Originally Posted by
waynesulak
Someone can check me on this but I calculated the speed difference on a 700c bike between a 52/11 gear and 50/11 gear at a cadence of 90 is about 2 kph or 1.25 mph.
52 x 11 90RPM = 33.7 MPH
50 x 11 90RPM = 32.4 MPH
50 x 12 100RPM = 33 MPH (This what I use on tandem and single)