Julian:
This is my take on it. The 11 tooth seemed to help the most with the 32-26 or 31-25 jump, and also helped with keeping the chain from hitting the inner cages. The inner cage thing drove me a little crazy. I had previously put thousands of miles on two off-topic Shimano long cage rd's, and still had pristine inner cage surfaces when I retired and gifted them, but these NOS Rallys would get inner cage scratches on the first ride around the cul-de-sac during tune up checking with the stock 10 tooth.
The side float seems to help with the overshift, but I think looking for a laterally flexible chain (and ultra versus standard spacing, and axle-dropout placement) are all in the mix on that one. I still have a little back and forth dance on the one machine that has the Regina Extra Oro chain (very stiff laterally).
http://www.flickr.com/
Sincere thanks for the list's interest on this one, and the wonderfully detailed observations. As with so many things we learn here, the tweak idea came to me from someone else ... a knowledged LBS owner in Independence, Missouri. He suggested a 12 tooth, and did not place an importance on the float feature.
Tory Werne Woodstock, Georgia USA
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[CR] re unspeakable tweak Thursday, May 06, 2010 3:28:05 AM From: "jujufilm" <jujufilm@paradise.net.nz> To: "" <classicrendezvous@bikelist.org>
Sounds interesting - I'm just wondering - is it the 'floating feature' thats making a difference or its putting an _11 tooth_ pulley in there thats having an effect (or partial effect) ? Cheers Julian McCarthy Auckland New Zealand (where the fixie set ups are getting close to outnumbering the derailleurs around town)