Bicycle Mechanics - Brake Release Problems

I have a '99 Giant OCR with Ultegra/105 mix. My rear brake (105) doese not release all the way when I release the lever after braking, and as a result the pads continue to rub the rim. I took it to my LBS, and they tweaked the barrel adjuster and lubed the brake joints (at the pivot, i guess?) and it solved the problem for the remainder of that ride, but it has come back. Any suggestions? Is there something that is overtightened, do I need to replace a spring?

I have a '99 Giant OCR with Ultegra/105 mix. My rear brake (105) doese not release all the way when I release the lever after braking, and as a result the pads continue to rub the rim. I took it to my LBS, and they tweaked the barrel adjuster and lubed the brake joints (at the pivot, i guess?) and it solved the problem for the remainder of that ride, but it has come back. Any suggestions? Is there something that is overtightened, do I need to replace a spring?

I'd try this: There is a little screw on one of the brake arms. It's purpose is to equalize the return spring tension on the two arms. Adjusting this screw so that both arms retract together may solve your problem. You have to exercise the brakes WITH THE LEVER to see how your adjustment is going. Just squeezing the caliper with your hand doesn't seem to work as well.

If it seems like you have to screw the screw in farther than it will go to make it work, try this: Unscrew the screw about half way. Now loosen the bolt that holds the caliper onto your frame and carefully reposition your caliper so that the two arms are about equi-distant from the rim. Now you can fine tune your brake with the spring adjuster screw again.

Hope that does the job for you.

Thanks for the tips. Ill give them a try tonight.

I don't exactly know but does the 105 caliper have this equalizing screw? My feeling is either your brake cable is sticking somewhere or the caliper itself is not 'centered' at the pivot mount. This usually causes one pad to continuously be very close or ride on one side of the rim.

I would make sure that the cables are clean and lubricated. If they are the originals from 99, they are overdue for replacement.

I would make sure that the cables are clean and lubricated. If they are the originals from 99, they are overdue for replacement.

what he said^.... definetly sounds like worn cables/housing. especially on a 5-6 year old bike. although it could be a spring tension problem.

It is possible the brake pivot is adjusted too tightly. Disconnect the brake cable and squeeze the pads to the rim. If the arms are not returning fully, the pivots may be the problem. For dual pivot service see http://www.parktool.com/repair_help/howfix_dualpivot.shtml

Its not likely....but if you are consinuously engaging / disengaging your brakes....it COULD be that your brake return springs are weak now....if turning the adjustment screw wont help....try taking off the arm and repositioning the spring

My b et would be on the cable binding in the housing. I would loosen the cable binder at the brake and check for the free movement of the cable in the housings. You will probably find that the cable/housing at the bar has a lot of striction. If so, go ahead and replace both front and rearcables and housings and put on some new bartape. I would also do shift cables and housings as well.

It could be the cable or housing. But it could also be the calipers themselves. I have Ultegra dual pivots from 1999 on one of my road bikes and was having similar problems with the rear "sticking". So I replaced the cables with teflon coated brake cables. No change. I took apart the calipers and saw crud and grime on the pivot surfaces. After cleaning them up, the brakes now work great. Silky smooth and no sticking.