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Old 02-18-12, 06:40 PM   #1
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centerpull brake booster dimensions

Can someone give me the thickness of the brake boosters that are sometimes installed on centerpull brakes? I have access to stainless and aluminum plate and can fab one up.

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Old 02-18-12, 10:04 PM   #2
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There's no easy answer. The rigidity of a booster diminishes as the arch gets taller. So there's a degree of proportionality between the arch height and thickness.

I've seen some made from 1/8" thick aluminum plate, and others forged (or maybe cast) in aluminum about 1/2" wide by almost 1/4". thick. The beefier ones are more typical on suspension forks where they may also serve to support the fulcrum where the housing ends.

In any case anything is better than nothing, and the booster requirements depend somewhat on the rigidity without the booster. I'd start with 1/8" aluminum plate, and use as much width as the clearance requirements allow.
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Old 02-18-12, 11:04 PM   #3
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Thanks. It is for a set of Weinmann / Schwinn approved centerpulls from a '71 Super Sport. I also need to get a set of the salmon pads to go along with it.

I think if I use some 1 1/2 x 1 1/2 x 1/8 angle or 2 x 2 x 1/4 (I might have some 2 x 2 x 1/8 laying around as well to try), then trim most of the leg off the one side, then I sould be able to cut out the arc and drill the holes. By leaving part of the leg, it should give it a bit of support, while not sticking to far out.


BTW, I saw that Mr. Brown only used it on the front. Any reason not to do it to the back?
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Old 02-19-12, 02:51 AM   #4
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Stainless steel , probably thinner piece of material, than an aluminum sheet..

You can buy carbon fiber composites in sheet form now too, so enjoy your experiment.

Whereas all weight shifts forward in braking this makes weight on rear wheel
near zero at points in time.

Last edited by fietsbob; 02-19-12 at 02:54 AM.
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Old 02-19-12, 08:28 AM   #5
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I tried this a few years back to see if there was any improvement.

I noticed none, but YMMV.

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Old 02-19-12, 10:55 AM   #6
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In line with top506's experience I am not sure you are going to see a lot of improvement. A booster will help prevent the brake posts from flexing out to the side, as is the case with V-brakes, but much of the force on centerpulls is up not out and the booster you envision would do nothing to prevent that movement.

I think the biggest improvement would be due to the pad replacement; I'd try that first, especially if the pads are as old as the brakes.

It would be interesting to hear the results of your experiment, though.
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