Bicycle Mechanics - Changing 42 to 39 on Tripple Crank

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SpotmaticF
11-13-02, 12:26 PM
Hello:

On my road bike I've got a Cannondale EX (2001) triple crank with 52,42 and granny chainrings.

I do not use the granny and want to swap the 42t to a 39t inorder to reduce redundant gear ratios (and get some lower ratios for the hills).

I am not sure which 39T shimano (or equiv) chainrings I need as there appear to be two versions with diff pick-up pin locations.

Would there be any benefit to getting a 53T ring at the same time (other than taller gearing)?

FYI I plan to buy 105 or Ultegra rings (or equiv), Unless someone can convince to me that DuraAce ring are worth the cash.

Thanks,

Matt

pokey
11-13-02, 12:33 PM
Shimano says that A type rings and B types have to be used together.In actual practice it makes little or no difference.
SpotmaticF
11-13-02, 02:01 PM
so, if I have a Cannondale EX triple crank, with Cannondale rings 52-42-3X, what Shimano type replacement rings do I need, A or B?

Thanks.

pokey
11-13-02, 03:13 PM
either. Since you say you will seldon shift from the granny to the middle anyway it won't matter.
John E
11-13-02, 09:18 PM
I cannot speak regarding Shimano, but I have found no significant difference between Campag.'s "A" and "B" rings.