HELP ADJUSTING A CALIPER BRAKE

[Rat Rod]

This is one of those maintenance techniques that I have never mastered and has always frustrated me. :x

It seems that when I try to adjust and set up a caliper brake on a bike I never get them to work correctly. The side that had the brake cable threaded through always seems to stick in towards the rim after the brake lever is released. I've tightened the main mounting bolt that holds the brakes to the bridge and that usually makes the caliper arms stick even worse. That has made me think that you shouldn't over tighten this bolt.

Is there some trick to getting both caliper arms to tighten down when you press the brake lever and then release freely when the lever is released? Is it because it's old technology and I'm too used to how well the newer cantilever brakes work?

The set I happen to be dealing with at the moment are a set of Dia Compes on this old GT.

I have installed a new brake cable and just can't get the brake caliper to work correctly.

 

[cashman]

Steve, try a tool called a third hand if you don't have one. It's a simple tool that holds the shoes at equal pressure against the rim while you tighten the anchor bolt. That might help. Thanks!!!

 

[Boardtrack fan]

Steve, don't over tighten the center bolt and make sure you lube the pivots. Slowly squeeze the lever and see if the pads contact the rim at the same time. If they dont take a screwdriver and place the blade on the spring right next to the center bolt. Tap on the end of the screw driver to twist the whole caliper in the desired direction. This should help you center the caliper and allow the pads to contact the rim at the same time. Sometimes the springs wear out and you need to remove them and bend them to give them back the desired amount of "spring". Make sure everything is lubed from the lever and cable all the way to the pivot that the anchors the cable to the caliper. Hope some of these tricks help you.

 

[rick74304]

Everything those guys said! lol What I do to save $ instead of buying a 3rd hand is use an old rim strip (the rubber tube protector thingy). Put 1 end against a brake pad, pinch the brake pads against the rim, and wrap it a few times. You can then hold it and a wrench in one hand while tightning the cable nut. Another way is a simple c-clamp, or even vice grips.
Hope that help Steve,
Rick

 

[ifitsfreeitsforme]

If I'm reading your problem correctly, you are having a problem with the spring tension not being equal to both sides. An old school way of getting both shoes to release the same distance away from the rim is to put a flat blade screw driver on the coiled up portion of the spring and lightly tap the screwdriver with a hammer, essentially pushing some of the spring back over to the side that is contacting the rim. Hope this helps. It is a difficult thing to describe. or if there are flats on the "axle" of the caliper you can use a caliper centering wrench or a cone wrench to center the pads after the proper tension has been set with the nut.

crude picture:

 

[Unchained]

Here's what I do if it helps...

I take a pair of vise grips and clamp the cable end very tightly after it has been pushed through the break arm lock nut thing with the hole drilled in it. (I'm also not a fan of caliper breaks and don't know the terminology ). I loosen the center frame crossmember to caliper bolt so that the brakes are tight but rotate on the bolt freely. Then I loosen the nut on the threaded bolt clamping the cable to the brake arm, pull diagonally away from the bike with the vise grips on the end of the cable, and re-clamp the cable down with the threaded bolt on the brake arm at the same time. If you pull in just the right direction on the cable, the rim is usually pretty perfectly centered between the caliper arms. Readig this over again, it seems very much like gibberish, I hope you find it remotely useful. :lol: Good luck with your brakes.