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help adjusting caliper brakes

Original Post
bernard wolfe · · birmingham, al · Joined Jan 2007 · Points: 0

caliper brakes aren't typically found on most modern mnt bikes, nonetheless i'm hoping someone here can give me some tips on adjusting them when it is the case that when the lever is pulled, only really one of the two caliper arms does the moving to engage the rim and the other basically doesn't move or there is not equal movement or travel by each arm independently as they engage to contact the rim.

Typically also accompanying this affliction is that the caliper is not centered with respect of either arms distance of travel to the rim. I believe by loosening the mounting screws and using the adjusting nuts that are involved with the bolt that mounts the caliper to the frame forks, one can reposition the caliper and center it with respect to the rim.....but even after doing this, i still have the case that when the lever is pulled, only really one arm is doing all the moving. How do you get the caliper to behave properly? I looked over some Y Tube videos on caliper maintenance and adjustment.....but none covered this specific issue........all seem to assume that when you pull the brake lever, you'll get equal, even action out of both caliper arms and i have seen many times where this just isn't the case

· · Unknown Hometown · Joined unknown · Points: 0

At the risk of suggesting the obvious: the one caliper that is NOT moving is probably gunked at the pivot point. Try taking it off completely, using a degreaser/cleaning solution, and also check the spings on both sides that spread them apart. They should exert roughly equal force and they could be gunked up too.

calitradclimber · · Unknown Hometown · Joined Aug 2001 · Points: 0

Is it possible that you have the caliper bolt too tight, so the brake can't rotate and self-center? Hard to know without looking at it. I bet it's something that your LBS could take care of very quickly and inexpensively though.

beetgreen Munson · · Unknown Hometown · Joined Nov 2009 · Points: 0

There are a few types of caliper brakes. If there are two pivots, like on a modern road bike, I suggest getting them as close to center as you can with the mounting bolt and then looking for a small centering screw for fine centering adjustments. I'm guessing that you have a single pivot in the center that also serves as the mounting bolt. You can get some limited success by loosening the mounting bolt, centering, and then tightening, but the act of tightening the bolt tends to knock them of center in the direction that you turn the bolt? Like Michael said, the pivot may be too tight, but if it springs back at all, either side, then yer fine. So now what?

It's the spring itself that needs centering. Many single pivot calipers have flats on the spring mount that will accept a thin spanner (cone wrench). if you have a tool that can fit these flats, make your adjustments there. Ok, you don't have one that will fit?

Try using two wrenches, usually 10mm , one on the back and one on the front. Turn both simultaneously in the direction you need to center it. That don't work, or the pivot bolt comes loose?

Time to get old school. Take a hammer (best bike tool ever) and a punch and tap the sping itself, just next to the mounting point, in the direction needed to center. If that don't work, yer fucked.

Guideline #1: Don't be a jerk.

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