Chainring cog combo

[ayceejay]

Disregarding the cost of chainrings versus the cost of cogs which set up do you favour (and why) smallest cog possible and appropriate chainring or some other combination? For instance 48 x 16, 45 x 15 and 51 x 17 all give 81 gear inches which would you prefer?

 

[RecordAceFromNew]

FWIW, the article from page 3 to 9 of this document might be of some interest to you in terms of efficiency comparison, especially if one's fixed/ss' chain tension is not fully adjustable and would be dependent on sprocket size.

 

[knightwhosaysni]

47*17. Even better is you can get the chain to fit with a prime number of links.

 

[ayceejay]

care to explain?

 

[ColinJ]

care to explain?

While we are waiting for a reply... I think it might be something to do with the theory that the same links on the chain don't mesh with the same teeth all the time. I vaguely remember somebody suggesting that it would accelerate wear if that happened, so it would reduce wear if it didn't!