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

(Example: Framebuilders:Dario Pegoretti)

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


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 -----
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,
> 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