What the 30mm?
Understanding the 30mm Crank Spindle
There are several 30mm Crank spindles on the market today with more to come. Below is a list of a few of them currently on the market today:
- Rotor 3D30 – length 110mm
- Rotor 3D+ – length 148mm to 158.5mm
- Rotor 3DF – length 148mm to 158.5mm
- RaceFace Cinch / SL – length 104mm to 197mm
- Specialized S-Works FACT – 68mm to 120mm
- Cannondale Hollowgram SL / SI / SISL2 – 104mm to 132mm
- FSA – 68mm to 110mm
- Praxis – 147mm to 172mm
- Cane Creek eeWings – 176mm
- Campagnolo Over Torque – 110mm to 135mm
Measuring Crank spindle length.
What Size Bottom Bracket for a 30mm Crank
There are two things to think about when you are looking for a bottom bracket, the shell width and shell diameter.
Measuring the Shell width.
Measuring the Shell diameter.
Bearing Diameter
The bearing diameter of a 30mm bearing is 42mm. If you shell diameter is 42mm then a bottom bracket will not work and you will need to a Press Fit bearing system. If you shell diameter is 46 of greater you can use any of the following bottom brackets below.
30mm Bottom Brackets
- External English (BSA) threaded bottom bracket
- PF30A have a shell Diameter of 46mm
- PF30 have a shell Diameter of 46mm
- Cannondale Asymmetric Integration (Ai) have a shell Diameter of 46mm
- T47 have a shell Diameter of 46mm and 47mm
- 386EVO have a shell Diameter of 46mm
- BBRight have a shell Diameter of 46mm
The difference between the bottom brackets is the shell width. Knowing the correct shell width and the crank spindle length will help you choose the right bottom bracket for your 30mm crank. You can also look at our chart on Bottom Bracket Standards.