Originally Posted by
tmh657
I switched back to the 172.5mm Sugino messengers today to compare. There seems to be more of a pedal strike issue with the 172.5's than the Dura Ace 175mm because the DA cranks have a narrower Q factor. The inside of the crank arm on the DA is almost touching the chain where as the crank on the messenger is a good 1/2 " or more from the chain.
I think this is a correct assumption. Tell me if I am wrong.
Also does it make any difference in acceleration with 144 bcd on the DA as opposed to 130 bcd on the messenger?
I know I am over thinking it...
Bolt circle diameter has NO effect on acceleration that you could possibly feel. The diameter of the chain ring and length of crank arm are the critical parts of the geometry. Where the chainring is attached to the crank makes very little difference (it is just a trade off between size of the spider and the geometry of the chain ring and doesn't affect gear ratio at all.