The chart above (from BruceBrown) is pretty nice. I think a 90 RPM cadence is a bit high. On a kindernay, if I fill in 75 for cadence, then a 42T will go 28 MPH and a 46T will go 30 MPH. Good top speeds. 1st gear moves from 5 MPH to 8 MPH comparing these two chainrings. Is that too high? As Reed...