Re: [CR] 151 campy crank RPM


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From: "ternst" <ternst1@cox.net>
To: "Thomas L. Hayes" <hayesbikes@nls.net>, <classicrendezvous@bikelist.org>
References: <009b01c4e04d$3fbef7c0$a046fea9@domain.invalid>
Subject: Re: [CR] 151 campy crank RPM
Date: Sun, 12 Dec 2004 22:21:59 -0800
reply-type=original

What a revoltin' development! Ted's turn. Nice links, allow me to connect the chain and sprocket to ya. Please think back, stokin' strokers, on the older racing cottered crank chainrings. 45/48; 46/49; 47/50; 48/51, 49/52 were the most common, also 47/52; and 48/53. Campy developed out of this and of course took it much further. The old 151 was good for 44 t outside or inside. anything less than three teeth difference in the front ended up with too much overlap or duplication. Good half step gearing which was the norm in151 era was any of the front with 14-16-18-21-24; 13-15-17-20-23; even 14-16-19-22-26, and others. If you look on a gear chart these are very easy to plot and you can see what would work and was common then. By adding a granny inside you could make up very nice touring gearing. F. Berto I think had some comprehensive charts made up years ago. The road chainrings were / are 1/2 x 3/32 " pitch. The track chainrings are 1/2 x 1/8" pitch and are slightly beefier to handle the explosive acceleration in fixed gear racing. Some lighter riders and pursuiters will use the road size chainring, cogs, and chain on their track bikes to get a lighter set up. These would wear somewhat faster. One can use the 1/8" chain on the narrow chainwheels, it's a trifle wider but works fine. One can't use a 3/32" chain on the 1/8" chainwheel I think the outside chainring peg for anti-chain jam which came along in the '70's was the result of chains getting narrower as they went to ultra 6 and 7 sp clusters. Before that was done we took our RH cranks to the machine shop and had them machine down the spiders to keep the chain from wedging down in. About eight months after we were doing this we read in one of the European cycling mags that the Euro mechanics were doing the same. We had a small chuckle, hi fives weren't in. Neither were our chains. Please fill in with some of your tricks, too. Ted Ernst Ted's Classic Bikes Palos Verdes Estates, CA 310-791-5521


----- Original Message -----
From: "Thomas L. Hayes"
To:
Sent: Sunday, December 12, 2004 5:19 AM
Subject: [CR]Outside chainring for 151 campy crank


What was the smallest (least number of teeth) chainring designed as the outside ring for a Campagnolo 151 pattern crank? And was there a specific chainring designed for track cranks that differs from their road chainrings?

Thank you.

Cheers.

Tom Hayes
Chagrin Falls, Ohio