Re: [CR]Rearward opening rear dropouts REDUX

(Example: Production Builders:Tonard)

Date: Tue, 9 Jan 2007 16:48:42 -0800 (PST)
From: "tarik saleh" <tsaleh@rocketmail.com>
Subject: Re: [CR]Rearward opening rear dropouts REDUX
To: Classicrendezvous@bikelist.org


Neil wrote: """ In October last year, there was some speculation as to the reason why bikes, especially track bikes, were built with rearward opening rear dropouts, and I believe that this issue wasn't resolved.

I've just bought a 1939 Claud Butler catalogue, which states that the purpose of these dropouts is to allow a change of gear ratios (i.e., by changing the rear fixed sprocket) without having to alter the chain length each time for a larger or smaller sprocket. The wheel would simply be located forward or rearward in the dropout to adjust the chain tension according to sprocket size. """"

Neal,

The butler quote is quite simply the advantage of rear facing dropouts, if you don't care about rear brakes and you want the Biggest number of gear ratios with a single chain length, you have to have the dropout in line with the center of the bb. Long out the back dropouts are the best way to acheive this.

A campy 1010 dropout is very useful, but it would be more useful for track use if it was inline with the bb. Most front facing horizontal dropouts are both shorter than 1010's and they are angled. This gives you far less useful gear ratios with a single chain lenght than a long out the back dropout. Short horizontals placed parallel to the brake are the most useless bike spec ever.

I am not sure I agree with Steven Maasland, out the back horizontals do allow you to get the wheel closer to the seatube than forward facing dropouts, yes you can't use all of the dropout, but you don't have to deflate the tire to get it out either as you do with almost all tight forward facing dropouts.

I don't really care that much, and I raced track (low key) for a couple three years and probably only changed my gear ratio at the track once, but i think front facing dropouts are not really that big an advantage for single speed use as Sheldon and others make it. Certainly for my single speed mountainbike and cross bike I would rather maximize gear ratios, because I change gear ratio radically race to race. I would much rather monkey around with my brakes than change my chain.

Later

Tarik

Tarik Saleh PO Box 208, Los Alamos, NM 87544 tsaleh at rocketmail dot com Bicycles, bicycles, bicycles: http://tariksaleh.com All sorts of bikes blog: http://tsaleh.blogspot.com

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