[CR]Ephgrave O'Brien 1954 photos; plus double-chainwheel advice?

Example: Component Manufacturers

Date: Tue, 30 Dec 2008 23:18:36 +0000
From: Simon P-J <simonpj@mac.com>
To: Simon P-J <simonpj@mac.com>, Classic Rendezvous <classicrendezvous@bikelist.org>
In-Reply-To: <C58054D1.566AF%simonpj@mac.com>
Subject: [CR]Ephgrave O'Brien 1954 photos; plus double-chainwheel advice?

Sorry - resending, because the subject line got truncated last time...

I would be grateful for any information about the frames that Les Ephgrave built for O'Brien, and also for your advice about an appropriate double-chainwheel to fit to this frame.

A couple of years ago I acquired this frame, believed to be a 1950's Ephgrave built O'Brien. (Serial number: HP27 ORO):


It was in a pretty sorry state, but cleaned up quite nicely. It has Campagnolo dropouts, and braze-ons for a front derailleur. I'd like to build it up BLRC style, and still have to find several parts, namely: saddle, seatpost, stem, bars, chain, a nice pair of sprints, a bar-mounted bottle set - and a chainset with a double-chainwheel.

I have tried to fit a Duprat chainset with double-chainwheel that I have - and found that the bottom bracket axle which I had bought as the right length for a double-chainwheel was too short to clear the bolts that attach the double-chainwheel to the crank. What length should I be looking for to provide clearance for a double-chainwheel?

The Duprat chainset and double-chainwheel are steel and pretty heavy. I'd be grateful for any recommendations for an appropriate double-chainwheel for a mid 50's BLRC-style bike. And tips on how to ensure a matching BB axle.

I have posted detailed photos of the frame. I'd appreciate any thoughts on any marks of Ephgrave's work. If you look closely at the photos of the tops of the seat stays you'll see that gold paint has worn away from a pattern which has three vertical lines crossed by one short line. Is this an O'Brien mark - or Ephgrave? - or one used by several builders?

All the best for the New Year,

Wyndham Pulman-Jones
Girton, Cambs., UK.