[CR] here we go with another can o' worms (was brake flex)

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From: "Mark Petry" <mark@petry.org>
To: <classicrendezvous@bikelist.org>
Date: Tue, 4 Jan 2011 14:05:36 -0800
Thread-Index: AcusW4PdWQ5CyxmjQY2BlN55vUvkFA==
Subject: [CR] here we go with another can o' worms (was brake flex)


I have read the brake flex discussion from Jobst as cited by Harry - the cosine error has to do with the cross cable angle, similar to what you find when you rig cantilever brakes.

I always felt that sidepulls, campy in particular, were superior in feel, modulation, etc to almost any sidepull, but that difference can be attributed to several variables in design and execution:

The campy brakes were issued with significantly better cables and housings than competitive offerings from Universal, Weinmann, et all. And yes the "modern" stainless steel cable and housing is FAR superior (less compression / induced hysteresis) than even the Campagnolo (Casoraghi) cable that came with the brakes in the "on topic" period.

A second variable that Jobst does not account for is the 3 rd piece in the sidepull, the yoke, which transfers all the braking loads to the frame. It is interesting to try a bike that has centerpulls with brazed on pivots, replacing the yoke - MUCH better, very positive lever feel and stopping authority. But a centerpull has several additional pieces when compared to a sidepull, and they all flex under braking loads.

Pads! Any new pad, the Kool stop being the best of the current crop, will stop better than 30 year old dried out crap. So mix and match pads till you find a set up that suits you, stops well, and does not squeal.

Last, rigging. This includes cable and hardware. Nice short cable runs, using modern housing if your build will tolerate it, and the best inner wires you can find, will really help get the most out of just about any braking setup. I like the Dia-Comp wires which have been run thru a die, they are super smooth. And an often overliooked point - the front brake should have a good solid mount on the fork crown. If the crown is curved, make sure there is a pillow block that is profiled to match, so as to get the best possible transfer of braking forces in this critical area.

Mark Petry

Bainbridge Island, WA 206 618 9642
   <mailto:mark@petry.org> mark@petry.org