Cantilever brake question

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chris3vic
Posts: 296
Joined: 25 Mar 2011, 9:00pm

Cantilever brake question

Post by chris3vic »

I've been tinkering around with my new Dawes Galaxy (a lovely bike by the way) but I'm experiencing some issues with the cantilever brakes, which are a type of brake a bit unfamiliar to me.

Basically there seems to be a lot of play in the brake lever of the front brake, and the cable running down the front of the head tube does not seem as taut as i would expect it to. That being said the pads are very close to the rim and it took a lot of fiddling about to get them spaced evenly so they were not rubbing on the wheel.

Brake action on the front is very loose though. I can pull the brake around 1cm before any cable is pulled at all. Its all a bit wobbly. Conversely the rear brake is very tight and seems like its functioning "normally"

I've checked Sheldons page on this but not found anything that seems to work. Another page suggested I "pull out the slack in the cable" and readjust the brakes. I've no idea what that means.

These are tektro drop bar levers by the way

Any help appreciated.
Brucey
Posts: 46939
Joined: 4 Jan 2012, 6:25pm

Re: Cantilever brake question

Post by Brucey »

it sounds as if the cable is not adjusted correctly.

In addition, if (when the cable is slack) the pads don't move away from the rim when you release the brake, then something is binding somewhere, or the springs in the canti arms are not able to work properly for some reason.

Very often cantis on new bikes bind because there was still some paint on the frame bosses before they were fitted.

If the canti arms are removed for any reason, the spring needs to be engaged in a little hole at the back of the boss; without this the brake won't retract properly.

BTW if the nipple is held in a slotted receptacle in the brake lever, a slack cable can cause it to come unhooked without warning, leaving you with no brakes. A slack or binding cable can be a significant hazard for this reason.

hth

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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cycleruk
Posts: 6244
Joined: 17 Jan 2009, 9:30pm
Location: Lancashire

Re: Cantilever brake question

Post by cycleruk »

Here is Park tutorial for cantilever adjustment/service.
There will be slight variations to your set up but the principle is still the same.
http://www.parktool.com/blog/repair-hel ... ke-service

Somewhere there should be an adjustment for taking up the slack cable.
A man can't have everything.
- Where would he put it all.?.
chris3vic
Posts: 296
Joined: 25 Mar 2011, 9:00pm

Re: Cantilever brake question

Post by chris3vic »

Thanks so much for the replies already

I forgot to mention that I've messed about with the barrel adjuster but there is still too much slack in the cable, though that does seem to tighten the loose brake lever slightly

I'm wondering if its simply a case up pulling a bit more cable through the clamp and readjusting everything.
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cycleruk
Posts: 6244
Joined: 17 Jan 2009, 9:30pm
Location: Lancashire

Re: Cantilever brake question

Post by cycleruk »

chris3vic wrote:Thanks so much for the replies already

I'm wondering if its simply a case up pulling a bit more cable through the clamp and readjusting everything.


Yes probably.
Re-clamp it and try. If not right then you can always put it back to where it was.
A man can't have everything.
- Where would he put it all.?.
chris3vic
Posts: 296
Joined: 25 Mar 2011, 9:00pm

Re: Cantilever brake question

Post by chris3vic »

More or less sorted this. Pulled about 2mm more cable through and messed about with the barrel adjuster until tension felt right, then balanced out the pads. Much better, though still not as much tension as the rear brake. I'm not gonna worry about it now though until I've done some actual miles on it
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