Rear brake problems

milanochase

hi all, just needing some advice on rear brake.

Wheels I'm using are mavic cosmics with the exlilath rim, reason for mentioning the wheels is because I've not had them for long and only started getting the problem when i got these wheels.

Basically my front brake is nice and sharp my rear brake even with it on full i can still cycle along my guess is either cable or the exilath brake pad, not sure which though any suggestions anyone?

northcliff66

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19768723#p19768723]milanochase[/url] wrote:

hi all, just needing some advice on rear brake.

Wheels I'm using are mavic cosmics with the exlilath rim, reason for mentioning the wheels is because I've not had them for long and only started getting the problem when i got these wheels.

Basically my front brake is nice and sharp my rear brake even with it on full i can still cycle along my guess is either cable or the exilath brake pad, not sure which though any suggestions anyone?

Try swapping the front pads with the back pads. That will help to tie down the issue.

Also, although you might not ride that way, use the adjusters to get the pads as close as possible to the rim before applying pressure. If you then apply pressure and its not the pads it has to be the cable or shifter.

AK_jnr

Cable/outers.

ic.

Do both brake pads touch the rim and squeeze it effectively? Or are the pads too far from the rim so that when you pull the lever, they do not move far enough to properly apply friction to the brake track?

sungod

are you using the exalith pads?

are they centred on the rims?

have you adjusted the calipers correctly? a couple of mm clearance at the rear is typical, too close and you'll get rubbing as the wheel flexes, also the calipers are designed for some clearance, too little and the leverage is wrong

milanochase

My pads are really close to the rim they are centred to the wheel aswell and they are exalith pads, the normal function all seems to be ok might just end up buying new cables as i haven't changed them for about 2 and a half years and ill just get the pads aswell since they're only £14. thanks for the replies

ic.

Not sure I understand how cables will help? Either the pad is pulled close to the rim correctly or it isn't.

New cables will only help smooth out the pull of the lever.

Are you saying you pull the lever as hard as you can, that the lever doesn't travel all the way to the handlebar, the brake pads close on the rim correctly - yet you can keep pedalling?

Cables are not your concern then. I'd be looking at brake pad alignment, coating on the pad or rim. Have you sprayed lube or other on either?

sungod

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19769247#p19769247]milanochase[/url] wrote:

My pads are really close to the rim they are centred to the wheel aswell and they are exalith pads, the normal function all seems to be ok might just end up buying new cables as i haven't changed them for about 2 and a half years and ill just get the pads aswell since they're only £14. thanks for the replies

pads sound like they're too close, if they are too far in you lose mechanical advantage and braking force is reduced

tbh i wouldn't worry about rear braking, it's only there to add a bit extra to the primary braking on the front

veryslowtwitch

It may be worth checking all the cable stops in case they need a ferrule, including the levers. Otherwise the outer can be pulled through the stop giving very weird spongy braking as the outer is stripped off.

crankycrank

Still not really clear what the problem is. Is it something in the cable/routing or the pads or?? OP help us out a bit here. Do you get a spongy feel or is it firm but just not stopping the wheel. As you said it just started with the new wheels I'm guessing it's not a mechanical problem (cables, routing, setup, etc.). Before buying new parts try cleaning off the pad surfaces and brake tracks with some strong detergent and finish off with some isopropyl alcohol. They may have just been contaminated with lube or ?? and if this doesn't work use some sandpaper on the pad surface. If you still don't have good braking then start looking at the mechanical part.