RE: [CR]brake caliper tension.

(Example: Humor:John Pergolizzi)

From: "Bowen, Steve" <Steve.Bowen@umusic.com>
To: 'Grant McLean' <Grant.McLean@SportingLife.ca>, <classicrendezvous@bikelist.org>
Subject: RE: [CR]brake caliper tension.
Date: Thu, 19 Jun 2003 12:01:59 -0700


A few months ago I purchased on e-Bay a pair of NOS Dura-Ace aero brake levers. They don't have springs in them. They're quite elegant, and the metal levers are a little on the small side.

1) Does anyone know when these might have been made, and what type of calipers they were intended for?

2) How well might they work with current Shimano double pivot brake calipers?

-----Original Message----- From: Grant McLean [mailto:Grant.McLean@SportingLife.ca] Sent: Thursday, June 19, 2003 9:25 AM To: Classic Rendezvous Mail List (E-mail) Subject: Re: [CR]brake caliper tension.

Gang:

The only thing I might add to Sheldon's great post is that the current generation of Record brake levers don't have a spring, and the spring tension at the caliper is adjustable.

Grant McLean Toronto.Ca

Sheldon "Springs" Brown Newtonville, Massachusetts wrote:

In the late '80s, there was a major change in brake design, initiated by DiaCompe, then copied by Shimano, and later by all other brake manufacturers. Instead of a very strong spring in the calipers/cantilevers, they installed a very weak spring, so weak that it could not reliably retract the brakes by itself.

To help the weak spring out, they added a new, also weak spring to each brake lever. Thus the cable was both pushed and pulled back to the rest position when you released the brake lever. As a result of this design, they were able to make the total sproinginess of the two combined springs very much lighter than the stiff springs needed for the older one-spring system.

This was also accompanied by various friction reducing features, including lined housing and nylon spring pads, ball-bearing caliper action, plus the improved cable routing of "aero" levers.

This system was called "BRS" (Balanced Response System) by DiaCompe; "SLR" (Shimano Linear Response) by Shimano.

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