Re: [CR]Why normal reach calipers on short reach frames?


Example: Events:Cirque du Cyclisme:2007

From: "Charles T. Young" <youngc@NetReach.Net>
To: <RaleighPro531@aol.com>
Cc: "Classic Rendezvous" <classicrendezvous@bikelist.org>
References: <14.20b673b1.2970d595@aol.com>
Subject: Re: [CR]Why normal reach calipers on short reach frames?
Date: Fri, 11 Jan 2002 19:59:06 -0500


Pete:

As long as the brake pads are the same distance from the pivot point (and the arms have equal amounts of flex), it shouldn't matter. The braking force will be solely a function of the length of a straight line from the pivot to the pad.

Charlie Young
Honeybrook, PA


----- Original Message -----
From:
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Sent: Friday, January 11, 2002 6:56 PM
Subject: Re: [CR]Why normal reach calipers on short reach frames?



> In a message dated 1/11/2002 5:59:44 PM Eastern Standard Time,
> CaptBike@sheldonbrown.com writes:
>
>
> > Short reach calipers generally have a reach range of 39-49. Long
> > reach is usually 47-57. (Talk of "normal" reach is likely to be
> > confusing, and I'd urge everybody to purge this ambiguous term from
> > their vocabulary.)
> >
> > A caliper brake has its greatest mechanical advantage when the pads
> > are high up the arms, close to the pivot. Back when long reach was
> > the "norm" a conscientious frame builder building a high performance
> > bike would locate the bridge and crown to maximize the braking
> > mechanical advantage. Especially, the old Campag single pivots had
> > such poor braking that this was a very nice touch.
> >
> > You may also see this on bikes made to work with both 630 mm (27
> > inch) clinchers and 622 (700c) tubulars. When the larger wheels were
> > installed, the shoes should be near the tops of the slots.
> >
>
> I'm in the middle of assembling an old LeTour using 700C rather than 27"
> wheels.
> I realized I'd have to use the 750 Weinmanns centerpulls instead of the 610's
> which were close but a hair short. I wondered about the braking.
> The question: Is there a difference in braking ability between shorter reach
> brakes with the pads at the bottom of the slots vs long reach with the pads
> mounted at the top if the pads end up mounted the same distance from the
> pivot?
>
> Pete Geurds
> Douglassville, PA