# Shimano 55 or 54 tooth w/ 39 inner?



## TricrossRich (Mar 26, 2014)

Has anyone tried running the Shimano 55 or 54 tooth rings with the standard 39 tooth inner ring, as opposed to the 42 that is recommended? Will it work? I'm interested in trying for my TT set up, would like the 54 or 55 tooth to give a little more gear pedaling downhill sections, but also to keep me in a better gear, centered in the cassette for better chainlink efficiency.

Thanks in advance...


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## cxwrench (Nov 9, 2004)

It will work, it's like a 50/34...16 teeth difference. That said, you're supposed to use a 42 w/ the big TT rings.


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## TricrossRich (Mar 26, 2014)

yes... the official answer I got was that it would wok, but might not be totally optimal shifting from the small up to the big. That being said, after researching the different ratio options more, I realized that going 55/42 with an 11-25 cassette, actually offered me more overall range than the 53/39 and 11-23 cassette, and the 11-25 cassette still has the 16t cog which is the one I always seem to want to be in.


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