Re: [CR]Max freewheel cog size for Campag rear der.


Example: Framebuilders:Jack Taylor

Date: Thu, 26 Jan 2006 07:42:01 -0800
From: Jack Fortune <jfortune@uoregon.edu>
To: classicrendezvous@bikelist.org
Subject: Re: [CR]Max freewheel cog size for Campag rear der.


> There is no hard and fast number for how large a rear cog a given RD will
> handle. It's all a matter of geometry. I believe a Campy NR was also
> supposed to handle only a 26T, but I've used them with a 14-28 FW and 52-42
> chainrings lots of times. There are lots of factors involved, including not
> only the geometry of the RD, but the chainstay length, the model of chain,
> the front chainwheel sizes, the chain length, the type of rear DO, and the
> position of the wheel in the DO's. In general, a smaller spread on the
> chainrings makes it easier to find a chain length that works with a larger
> rear cog. With a 46-50 front, I'd guess it shouldn't be that hard to handle a
> 14-28 on the rear. Be sure you have a good chain tool. You'll probably have
> to try several chain lengths before you find the right

I'm running a 13-28 freewheel with 50/41 chainrings on my mostly original 1971 Raleigh International, which has a NR rear derailer. It shifts nicely - but of course I can't use big/big & small/small sprocket combinations.

regards,

Jack Fortune