Hub Gearing Calculator

Gear Ratio % Increase   Equiv. on Fitted Equiv. on 32t Equiv. on 22t   Overall Ratio Gear Inches Metres Develop Gain Ratio   Kph Mph

Instructions:

Enter the number of teeth you have on your front chainring, followed by the number of teeth on your rear cog. Then select your wheel diameter and rim width in millimetres - you can either use the dropdown to pre-fill the boxes or enter them yourself. Using the radio buttons will enable you to convert common tyre sizes from different standards to ETRTO sizings. Finally enter your crank length and then your RPM to enable your speed in MPH and KPH to be calculated. You can toggle between different hub gears by hitting the various buttons at the top of the table.

Inputs

Front Chainring No. of Teeth
Rear Cog No. of Teeth
 
Select your Tyre Size  
Etrto French German British Imperial British Modern USA
Wheel Dia (mm)
Tyre Width (mm)
 
Overall Dia (inches) 
Overall Dia (mm) 
Wheel Circ. (mm) 
 
Crank Length (mm)
Crank Circ. (mm) 
Crank RPM

Notes

This page requires javascript to be enabled. It is in beta so may be a little shonky in places. Any comments for improvements etc please mail me : hub [@] onehillside DOT com.