Re: [CR] Mafac Brake Boosters

(Example: Humor)

Date: Mon, 7 Dec 2009 10:44:08 -0800
From: Jerome & Elizabeth Moos <jerrymoos@sbcglobal.net>
To: <classicrendezvous@bikelist.org>, Mark Petry <mark@petry.org>
In-Reply-To: <092e01ca7767$5326d0b0$f9747210$@org>
Subject: Re: [CR] Mafac Brake Boosters


Having completely missed the MTB (and BMX) thing, I'm not sure I've ever completely understood brake boosters. What exactly do they theoretically do? Since they don't change the attachment points of either the brake shoes or the straddle cable, they therefore do not change the effective length of the caliper arms. So unless I'm missing something, it would seem they have no effect on mechanical advantage. What they would seem to do is stiffen the calipers and reduce flexing of the caliper arms under hard braking. Was caliper flex found to be a big problem on early MTBs? To me, brake "boosters" would imply improving mechanical advantage, so maybe they should be called brake "stiffeners" instead. I can see how a litte stiffening of the arms might eliminate the famous Mafac squealing.

When did Spence Wolfe fist make his brake boosters? If it was about the same time as the Alpine RD cages, he must have predated the MTB ones by at least a decade. So why did no one else find this necessary until the advent of MTBs?

Regards,

Jerry Moos
Big Spring, Texas, USA


--- On Mon, 12/7/09, Mark Petry wrote:


> From: Mark Petry <mark@petry.org>

\r?\n> Subject: [CR] Mafac Brake Boosters

\r?\n> To: classicrendezvous@bikelist.org

\r?\n> Date: Monday, December 7, 2009, 12:01 PM

\r?\n> I believe Robert Broderick has made

\r?\n> some reproductions of the Spence Wolf

\r?\n> brake booster plates.

\r?\n>

\r?\n>

\r?\n>

\r?\n> http://www.wooljersey.com/gallery/broderir/For-Sale/MAFAC-booster-plate/

\r?\n>

\r?\n>

\r?\n>

\r?\n> Not sure of the price,  contact Robert at rsb000@hotmail.com

\r?\n>

\r?\n>

\r?\n>

\r?\n> Mark Petry

\r?\n>

\r?\n> Bainbridge Island, WA