Shimano Hub LED lights working sporadically

If I understand you, you have a hub dynamo that powers lights in the front and in the rear.  You don't make it clear whether you have a battery or not; if the lights stayed on after a minute or so (when everything worked properly) when the bike wasn't moving, then you have a battery.  If the lights fade and die a minute or so after you come to a stop, and then work again when you get rolling again, then you don't have a battery.  It's very unlikely that you have a battery next to each light, because that would make the system more expensive for very little benefit.

Your problem is most likely a loose connection between the light and the power source.  If you have a battery, then the battery is the power source; if you don't have a battery, then the power source is the hub dynamo.  An electronics technician would look at each connection between the light and the power source.  You could have a loose contact, or a corroded contact.  If the contacts are corroded, you can often remove the corrosion temporarily with a rubber eraser, a piece of fine-grained sandpaper, or an emery board that ladies use to file their nails; try the gentlest options first, because if you remove the metal plating on the contact, then the contact will corrode again very quickly.

Corrosion is often caused by moisture getting into the contacts; if the connector has a gasket, then check to see if the gasket is sealing.  If the connector is supposed to keep water out, but doesn't any more, then the usual fix is to replace the entire connector, which takes electronics repair expertise.  If your lights are several years old, then corrosion could have happened naturally.

Good luck finding and fixing the problem.  If you can't fix it, your LBS or an electronics repair shop can probably do the job.


Looks like this is what's called a "mid bottom bracket". They seem to be common on BMX bikes. They use bearings that press into the frame. I found a video that shows how to remove and install a new one. It seems like the spindle should slide right out from the video but on the bike I was working on it didn't seem like that would have been the case, but I didn't really try to slide it out.


It depends on your cadence (number of times you're turning the chainrings). If you fix the cadence, largest chainring (gear in the front) and smallest cog (gear in the back) will be fastest.

In practice, you will not be able to keep up the same cadence on all gear combinations, so depending on the cadence you can keep, a smaller chainring in the front and a larger cog in the back may end up being faster (since you can use a higher cadence) than a larger chainring and smaller cog (which, if you could spin at the same cadence would be faster, but you can't).

You can use this calculator to see what speed you get for a given cadence for the chainrings and rear cogs on your bike.


Which disc brake pads do I need for Tektro Auriga?

Not an answer you want to hear, but Tektro parts are very sparse because they are entry level, and low budget. No one really makes parts for them other than tektro. So if its discontinued you may see if a bike shop can make something else fit, but online you will likely not find a match by visual.

Avid or hayes make brakes that are more universally supported.


Replacement for 52 tooth chainring Ultegra triple ( 6503 ) 9 speed

You should be able to replace your chainring this with any 9 or 10 speed chainring that is 110 BCD (which is the Bolt Circle Diameter for the spider on an ultegra triple crankset).

Tiagra/105/ultegra replacement rings should all fit, as well as most 3rd party manufacturers replacement rings.  Make sure the ring you want to use as a replacement has ramps and pins so that it will work as well as the original.  Stick with shimano parts to be sure of the best performance with the ultegra drivetrain.


Can a 2012 Carrera Vulcan run 26 x 2.25 tires?

Tire sizing is essentially witchcraft (See http://sheldonbrown.com/tire-sizing.html) for mixing conventions and what not. Even if you have two tires of the same dimensions (say 26x2.25), you may not be able to mount both of them due to knob patterns (a "larger" labeled slick may fit where a "smaller" labeled knobby squeezes by due to the height and width of the knobs) or slight dishonesty in sizing preventing the frame from clearing things properly. Also, your rims need to be able to take the tire size as well. This all may also depend on the particular frame size you have as well. You should probably go to your LBS and try some 26x2.25's in the space or at least do some measurements on the clearance of the tire in the frame (it may not be the same in the front and back, so you may be able to run a larger tire in the front).

It seems to be a Halford's bike (which is like REI level bikes? not from teh UK), so there aren't product pages for it archived, so I don't have any specific sizing information I can help with. http://www.bikeradar.com/us/gear/category/bikes/mountain-bikes/product/review-carrera-vulcan-12-45673/ says they fit a Continental Mountain King 26x2.2 on there in the comments but doesn't mention how much more it will clear (which you'll have to actually go out and try similar tires as to the one you want).


Barring a drain hole somewhere,  a drain hole allows air to move so equalizes pressure. A sealed system will create negative pressure with temperature changes and suck in water around moving parts. The bottom bracket or fork are the only other places a typical frame has holes that would allow water to escape.

Given these probably about as inconvenient to remove as the seat post, the only real option you have is a drain hole.

You could always upgrade :) to an external routed dropper so its possible to remove the post, or install a long enough dropper cable that you can pull the seat post, and either cable tie it in a loop after it exits the frame (I know, you are rolling your eyes right now.)

Question I have to wonder is where is the liter getting in.


Brakes periodically make "finger nails on chalk board" sound

Sounds that bikes make are difficult to describe.  "Fingernails on a chalk board", so sort of a high pitched dry scraping noise, not a squeal, squeak or scream?

That sounds like something ceramic, stone or metal rubbing against the metal rim to me. The last loud noise where it then goes quiet could be whatever it is getting turned just before getting entirely dislodged. Does that sound about right?

I'm not an expert, but my best guesses:

Poorly made brake pads made with chunks of stuff in them.
You're picking up some sort of grit that's getting stuck in the brake pad.

The consistent pattern points much more to the pads being manufactured that way. But I've had similar kinds of sounds when I picked up a bit of sand on the rims.

Brake pads aren't solid rubber/poly-whatever, the're actually a compound, typically with a sort of ceramic or metallic material embedded in the rubber-like material.  Poorly made brake pads can have large chunks of that material instead of consistent fine particles.

Either way, when the noise starts, examine the brake pads. You'll probably see something embedded in the pad that you can pry out with something pointy (screwdriver, tip of a knife) or scrape out with a razorblade. It's quite possible it's something the size of a grain of sand, not a huge chunk.

And if it definitely looks like it's something that the pad was manufactured with in it, consider replacing the pads with a different brand; It's likely that your rims are getting worn faster.


The tread on a road bike's tires is really quite unimportant and purely cosmetic.  Road bike tires have tread patterns because they sell better, not because they perform better.

Here's some questions to ask to decide about replacing a tire:

Can you see any of the fabric?
Are you getting flats more easily than you used to?
Is any part of the tire bulging out or lumpy?
Are there visible holes/gashes in the tire?
Does the wear indicator indicate you should replace?  (Some tires have dimples or grooves that are there to indicate when the tire should be replaced.  Some have an alternate color of rubber underneath, and when that shows through the tire should be replaced)

Smooth tread is actually ideal for road conditions, but not commonly found on tires.  If you're on hard surfaces such as pavement/asphalt, the tread doesn't help you and actually slightly reduces contact area and increases rolling resistance.  On most road tires the minimal tread pattern is just cosmetic to make their customers feel better (since a smooth tire looks slippery).

See also: Sheldon Brown's comments on tire replacement and tread patterns

If you plan to ride through mud, sand or other soft surfaces, you need tread.  So when you no longer have tread on your mountain bike or cyclocross bike's tires, it's time to replace them (unless you plan to only use them on the road).


How can you recognise a quality steel frame?

Some things differ if you are looking at a new or a used frame, but here are some suggestions:

First, when you say you are looking for a steel frame, what you probably mean is a ChroMoly Steel alloy frame.  This would be a frame made from tubes where chromium and molybdenum  were added as the steel was refined.  Frequently you will see a sticker on the tube with a number like 531, 631, 725 or 853 which is used to describe the particular blend.

Second, spotting a high or low quality frame has become more difficult over the years as machining and welding techniques have filtered down. With older frames you definitely want to look at the quality of the welds and brazing, as well as the paint.  Welds may be smooth, or have a regular pattern.  Watch out for welds that look rough, 'globby' or irregular.  It used to be that the use of lugs was a hallmark of lower quality frames, but today you see them more often on high end boutique or custom touring frames.

You may also want to feel the bottom sides of the tubes for a "seam".  On older low quality frames you frequently find rolled tubes, where the steel was a flat sheet that was then rolled and welded length-wise.

Finally, the durability of a steel frame is largely a function of the paint quality and maintenance. Water and rust are the primary enemies of a steel frame.  If buying used you will want to closely inspect the area around the bottom bracket, dropouts, and the whole underside of the bike for chips, cracks and visible rust.  For long life, as well as the low environmental cost, steel v. aluminum is probably a wash.  In the US and most the developed countries both aluminum and steel recycling is around 50% and the production costs and impacts are pretty similar.  And while corrosion may be an issue, an aluminum frame won't rust.

Good Luck.


What's the difference between galvanised brake cables versus stainless steel?

Galvanised ones rust eventually. Especially in the high wear areas. Stainless steel ones don't rust, but possibly don't deal quite as well with sharp curves.

Unless the extra dollar is critical, always buy the stainless steel ones. The bike shops I've been in don't even sell galvanised ones any more because the price difference is so small and the benefit so far outweighs it.


Need guidance on selecting proper Gates belt drive components for my belt-ready frame

The Gates CDX system is supposed to be a bit better than the CDN, but they share the same belt and sprocket design. I believe the rear sprockets are interchangeable. CDC is a different design without the center guide.

You want the 3-lobe sprocket to fit on a Nexus SG-3C41 hub. Videos of how to install these are readily findable on the Web.

Without knowing what crank you have it's hard to give specific guidance. You need to know the bolt pattern and bolt center diameter (BCD) of your crank to find the right front sprocket.

The trick with Gates belt drives is that they are pretty sensitive to alignment of the front and rear sprockets. You need to know the chainline of the hub and sprocket and make the front sprocket on the crank match that. )Poor alignment may be why your current setup keeps throwing the belt.) If you have a square taper bottom bracket and crank you can adjust chainline by getting a different bottom bracket with a different axle length.


Can I use a spoke tension meter to fix my uneven pre-tensioning prior to truing?

You're in the "iterative" part of truing.

Try loosening a tight spoke by 1/4 turn and tighten the spokes either side by  1/8th of a turn.   Then spin and find the next tight one.  You could use a tension meter to identify tight ones, but touch works pretty well too.

Then move to checking for "out of round" for a bit.  Keep making the worst bit better, then move on.  Remember to relieve the wheel and check it again.

Don't assume that if all spokes had the same tension that the rim will be true... sadly its not like that at all.  There will always be some tension variation around the same side of the wheel.

Even minor variances in the rim and spoke length can cause tension variations in a completely true wheel.   I missed putting spoke prep on one spoke thread, and it needed to be significantly different tension to all other spokes in the wheel.  That was a puzzler!


Are road tyres suitable for any off-road riding at all?

If you're looking for a general purpose bike for commuting and towpath riding, you probably want to avoid a standard road bike, they are very specialized and have very small tire clearance.  Typically supporting tires no larger than 28mm and often lack mud guards or rack/pannier mounts.

However, touring bikes or steel cyclocross bikes (if they have rack and fender mounts), tend to be great choices for those purposes.  Both will often have clearance for tires up to 35mm or larger which you can use for off road riding and have a more traditional road geometry versus the more upright hybrid geometry.  However, if you prefer the more upright stance and flat bars, then a hybrid may be more well suited to you.

I would make sure that whatever bike you get does have rack/fender mounts if it's going to be used as a commuter.  You never know if you'll want to start using a rack and panniers to carry your gear off your back or fenders to keep you drier in the rain.

You can get knobby tires for any of these bikes, but I would stick with high quality, puncture resistant road tires wider than 28mm.  Even slick tires that are 35mm should be fine for towpath riding, I wouldn't take them on singletrack though.


Does it matter what way the tires go if no directional arrow?

Tires with directional arrows usually have a tread that's asymmetric in terms of rotation of the tire about the hub (i.e. the tread appears to "point" forward or backward along the direction of travel of the bike).

Asymmetric tread is designed to improve traction in certain scenarios. For example, they can be designed to encourage water, snow, mud, and other liquid or semi-liquid items to move out from under the tire, improving traction. Mounted incorrectly, they will do the opposite and encourage the same stuff inward toward the center line of the tire.

The direction arrows you mention are to reduce the guess-work and just tell you exactly how to mount the tire to get the tread pointed the right direction. If there is no explicit arrow, look at the tread and see if it has a pattern that "points" in one direction (forward or backward). In every case I've seen, the pattern should point behind towards the back of the bike when it contacts the road, or forward when you look at it from the top.

If there is no direction arrow, and the tire is either slick or has a symmetric tread (doesn't "point" forward or backward), I would say mount it either way. Shouldn't matter.

Also, make sure to look very close for the arrows. Sometimes they're painted onto the tire and easy to see, but other times they're just traced with a raised ridge of tire rubber and that can be hard to spot. Check the entire perimeter of the tire on both sides, in good lighting.

Summary

Did the tire manufacturer include an explicit rotation direction arrow printed or embossed on the tire? If so, follow that.
If there is no explicit rotation direction arrow included by the manufacturer:

Is the tread asymmetric in the direction of rotation, i.e. does it appear to "point" forward or backward? If so, mount the tire so the tread is pointing
forward when viewed from the top of the bike.
Is the tread symmetric (doesn't appear to point forward or backward)? If so, mount it either way, rotation direction doesn't matter.


Tubes sticking to tires are pretty normal and not a problem, especially if the tube has been in the tire for a long time. Some people put talc or whatever in a tire to avoid this, but its not necessary.


What is the difference between a sidewalk and a mixed use path?

What is the difference between a bike path (or mixed use path) and a sidewalk?

You're allowed to ride on a bike path, you're generally not allowed to ride on a sidewalk. The visible difference is the signage on the bike path saying bicycles are allowed there.
A sidewalk is normally the default label for any non-vehicle path next to a road. They're almost always restricted to pedestrians and mobility vehicles (prams, wheelchairs), usually with wheeled toys also allowed. The detail of how those are defined varies, but in general it's "things that move at pedestrian speeds".
Mixed use or shared paths are distinguished by their signage. Somewhere near the start and end will be signs saying "bicycles allowed" or "horses, bicycles and motorbikes allowed" or something similar. Often in graphic form rather than text. The local laws will define exactly where those paths start and end, but the people building them often don't know or care what the law says, leading to situations where cyclists have to dismount, walk their bike one or two metres, then they can ride on the shared path. Obviously no-one does that, but occasionally someone gets ticketed for it (or presumably in the USA, shot).
Specifically in Maryland:

Shared-Use Path A bikeway outside the traveled way and physically separated from motorized vehicular traffic by an open space or barrier and either within the highway rightof-way or within an independent alignment. Shared-use paths are also used by pedestrians (including skaters, users of manual and motorized wheelchairs, and joggers) and other authorized motorized and nonmotorized users. (Maryland MUTCD, 2006)
Sidewalk That portion of a right-of-way designed for preferential or exclusive use by pedestrians.

This official pdf seems to have collected all the bicycle-related parts of Maryland code and there's a summary on an official website. You can only ride on a sidewalk where specifically permitted by local rules, and interestingly wheeled toys, unicycles, and mobility scooters also need special permission to use sidewalks. They don't mention prams, so I suspect "wheeled thing that you push or pull" counts as a pedestrian.


Transition between hybrid bike and endurance road bike

You probably just have to get used to the geometry of the endurance road bike (since most hybrids are closer to MTB hardtail geometry), which can be helped with bike fit, so the drop bar and saddle are positioned in a way where you can use all the hand positions of the bike (hoods, drops, middle of the bar, sides, etc.) efficiently and comfortably for the type of riding you're doing.

Also, you should be more aware of road hazards, since most endurance road bikes have weaker wheels than a hybrid, to save weight - bunny hopping can be useful for this.

Also, if you're using clipless pedals (or clipped pedals) on the road bike and not on the hybrid, make sure to practice clipping in and out before you hit the road (unless you like your face hitting the ground...)


Is there a way to hop up onto a parallel curb?

You're talking about a "bunny hop" and it can be done at speed on a loaded bike but it's high risk. You'd almost certainly be better off jumping off the bike and rolling. US Bike Trials call it a "side hop", but in anglonesia I've mostly heard it called a bunny hop.

Here's a photo of the 2006 Cycle Messenger World Champion doing more or less that at about 30kph, but wearing a backpack rather than panniers:

Note that at the world championships for people who ride loaded bikes fast all day about 3/4 of the competitors slowed down and used the pram ramp or just stepped up the curb (my photos are of the ones who took the more exciting approach, obviously). In this case they rode along the road, then had to go onto the footpath and turn very slightly onto a path, so slowing down to use the ramp definitely cost them time.

If you're expecting to do this, IMO you're better off learning to dive roll properly. Either through a martial art like aikido or ninjitsu, or through gymnastics. That skill will help you in a much wider range of situations than "if I have a couple of seconds to get organised I can bunny hop". Also, the most likely result of trying this is that you end up hitting the curb with the bike, then the pavement with your body. So rolling will be useful either way...

For me, it took a slightly disturbing number of crashes in my late youth before I was seriously injured, largely due to my ability to roll (loosely speaking, via martial arts training). And when I did eventually break my humerus it was because a roll failed. Even now, I've been riding everywhere for 30-odd years and still my major injuries have all occurred through both my own stupid fault and in effectively single vehicle accidents. The "hit by car" ones have all involved a bit of flying through the air, a roll then a lot of very politely explaining to the motorist that I would like them to give me their insurance details. Now. THANK YOU.

FWIW, I can do a hop like the one shown, on my commuter bike, with panniers, but only with careful preparation and a 90° approach. Jurgen's flying leap approach is not one that I'd try if there was any way to avoid it.


How can I tell the difference between a J.I.S. and ISO square taper bottom bracket?

The width across the narrowest part of the flats (end of spindle):

JIS = 12.65mm

ISO = 12.33mm

Use calipers.


It could be a couple different things but new bike and metallic click plus only happening pushing hard on the right crank points to a very high likelihood of the chain rubbing against the front derailleur cage. This could be caused by either or a combination of:

The front derailleur cable has lost a little tension, which is common as bikes break in. Solve by tightening the barrel adjuster, which is easy to search for here.
The front shifter has trim stops you're not using properly. Again there are many questions about this here. This is more consistent with a shop getting it back and spending some time on it and the noise still persisting. Shop people will use the trim stops without thinking when they test ride a bike. Making sure trim usage is gone over with each customer is something that can fall between the cranks in sales and service interactions, and complicating matters is that some customers vibe like they don't want or need to be taken to school.
The front derailleur high limit screw might be too far in, although depending on the bike/crank/chainline/chainrings it could be how it is for a reason.


How do I place the seat back 20 cm with a full suspension bike?

The only safe answer is to buy a bigger bike frame.
When your adaptor fails, you will descend rapidly onto the rear wheel.
The remaining original seatpost has an excellent chance of tearing your chest open, and impaling your head up through the jawbone.
While this is definitely creative, its absolutely not the right answer.
Buy a bigger bike frame.

If you're under 20, then there's a good chance you're still growing.  Even more reason to buy a larger frame bike.


The pros of buying pre-built are the cons of building your own.
Each approach is born of very different requirements.  That is, the person who is actually likely to build their own is very unlikely to buy off the shelf and vice versa.  (I assume that 'build from scratch' also covers getting the LBS to do it for you to your specification).
I would caution everybody thinking of building their own that you will get much better 'value for money' if you buy pre-built.  A $1000 pre-built will get you much higher quality parts than a $1000 build your own.  This disparity seems to reduce the sillier the price becomes at the high end.
You will need access to some specialized and expensive tools (thanks Gary!) and the skills to go with them.
There is, as always, an intermediate stage where you source everything yourself but have the LBS do the trickier jobs like headset pressing, bottom bracket cups and steerer tube cutting/star nut pressing.  Just remember that your LBS is a business and needs to make money - so buy the parts from them if you want them to fit them!
Buying New
Pros

Integrated package
Lowest cost
Guaranteed that all the parts will fit and work together
Just go pick it up from the bike shop and you can ride
Don't need to know as much about bikes
Possibility to test ride (usefulness varies, often takes a while to get to know a new bike)

Cons

No choice of components
The color frame you want is either too cheap or too expensive!
Often component compromises are made to reach a price point
You don't get to choose what factors to optimize for

Build Your Own
Pros

Get exactly what components you want
You can choose what to optimize for
You can get your frame color
You choose what compromises you make within your budget
Every part is chosen for a reason and you get to spend hours researching it
The incredibly deep satisfaction you feel building a bike from scratch
Knowing that nobody else is riding a bike like yours
You may need some very specialized (read expensive) tools and you end up with the ability to use them.

Cons

You spent hours researching every part
Building wheels from scratch is not for the faint hearted, but it is rewarding
It's the most expensive way I can think of to get a bicycle
You may be more prone to 'overprotective parent syndrome'
You may need some very specialized (read expensive) tools and the knowledge to use them
You must be comfortable filing and sanding and abusing your frame (think headsets and bottom brackets)
You will make mistakes with part compatibility
It takes a lot longer to get riding
Only feel how the bike rides after spending a lot of time end money, although you can often find people with similar bikes to test ride (see above)


Indexing 6 sprocket rear derailleur, having trouble reaching largest sprocket

Returned to this this morning, and have found that the high limit screw could be let out a bit more, and now that is done the chain reaches the large sprocket just fine! Apologies for being dense!

I am now finding that I can index it fine for going up from the low sprocket, or coming down from the large sprocket, but not both, but I'll work on that....


Grease or anti-seize for alloy thru-axle-to-QR adapter?

Anti-seize is the best from the standpoint of corrosion resistance and it has washout resistance that surpasses the greases usually used on bikes. The reasons it's not used on bikes more are that it's messy, another thing to have, and it takes a pretty extreme or specific situation for grease to not be enough. Tradition plays a role too. You can use it here and in all other metal-on-metal assembly prep spots where you'd use grease otherwise. The parts won't mind, but it's up to you whether the messiness is worth it. I would never use it on thru-axle or QR shafts because of the mess factor when the wheel is out.


Your brake is certainly not properly set up. Do not ride the bike in this state!
The rotor's brake track must run fully between the brake pads. The radial dimension of both match.
You rotor may be too small for the brake it its present set up, your wheel not properly inserted, or the brake caliper not mounted correctly.
Check your brake's manual for adjusting it to different rotor sizes with adapter plates. Often an adapter can be flipped to accommodate 140 mm and 160 mm rotors.
As general advise: do not fix it yourself.
Ask someone who knows what they are doing, for example, a certified mechanic. That you have to ask this question indicates you are not ready to tinker with brakes that are relevant to rider's safety.


Very short-pull derailleurs designed specifically for 1x6 drivetrains?

In theory you could get a short-cage derailleur, but that would add significantly to the parts cost and not really be much better.

Back when I did a lot of fixups, it was all about making the bike as good as it could be, without spending anything on the more expensive items.  We'd often replace brake pads and cables with new, but items like cassettes and derailleurs were very rarely bought new.

Fixups are a different mindset to working on your own bike.

Instead, we'd knock down bikes that were too-far-gone, and put the usable bits into storage bins.  During downtime, volunteers would clean and recondition components, then return them to storage.  So later, if someone's fixing a bike and finds they need a rear mech, they'd pull one from the parts storage bin for rear mechs and fit it up.  The old part would be either cleaned and serviced, or scrapped for metals which earned a couple hundred dollars perhaps twice a year, but each time it was a truckload of pre-sorted metals.

The expertise comes from deciding how dead a bike has to be to go to parting-out vs what's worth saving.  That is affected by how busy the operation is, what parts are low-stock.  Your local area also affects the supply line - there are always old bikes turning up.  And finally the ultimate limiter is how much space you have for storage.


Ask for Recommendation for Biking Outfits

It's not really clear what you mean by look professional.

If you mean a professional cyclist, then a cycling outfit is the way to go. They are designed to be comfortable for cycling, and to keep your leg muscles warm.

But if you mean professional as in office worker professional, then that's a problem that many of us struggle with.

Firstly, how far do you ride? The further you ride, the more likely it is that your clothes will be sweaty and you'll want to change. If it's not that far, in warm weather many biking students here wear long baggy shorts and matching tops, like skateboarders. But you wouldn't say they look professional.

The other way to go is to change clothes. Depending on the size of your campus and how modern it is, it likely has a decent gym with showers, and maybe locker facilities. Many students take gym membership to access those facilities; you can keep a change of clothes, and a towel there, and shower and change before classes.


I'm pretty sure the amount of tension required to downshift is almost entirely determined by the derailleur's spring. Try down/upshifting without the derailleur attached (just holding the cable in one hand whilst shifting with the other), it will take almost no force to do so.

Cable condition can have a big impact on how much pressure it takes on the shifter to shift up/down. If this might be an issue for you try replacing the cable (either inner/outer or both depending on how good/bad your cables are).
I've recently replaced the cables of the front derailleur of my mtb which were in very bad condition even though they looked ok visually. It took so much force to shift (both up/down) that I feared I might break the shift levers. After replacing the cables it shifts like new.

Cleaning/lubing your derailleur might also help make it easier to shift up/down.

If your derailleur limits are not set properly this might cause the up/downshifts at the extremities (lowest ad highest gear) to be more difficult/take more pressure to shift due to the limit screws blocking/halting the movement of the derailleur.

As far as I know there is no such adjustment on shifters since the force required is not determined by the shifter but rather but the force required to move the derailleur (and also by the leverage ratio your shifter has (amount of movement of the lever compared to amount of movement of the cable caused by this lever movement) but this is -as far as I know- non adjustable.


That’s a Rollfast Skoot, probably late 60s or early 70s.

If you were hoping it’s valuable, in its current condition it’s probably not worth very much. There’s a nearly identical but fully restored one on eBay right now. Keep an eye on that and see if it sells for asking price or not. Then you can decide if you want to put the time and money into restoring it.


Cyclocross touring, studs for SPD shoes?

Unless you plan to do a lot of sprinting up muddy hills to jump barriers, the studs are just extra weight that makes annoying noises when you're walking around.

SPD is great for touring since you can easily walk around in the shoes, the studs detract from that without adding much benefit.

You can get small "set screws" to fill the holes where the studs would go. This prevents
the threads getting filled with dirt in case you decide to use them later.

https://www.boltdepot.com/Metric_set_screws_Allen_Cup_point_Stainless_steel_18-8.aspx


Adjusting pedal / crank / other components to account for different leg sizes

I've done the same thing in the past, heel shims, cleat wedges, pedal washers, insoles, etc.

The one thing I can say is that it's a slippery slope once you start fiddling with these things.

One small adjustment effects all the others and it's very difficult and time consuming to get it right, which you probably never will without 3rd party perspective and expertise. No to mention there are a bunch of other things that can be causing your pain besides leg length difference; fore/aft foot tilt, knee alignment, saddle position, etc.

The real solution is to get a professional bike fitting.


Not necessarily.

For one thing, many cartridge style bottom brackets will have some spindle exposed when the crank is mounted. This is because even though two bottom brackets might both be 68 mm, one may have a longer spindle than the other. If you mount the same crank on both bottom brackets, it might fit flush against the bottom bracket shell on the shorter spindle, but would have a gap on the longer spindle.

More importantly, most cranks curve outward from the bottom bracket so that the cranks will clear the chainstays. You can see what I mean in this picture:

That's obviously an external bottom bracket, but a crank that sat flush against the bottom bracket shell would have to have an even more significant curve to clear the chain stays (assuming the crank arms were the same length, thickness, etc).

Technically, Q-factor refers specifically to the distance between the point where the pedals attach to the crank arms.

However, many people refer to Q-factor in the broader sense of the distance between your feet when pedaling. Given this broader definition, your Q-factor would also be affected by the length of your pedal spindles combined with the position of your feet on the pedals, whether you're clipped in or riding on platforms.


Issue with PF30 BB on Boost frame - 2-3mm crank arm clearance

RaceFace makes cinch spindles in various lengths. I assume you have a version for 68/73mm bottom brackets. There's also a 100mm bottom bracket spindle option. It will certainly fit, but Q-factor might become too wide for your liking. Theoretically, you can also order a custom length spindle and spacers from some CNC manufacturer.


How to increase friction on a Shimano SIS+Friction rear shifter when it is in friction mode?

There should be a screw opposite the D-ring that you can tighten down to increase the friction on the shifter. On a shimano shifter a flat head driver should be used, but you can use something like a dime if you're in a pinch.


Nearly all mountain bikes from early 1990's to early 2010s (which is 2 decades) and even now many low cost bikes, use Hollow axle QR on an open dropout without any concern. Sure the opening faces down, but many MTB's spend plenty of time with wheels in the air.....

When pedaling the wheel is pulled forward with extreme force. When not pedaling, the action on the axle moves to a very small upward pull (depending on the derailleur angle). The QR would have to be extremely loose for the wheel to drop out.

Is it a concern - for a manufacturer of frames intended to run as you desire, the lawyers would be insisting on lawyer lugs to protect against liability when someone does not do up the QR. However, if the QR is done up, its not a concern at all.


What makes the bicycles in Amsterdam suitable for riding with jeans on?

In places where there are lots of bikes, most people who are riding them are making short journeys purely for transport. For a short ride of a few kilometers, it really doesn't matter what you're wearing. Any clothes that are comfortable to wear in general will be comfortable to wear on a bike for fifteen minutes.

People who are riding longer distances, pushing harder and aiming for fitness rather than just getting from A to B will start to consider clothing that's more oriented towards exercising and people who are going even farther and pushing even harder will start to wear cycling-specific clothing.

I see this exact thing when I cycle at home in Oxford. If I cycle directly into town, most of the people I see on bikes are just wearing whatever clothes will be appropriate at their destination. If I take a more circuitous route around the outskirts of town before heading into the centre through an area where not many people live, I see a lot of people wearing "general exercise" clothing. If I head away from town, out into the countryside, most of the cyclists I see are wearing clothing designed specifically for cycling.


How can I improve my downhill mountain bike as a commuter?

You really can’t change it that much. A dual-suspension downhill mtb will always have limitations, most notably its weight, wheel size and width,  and geometry.

Instead, get a used, 1970s, steel, road bike for your commute. It should cost you roughly $50-150 euros or dollars.

You’ll be amazed at how light a road bike (even a steel antique) will feel compared to a mountain bike. My 1975 Peugeot MX-18 weighs just under 11kg (I did swap the steel rims for alu ones). This is half the weight of your mountain bike!

A road bike, even an old one, will be faster over paved surfaces and learning how to “float” over cobblestones and rough surfaces will help your mountain biking skills.

Finally, since a used beater is so cheap, you won’t worry as much riding it in all weather conditions or about bike thievery.


Need a well-fitted bike for urban commuting

If you hadn't mentioned "tiny frame" and back pain, I'd agree with mgb about minor changes to your existing bike instead of getting a new one.  It sounds like you need a bike that fits you and you have a bike that's too small. There might be a few things that could be adjusted to make a too-small bike work better, but it's likely you're better off getting a new bike that fits right.

We had a similar (not duplicate, I think) question a while back asking about a very similar round-trip distance, etc, you might find reading the question, answers and comments there helpful: What bike+equipment for a long daily urban commute?

A "hybrid" is a bicycle with smooth (road) tires and flat (mountain bike) style handlebars. There's a lot of subtypes that are also "hybrids" such as "commuter", "urban", etc. A lot of them are actually very similar to each other.

From what you describe, I think a good option for you would be a basic "commuter" with smooth tires, flat handlebars and the option to easily add a rack and fenders. It will have handlebars like what you're used to, but roll better (and faster) on roads.

I have a similar length commute and went with a "touring" bike. (basically a heavy duty road bike designed to be able to carry plenty of cargo).

The lower-end "cyclocross" bikes can make really good commuter bikes once you replace the tires. Cyclocross bikes are like road bikes with knobby tires (and often disc brakes). The lower end ones often have the stuff for mounting a rack and/or fenders on them.

Some things to note:

Consider drop handlebars (road bike) because the choice of handlebar positions can help keep your hands from getting tired on long rides. If you don't like them don't worry about it, though.
I would avoid any kind of suspension (some "comfort" hybrids have some). They don't do you much good on roads and on a cheaper bike it will just add weight and add one more thing that could break. Stand on the pedals with elbows and knees slightly bent when you see rough patches ahead instead.
A big heavily cushioned seat can be tempting, but will tend to press into the muscles that you're using to pedal, press into sensitive areas, and rub against things. A lightly padded seat that's just wide enough that you're sitting on it with your pelvic bones will be better for long rides even if it takes a little while to get used to it.
Try out the bikes. Most shops will let you try a quick ride around the block or something like that.


You can use most common Shimano rear mountain derailers made for 9 speed cassettes or fewer.

Currently, good value choices would be the mid-range Deore RD-M591 for a bike that sees a lot of use that you want to keep going, or Altus RD-M310 if you want the cheapest reasonable option. Both meet or surpass the total capacity, min/max sprocket size, and max chainring difference numbers of RD-TX30, so they'll both be compatible anywhere TX30 was.


Shimano Deore RD-M591 is a comparable part which you can still find -- this is probably what I'd use. If you want to go a bit cheaper, Shimano Acera M360 will work too.

You can use any 7-9 speed Shimano rear derailleur to replace another 7-9 speed Shimano rear derailleur provided it has the appropriate capacity (*) for your setup (at least big chainring - small chainring + big cassette cog - small cassette cog) and largest cog rating, since the cable pull is the same. 10 speed onwards has a few more cases.

(*) Capacities tend to be conservative -- you can usually exceed them by a bit if you don't use absurd gear combinations.


From Sheldon Brown

  The normal technique is to measure a one-foot length, placing an inch mark of the ruler at the side of one link pin, then looking at the corresponding link pin 12 complete links away. On a new, unworn chain, this link pin will also line up exactly with an inch mark.

From what I can see in the second photo, the edge of the ruler represents the 12 inch mark, which lines up exactly with the middle of the pin on the end of (what I assume is) the 12th link.  The chain looks fine to my eyes.  (For what it is worth it has been my experience that KMC chains are pretty tough.)

The difficulty with using a ruler is also why chain wear tools also exist, these also include wear on the rollers as part of the measurements (which measuring the inter-pin distance will not consider).  Worn rollers will affect the realized pitch of the chain.

If your chain ring is too worn, the teeth will look like a shark fin and a new chain will slip under pressure.  For more info see: Does this chainring need to be replaced?  If your middle ring does go, I would suggest looking at replacing it before you change the whole crank set (Just my opinion!)


Will a 9 speed front derailleur work properly with a 10 speed sprocket?

As long as your front derailleur matches the number of gears on your front chain ring (2 or 3) you should be okay.

That being said, you may run into issues with different manufacturers or groupsets working well together. Are you using the same make / manufacturer in the front and rear? (e.g., I know Shimano makes both a 9 and 10 speed version of the 105 groupset and I am fairly sure the front derailleur is the same).


What's the power loss to a squeaky chain?

This seems to answer your question:
https://cyclingtips.com/2020/05/how-many-watts-does-a-dirty-chain-steal/
It suggests a dry chain loses 7W out of 244W, which is 2.9%.
Your % speed loss will depend on your speed and aerodynamics - if you are producing, say, 80W, and cycling at 10mph on a flat road, then you could expect to lose almost that much time (so maybe another 100 seconds over an hour). At higher speeds, say 25mph on a flat road, then almost all of your losses are aerodynamic, so it comes increasingly true that your gains (or losses) are proportional to the square root of power losses, so you could expect to lose perhaps 1.5% of your time, so something like 54 seconds.
Of course stopping to lube isn't a bad thing as it helps avoid that little bit of premature wear to components meaning your chain lasts a few more miles, but  if it was raining or whatever, it is probably better to just keep going, as it would just wash off anyway.


SRAM XX1 is their new single chain ring setup. Very expensive and I have not even tried a demo, very wide range on the rear 11 speed cassette (10 x 42) and lots of chainrings available for the front.

My understanding is that the chainrings are designed to 'hold' the chain on. The chainring teeth are designed (wider and taller) to have a better grab of the chain.

Good review/article here: http://www.bikemag.com/gear/first-impressions-sram-xx1/
Good image of the chainring enlarged teeth here: http://www.bikemag.com/gear/srams-1x11-group-new-details-emerge/


What does the term pannier really mean? Does how the bag is hung matter?

In English, panniers originally referred to bags slung across the back of an animal (such as a horse), such that the weight hung down on either side of the animal. This keeps the weight lower so that the animal won't be as off-balance, and distributes the weight evenly.

On a bicycle, the term is used for containers that resemble that, even if it's only on one side.  Specifically, bags that hang on the side of a rack. It's also used for containers that aren't bags, such as buckets, baskets, or hard cases; though most often for bags. The term is used equally for bags on the side of a rear rack or front rack.

A pannier could attach itself to the side of a rack (typically via hooks), or you could have a single unit where two side-bags are attached to each other and held on by the attachment between them sitting on top of the rack. The attachment could be as little as a strip of cloth, or as much as a whole third bag that fits on top of the rack. Even if it's one unit, something that hangs on both sides would be pluralized as "panniers" while a single bag on one side is singular ("pannier").

If a bag is designed to fit on top of a rack without hanging down the sides, it's not a pannier. Typically those would be called a "rack bag".

A bag that hangs from the saddle (seat) is a "saddlebag". However, on a motorcycle, saddlebag and pannier both refer to containers hanging on the sides (the saddle on a motorcycle generally extends to the back). On motorcycles, "saddlebags" are commonly hard cases that wouldn't otherwise be called "bags". The huge difference between a motorcycle's "saddlebags" and a bicycle's "saddlebag" sometimes causes people to incorrectly refer to bicycle panniers as "saddlebags" even though they aren't attached to or even near the saddle (seat).


Can I replace a 3-gear crankset with a 2-gear one cheaply and efficiently?

On MTB you don't get such thing as 2-chainring cranksets. Cranksets come in parts: cranks, bottom bracket and chainrings.

If you are buying crankset separately, chainrings are not included. This is to provide a better flexibility in chainring selection: different materials, shapes and tooth numbers. On cheap cranksets you can not separate chainrings, and in this case you'll need to replace the whole assembly. So one of your options would be to check if your crankset allows to remove the granny ring. If you have chainring bolts there, you are in luck: take the granny ring off and adjust the front mech.

If your chainrings are moulded into the crankset, you'll have to replace the crankset, and that might be not a simple business. In this case it's quite likely that you have square taper bottom bracket and these days it is not easy to find a descent crankset for square taper. So you'll have to replace the bottom bracket as well... and this can be a world of cash spent just for removing a granny ring. Not really worth it, unless you want a better quality/lighter cranks.


No. 29" tires fit on larger wheels than 27.5".

In principle you can switch to smaller wheels if your bike has disc brakes, but that will lead to other problems with ground clearance and handling.


Repair parts from Shimano - What are these part for?

The yellow block is a 'bleed block' which is a spacer which replaces the brake pads when bleeding brakes to keep the pads away from oil and to avoid over filling the system.

The white cylinder with o-ring is a funnel extension, which makes a funnel compatible with your road levers when bleeding the brakes (mtb levers don't need it).

The two metal pieces are often known as connector inserts, or barbs, which go inside the hydraulic hose when installing brakes or shortening hydraulic hose. They are essential to prevent crushing the hose. These are just spares. They would normally be found alongside brass olives which are also required to do these tasks.


How to choose a compatible set of chain, cassette and chainring?

Bicycle chains are standardized. In general, cassettes, chains and chainrings are compatible with each other across manufacturers.

You just have to make sure you select a chain and chainrings that are compatible with the number of sprockets in the cassette. The number of rings on the crank does not matter.

(The difference is driven by the need for progressively closer spacing of the sprockets in the cassette as the number of sprockets increases. Chains for more speeds have to be narrower, which also affects chainring spacing and design.)

6, 7 and 8 speed systems all use the same chain width. Any manufacturers 6/7/8 speed chain will work for you. Similarly, any chainrings that fit your crank spider, and are designed for 6/7/8 speed systems will work.

SRAM and Shimano use the same free-hub body 'HyperGlide' standard (introduced by Shimano) so their cassettes are interchangeable. Other manufacturers such as SunRace use this standard too. Just check that cassettes are specified as Shimano / SRAM compatible.

A couple of notes.

A cassette is technically a stack of sprockets that fits on a free-hub style wheel hub, where the freewheel mechanism is built into the hub. There is a older standard known as a free-wheel where the freewheel mechanism and sprockets come as one piece. If you have an older or inexpensive bike you should check which you have.
If you replace the cassette you must replace the chain, as a worn chain will very quickly wear out cassette sprockets. Chainrings wear slowest. It's worth inspecting all three as one or two may not need replacing.
If you are thinking of larger chainrings or a cassette with a larger largest sprocket, you need to check if your rear derailleur can handle the increased difference between smallest and largest sprockets.


Can heavy tires handle anything that the trail can offer?

I certainly feel your pain about having to repair tires all the time. I've been stuck 10 miles from the trail head with a cut in a tire that caused me to constantly stop and add air as I limped back (second tube of the day).

Bigger, beefier tires will help, but if your plan is to make it up the hill with your friends and not be totally gassed then I wouldn't recommend full DH tires. I switched out my rear on my AM rig from a 2.35 to a 2.5 and boy does it chug when laying down the power. On the other hand, I can point it downhill and not even worry about it, and the grip is fantastic.

For good, all-around trail tires check out something in the 2.35-2.4 range that's made for All-Mountain/Enduro as these usually have thicker sidewalls and harder rubbers.

As for going tubeless, that will certainly help. The sealant will handle most of the punctures that you're likely to get, but I have heard of folks getting numerous punctures that have slowly bled the air from a tire. The problem with tubeless when riding more aggressively and on harder terrain is burping, where the tire briefly comes out of contact with the rim and you lose some air pressure. No amount of sealant can prevent that.

My bottom line recommendation is to go with a split tube/tubeless setup. You can hit everything from fast XC trail to full on DH and be covered in the case of punctures and big hits. Sure it's a little heavier, but you won't be running big huge tires either.


This might work, but probably not as well as using dish soap and water.
Because greases are made up of nonpolar chemicals, they are best dissolved by either nonpolar solvents or detergents. Nonpolar solvents are fluids made up of nonpolar molecules, which stick directly to the grease molecules they dissolve. This category includes things like acetone, petrol, and mineral spirits. These make good degreasers, especially if they're volatile enough that they will evaporate (otherwise you've just replaced one oily substance with another). WD-40 is in this category.
Polar solvents similarly stick to polar molecules or ions, so that's why you can use water to wash something covered in salt (where it dissociates into Na+ and Cl- ions in solution) but trying to do the same with acetone would be much less effective. This category includes water and alcohols.
Detergents (such as dishwashing liquid or laundry soap) contain chemicals with large molecules having a polar end and a nonpolar end: the polar end sticks to (polar) water molecules and the nonpolar end sticks to the grease molecules, allowing both detergent and grease to be washed away by water. This might be your best bet for common household chemicals, google shows quite a few people reporting good results for using it to clean bike chains.
EDIT: After prompting from gschenk I'm reminded that ethanol is actually a decent solvent for nonpolar molecules as well, due to basically having a polar end and a nonpolar end. Still, as a spray it will just slightly dilute grease. You might be able to use it by putting the chain in a container with it and shaking it around a lot, but you would have to do the same with a detergent, and the other additives in the sanitiser aren't going to do you any favours.


Its likely that your bad shifting is due to messed up cables or a misadjusted derailleur.

You can either cut the cable crimp off at the end of the cable with a pair of pliers, or pull it off with a pair of pliers.

As for replacing the cable housing, you can either get your bike shop to cut a piece of housing of the right length by taking your old housing to them, and cleaning up the cut with a file + awl so its flat and the hole is completely open, or you can buy housing kits from companies like Jagwire and cut it yourself (but you will need a bicycle specific cable+housing cutter like Park Tool CN-10 or a dremel to cut the housing properly). There is a nice tutorial on how to replace your housing here. Another good page on prepping housing is here.

As for replacing just the housing vs replacing the housing + the cable, its generally a good idea to just replace the housing + the cable, just because its not all that much more expensive and if your cable has some rust on it or has been damaged, it may lead to poor shifting even with new housing. I always replace the cable and housing together, just to avoid problems.

EDIT: I zoomed in on the picture. The cable is toast. Get a new cable.


Falling over on carbon frame bike -- likely to cause damage?

In practice, there is one thing I've seen enough to call it a pattern: aero/teardrop carbon seatstays and chainstays cracking near the joints after being flexed excessively during a crash. Some of these combine very light construction with a very flat joint in the side to side direction. Some frames like this you could probably break by falling over at low speed enough times. I'm mostly talking about the kind of tubes you'd see on a tri bike.
Most carbon bikes have nothing like the above vulnerability and, falling over at low speeds, realistically would only get damaged in a major single point impact to a tube. You could probably get that to happen if you fell on the wrong thing.


Is the head angle on full suspension bikes given with or without sag?

Generally they are measured unsagged. Usually, as @alex said, it doesn't matter, since they are full suspension bikes, but some setup (e.g setup for super steep races) where you want your rear end softer, it would matter.

Some hardcore hardtails (e.g the blue pig of http://www.ragleybikes.com/) measure the head angle in a sagged situation. Because they are hardtails they only nose dive under the rider's weight.


Not enough space between front mounted child bike seat and rider

I found something called a "mother steering" ("moederstuur" in Dutch). We replaced the steering bar of our bike with this, and viola, ~20cms of extra space between me and the mounting point of the bike seat!

Disclaimer: the steering we bought is heavier than the original steering, it took a couple of days to get used to it

There seem to be a few different such products, serving a similar function, at least available in the Netherlands.


Is it more dangerous to use a bike lane or to ride in the road proper?

In general, bike lanes (and other bike facilities) appear to be safer. Of course this is not always the case, but the general trend is that bike facilities, including lanes, tend to improve safety in the cycling environment.
One study from 1997 by the Transportation Research Board,

Major streets without bike facilities are where the most bike crashes happen, followed by minor streets without facilities, bike paths, and then bike lanes.

Another one by the Environmental Health Journal in 2009,

A review of 23 studies on bicycling injuries found that bike facilities (e.g. off-road paths, on-road marked bike lanes, and on-road bike routes) are where bicyclists are safest.
On-road marked bike lanes were found to have a positive safety effect in five studies, consistently reducing injury rate, collision frequency or crash rates by about 50% compared to unmodified roadways [61,62,65-67]. Three of those studies [61,66,67] found a similar effect for bike routes. One study [63] found that there was an increase in crash rates in the year following installation of marked bike lanes on a major road, especially for a section counter to on-road traffic flow, but this effect was not sustained over the long term.
Although the effect of infrastructure design on cyclist safety was first studied more than three decades ago, the literature on the topic remains remarkably sparse. This review highlights opportunities for more detailed and controlled studies of infrastructure and cycling injuries.

Another from Pub Med in 2011,

...Results. Installation of bicycle lanes did not lead to an increase in crashes, despite the probable increase in the number of bicyclists. The most likely explanations for the lack of increase in crashes are reduced vehicular speeds and fewer conflicts between vehicles and bicyclists after installation of these lanes.

Finally, a memo from the New York Mayor's Office in 2011,

When protected bike lanes are installed, injury crashes for all road users (drivers,
pedestrians, cyclists), typically drop by 40 percent and by more than 50 percent in
some locations

Based on personal experience, I think that bike lanes are safer when well designed and maintained. I normally use available bike lanes in my city; however, with the caveat being that I make every attempt at maintaining awareness of the surroundings. I'll just say that bike lanes are pretty much useless for the oblivious cyclist; otherwise bike lanes are a good idea.
Observations (so my personal opinion):

Bike lanes and paths are more or less dangerous depending on the location. Some cities/countries have good cycling infrastructure and some do not.
Oblivious cyclists are always in danger. So, there's a point to be made that cyclists need to be highly attentive to conditions at all times.

Bikes Belong has links to a plethora of bicycling research and statistics.


I intend to use it as an mtb or gravel bike

I assume you mean "MTB" as "cross-country", and I assume you do not plan to take part in competitions, except in those meant for absolute beginners.

The most important thing you could have done is to change tires to the widest the frame/fork would fit. However, this bike already comes with tires 35 mm wide, and I am afraid those are as big as one can squeeze there. You might want to change them  to ones with more "off-road" tread, but that would mean sacrificing the width, and I am not sure it is a reasonable trade off.

The next thing would be lowering the gear range available to you. Front of your bike has a triple with 28/38/48 teeth, and the rear cassette is 14-34 teeth. You are unlikely to ever use the front 48 teeth chainring offroad, while having a smaller smallest chainring is desirable; something like 22/34 at the front is what I typically use. Similarly, he rear cassette should have as big teeth count as possible, e.g. 11-36 or even 11-42 are likely to be achievable on the rear wheel hub you have now.

Changing gears as I described means you would have to change everything around them: rear and front cogs, rear and front derailleurs, rear and front shifters, the chain and possibly the cranks. Of course, you might be able to just find a bigger cassette or tighter front chainrings compatible with your existing system, but that is unlikely given that your drivetrain uses 7-speeds at the back.

The amount of changes I listed (+ installation costs) would cost you as much as a new bike. Your current bike is really just tuned for the city transportation task.

So if you are serious about offroad riding, just go and sell the current bike and buy another one more suited for the task. Otherwise, just try riding your current bicycle where you want it; I'd say nothing prevents it to conquer regular gravel roads and easiest singletrack. Lower the tire pressure to have a bit of more cushion, swap in decent pedals to avoid feet slipping, take it slow, know your limits, and have fun!


Shimano Tiagra Rear Derailleur - Barrel Adjuster Won't Screw In

just in case someone else stumbles upon this while trying to solve a busted thread for the barrel adjuster, I managed to solve this yesterday by rethreading the aluminium derailleur housing gradually by going with smaller size thread screws first, then finishin with m5, that's the size of the barrel adjuster screw thread, which was in my case still intact. The problem was that a bike mech was lazy and didn't want to adjust the cable tension manually, so he/she unscrewed the barrel adjuster so far out of the derailleur, that it only held itself in place by 2/3 bends, in which case the leverage on those bends in case of an impact on the barrel adjuster is so great, that the soft aluminium thread inside the housing has no chance of withstanding that.


Changing wheel size - what should I know?

• Swapping the wheels usually needs a little derailleur and brake adjustment, no matter what. You still might need to adjust the high and low limit. And, reposition the caliper, if  hydraulic. If mechanical, most have the pad adj knob, and barrel adjuster.

• Since you're coming from a hybrid wheel, going wider is an issue with the seatstays. But, if you are riding in thicker mud, a narrower rear tire is better. In fact, they way it'll have to work is ideal, with a wider front, skinnier rear. The width measurement does NOT include the knobs. They could rub, if wide enough. But, usually a deep chevron style tread is better for rear mud tires.

• The 650B is coming back into mainstream, after a long-abandoned experiment. So, you'll have more choices of wheel and tire. It will be $$ because of the exclusivity.

• Many wheel sets will have 100/135 spacing. Make sure you get non-thru axle hubs, just the 100x9 and 135x10 QR axles.

• Make sure you get the correct rotor mounting system. Mostly, there is center-lock, which uses a cassette lockring, and then the 6-bolt design.

• The rotors will be in roughly the same position between both wheelsets. I do not recommend extensive lateral dishing of the rotor. It's good practice to be handy at repositioning the calipers. Even taking off and reinstalling the same wheelset can still rub, no matter how perfect the brakes were before.

• Don't worry about similar levels of cassette wear. Replace the chain more often, and use the gears a lot. Nine speed chains came down in price recently. If the chain is worn now, most definitely. But, this discrepancy will happen with prolonged use of one wheelset. If you use both wheels a lot, it won't happen as quick.

• Narrow mudgards obviously won't work as well with fat tires! There could be some splatter.


Should I multiply maximum tyre load by number of wheels to get maximum bike load?

It is unlikely that the “weight” listed is the capacity of the tire to support weight, but more likely the maximum internal air pressure in PSI (pounds per square inch).

If it is weight capacity, then yes, each tire will support 75lbs, so a balanced load over 3 tires would support 225lbs. That assumes equal weight on each tire, though, which is difficult to achieve.

Edit:

Since the weight listed on the side of the tire is actually 175lbs, that is much more realistic as a max weight capacity per tire. That would make the total supportable weight for a balanced load 525 lbs.


Washed my bike with water and muc-off only, now my brakes are weak

No, they probably will NOT get better without help.

The cleaner that you used is probably the problem. Maybe WD-40 overspray too; that stuff gets everywhere and it only takes a bit to ruin your brake pads. BTW WD-40 is usually NOT the best choice for ANYWHERE on a bike.

Disc brakes are great in a lot of ways but they have a couple vulnerabilities. One of these is that the pads can be contaminated and then the brakes don't stop well. Although you can soak disc brakes in mud repeatedly and they'll be fine, a drop of a solvent, cleaner, or lubricant can ruin the pads permanently.

No matter if they're "mechanical" cable-actuated, hydraulic with mineral oil or DOT; bottom line, the brake pad material is super sensitive to fouling. I got brake fluid on my (metallic material) pads years ago and brought them back to life by removing them and soaking in various solvents including alcohol and acetone and scrubbing with a toothbrush. Another time I got an unknown contaminant on organic pads, tried the same technique and... all I got was a bunch of contaminated solvents and another trashed toothbrush. I even tried sanding the pads and they still didn't work.

So, you can try the remove-soak-scrub-sand technique, or go buy yourself some new brake pads.

Just make sure the braking surface on the rotor is CLEAN before you put in the new pads.


As for the vehicle most buyers need only consider the size of hitch they have, 1 1/4" or 2" are the typical sizes and try to get a hitch of the same size. You can usually get an adapter to fit a rack that is sized differently than the hitch.

Typically the hitch racks sit a bit back off the rear of your car to accommodate rear features of most vehicles. I'd only be worried if they had a spare tire mounted on the rear of the vehicle.


I believe the cracks are just in the paint, not the alloy.

Only the white paint is cracked, not the black, the cracks are evenly spaced and run in all directions rather than the single direction a stress crack would follow.


connecting center pull dia-compe lever cables

dlu. exactly. thanks for the terminology reminders. it seems like the socket is upside down. the slug is stepped down from about a 1/4" to an 1/8" so it has to go in that hole which is shaped to accept it and the cable comes out the opposite side of the socket through the smaller hole. what am i missing?

I think the only thing that you're missing is the knowledge that the part that anchors the cable (with the hole) is free to rotate. One way to get it to go back is to take the end of the brake cable and catch the edge of the socket or slot and then drag the cable out again. Usually this will get the "socket part" to spin back around the way it should be facing and you can drop the cable in for real.


Yes. The front brake provides basically all of the stopping power in a bicycle, and recent tests in Bicycle Quarterly show that, in emergency stops, the distraction of attempting to use the rear brake may even increase stopping distance. Maximum bicycle braking power is achieved just before the bicycle starts to pitch over, as the rear wheel lifts off the ground. Once that occurs, it's trivial to lock the rear wheel with a brake or by using your legs on a fixed gear.

The main disadvantage of having a front brake only in extremely hilly situations is not being able to dissipate some of the thermal load of braking between both rims, so you risk overheating the front.


Hub rebuild - cone dust cap conflict, hub integrated vs pressed on cone?

I went with the original integrated covers on my hubs without the pressed on caps on the cones.  To remove the caps from the cones I just used a sock to sit on the dust cap and give it a good whack with a hammer and it came right off.  If my new cones ever do come with a large enough cover then I would probably go with that.


Can I change chainring size on a dirt jump bike?

It's called a chain ring and, yes, it can be changed to whatever you want it.

http://www.commencal-store.it/shop/895-thickbox_default/mountain-bike-dirt-jump-commencal-absolut-al-2014.jpg

The dirt bike above has cranks which seem to use chainrings of type 104mm bcd 4-bolt. So any 104 bcd chainring will do the job. E.g:

(source: cyclesportsuk.co.uk)

  if it is small then that means you have to pedal a lot more to go faster

That is correct, but usually those bikes have a very small cog at the rear. So you really don't have to pedal like crazy to go fast. Note though that the main purpose of those bikes is not to go fast but to jump.


Can I fit a 26x1.25 tyre to wheel with current tire 26x2.1

I regularly run 50mm and wider tyres on narrow rims which is the opposite of what you want to do, but suggests that your actual rim width might be narrower than you think it is. Viz, you might find that you have 25mm or narrower rims, in which case a 32mm tyre is perfectly reasonable.

I have run tyres narrower than the rim in the past but I don't really recommend that on leaning bikes. In this case, the question is for a trainer where leaning isn't an issue. The problem is that when you have (for example) a 45mm rim with a 25mm tyre extreme leaning can make the rim hit the road, at which point you will lose traction and crash. But this is an extreme problem, you're very unlikely to experience it in normal riding.

The increased pressure shouldn't be an issue unless you have exceptionally lightweight rims, but I'm guessing from the question that this isn't the case. If you do have a high-end carbon fibre mountain bike with ultralight, extra-wide carbon rims they should have the maximum rated tyre pressure printed on them or listed in their specifications. You should respect that. But that's not normally done for aluminium rims because the rim isn't the limiting factor for tyre pressure.

I've blown the sidewall off a rim, and running a narrow rim with wide, high pressure tyres was likely part of the cause for that. The manufacturer replaced the rim without questions, however, suggesting that they agreed that it was a weld fault at the join (where the blowout started). But you're not doing that, you're running a narrow high pressure tyre on a rim that is most likely capable of working with a wide, high pressure tyre. I would not worry about this, especially on a trainer where you're more likely to suffer hearing damage from a blowout than major crash injuries.


A subset of panniers that are designed for shopping bags are often called "grocery panniers," the distinguishing features being an open top and dimensions similar to the base of a paper grocery bag (not that you can get those very much anymore).

They are typically easily removable (just hooks), and in my experience do not bounce around alot, as was suggested in another answer. There is an elastic cord to the lower hooks that keeps them secure.

If you want to leave them on your bike, they do fold compactly against the rack and usually have velcro or snap closures to hold them folded. I usually just remove them when I'm not using them.

Here is an example:


it has never had an oil dunk - but it is just about to get one.
I have found out the cause of the broken hub!
I decided to dismantle the hub and found the cause almost immediately - it is a completely shattered ball bearing cage on the non-drive side of the hub. Cost of a new one - less than a fiver. Great relief.
So relieved in fact I have decided to service the hub myself and have sent for the special Shimano hub grease and "dunking" kit - at a cost of over £80!
It looks pretty straight forward (hopefully not famous last words).


Just wave him past, that's what I do. I don't draft and I'm not interested in someone drafting off me. Nor am I particularly interested in being polite to someone who is interfering with my ride or looking around worrying about them.

Waving someone past is a pretty universal hand signal I would think. I use it with cars, cyclists, and anything else.


How to practice jumping over cars with disc brakes and SPD shoes?

More useful for you would be going along to a basic aikido course, or if that's not available judo, gymnastics, ninjitsu or some other form that teaches you how to roll. Forget the holds and throws and just learn how to roll. When you can confidently run full speed at a waist-high obstacle and dive-roll over it, you'll be in a better position to survive a bicycle-enhanced version of that.

Find a grassy children's playground with a suitable step, bank or ditch, and practice going over the handlebars. As freheit suggested in comments, wear protective equipment. I suggest starting slowly and using an old BMX rather than a bike you care about. The bmx will be easier to get off as well as cheaper.

To be honest this isn't something I would practice. What I get people to do when I'm training them is just turning the bike to one side and fall away from it. At walking speed. The idea is just to convince them that they're not going to die if they fall off, and to give them a few tips on keeping their arms bent. Mostly I use it to sell them on the idea of cycling gloves (and not riding in crappy footwear). Note that I've only done this where helmets are mandatory, but otherwise I'd also be selling people on helmets.


The drivetrain on my bike needs replacement, given the cost, do I just get a new bike?

I think the appropriate question is not what you paid for the bike, but what it will cost you to replace it. Almost any bike can be repaired (although the grandfathers axe problem also occurs).

I think it's worth doing the quotations yourself. Go over the bike properly and work out which parts need to be replaced, what tools (if any) you will need to buy, and what that will all cost. Then look at the cost of a working second hand or new bike. One advantage of the new(er) bike is that it doesn't have to be the same as your existing bike - if you've been wanting a bigger frame or something the new(er) bike can have that. Of course, a second hand bike will probably also need bits fixed up, which is something to add to the cost.

My expectation is that unless your current bike was fairly good to start with that a new bike will work out cheaper. But if you enjoy working on your bike you should count some of the cost as entertainment (I am building a four poster bed and selling it to my partner this way :)


Should spoke tension be measured before or after adding a tube and tire?

Jobst Brandt's definitive text "The Bicycle Wheel" has this to say on spoke tensioning:

With tensioned wires as spokes, the wheel can support loads only to the point where its spokes become loose. At this point the wheel will collapse. Therefore, for greatest strength, spokes must be as tight as the rim permits.  Structurally the
rim supports spoke tension as an arch that is compressed by the inward force of the spokes. The load limit for most rims is far less than what the spokes could deliver if they were tightened to their breaking point. So in a conventional wheel, it is the rim that limits wheel strength, not the spokes. A rim can be subjected to spoke tension near its elastic limit because, during use, almost no net tension increase occurs.
In practice, however, spokes should be slightly looser than the maximum the rim can sustain, because at maximum tension, failure of a single spoke can severely deform the rim.

Given that strategy you should not tension the wheel based on any additional compression from the tire and tube, since getting a flat could result in rim deformation or damage.

"The Bicycle Wheel" provides the equation for the decrease in spoke tension under tire constriction, if you're curious.  His measurements on a 36-spoke wheel with spokes at roughly 100kgf and a 25mm tire with 45-degree cord at 115psi give a reduction of total wheel compression from about 5700N to about 5300N.

In practice you should verify that your spokes decreased in tension evenly; if they didn't you should ensure that you properly stress relieve the spokes and retension them.


Can an individual gear/cog on the rear cassette be replaced?

According to the late great Sheldon Brown, yes you can change an individual sprocket in a cassette, at least for Shimano.  Some cassettes have small bolts or rivets holding the gears together, but this is for convenience.

Most Shimano cassettes made in the '90s or later have a feature called Hyperglide (probably a registered trademark) that enables smoother shifts, by allowing the chain to engage two adjacent sprockets simultaneously.  Hyperglide works by giving each individual tooth a more complicated shape to facilitate shifts to and from each sprocket.  In order for Hyperglide to work, the adjacent gears have to be carefully matched to each other.  So if you change a sprocket for another sprocket with a different number of teeth, then shifts to and from that sprocket won't be as smooth.  But as Sheldon pointed out, that's what everyone was used to for decades before the invention of Hyperglide, so that needn't bother you.

I haven't been able to find anything on Sheldon's site about changing sprockets for Campagnolo or SRAM, but I would assume that those brands shape their sprocket teeth similar to the way Shimano do, and so similar concerns must apply for those brands also.

Personally, if a few of the sprockets in my cassette were worn, I would just change the whole cassette (and the chain also of course).  You're unlikely to save any money or hassle by just changing one or two sprockets, because the vast majority of bike riders change the whole cassette.  Most people who want to change just one or two sprockets want a particular combination of gear ratios for specific reasons.


Presumably that's 52 cm. Generally, a crack in an Al frame (or most frames), especially in an area which gets a lot of stress makes it scrap (esp. if its supposed to be used off road).

Given this, I'd scrap this frame.


Barrel Adjuster Strategy - What's the best way to use barrel adjusters?

I think you've described best practice for a couple of reasons. Firstly, cables will not tighten themselves, only slacken, so you provide the greatest adjustment to the bike owner; they have the full thread of the adjuster to use. Secondly, the only adjustment the owner can make in the first instance is to tighten the cable. The uninitiated rider can't slacken their own cable by mistake. Thirdly, if somebody else sees your work, if they notice this detail they will see it as best practice too and see that you took the care to get this right.
Reasons to do otherwise, that I can think of are if it's your own bike and you want to make adjustments in either direction because you know what you're doing,  or if you are instructing someone remotely, such as online, you can tell them to set it halfway to begin with, which is a little more forgiving of their skills in setting the tension correctly.
That's it really, your options are to wind it all the way in and then set up the cables, or to set it not all the way in to make use of the adjustment.
Sometimes when setting up a particularly cheap component, there is so much flex in the brake for example that fine tuning without using the adjuster is a bit of a pain. But those should be rare examples.
It is fairly basic procedure to set up a v-brake or cantilever caliper such that it has good braking lever travel and you can also release the noodle or straddle wire to open the brake up and remove/insert an inflated tyre.  However, if one finds this difficult to achieve, then setting the barrel adjuster halfway allows one to slacken the cable to remove the wheel. Sometimes noodles are difficult to un/hook if the cable is on the tight side.


Does it look like this?

That's a top of the line model for the time, weighing in at 9 kilos, for a steel bike.

Here's the year's specs for 1988

And here's a story with more info


Not able to shift to largest Chain Ring - Lever not clicking, when cable is connected to FD

Before tightening(attaching) the cable at the derailleur end, make sure the you have released the shifter all the way.

Sounds like you may have had the shifter in 2nd position when you attached the cable, therefor you don't have enough cable 'left'. So without more details we can't tell whether you are shifting up or down.

In addition, when installing the cable be sure that the cable-tension 'screw' at the shifter end is turned in (almost all the way).

An easy way to check your cable function (before attaching it to the derailleur) is to pinch it with you fingers, at the derailleur end, instead of tightening the cable nut. Now when you shift gear you will feel the cable pull your fingers in. If there isn't a smooth action, you know you have cable(or cable routing) issues. If the motion is OK, shift down all the way and you will feel the cable extend at your hand, then you tighten the nut.


Does any rental car company offer bike racks?

If you could rent a van or SUV you may be able to load the bikes inside the vehicle.


how to calculate square tapered BB spindle length when coming from external threaded bearings

The spindle length is defined from the crankset, not the frame. There is no relationship between your Tiagra (external) and the future FSA (tapered). You should find with the FSA crankset the data of the required spindle length.


If I were to describe this bike to someone, I'd say this is a city commuter bike with a semi-step through frame and windswept (or cruiser style) handlebars.

It looks like the Linus Roadster is very similar looking to this, or the Linus Mixte. Also the Public M7 or C7 is like this but more upright/chill.

You can probably mention these details to a local bike shop and they can help you with something similar. Note that the handlebars and seat are at about the same level, so something to look for to get a similar feel as your old bicycle.


Can I fix or replace the quick release lever on my thru axle?

Anyone have an idea as to whether this is fixable?

It's not worth it.

Quick release skewers are cheap.  The medical costs you might incur if your "fixed" one were to fail while you're riding won't be - even if you have full medical coverage and no amount of medical care will cost you money, the non-monetary costs of any potential injury from a front wheel falling off while riding are potentially huge.

Buy a new one.


We've spent our entire evolutionary history under the sun, but also aging quickly and dying at young ages. The evolutionary history argument just isn't very compelling.

The current consensus is that sunscreen helps prevent skin cancer, and skin cancer is indeed common. On the other hand, I have seen references to theories suggesting that sunscreen might increase a certain type of cancer or decrease vitamin D production, but these do not seem to be widely accepted. An in-depth discussion of this is probably more appropriate for Skeptics.SE than Bicycles.SE.

In the meantime, just use sunscreen.

EDIT: As heltonbiker pointed out, burning and cancer susceptibility depend on your skin, and most people develop some protection from tanning. I personally wear sunblock during mid-day rides (between about 11:00 and 3:00), when the sun is directly overhead, but I'll leave it off for evening and early morning rides.

If you're burning instead of tanning (even if you don't mind the burns), you're probably getting too much exposure and should use sunscreen more often.


The best suggestion I can make is to read "The Art of Wheelbuilding, by Gerd Schraner".

As for materials:

Use aluminum, double walled rims. They are stronger, lighter, and believe it or not easier for a new wheel builder to get true and round than steel rims will be.
In addition, steel rims for a road bike will be difficult to come by in new condition.

Spokes:

There are major differences in the strength and pliability in steel spokes. Even if you ignore spokes from other materials, which you should, look at double butted (usually 2/1.8/2mm) steel spokes from DT Swiss, or if you want really high quality, use the ones from Sapim. Read the Art of Wheelbuilding for more detail on why.

Use a high quality hub, something with a forged hub shell, and good quality bearings. Shimano Ultegra or Dura Ace, if you want good, loose ball bearings. Hope, Phil Wood, or any number of others for good quality sealed bearings.

Use brass spokes nipples.

You will need the following tools:

A good quality truing stand
A set of good spoke wrenches
A nipple driver (broken link, see Park nipple driver instead)
A quality tensiometer
Spoke Freeze or similar (broken link, see Pro line Accessories or at wheelbuilder.com).
Method of determining spoke length
The components listed above
Time and practice.

I hope that helps.


What are the shimano rear derailleur families?

Cross country component

XTR [M980] (10 speed) – Top of the range for cross-country mountain
bikes
Deore XT [M780] (10 speed)
SLX [M660] (9 and 10 speed), replaced Deore LX
Deore [M590] (9 speed) Entry level cross-country mountain bikes
Non-series (brakeparts, cranks and pedals)

Trekking component

Deore XT
Deore LX
Deore

Downhill/Freeride component

Saint [M820] (10 speed) – Top of the range for downhill and freeride
bikes
Zee [M640] (10 speed)
Hone [M600] (9 speed) – discontinued in 2008

Recreational mountain bikes component

Alivio [M410 and M430] (8 and 9 speed)
Acera [M360] (8 and 9 speed)
Altus [M310] (8 speed)
Tourney (6, 7, 8 speed) – Includes several different levels of
quality, and can be found on department-store bicycles

The above list was pilfered from Wikipedia.

You're probably best to go with Acera again, to ensure it's compatible. I've had one fitted to my hybrid in the last year, so they're still available.


Presta valve in a Schrader rim hole: How to use / do I need a rim hole reducer?

With the Mavic adapters, the lip is supposed to go on the outside. They're not intended for use with single wall rims, hence the problem you're having.

On a single wall rim like yours with the relatively deep, narrow channel in the rim well between the reinforcing sections, none of the reducer grommets available are going to work very well. The other option are the aluminum ones, which are usually superior, but they install on the inside and here they wouldn't work.

Those Presta nuts that sink into a Schrader hole are bad news. They do nothing to prevent the core problem of Presta tubes in Schrader holes, which is stress around the valve from not being supported by the rim eventually causing the tube to rupture. Maybe on a single wall rim this is less of an issue, but I still don't like it.

Just use Schrader tubes. 700x23-25 / 27x1 SV tubes are perfectly common.


Specific to your bike?  Nope, no idea.

But you can test if its a full housing by push/pulling the housing where it enters the bike and see/feel if it moves at the exit point.  This is often visually like a wire disappearing into a wall.  By threadding the NEW inner into the OLD outer in place, you can then pull the OLD outer out the back and feed a NEW outer up using the NEW inner as a guide.  Its easier to do than describe.

If that doesn't help, release the inner wire down at the mech to give you some slack.  Then gently pull the outer away from the frame entrance or exit.  You will probably see the inner cable disappear into the frame.

Try and pop any cap or cover loose.  If this works easily, then your bike has no guide pipe inside the frame, because you can tape the NEW inner to the OLD inner and guide it through.  You'll want to pre-fit the new outers at the front of the bike first, and probably end up having to cut the head off the OLD cable.

The hard thing now is risking whether there's a guide pipe inside the frame.

You might get an idea by feeding the OLD inner into the frame at both ends and listening for a "tink" of the steel wire hitting the frame on the inside.  Won't help on carbon bikes.  If you DO hear a metal tink then its probably not piped inside.   If you DON'T hear a tink, means nothing.

Basically now you have to pull the inner and then push a new one in and hope that it doesn't drop into the frame.

Specific to your bike, I see this image:

Zoom in and there's a loop of black inner cable that drops out just in front of the bottom bracket and loops underneath.  Look to be a medium sized square/rectangular plate that may undo.

Please have a close look there and see if the plate comes off easily.  Do take some clear photos and post them in your own answer, showing how you found it.


How dirty should the chain and the cogs be before I should consider cleaning them?

Ultimately its going to be down to how zealous you want to be.

When you think of cleaning a chain, you need to think of two things. First, there is the cleaning - getting off the dirt and lube that has caked itself onto the chain. Then, there is lubing the chain to make it run nicely, (As part of a lube you'd maybe give the chain a rub with a dry cloth to try and get surface crap off, but wouldn't be soaking it in degreaser).

When maintaining a chain, you wouldn't necessarily do both of these at the same time. You would lube the chain quite regularly, but most likely would clean the chain less frequently. You'd never clean the chain without also lubing it.

For frequency of lubing, the answer is "it depends". We all have different preferences. If its a bike that doesn't get ridden often, you'd maybe lube the chain before every ride. A commuter, ridden daily, you'd maybe lube every week or two.

Also, you need to recognise that there are (many) different types of lube, for different conditions. The viscosity varies a lot between them. So if you're putting a lightweight dry lube on your chain (which you might do in the summer), its going to be far less likely to muck up your chain than a gloopy wet weather lube.

So the answer to "when do I clean it?" is also "it depends".

Ideally you don't want any dirt on your chain. That would improve both smoothness and chain life. So the anal extreme is to clean and lube it after every ride.

But most probably you'd go through the "lube" process several times before you considered degreasing. And, as I say, the lube you use will determine likely you are to pick up crap off the road. A wet weather lube, for example, might be good at repelling water, but it's corresponding stickiness will also attract dirt.

If I were to stick my finger in the air I'd say that personally I give my chains a thorough degrease probably around 3 times a year (on the bikes that I ride regularly). But knowing when to do this, I judge this by looking how much crap is on it as I'm lubing it - it's certainly balanced toward winter/wet riding, but it's a judgement call.

Give the cogs a decent clean at the same time as you clean the chain, otherwise you're just going to transfer muck from on to the other.


Can an IGH have the same maximum overdrive-ratio as a crank-sproket setup?

If we use the Sheldon Brown Gear Calculator set to metres development (although any other unit will work adequately), we see that the range for a 39-53 x 34-11 system is 2.5 to 10.4 metres developed per crank revolution, yielding an overall range of 416%.

The widest range options from various companies are the Shimano Alfine 11 hub, which has a range of 409% - essentially the same - and the Rolhoff Speedhub 500/14, which has a quoted 526% range.

Compare to a Sturmey-Archer AW three-speed hub, with an overall ratio of 178% based on its stated ratios of 1.33, 1.00 and 0.75.


How much does a front wheel last with disc brakes vs calipers?

It will heavily depend on the conditions, but it's not something you really have to worry about.

At a rough estimate I have 25,000 km on my hybrid, with v brakes (there shouldn't be a huge amount of difference between rim brake types). I ride in all weathers, and much of the distance is commuting with some longer road rides and dirt tracks. There's plenty of wear left in the front rim, going by the groove that's there to indicate that, and most of my braking is at the front. This is an aluminium rim, and one built more for strength the lightness.


Lets get the social aspects out the way - you can lead a horse  to water and all that stuff.....: Hows your relationship - will he listen to you and is he prepared to take clearly well intended advice. Also does he believe he has a problem and does he want to fix it. If any of these answers is no there little you can do except ruin you friendship. Till hes ready, wait at the bottom of the hill for him, cut him plenty of slack and make sure you both enjoy the riding - if appropriate laugh with him, but never at him.

After a night in hospital and metalwork keeping my wrist together, it took years for me to be able to ride a track with large drop off to the side - especially the right - comfortably, yet and off over the handlebars never phased me. After a big off you subconscious needs to be convinced you will not be hurt if it happens again, or it will not happen again, the only way it learns is through repetition without the consequences. You mate has learned hitting the front brake throws you over the bars, so his subconscious will not let him do it.

Presuming hes ready to learn, the and hes is willing to learn from you - Look online for some videos - watch for the rubbish that is out there but you seem to know what you are looking for so should be all right there.

Chose something he can currently ride comfortably, that you ride faster, with more control and/or more comfortable. Ideal would be a could of tight switchbacks that can only be ridden fast using the front brake to slow into them, yet back only braking merely means you have to go in slower. Safe run out if you don't make it is essential, bonus if its a lake or river that gets you wet or in front of a big crowd of onlookers who will give a good cheer at the screw ups.....The idea is to get something that is safe (physically safe as well mental and ego-safe). He needs to ride something that is not doing in his head, that his subconscious is going "bring it one, this is easy" while his conscious is think how to do it faster/better.

If possible video you and him riding it on the first run and keep it for later. Point out where you are braking differently and ride it for a half day. Each time, both of you try to go faster/more controller/better. If you get bored or it gets too easy, find another spot just a little bit harder.  The aim is ride technically easy ground perfectly before progressing to harder sections.

At the end of the session, review the video of the first and last run over a beer....

Work out if you are going to mix this in  with some rides, at the end of a ride is good, but make it really easy as your both tired. A special trip is well worth it.


Unfortunately you have no good solutions here.

There is no reason why the shifting should not work with a missing sprocket, you just have to get the indexing correct. The jump from 19 to 23 may be poor though. You may be able to prevent the shifter from shifting off the truncated cassette by winding the low limit in. This is obviously a kludge and you are missing a gear ratio.

You can't use a 10 speed cassette because the spacing of the sprockets is different on 10 and 11 speed cassettes. Also 10 and 11 speed chains have different external widths. See http://blog.artscyclery.com/science-behind-the-magic/science-behind-the-magic-drivetrain-compatibility/

Shimano retained the 10 speed freehub body width for 11 speed MTB groupsets. The reason this works is that the large inner sprockets can overhang the spoke flange slightly. Some Shimano 11 speed road cassettes can also do this, but they are all wide range models with 36 tooth or more (I think) large sprockets.

If you have a 5800 SS (short cage) derailleur the max large sprocket is 28, is you have a GS (medium cage) the max large sprocket is 32. See https://productinfo.shimano.com/download/?path=pdfs/archive/2017-2018_Specifications_v028_en.pdf, search for 'RD-5800'.

Really the only proper solution is to get a a wheel with an 11 speed hub.