RPM=MPH conversion HELP!!!

[bike_man0079]

Does anybody know how to convert RPM to MPH such as (90 RPM to ?MPH)
Any help is appreciated.






Thanks and God Bless!

 

[Walrus]

It depends what gear you're in...

Use this calculator on Sheldon Brown's site. It allows you to enter your gears, then select the "x RPM to MPH" option and you'll get what you need.

http://sheldonbrown.com/gears/

If you're unsure...
Wheel size will be "27 inch" if you have a regular road bike.
Crank length is most likely 172.5
Under Gear units, select "MPH @ 90rpm" or any RPM you want
Enter how many teeth are on your chainring, eg 53 39 if you have a double
Select one of the stock cassettes, eg 9 Speed 12-25
Leave the Custom Cassette and Internal Hub as is.

Then click Calculate.

 

[AussieRob]

Fixed Gear Feaver also has a free excel version that trackies use