Hello, I am Bruce link=topic=27141.msg360227#msg360227 date=1168259616]
I was playing with Google's Calculator, and came up with a formula for calculating cadence that I thought I'd share.
Just go to
Google and type in
((SPEED miles per hour)/(CIRCUMFERENCE metres) * (SPROCKET/CHAINRING) in (minutes ^ -1)
with appropriate values for your SPEED, wheel CIRCUMFERENCE, and SPROCKET and CHAINRING tooth counts.
e.g.
((31 miles per hour) / (2.155 metres)) * (19/49) in (minutes ^ -1)
Gives 149.6 rpm.
("minutes ^ -1" just means rpm).
You can change the units, e.g. speed in km/h, or circumference in furlongs, and Google with handle it automatically.