Did I get this right? if not what is the way please write it as if using a calculator. I don't understand math. 52 sprockets / 12 sprockets on the rear= 4.333 ratio? X 60rpm crank speed x (20â€ x pi=62.8inch circumference) = 16327.987 inch min. / 12 inch = 1360.6655ft/min. and then 5280/1360.6655 = only 3.88 mph???

Your error is in the last conversion. Allways write out the units and make sure they cancel . What you did: 5280 ft/mile/1360 ft/min Your units end up minutes/mile. 1360 ft/min *1mile/5280ft* 60min/hr= 15.45 mi/hr

so it should read like this? 52 sprockets / 12 sprockets on the rear= 4.333 ratio? X 60rpm crank speed x (20” x pi=62.8inch circumference) = 16327.987 inch min. / 12 inch = 1360.6655ft/min. and then 5280/1360.6655 x 60 =

52 sprockets / 12 sprockets on the rear= 4.333 ratio? X 60rpm crank speed x (20â€ x pi=62.8inch circumference) = 16327.987 inch min. / 12 inch = 1360.6655ft/min. x 5280ft x 60min/hr= 15.45 mi/hr