Check before you buy

We want you to be really happy with your GTRO Gearbox.
To be sure you’ll be able to install it on your bike, please check the following:

Bottom bracket shell

Bottom bracket shell is the pipe that the axle of your crank goes through. The main thing you need to check before you buy is the BB shell type. GTRO is compatible with all the frames that use 68 mm or 100 mm wide BB shells, English thread.
If you are not sure what BB shell your bike has, you can do one of the following:

1. Ask your bikeshop – they will surely know!
2. Send us:

  • your bike brand name and model name.
  • (optional) few photos of your BB area, from a few angles.
  • (optional) write us what is written on your BB, usually on the BB cups.

Contact Form

Accepted files formats: pdf, gif, png, jpg, jpeg. Max size: 5mb

3. Search it on the Internet with a phrase like:
“<your bike brand and model name> bottom bracket”

For example:
“Giant Anyroad bottom bracket” where:
“Giant” is brand name and “Anyroad” is model name.
You’ll probably be directed to the bike’s specs web site.