F.1.2. What should I measure?

- What is the inner diameter of the bottom bracket shell? Most b.b. shells use BSA standard. No need to measure it, if it is a BSA size (inner diameter of 33.6 up to 34 mm).

- Is the wall thickness at least 2.5mm for a steel b.b. shell and 3mm for an aluminum b.b. shell?
- Is the width of the b.b. shell at least 68 mm and not more than 73 mm?

Go back