates, called the Eco Tension Tester, which does exactly as described above, in a more professional manner. Perhaps it will help describe the intent of the method I described.

With the dropout style you posted in your image, the alignment is actually set with two things.

Wheel centering - the wheel needs to be equally centered between the chainstays. This is a do it by eye and feel job, although you can gauge your success by measuring from the rim's brake surface to the inside surface of your chainstay, assuming your wheel is properly dished over your hub.
The second thing which affects the belt alignment on the pulley is your "chain" line. With the District, this alignment is set with the length of the bottom bracket spindle. The more perfect the chainline, the less likely you will have issues with the belt rolling off the cogs. Most bike shops have a tool like the Park Tool CLG-2 for measuring chainline accurately, although it is designed to work with a toothed cog.

If you have consistent issues with the belt rolling off the cog, and your dropouts are evenly set up in the frame, and your wheel is centered, find an LBS to check your chainline.

You may need to swap the bottom bracket axle to get more perfect chainline, in order to solve this issue. Assuming the bike has not had the BB replaced by you, it may be wise to ask the shop where it was purchased whether it is the original BB, and whether they will help with any chain line issues under warranty status.

EDIT 2: It actually appears that belt "alignment" issues are directly related to belt tension with the Gates Carbon Drive belts. If the tension is correct, they track well. If it is too low, they will track toward the frame. Too high tracks away from the frame.

I hope that is helpful.


How deep does snow have to be before it becomes unrideable?

Riding in snow depends on a bunch of factors, so you won't really ever be able to know unless you just go for it and try it out.

What bike/wheels you have

Should be obvious. Mountain vs Road, 26" vs 29", wide vs skinny tires, etc

Your skill level in snow

The better and more comfortable you are in the snow is important. I'd say its the most important factor apart from the bike. While some have trouble steering in just an inches, others can handle nearly a foot or more.

Tracks in the snow

You mentioned fresh snow, but I'm going to include this as part of a general answer. The difference between fresh snow and tracked snow is huge. Tracked snow is vastly more difficult to bike in. With just a few inches of solid snow and some criss-crossing tire tracks, it can be nearly impossible to ride at any significant speed.

Consistency of snow

Lastly, fresh powdery snow is a lot easier to go through than wet solid stuff. But powdery can be far worse if a hard icy surface lurks below the snow.

Bottom line: Just go out and ride through snow and see what you can handle, then ride through something a little tougher. Best part is, the soft snow makes falling easier!


How do I descend faster on the straightaway?

Qualification

Your question is missing specifics such as hill grade, but let's assume you are talking about steeper grades where it is relatively easy to hit speeds above 40 mph.  Second you didn't mention environmental conditions (such as cross-winds) as some positions become rather dangerous if you are hit by a cross-wind or are descending a rough road.

Focusing on Body Position

While equipment has an effect, your single biggest gains will be improvements in your position on the bike.  However please note that some of the more aerodynamic positions also unbalance the bike making it more unstable, increasing the probability of a crash.

A reasonably safe and efficient position is to keep your weight back and get your your body into a wedge position (see image below). By getting down far enough the wind should hit your back rather than your chest, preventing your chest from acting like an air scoop.  Also notice that the hands are brought in as close as possible to reduce drag generated by the arms.  You should also bring your legs in as close to the frame as possible. Your goal is to present as little profile as possible.

(Source: Bicycling)

You can further tweak this position by bringing your body further forward and your face closer to the handle bars.  This reduces the gap between your handlebars and your face/head reducing turbulence and shielding more of your lower body from the wind. In this case the rider has his hands on the drops as he is also navigating turns.

(Source: youtube)

More Unstable/Dangerous Derivatives

It is possible to get into even more aerodynamic positions.  The fastest position I have found is taking the position found in the first or second image and getting your head and body in front of the handle bars and tucking in all your extremities in the remaining spaces (the rider below is partly doing this).  In the most extreme case your face should be an inch off your front wheel and your chest on your handle bars (not shown).

DISCLAIMER - In such an aggressive position, you cannot see properly and if you hit any sizeable bump or are caught by a cross-wind you WILL CRASH.  That said it is also very fast and can be dangerously addictive. I have found I could gain an additional 10-15 km/hr over more safer positions, but only typically do it for short stretches.


Yep, that looks like some pretty extensive cracking.

I'm sure this is obvious to you, but do not ride this bike as the frame may fail catastrophically.

Update:

Sorry your three year old frame failed. I would not expect a full suspension frame to fail in that time. You may want to contact Rocky Mountain to see if they will do anything about it.

On the other hand, kudos to you for being able to ride the bike hard enough that you broke it :-)


Can I run a dual crankset with a chain guide tensioner?

This is a common setup for many freeride bikes, as it allows uphill pedaling and a bash guard.  However only certain models of chain guide support this, and the one your son has doesn't officially (though it wouldn't hurt to try if you have a crankset to test; it might affect the derailleur ...).  The DRS is eThirteen's 'official' dual chain guide.


Correct tool to remove Uniglide freehub?

The freehub attaches to the shell with a big hollow bolt you access by poking a 10mm allen into the drive side. You can transplant an HG freehub body onto it, ideally one of the same or similar length (6, 7, and 8-speed UG existed) and also a matching cone and other axle hardware for the drive side so that the sealing works right. The upside here is a replacement cassette will be much more obtainable when the time comes. Wheel dish should be checked and corrected when you do this.
But, your question: to do a simple de-gumming type clean, the expedient thing is to take the freehub body off the hub, gently pry up the rubber seal on the back and take note of its direction, then run through whatever thoroughness level you deem necessary in of solvent/air/oil. Usually just working in something like Tri-flow or other light oil with penetrating qualities is good enough.
The 4mm splines take the Shimano TL-FH40 freehub body disassembly tool. This is one of the most fantastically seldom-used tools in all of bike wrenching. Full disassembly of the freehub is almost never necessary to get them working, and is very time-consuming because of the large number of teeny bearings inside. But, it is the only way to adjust acquired play out of a Shimano freehub body, which is done by removing one or more of the micro shim washers inside, which are there for that purpose.
The race that the FH40 engages with is reverse threaded to resist bearing precession loosening it. It's got things spinning against it on both sides so how that works is way above my head.
Edit: If this is 7400-level Dura-Ace, the freehub body attaches with a TL-FH10 and is only interchangeable with other similar Dura-Ace Uniglide freehub bodies. The 7400 hubs are the only Uniglide models with this caveat, to my awareness. Some hack replacements with more common units have been done, but I don't have anything to report about that.


Mechanical Shimano Deore Disk Brake - How to fix lack of bite/grip

Mechanical disc brakes can work well, but they need to be set up just right for top performance. There are a few aspects:
Pad condition: you have new pads which is good because they will be flat and clean. They can be scuffed lightly with sandpaper to be refreshed when necessary, if a little dirty, or hardened/glazed. They need to be uniformly flat and not worn unevenly, with a matt complexion.
Disc condition: it needs to be running straight/true and free from contaminants like oil, but bedded in, where a fine layer of pad material is transferred to the disc to increase friction. You mention braking 40+ times, this is the bedding in process, but I start doing this very gently and increase the duration and force as the brakes warm up. You might like to clean the disc with ipa alcohol or brake cleaner to reset them, then re-do the bedding in.
Pad positions: the inboard pad is fixed in position, but can be positioned with the Allen key adjuster (5 mm) on the inboard face of the brake caliper. It must be as close to the disc as possible without rubbing the disc; you can find the setting where it rubs gently and back off one click. The minimal gap ensures the disc doesn't get bent much out of vertical when the floating pad operates. This is critical for maximum power. If you can see the disc getting flexed sideways a lot then something isn't right. This is something to monitor and adjust in use, to account for pad wear as it is not automatic like with hydraulics.
Cable tension: finally the cable tension is set up. This is to give acceptable lever travel, but it has the least effect on braking power, the previous points are more relevant to power. You could set this up to your preference of early bite point or late bite point, but well clear of the bar when the lever is pulled. The previous points are more effective in getting sharp brakes than the cable tension, and you can set it with the pinch bolt, in combination with the barrel adjusters.

If any of these aspects are not set up optimally, the braking performance does drop noticeably, so work through them methodically. Finish with a bedding in procedure which is gradual and patient, to really get them sharp.
From your comments, it sounds like the inboard pad is out of position and causing your problem. if that rotor is pushed out of vertical any more than necessary, then the contact is reduced and power is lost. You need to locate the pad adjustment screw and get the fixed pad closer to the disc.


Ordered a pair of Fizik R4s a size too big. Will it make a difference?

Everyone will agree that it is best to have shoes that fit properly.

If the shoes don't fit perfectly, it's better to have shoes that are a bit too big, rather than shoes that are a bit too small. As we warm up our feet swell slightly, and if the shoes are too small then the blood circulation can be restricted. That can lead to cramps or numbness.

The issue with shoes that are too large is that the foot could move inside the shoe, causing blisters or other injuries, and reducing power transfer.

If wearing an extra pair of sox and cinching the shoes tightly stops any movement, then you'll be fine.

One concern you may have is cleat position. With shoes that are only one size different, I don't think that will be an issue; you should be able to position the cleats as usual. And research has shown that our preferred cleat position is largely a matter of tradition, and make extremely little difference for power transfer.


How much of a difference does giving blood make to recreational cycling?

If you are riding near your aerobic limit you'll definitely discover that you've lost aerobic capacity during the next 12-24 hours. It can take that long to replace the red blood cells you've lost.

Since a blood donation is about 10% of your blood capacity, your aerobic capacity will be down by 10%

I wrote the rest of this before I saw your comment that you've given blood many times. I'll leave it in the post for future readers.

Initially, the main issue is blood pressure. Plenty of fluids are recommended as soon as you finish giving blood. It only takes an hour or two to overcome this.

The conservative advice would be to avoid cycling for the next 24 hours. Until you know how you react to giving blood this is what I recommend. After giving blood a few times you could try riding gently and see what happens. I would still avoid riding on roads in traffic.

Edit: see also the link provided in the answer by @super.


Skipping on new chain, new cassette, new derailleur

You could try removing a link or two from your chain to reduce the amount of slack in it.  A chain that is too long may cause skipping.

(Ensure you can still reach your entire gear range with the shortened chain length)


What is the difference between Light and Motion's Urban 800 Chainbreaker and Urban 800 Anchor Steam bike lights?

Just the color. The products are identical. Light & Motion lists their different color variations as separate "products", probably due to some limitation of their store site engine.

Note that there is an Urban 800 Fast Charge version, which in addition to coming in different colors, actually is a different product physically.


Most of this is included in the comments...  I'd start with derailleur alignment.  Once that's done, you'll need to do some light tuning on the cable tension and limit screws to make up for any changes.  If that doesn't fix it, maybe a new chain would help.  Try borrowing a different wheel(with the same number of gears) to see if it still makes the noise, that will eliminate the cassette and hub body from possibly being the culprit.  I know you're saying it's coming from the derailleur, but it's sometimes difficult to tell when all these parts are so close together.  In the long run, though, if it's noisy, it may just be noisy.  If it's functioning right, it may not be worth messing with.


How do you tell what brand/make/model of bike I have?

The serial number on its own is basically useless. They're not like VINs on cars: there's no global database of them and they're not even guaranteed to be unique. Each manufacturer of frames uses whatever scheme they want, and the serial numbers are purely for their own stock control.

To identify the frame, you need to compare its appearance to frames whose manufacturer you know. However, unless there's something very distinctive about your particular frame, it's unlikely that anyone will manage to identify it. Most frames have nothing particularly special about them, and many are made in enormous factories in China that sell frames to whatever brand wants to buy.

If you've identified a small number of possible manufacturers, the format of the serial number might allow you to tell which of them is correct. But even then, it's something of a long shot.

See also, Why shouldn't I care what model/make/year my bicycle is?


When to buy an enduro bike: autumn or spring?

Generally late fall (when new bike are arriving on dealers showrooms) or in the middle of winter (when dealers want to move inventory just to help cash flow).

Of course, the older a bike is, the more likely it is to be discounted, but it will also be less likely that you will find the size/spec. that you want.


Does anyone know the age of this Legnano Bike?

according to this site:

http://www.classicrendezvous.com/Italy/Legnano/serial_numbers.htm

Can't be too sure, but i would guess it's manufactured around early sixties. Probably 61 or 62.


How often do you need to bleed your Avid Elixir 1

Firstly, I do not believe (from your description) that air is the culprit here. Air is a gas and therefore can be compressed in a closed system such as a bicycle brake. As PeteH pointed out, air would lead to a brake lever feeling spongy, not tight.

If you say the brake is tightening over time then I would be inclined to think that there is water being absorbed into the system. DOT fluid is hygroscopic, meaning it draws in moisture from the atmosphere which is one of the reasons DOT fluid should be replaced every 12-24 months at most. Although the normal rate absorption is ~3% a year so having your brakes bled three times since April seems a little much, so if it is due to water in the system then I would be looking to have the brakes replaced (ideally with Shimano ones!).

Secondly, how is the bike stored when you're not using it? We were told by a SRAM tech that bikes should not be hung up by the front wheel as this allows air to accumulate at the reservoir in the lever. However as said above air would leave the lever feeling spongy, not tight.

Before you take the bike back to the shop, could I ask you to let a little of the fluid out from the system and then try the lever again? To do this, you'd need a T10 Torx, a cloth and some disposable gloves.

1) With the bike upright, use the T10 Torx to slowly undo the little screw sealing the reservoir, while at the same time holding the cloth just below. Do not take it fully out, only far enough until you see fluid leaking from around the sides. Anti clockwise to loosen, clockwise to tighten.

2) Once the fluid starts to leak onto the cloth, very slowly/gently pull the lever. You should see the fluid flow a little quicker.

3) Once you think you've let enough fluid out and while still holding the lever, tighten up the screw. It is important to keep the lever pulled at all times while the screw is undone as this will prevent air being sucked back into the system when you let go of the lever! Once the screw is tight, release the lever.

The idea is to let a little fluid out and try the lever. Then let a little more out if needed. It's easier to remove fluid than add fluid and remember and DO NOT let go of the lever while the T10 screw is loose!

If this works, then I'm sure there is water in the system as what you've effectively done is reduced the volume back to where it was at when the shop bled it. Although doing this will not remove the water, only the water/DOT mixture. So if I were you, I'd be looking for some new brakes (Shimano M615 are fantastic VFM and we've done this for many customers in our store).

Goodluck!

Edit: Thanks PeteH! The bikes we sell in the shop (Boardman/Carrera often come with this model over filled from factory). Yes as Warren says, once the fluid begins to soak onto the rag, nip up the screw. It really is only a tiny amount - usually. You shouldn't have to press the pistons back while draining the fluid. The idea is to squeeze the lever to push the fluid out the lever port, hold the lever while you tighten the screw and then release the lever. Releasing the lever after tightening the screw should automatically draw the pistons into the caliper as it will create almost a vacuum inside the closed brake system. If you need pictures to show steps let me know and I'll get some!


Barrel adjuster for sram gx rear derailleur?


What's the best way to repair a small hole in a tubeless mountain bike tire?

At home? On the trail? How big a hole?
If it’s around 5mm or less you can use a “bacon strip” tubeless plug. If it’s larger you are probably going to want to glue a patch to the inside of the tire. Proprietary plug systems are similar to bacon strips for utility just quicker & more expensive. A plug of any kind can be considered a forever fix.
Sidewall slash? You might be lucky by sewing the cut with dental floss and then patching from the inside but also be prepared to let it go and buy a new tire. Your risk vs cost calculation is your own. I don’t want to be stuck 20km from home with an unusable tire.


How difficult would it be to maintain 17.5 Mph for an hour?

The short answer is: not that difficult. The long answer requires some explanation.

The equations of motion for a rider on a bicycle are well-understood if not always well-known. The power needed to propel a bicycle on firm flat ground (as on a velodrome) varies approximately with the cube of speed. Thus, to double your speed, you would need to increase your power output by approximately a factor of eight; riding at half-speed decreases your power output to approximately one-eighth of full-speed power.

As may be obvious, Brad Wiggins was highly trained and highly optimized in both equipment and position to minimize his coefficient of rolling resistance (Crr) and aerodynamic drag area (CdA). That means even at 17.5 mph he could very possibly use less power than most cyclists would.

That all said, this bicycles.stackexchange answer discusses the equations of motion for a cyclist, from which you could calculate the power required to ride at 17.5 mph on a velodrome using reasonable estimates of Crr and CdA. For most average-sized adults, not highly optimized for position, a reasonable estimate of CdA on a standard pursuit bike similar to but not identical to the one used by Wiggins would be around 0.275 m^2. For this example, then, one could cover 17.5 miles on the velodrome at right around 100 watts of output. In comparison, an average sized man, walking on firm flat ground, would expend roughly 75 watts. So riding a velodrome at 17.5 mph would be more difficult than walking at normal speed for an hour but not horrendously more difficult. However, because of the cubic relationship between speed and power, riding at 20 mph would require nearly a 50% increase in power over riding at 17.5 mph, and riding at 25 mph would require a trebling of power. Many non-sedentary adults can produce somewhere between 2.0 and 3.0 watts/kg for an hour, so such a 75 kg man would be able to maintain between 150 and 225 watts for an hour. As you can see, many (but not all) adults would be able to maintain 17.5 mph, but not as many would be able to maintain 20 mph, and relatively few would be able to maintain 25 mph.


Can I keep using my outer tube tyre with a hole in it

A thorn hole in an inner tube is totally patchable.  A 50 cent patch is a lot cheaper than a new tube.  Stop consumerism!

As for the hole, it depends if the inner tube pokes out or not.  The get-home fix is to line or reinforce that area with something laid between the tube and tyre.

On one tyre I ended up adding a patch to the inside of the tyre, which worked well enough.  It lined up against the matching patch on the tube.


It won't work very well at all. Superglue, unlike rubber glued with rubber cement, doesn't stretch. It will probably open up again as soon as you inflate the tyre. If it holds at first, it's likely to let you down soon.

If you're absolutely desperate it might be worth a try, especially if the tube doesn't have to expand much to fit the tyre, but only to get you home or to the bike shop. And it's risky - the tyre could go down quickly when you don't want it to. You'd probably have to replace the tube after that as a proper patch wouldn't stick to the dried superglue.

Among household glues, evostick or a similar contact adhesive (that's used in the same way as patch cement) would be a better bet, but would still probably write off the tube


What are the pros and cons of a Turbo Trainer over Training Rollers?

Stand trainers

Pros

no concerns of falling over/slipping off, especially for certain types of training, e.g. one-legged drills
better for interval/spike training, where transitions in speed are not smooth
more options for variable/controllable resistance

Cons

less natural riding style because of bike's fixed position
may develop pedal stroke imbalances (or allow them to go undetected)
requires special mounting skewer (most brands)
can cause significant tire wear

Rollers

Pros

more natural style; bike responds more like actual riding
can help develop smoother pedal stroke and better form

Cons

easy to fall off and cause damage (to body, bike, and surrounding objects)
fewer options for variable/controllable resistance (only a few makes/models offer this and they're expensive compared to options for stand trainers)

Many folks I know have both a stand trainer and rollers and focus their training using the relative strengths of each type, i.e. stand trainer for "power" workouts, and rollers for "form" training.

As to your specific concern about natural movement: there is at least one stand-type trainer that is somewhat more natural than a fixed stand. It is considerably more expensive and occupies a lot more space than a normal stand trainer, though.


You normally need to take the pads out and lever the pistons. The pistons have a tight tolerance and jam easily.

Its possible to do it with the pads in but you need a narrow enough tool to get all the way between the pads, that is strong enough to put the force need to retract the pistons. You also risk damage the pads.

There cannot be too much fluid unless you bleed the brakes with the pistons extended. The fluid that pushed the pads out will return the reservoir, however this needs a happens quite slowly- you need to apply a gentle force to the pads for a long time rather than a brute force it.

Worth watching


Can't get the front brakes to stop these style bikes

Welcome IRMacGuyver!

Looking at the photo, it appears you have the cable housing barrel adjuster attached at the lower point between the two arms (on the front caliper), with the cable clamp nut at the higher attachment point (back caliper). Except for images of Bropton brakes, I've never seen that arrangement.

Try reversing the connections so that the barrel adjuster is on the back caliper, with the housing coming from above. I believe you'll find that provides better braking power.


Exact dimensions for Wheelsmith Rim Rods?

Why bother? There's 5 sets on eBay right now:

Wheelsmith Rim Rods on eBay


How to loosen cable tension in disc brakes

I got the following from this website, and if you go to the website there are pictures as well.

  On the actual brake, loosen the caliper fixing bolts with an allen
  key, both top and bottom. Once you do that feed the cable through the
  brake caliper from the barrel adjuster at the top of the caliper
  through the fixing bolt at the bottom, and once you have achieved the
  correct tension then fix it down by tightening the bolt with an allen
  key. The next step is to squeeze the relevant lever whilst jiggling
  the caliper sideways in order to help it find its best seated
  position. Once you have done this, and keeping the relevant lever
  squeezed, you can now tighten the top and bottom caliper fixing bolts.
  After this, you will need to back up the inner dial (fixed pad) a
  couple of clicks before ending up with the brake pad in the middle of
  the caliper.


Have they ever made a bicycle with in-hub gears both at the crank and wheel?

Its unnecessary from a gearing range perspective and adds extra complexity, I suppose. Number of gears, number of distinct gears and gear range are all different things. Having 63 gears over the same 5.26x range that a Rohloff gives isn't much of an advantage unless you actually find the Rohloff gears are spaced too far apart (very few people do). You get complex shifting for little benefit.

People have made gearboxes in the bottom bracket and crankset (e.g. Pinion, Schlumpf, among others). You could put these with a hub gear or a derailleur system, if you wanted to (in fact, the Schlumpf link before markets the Schlumpf as a partner for the Rohloff internal gear hub), but you're adding another level of complexity to your drivetrain which gives you one more point of failure. Add that to the fact that you can have CVT's or 14 speeds in an internal gear hub (IGH), and you have more unique gear combinations than you necessarily need to begin with. In your proposal, you would probably add a bunch of redundant combinations. And I don't think theres a market for it.

That being said, if you want to go crazy, you could try to beat Sheldon Brown's 63 speed, which combines an IGH with a multi-speed cassette and a front derailleur (*). But with proper component selection, these days, you can get more gears than you could possibly know what to do with for IGH drivetrains (using a single chainring, but you could use a front derailleur if you wanted to, with a suitable chain tensioner) or derailleur drivetrains (using 1 or 2 or 3 or 4 chainrings; there are extenders to do more than 3 chainrings on a triple ).

(edit) The issue is torque limits on hubs. Rohloff publish theirs, chainring:sprocket ratio of 2.5 for heavy riders and 1.9 for most people. Shimano and SRAM don't, but have been known to refuse to service over-torqued hubs. So you can put a Schlupf Speed-Drive on on Rohloff to get about 4 more gears at the high end (Speed drive 1.6x, Rohloff spacing is 13.5%, log(1.6)/log(1.135)=3.7).

You could combine an 18 speed Pinion with a 14 speed Rohloff to get 252 gears over a 33.4x range. But the Rohloff ratio limit means that with a small 406 wheel you'd have a bottom gear of about 0.8m.... and a top gear of 26.7m taking you to 144kph at 90rpm. That's the current world speed record (2017).

(*) On the Bicycles.SE chat, I worked out a realizable drivetrain using off the shelf IGH's and derailleurs and what not that had way more than 63 speeds. Unfortunately, I don't remember what the components were. But, if you really want to, you could buy the parts and put them together to have your proposal work.

(edit) Perhaps a quad chainring with 12 speed cassette and SRAM 3x9 hub, modified to fit the 12 speed cassette.


Bike sizing question - are these two sizes actually that different?

You'll get 40mm more stand-over clearance with the 52 over the 56.

As the reach is about the same on both sizes you will not be cramped by the frame, but I suspect the 52 may come with a shorter stem. You may need to buy a longer stem with a little more rise to get the effective (to the handlebar) stack and reach that you need.


The geometry of this frame looks odd. 622mm wheels are too large to fit comfortably in a 51cm frame. Usually sizes this small are made to compensate with very steep seat tube angle to let the rear wheel forward and very shallow steering angle to avoid toes clipping front wheel. This bike has been made the other way around and that is why it looks and feels strange.

With saddle as low as shown in picture, the frame is too high for you. With horizontal top tube, there should usually be about hand's width of seatpost showing. The saddle should be roughly horizontal.
Longer handlebar stem or less swept back handlebars will help.
This is a problem with all small frames with large wheels. Is the fork the original one? Some older bikes came with steep steering angles and very high fork offsets. The offset eliminates some of the problem with toe overlap but makes steering twitchy at high speeds.
32mm tires are the absolute maximum size to fit inside short reach brakes. Normally the kind of brake is used with 23mm to 25mm tires.

Edit: @Will's comment led me to the idea that this bike could have been a 650B or at least converted into one. That would reduce the standover height and allow wider tires and also explain the strange-looking angles. Smaller wheels would lower the bottom bracket, so saddle would still look too low.


Can I use mountain biking cleats on a road shoe...?

Yes, this shoe also accepts the MTB-style two bolt cleats.

Three-bolt and two-bolt cleat pattern fits all major road and mountain
pedals.

(from https://www.specialized.com/jp/en/sport-road-shoes/p/117510?color=&searchText=61217-3238)
They will accept Shimano SPD, Crankbrothers and other MTB cleats. However, the sole will get deformed or damaged. With some cleats this is expected and even true MTB soles will get signs of use of these cleats. I am not completely sure about SPD, but for Crankbrothers the sole is in a direct contact with the pedal so the pedal directly pushes into the sole and it will certainly make some imprints during the use.
There are sole protectors available by Crankbrothers. I have no idea whether they also work for SPD or whether Shimano also sells some, but some vendors (like Ryder) make SPD-compatible cleats that include sole protectors in the package.


Is there a difference in having tires filled with CO₂ vs air?

This is a debate that gets picked up on every bicycle forum known to man (okay, that might have been exaggerating a bit). Typically you start to ask the question when you notice that the morning after you have used your CO2 cartridge, your tyre is ridiculously low.

By no means am I a chemist but, as it has been explained to me, CO2 and butyl are more soluble than N2/O2 and butyl. Most tubes are constructed from butyl (fancy pants cyclists will sometimes use Latex tubes, haha). Due to the increased solubility you can expect that a CO2 inflated tyre will need re-inflating sooner than one you pump up by hand.

http://www.madsci.org/posts/archives/may98/895552329.Ch.r.html

While the explanation above is dealing w/ escape from balloons I am going to assume that we can take that information and apply it to our discussion.

Now, if i am incorrect (which I often am) please let me know!

I just noticed I didn't tackle the temperature issue. I do know that temperatures exceeding 50 degrees celcius (above 125 farenheit) can result in the potential for ... explosive fun, in regards to CO2 canisters.

http://www.stayfill.com

This company has a proprietary gas blend that won't leak from your tubes apparently ... ... ...


Screw cap stuck in adjustable stem connection, how to remove or reattach?

This is your stem.

As you can see, it is the whole unit from the bars to the top of the fork, including the adjustable bit in the middle. Most dan't have this and I think this is where the confusion is coming from.

To remove your bars for packing, it is usual to remove the 4 bolts on the face plate on the stem. That is the part immediately touching the bars.

After you've removed the bars, you'll want to tape or strap them to the frame somehow so they're not dangling and pulling on the cables. You shouldn't need to remove anything else.

Do not remove the bars by undoing the 1 bolt that adjusts the angle, as you have already, I can't find any diagrams of how it all works.

Do not remove the bars by undoing the 2 bolts that hold the stem onto the fork as this will remove the forks as well.


Cannondale CAAD Optimo Tiagra 2020 CREAKING

return the bike to Cannondale as there is a welding fault in the area north of the front part of the frame

If true, that bike is probably not safe to ride.  If the shop showed you where the problem is, posting a picture of that area would probably be useful.  For what it's worth, if the shop that sold you the bicycle says it has an unsafe frame, I'd tend to believe them as that's an admission of a serious failure on their part, especially if they assembled the bike for you.
If the frame is faulty, Cannondale should warranty it no problem.

I can clearly hear the creak is coming from the crank area and appears to only creak when pedalling

That does not rule out frame issue causing the creaking sound.
First, it is extremely hard to isolate the actual location on a bike where a sound is coming.  And even then, because the components of the bike and and do conduct sound, where the sound appears to be coming from might not actually be the source of the sound.
Second, pedaling puts stresses on the bicycle that don't exist when you're just coasting.  Since significant power is applied to one pedal at a time, and the pedals are off-center, pedaling introduces twisting and sideways forces to pretty much the entire bicycle.  So a noise that is synchronized to your pedaling could be caused by something like a cracked front rim.
Finally, and completely independent of any frame weld issues, if the bike has a press-fit bottom bracket*, those are notorious for being noisy and a constant source of creaks and cracking noises.  This is a Google search for all the questions here about noisy press-fit bottom brackets: https://www.google.com/search?q=press+fit+bottom+bracket+noise+site%3Astackexchange.com
* - It likely does, but I can't confirm that from the product page as there doesn't seem to be a 2020 page but only a 2019 page that doesn't actually specify the bottom bracket type.


How to treat rust spots on a steel frame without stripping the paint completely?

I would lightly rub the offending area with steel wool. The idea is to not completely remove the rust but to dislodge any paint that is intact but not bonded to the metal. Apply a rust restorer or converter. Rustoleum is one brand but there are many others. Apply the converter to the prepped areas per the instructions. The chemical process converts the rust and leaves a coating on the bare steel(typically black). You can then cover the areas with either touch up paint or nail polish of a similar color. If you visit a Hobby Shop they have small bottles of enamel paint that you could custom blend to get a close match.


Can I get a bright rear light using AA batteries, or is there a compelling reason why nonreplaceable batteries are so widespread?

Most modern lights use rechargeable lithium ion batteries. Those come in three form factors: Pouch cells, cylindrical cells and coin cells.
Pouch cells come in a lot of different dimensions which gives manufacturers a lot of flexibility when designing the product. They also have cables directly attached and are quite fragile. Good for weight and size but bad for handling by a user.
Cylindrical cells like 18650 have a relatively robust metal shell. Sometimes they are user replaceable but somehow this never caught on. Most of the time they are directly soldered or combined into a battery pack (most older laptop batteries are just a plastic shell and some electronics around 18650 cells).
Coin cells are usually directly soldered to the circuit board. I guess you could make a coin cell holder but that just increases size and weight and introduces another point of failure.
So only the cylindrical cells could really be replaced by a normal end user.
Another factor is charging current and voltage. Lithium ion batteries differ slightly in charging cutoff voltage and charging current. Some can be charged up to 4.3V, others only up to 4.1V. Charging a 4.1V cell up to 4.3V can cause it to go up in flames. So if the device has a built-in charger you’d somehow have to make sure that a cell with the correct charging cutoff voltage is inserted or that the correct voltage is selected. I guess yet another factor is that a battery charge level indicator can be directly integrated into the device’s circuit board instead of being a separate circuit inside the battery. Charge level indicators either estimate the level via battery voltage (which again, varies slightly between LiIon batteries) or by measuring the energy going in and out of the battery (Coulomb counters)
Apart from that there are generally some advantages in not having a hatch and battery holder for user-replaceable batteries.

Less complexity (more robust, cheaper)
Easier to make dust and waterproof
Smaller
Lighter
More flexibility in the case design
Product only lasts about 5 to 10 years. Of course that’s only an advantage for the manufacturer because they can sell you a new one.

There is simply no easy way to make a tiny, water-resistant, 40g light like this with a 420mAh Li-Ion battery and have it user-replaceable:


You don't have to replace it with the exact same rim. Your wheel doesn't appear to be anything exotic, so anything with the same diameter (700/622 bsd) and the same number of spokes (20?) should be compatible. You'll also probably want to look for something that is about the same width, although you can make small changes to this depending on your needs and availability.


Pedals won't turn normally following strange noises

PeteH has implied it, but sounds like something has gone drastically wrong in a bearing somewhere.  I'd suggest you remove the chain from the front chainring and try to spin the pedal crank.  It should turn easily, with no side-to-side slop.

If not, check the rear wheel for the same, it should not feel gritty or notchy, and should not have sideways movement.

Depends on your mechanical inclination if you want to try fixing this, or give it to a LBS (local bike shop).   Related: I'm reasonably competent at bike stuff, but I got them to reinstall my front deraileur properly because after three goes I still couldn't get it right.  Took the shop an hour and cost me $52, which was a good trade-off IMO.


Will trailer be my best option? If not, what is?

From your other question - your budget for the bike was 300 euros.  You'd spend that much on a trailer alone.

Trailers more than double your rolling resistance, and increase your windage area a lot.  Riding long distance with a 2 wheel trailer is unpleasant.

You might build your own trailer, there are many plans around the web for this, using a square of metal or timber, two wheels and either a seatpost or a rear-axle hitch.

Another possibility is a single wheel trailer, which carry a bit less but are more useable on singletracks and narrower roads.

Making a trailer with a locking bin could solve your security problem, but it still needs locking closed and locking up to something when unattended.

In order of preference, top of the list would be front and rear panniers, then a frame bag, then a trailer, then a rear rack with your pack on it, and lowest on the list is a backpack on your back.


What are advantages and disadvantages of CO2 inflators over frame pumps?

Advantages:

Fast - generally these fill up your tire much faster than you could with a pump
Less effort - hook up, push button, no pumping
Possibly less weight (but I haven't compared weight of smallest pumps to CO2)
Lower initial investment - a valve and 2 cartridges generally seems to be cheaper than a good small pump.

Disadvantages:

Consumable cartridges - which is a cost issue if you have to fill up often
No backup - if you patch a flat and don't get it quite right, you don't have a way to fill up anymore.  You could carry extra CO2 cartridges, but then you could lose the weight advantage.
Limited on what tires they work with. Big tires will get less pressure.
Less friendly - if your friend gets a flat and you've got one cartridge, will you loan it? If you've got a pump it's no problem at all.  I've helped out complete strangers with my pump before.
Goes low faster. CO2 seeps through the tube a bit faster than air, so you'll have to top off the tire sooner than if you'd used a pump.

One possibility to consider is a combo unit.  Generally the pump on those is terrible, but it should be enough to get you home if you run out of CO2.  Or carry both a pump and a CO2 valve and a cartridge.  That way your first flat can be fixed super-fast and you avoid all the disadvantages (and the weight of a simple valve and one cartridge isn't much).


Do helmets go out of style and get discontinued by manufacturers?

In most bike shops, if they have a helmet in stock, they will sell it even if it's last year's model, rather than ship it off to a remainder seller or some such.  But, of course, if they sell the helmet, and the model changes next year, they will not get more of the old ones.

I would guess that helmet manufacturers turn over their product line about every three years, doing a little bit each year.  There's no good way to know if this year's model will be around next year -- it might or it might not.

So you figure the odds.


I think there are a couple of flaws in your knowledge that help determine the prevalence of skinny tires.

Firstly, narrow tires exhibit significantly less rolling resistance than larger volume tires. This has benefits and drawbacks, with the benefits being easier commuting due to less friction. The drawback is that there is a smaller contact patch with the ground and hence less grip, but on smooth paved roads, asphalt etc. this is not a large problem. Also, slick tires increase the grip due to more rubber contact and less grooves between knobs compared to a similar volume and diameter knobby tire.

Aerodynamics is not a huge factor in the equation, as you pointed out, since low speeds around 20km/h are only marginally effected by air.

On the issue of air pressure, I think the pressure-for-pressure comparison between skinny tires and larger volume tires is a bit of a misleading statistic. Skinny tires run exceedingly high pressures - racers are all known to use upwards of 80psi and as high as 120psi! Compare this to a larger volume tire, like that on a mountain bike, and pressures of around 30psi are about the norm. MTB tires like this are often rated for much higher pressures than they will ever need, but many will take use of this in order to use a MTB tire on the road, for example (I often run 50psi on 2.1" MTB tires for more efficiency on the road). Pressure ratings on tires simply refers to the uppermost limit of safe use before there develops a significant risk of tire blowouts or some other failure. However, the relationship between rolling resistance and tyre pressure is completely different for road or MTB use. On a MTB, lower pressures offer lower resistance due to their ability to deform and mould to the terrain, essentially flattening out the ground. This effect is useless on a paved road, where the surface is almost completely smooth. So on a road bike, or a city bike, higher tire pressures will correspond to a lower rolling resistance, and thus a smaller volume tire would be preferable.

One thing to note is that tire pressure makes little difference to rolling resistance at high pressures (until the pressure is low enough for the tire to be deemed flat, which is always bad). Consequently, a skinny tire will have to be pumped up less often. Factors that make more of a difference to rolling resistance are the compounds used in tire construction, tire shape and tread patterns.

Finally, in my experience, punctures are not any more likely to occur on a small volume tire. If anything, they would occur less due to the decreased footprint/contact patch. The main cause of punctures are surface conditions, such as glass shards, sharp rocks, nails and other debris. These objects are equally likely to be found on any given bike, but easier to avoid with a skinnier tyre, because the gaps between hazards are relatively larger compared to the contact patch. I believe the reason for this assumption is that high pressure tires can have much more audible and noticeable punctures, and the escaping air will do more damage to the damaged tire when pumped to 120psi than 30psi. The puncture itself is no more likely to occur in the first place.

In conclusion, city bikes that are optimised for paved, sealed roads are prime candidates to use skinny, almost race like tires and consequently reap the benefits they offer, as their daily use will almost never take the bikes outside of the optimum conditions for such a tire.


Do chains on single-speed last longer than those on geared bikes?

Single speed last longer and cost less.  More metal and less (no) flex.

SS comes in 1/8 and 3/32.
I would contend a SS 3/32 of the same basic construction is stronger than a 3/32 7 speed because it does not need to be built to flex and it is not flexed.

I am not finding any pictures of 3/32 SS chains and the chain on my SS bike is 1/8.
So I guess it is not really a straight comparison.
But a SS will take a 1/8 and geared will not so it is a fair comparison.

Also SS is built to take the abuse of a fixie.  In a fixie the chain has to take the braking force and gets hammered.  Note the question is SS not fixie.


My trick is to find nail polish that roughly matches the finish. It's easy to apply, quick to dry, and will prevent rust and oxidation for quite a while.  It's not a perfect finish match, but there are quite a lot of colors that come close.

If you can't find an near-perfect match try mixing two or three colors. Just remember the basics; with few exceptions all colors are derived from shades of the primary colors (red, yellow & blue) and black and/or white, e.g., orange can be derived by mixing red and yellow. Then you've got glitters and iridescents (whole different ballgame). But nail lacquers can be picked up at pretty low prices and if you're not good with mixing colors find a friend who is. You should be able to get a near-perfect match! One last thing, avoid mixing brand-to-brand if possible; otherwise you may have adhesion problems.


Which pannier racks give the best heel clearance?

Heel clearance is more of a pannier issue than a rack issue (as some noted in the comments). Most high quality panniers have adjustable hooks you connect to your rack, and you can usually shift the hooks to provide sufficient heel clearance. This is something you should more take into account when buying panniers. Good examples of brands that allow you to set them up to provide heel clearance are Ortlieb and Vaudé. Both are rather high-end, but they are also nearly 100% water proof.

Regarding your comment about racks collapsing: If all you carry in your panniers is whatever you use during a workday this shouldn't be an issue for the first few years of use. I have had racks break, but only after cycling thousands of kilometers on all types of hard surfaces with full camping gear.

I don't have any specific rack advice. I always just buy whatever the nearest bike shop to where I am is selling. I have good experience with Cordo, topeak and Bor Yueh rear racks and lowriders. Always the models mounted to at least the axle, I've never tried any of the seatpost mounted models.


Alwasy getting a flat rear tire on my 14"inch folding bike

There are a few possibilities:

The culprit is still stuck in the tire. Carefully check for any glass shards, pieces of wire, thorns etc.
Something is sticking out of the rim. Check if the rim tape is properly seated and covers the spoke holes completely.
You are using insufficient tire pressure and getting pinch flats (”snake bites”). Usually you’ll get two long-ish punctures on opposite sides of the tube. If you are riding on roads only and are on the heavy side it’s probably a good idea to go up to the maximum pressure the manufacturer recommends.
You are pinching the tube between rim and tire during installation. Or damaging the tube with tools. Install without tools if possible. Inflate to a very low pressure after installation and check if the tube is pinched anywhere by pushing the tire away from the rim and looking into the gap.
You are simply having lots of bad luck or there is a lot of debris on your roads in combination with a fragile tire. Get ”puncture proof” tires if you ride on roads with glass shards, thorns etc.

General advice: Install the tire with the label aligned to the valve stem. This way, after you’ve found where the puncture in the tube is you can check the corresponding area of the tire and rim.


DMR make hinged clamps for mounting chain devices and bottle cages. 3 different sizes and there is a 31.8mm which should be perfect. Easy job to retro-fit an existing QR lever and bolt I reckon?

Part Number: DMR-CLP-286

Alternatively here is something from a different application that would probably work. You might be able to contact the company for a 'sample' :)

URL: Staff-Lok Collar

(it's steel)


Another stem diameter question (French steerer)

Your main concern of the stem becoming stuck, is valid. It requires you to remove the stem and re-grease it more often than you otherwise might. I'd recommend twice a year minimum. Sanding the stem is a viable option, first determine how high you need the handlebars to be, then rap tape over the part you are sure you want exposed above the locknut of your headset, then sand for 10 minutes, and check if it fits. You may need to sand the wedge as well. If it doesn't fit yet, sand it again and check every minute or so, it usually takes about 15 minutes or so. I've had AVA stems fail before and I was very lucky, Cinelli, TTT, and others made stems for French bikes and 25.0 handlebars, but they're getting hard to find. I prefer sanding Nitto stems as they are well made and have models to get the bars up higher for riders who need a more upright position.


Big at the front should generally not be combined with big at the back, for two reasons.

It forces the chain to use a non-straight chain path, (hence "cross chaining")
The derailleur spring has to stretch out forwards to allow the chain to be mostly on the cogs.

You also want to avoid small front and small rear, for similar but opposite reasons.

The chain does the same out-of-line crosschaining, merely in the other direction
The derailer has so much extra chain to take up that it ends up folding completely up and the chain can rub on itself passing around the two jockey wheels.  At extreme cases the chain can catch itself, and wrap itself around a jockey wheel.  This tends to bring pedalling to an abrupt halt.

Chains wear out no matter what you do.  Grit from roads, salt, and plain old usage wear a chain.  You're recommended to fit a new one every 2000 km, but different brands have different numbers, plus your usage comes into it.
If you ignore the chain then it will slowly wear out the rear cassette, and then starts on the front chainrings.  A $30 chain a year is cheaper than a new cassette and chain every two years.


I want to know how often do crashes happen to bikers?

I think it depends on how you ride (and what you ride, and where, and when).

For example, I was talking with a young man recently, who owns a racing bike. We were talking about where we ride and I told him that I'm not comfortable on a road which has two lanes in each direction and a speed limit above 50kph/30mph. He said, "That's ridiculous." I remembered that he'd said earlier that he'd broken bones by slipping on a wet man-hole cover when tearing round a round-about, and replied, "Perhaps, but I've never broken any bones."

I guess I ride with caution: not always slowly, necessarily, but definitely varying according to how I feel (and what my past and present experience tells me) about the road conditions. I'm commuting, not racing.

I fell off three times in the first week of riding my current bike: twice, from slipping on ice, once from not unclipping in time when stopping; each of these times I was travelling at about 5kph/3mph or less, and so not hurt (not even scratched, wearing a winter coat, just one mild bruise).

Going downhill for example now, I'm concious that there might be sand or gravel on the road, that the pavement may be cracked in places (by frost, this is in Toronto). I don't ride slowly, but I do try slowly enough, to stay in control: compare that with this answer.

When I posted this question most people answered that I needn't expect to fall at all again.

The reason I'm not comfortable on a multi-lane road is that, on such a road once, during rush hour, a motorist hit me from behind by trying to undertake someone else while I was in the curb-side lane. Well, that hurt (me and my bike). Luckily it didn't stop me riding, but it did stop me riding on that particular stretch of road, and made me more wary of being hit from behind. I don't expect it will happen again: partly because I avoid that kind of road now, partly because I'm more cautious, sometimes stopping by the side of the road to let a rush of cars overtake instead of pulling out into traffic and just hoping that someone will slow down for me.

  Also how do you recover from them, both physically and mentally?

Is "how to recover physically" a medical question? It depends on the injury: see this Q&A for some details.


Could i break Shimano Nexus 7 with no cable attached?

Yes, that's fine.

You won't damage the hub that way, although you might damage the cable attachments if they get caught in the chain, or lose some pieces. Single cable systems work by pulling and releasing the cable, and one gear is always "cable completely slack", just as it is when there's no cable there. Like what you did.

It's just like a rear derailleur system in that regard - without the cable the spring in the derailleur pulls it to the highest gear, and it just sits happily in that gear while you ride. Your hub is similar, except that the spring is inside the hub where you can't see it.


Lever throw is how much the lever moves in total.

Cable slack is how slack the cable is, ie. how much you have to pull before the brake pads start moving.

Park Tool says:

  Squeeze lever to test caliper brake. Adjust lever modulation setting by moving pads inward or outward from rotor by using both pad-adjusting knobs. To maintain the 2:1 ratio, turn the fixed pad-adjusting knob twice as many clicks as the moving pad-adjusting knob. For example, if a looser modulation is desired, turn the inner pad-adjusting knob counter-clockwise 4 clicks and the outer pad adjusting knob counterclockwise only 2 clicks.

The throw will be controlled by the total gap between pads and disc. For a short throw, a small gap, pads screwed a long way in, for a longer throw pads further apart, pads screwed out.


Can a road bike's rear derailleur be used for either a 9 speed cassette or 10 speed cassette?

The spacing between 9 speed and 10 speed is controlled at the shift lever.

A 10 speed rear dérailleur will work with a 9 or 10 speed cassette and shifter. A 9 speed rear dérailleur is not compatible with 10 speed.

The width of the chain and the cogs is the biggest issue. The pulleys on a 10 speed dérailleur are narrower, and a 10 speed chain will not rest correctly on the jockey pulleys of a 9 speed dérailleur.

That does not mean it will not physically work, only that the shifting performance will be slow, you may drop gears unexpectedly, or have the chain skip unexpectedly.

Long story short, 10 speed should be 10 speed all the way throughout your bike for it to work consistently and properly.

Cable tension has nothing to do with cog spacing. That is designed into the shift lever. It is not adjustable, except by replacing the shifter.
I hope that helps.


What is a good method for constructing dirt jumps?

Jumps takes time and effort to do right.   If you're going to rush or do a half-arse job then don't even bother starting.

Design is important - you need to consider run up space before and run out space afterwards.   Make the jump wide enough to give options - a metre would be a fair width unless you're making it difficult on purpose.

Bailing-out options - riders will ride around if it looks too hard, you may make the jump really wide to reduce this, or make it longer to go around.

Try to avoid digging a moat around your jump.  Source the dirt from metres further away, you want to avoid having water collect on your track, because wheels and water means erosion.

You're aiming for a smooth curve on the face, so build up your jump a few inches then stomp or compact it.  Damp soil will compact better than dry.

Deeper inside the mound you can use big rocks for bulk, but still pack the soil around them.   Trees and wood is not so good, it will rot.   Tanalised timber is okay for surfacing.

As your jump rises, keep tamping it down.  Use water to dampen it.

Remember it doesn't all have to be built in one sitting.

You can use shingle/stones to help reinforce the surface, but don't put sharp edges facing up.  Big flat river stones are okay in moderation.

The top - I'm not so sure on this.  You want to curve it back down quicker than you went up, but you must not have a lip or a sharp edge.... it won't last.   Jury is still out on timber at the top.... if you were building a jump with a wall on the far side (ie you have to get off the ground) then timber supports will be required.

The danger of timber is wear over time may create a tyre-grabbing rut right before the edge, where it's too late to stop.

Finishing - use a watering can or hose with a shower spray to smooth off the surface.  A flat spade or rake may be useful for smoothing, or you could even use a garden roller.   Also you might want to use some matting or concrete pavers to minimise erosion and to assist traction.

Final thought - do get permission to do what you want to.   Or do it on your own land.   Don't go damaging trees or wrecking other things to make your jump.

Edit: I forgot to add maintenance.   Do periodic work on your jumps, to fill erosion or ruts, or just generally clean up.  Rubbish laying about attracts other rubbish so keep it pleasant.


Assuming your bike is made out of steel (since aluminium and carbon fiber don't corrode in the way you're most probably worried about):

Get "helicopter tape" to protect any areas of the bike that might get dinged (the top tube and down tube from parking the bike against parking meters, etc.). Or if you're cheap or worried about theft, use ugly duct tape / pipe insulation / electrical tape/etc. I use retroreflective tape which serves two purposes -- keeps me lit up at night and protects me against scratches.
Make sure your rear right chainstay has a chain protector on it.
Get some touch-up paint from either your bike dealer or from an auto-parts shop and make sure to quickly touch up any dings and scratches. This is where corrosion will start.
Get some Boeshield or frame corrosion protection spray (JP Weigle Frame Saver is another brand) and spray the inside of your frame. The seat tube and top-tube can be sprayed if you take the seat off. The down-tube often has a drain hole but can be hard. Read the directions of what you're using to make sure it's safe for your bottom bracket or headset.
Spray boeshield or another waxy protection film on all exposed bolts.
Try to never leave your bike out in the rain and if you do, wipe it down as soon as possible.
Keep your bike clean. Dirt and salt attract water and aid rusting.
Occasionally make sure all of your frame drain holes are clear.
Don't worry about a little rust, wear it with pride.

Many of the answers here are also applicable: How do I make my frame water tight?