Mechanical Guideance - This is why I don't do things myself
Discussion
It is the little lip that wears on the pad catching under the rim edge, usually this doesn't catch, but it will if the wheel is not central. Put the bike on the floor and slacken the Q/R, then re-tighten. This should ensure the wheel is back in properly. Failing that, remove the wheel and trim off the wear lip on the pad.
The fundamental problem is the brakes have not been set up correctly though, a common problem even from new, especially on hybrids as the stays and fork legs are a long way from the rim.
The fundamental problem is the brakes have not been set up correctly though, a common problem even from new, especially on hybrids as the stays and fork legs are a long way from the rim.
Dizeee, the Sheldon Brown bit about centering is the bit that is relevant in this case, I believe. It's not really that complex, despite the fact that I used to fear them as you seem to. In fact, I switched some between bikes only recently. My son's 'college clunker' had ultra cheap black nylon cantilever arms, and they were a bit 'flexy'. So I stripped some metal ones off the wife's (broken) bike and swapped them over. All that resides under the Allen bolt that attaches them to the bike is a little spring. There are (on Boy's bike at least) three small locating holes on the attachment point. Moving the end of the spring into a different hole can tighten the spring a touch if turning the 'spring adjuster' screw doesn't have enough impact. Also, crud can get under the cover, gumming up the spring, but it can be cleaned up and re-greased. I found all of this out during a "nothing to lose" strip down of a completely floppy cantilever arm, which turned out to be caused by the spring slipping out of the locating holes. Just remember to 'balance' the brakes by easing off on the spring adjuster screw on opposite side to the one you are tightening. There's an element of trial and error, but unless it's actually broken you'll get there in the end.
https://www.youtube.com/watch?v=pya1VJ4NQ0c
https://www.youtube.com/watch?v=b4JejHiKFcE
https://www.youtube.com/watch?v=pya1VJ4NQ0c
https://www.youtube.com/watch?v=b4JejHiKFcE
anonymous said:
[redacted]
Have you tried putting the back seats down?Sorry, just reasserting the balance of the universe.
I think that this sounds like a snagging cable as someone has already suggested - make sure that, by pulling the cable to dislodge it from the eye in the cantilever arm, you haven't also accidentally pulled it loose from the barrel adjuster on the brake lever. This used to happen on my old Saracen hybrid fairly regularly.
anonymous said:
[redacted]
Well when I saw this bit:anonymous said:
[redacted]
I thought the next bit would be about asking which £10k carbon framed, full suspension, Pinion gearboxed, Gates carbon drived, fat tyred hybrid you'd need to replace it as clearly a hole in the tyre and tube would make it a write off.Better?
Guarantee that this is down to a combination of wheel not being aligned correctly the last time it was put back in, and corresponding brake pad setup...
If the wheel went in a bit skewiff last time and the QR was tightened, then the brakes adjusted for the skewiff wheel, you'd have a b
h of a job trying to get the wheel to go back in exactly the same next time meaning you wouldn't need to touch the brakes.
So, try this...
When re-fitting the wheel, do so with the bike the correct way up, and lean down over the handlebars applying your body weight downwards on to the front forks/wheel BEFORE and as you tighten the QR (same applies to the rear wheel, leaning on the saddle instead). This will ensure that it is centred and has nowhere else to go, and you will be able to do this every single time you have to re-fit the wheel.
THEN set up your brake pads so that they are contacting the rim appropriately (either flat if you like a positive feel/don't mind a bit of squeal, or with a bit of toe-in if not).
Also, make sure that where the brake pads have worn based on the previous setup, that a lip or similar hasn't worn on to the bottom edge of them, meaning they hook under the rim when applied. If there is, take to it with a bit of sandpaper or a file, or replace the pads if they are too far gone.
Once hooked back up and pad position is adjusted, then you can look at the spring adjustment screws on each brake caliper arm. Wind in to tighten the spring, wind out to loosen.
If you're still having problems, with the brake caliper arms not returning, then it'll either be:
If the wheel went in a bit skewiff last time and the QR was tightened, then the brakes adjusted for the skewiff wheel, you'd have a b
h of a job trying to get the wheel to go back in exactly the same next time meaning you wouldn't need to touch the brakes. So, try this...
When re-fitting the wheel, do so with the bike the correct way up, and lean down over the handlebars applying your body weight downwards on to the front forks/wheel BEFORE and as you tighten the QR (same applies to the rear wheel, leaning on the saddle instead). This will ensure that it is centred and has nowhere else to go, and you will be able to do this every single time you have to re-fit the wheel.
THEN set up your brake pads so that they are contacting the rim appropriately (either flat if you like a positive feel/don't mind a bit of squeal, or with a bit of toe-in if not).
Also, make sure that where the brake pads have worn based on the previous setup, that a lip or similar hasn't worn on to the bottom edge of them, meaning they hook under the rim when applied. If there is, take to it with a bit of sandpaper or a file, or replace the pads if they are too far gone.
Once hooked back up and pad position is adjusted, then you can look at the spring adjustment screws on each brake caliper arm. Wind in to tighten the spring, wind out to loosen.
If you're still having problems, with the brake caliper arms not returning, then it'll either be:
- Gammy brake cable - lube or replace
- Brake caliper arm spring pin not located correctly - remove caliper arm and re-seat spring pin in fork/frame correctly
- Fadged brake caliper spring - replace brake caliper
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