Originally Posted by miamijim

Not that it realy matters but a 53/12 is more efficient even if its the same gear inches as a 50/11.

"In a derailleur transmission there is often a difference of 1 to 3% in effieciency between adjacent gears. A 1% improvement in efficiency will mean 12 seconds or more in a 25-mile TT.....A 52/15 gear combination will have a higher effieciency than a 42/12...For high effieciency the trick seems to be avoid combinations using sprockets smaller than 14t."

HIGH-TECH Cycling, Second Edition, P.37 Edmund R. Burke, Phd, editor