Campagnolo brake set. Why does the rear brake float?
10-30-24, 05:25 PM
#1
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Campagnolo brake set. Why does the rear brake float?
I'm trying to install a set of Campy Record titanium brakes. The front went on just fine, just like old school campy, or any shimano, or tektro, or whatever. But the rear brake will not tighten down--the brake arms rotate on the mounting bolt. No, the cylindrical mounting nut is not bottoming out before it tightens. The free play is in the brake itself, between the spring assembly and the brake arms. Is this intended, or is the brake defective? If it is intended, how do you keep the pads from dragging against the rim?
as always, thanks in advance for your wisdom and experience.
~Alan in Silver Spring MD
as always, thanks in advance for your wisdom and experience.
~Alan in Silver Spring MD
10-30-24, 05:48 PM
#2
You may be describing a single pivot brake, which Campy continued to use on the rear after dual pivots. You tighten the mounting bolt and center the brake with a wrench of the nut shaped part just on the other side of the brake bridge from the mounting nut. Both arms "float" and are centered by their respective springs by turning the center post.
If that isn't your problem, you'll have to explain this differently. All "old school" single pivot brakes are like this.
If that isn't your problem, you'll have to explain this differently. All "old school" single pivot brakes are like this.
10-30-24, 06:35 PM
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In short, it's not supposed to float. You're supposed to center it and tighten it against the frame's brake bridge.
10-30-24, 06:48 PM
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10-30-24, 08:18 PM
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Does the center/mounting bolt tighten with the recessed nut? If a single pivot does the center bolt portion that the spring is contained in stay tight WRT the center bolt, and thus the frame? Please better explain "float"?. Do you mean the caliper arms flop about fore and aft as well as rotationally? Or only rotationally about the center bolt? How much cable slack/lever pull is there before the pads contact the rim? Does one pad stay tight against the rim when the lever is released? Andy (who suspects a single vid or photo series would provide a lot of data)
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AndrewRStewart
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10-31-24, 08:53 AM
#6
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By float, do you mean if you grab the caliper arms, you can rock the arms side to side with a little effort? That is normal on the rear single pivot. But, they shouldn't flop around. And they should stay centered after applying and releasing the brakes.
Last edited by gearbasher; 10-31-24 at 08:56 AM.
10-31-24, 09:27 AM
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It depends on the bike. Older bikes didn't provide for recessed nuts, so they came with longer mounting bolts and standard nuts. New bikes use recessed nuts, so brakes for use with them came with shorter bolts and recessed nuts. So look at your bike. If you have the wrong bolt and nut, you will have to shop around. Replacement bolts are available, and every local bike shop has a draw full of spare recessed Allen nuts.
10-31-24, 09:34 AM
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Tighten the attachment nut against the nut that holds the spring. This nut also centers the caliper. In the old days we had brake spanners, but in a pinch you can use a cone spanner. I forget whether it's 13 or 14 mm. The two nuts at the front of the caliper are to adjust the free play in the arms. You want that snug enough so they don't twist on actuation but loose enough so they compress and retract freely. A little lubricant in there helps.
