Re: [CR] Campag Sport and pulley friction - Bullseye Pulleys now Bullseye pulley installation/spacers

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Date: Thu, 10 Dec 2009 09:29:54 -0500
From: "George Allen" <>
To: <>
References: <>
In-Reply-To: <>
Subject: Re: [CR] Campag Sport and pulley friction - Bullseye Pulleys now Bullseye pulley installation/spacers

All the Bullseye pulleys I've attempted to use were significantly narrower than the stock Campy pulleys. Bullseye included spacing washers with their pulleys to address this issue but for the proper spacing one was forced to use two washers on one side and three on the other side. I never thought this was a good idea vis a vis shifting performance but does it make any difference if both pulleys are spaced the same way. Also, I suppose I could make some custom spacers to center the pulleys perfectly. But is this necessary? BTW, I can't think of another word that ends in -ey and the plural is -eys instead of -ies.

George Allen with way too much spare time during our slow season at work in Lexington, KY USA

verktyg wrote:
> Mike,
> Here's a link to a recent review of ceramic bearing pulleys on the
> Competitive Cyclist website:
> They go into detail about Roger Durham's Bullseye pulleys and how he
> came to make his claims.
> I've used Bullseye Pulleys on a number of bikes, not because of any
> claimed improvement in performance but because they were smoother
> running and quieter than most plastic pulley wheels.
> I still have some in use since 1975!
> I found that they don't work well with the narrower 6-7-8 speed chains
> such as the SRAM PC48 and PC8xx families. I had to file down the sides
> on one pair to get them to fit the new chain.
> Chas. Colerich
> Oakland, CA USA
> Mike wrote:
> Jan Heine points out that there was concern about pulley friction up
> until the Campag Gran Sport was introduced. The Simplex 543 and the
> Huret Louison Bobet dérailleurs were perhaps the most well known of
> many that addressed the problem by having chain detensioning devises
> built in. Those of you that have ridden a bike equipped with a single
> freewheel or a Campag. Corsa or Paris-Roubaix will know how fee
> running the transmission is when you get rid of pulleys. It seems
> strange to me that no one bothers these days. Sure it makes very little
> difference to the amount of energy required to propel the bike but
> every little bit counts.
> Some years ago an American manufacturer, I can't remember who, made
> custom ball bearing equipped replacement pulleys and in their
> advertisements they had a chart showing just how much energy
> (friction) one would save using them.
> _______________________________________________

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