Drivetrain & Hub

This calculator gives gear ratios for several speedhubs, lets you compare hubs and drivetrain configurations and helps finding the right chainring ~ sprocket combination. Personally I always keep the development in the center~speed between 4.2 and 4.5 meters per revolution.

It gives Development (meters per revolution), Gear centimeters and Gear inches, Gain ratio, Revolutions per kilometer and mile and Revolutions per minute at any given speed. Read more on measuring bicycle gears in this article by Sheldon Brown.

If your browser allows cookies you can save up to six configurations for next visits or for quick switching between different configurations and comparing them.

If your hub is not in the list and you know it's gear ratios you can enter them by selecting 'Custom' in the hub-list first. I would appreciate it if you would send me the data so I can supplement the list.

This calculator also gives as many specs as I could find on several speed hubs. Let me know if you have more info to share ;-) .


Chainring (teeth front)
Sprocket (teeth rear)
Wheel circumference (mm. / inch)
Wheel diameter (mm. / inch)
Crank length (mm. / inch)


Spd Hub
ratio
Inc.
%
Dvlp.
m/rev
Gear
cm / in
Gain
ratio
Revs per
km / mile
Revs / min @
kph / mph
1  
2
3
4
5
6
7
8
9
10
11
12
13
14

Gear range

Number of holes
Spoke hole diameter (mm)
Axle length (mm)
Over locknut distance (OLD) = Dropout distance (mm)
Axle diameter (mm)
Flange diameter, left / right (mm)
Flange to ½ OLD (centerline), left / right (mm)
Chainline (½ OLD to sprocket): cup in, flat, cup out (mm)
Brake
Housing material
Weight (g)
Lubrication

Most of the hub ratios were found at Cycletech.