BSA is another way of stating English threading. The initialization comes from Birmingham Small Arms, which made bicycles. English threading on road bikes mean a 68mm-wide, 34mm-inside-diameter shell with reverse threading on the drive side. It's the most common threaded standard employed today. This kit allows you to fit 30mm cranks, like those from Rotor, to fit in the tight space of this 34mm spindle.
Choose between two bearings types for the cups. Standard Bearings have low drag thanks to hardened-steel races and our CeramicSpeed Balls. Coated Bearings have those same balls installed on coated, hardened-steel races for longer life and less bearing drag.
Note that the threaded extensions of this BB's cups that thread into the frame are thin, as they need to fit a 30mm spindle inside the cups.
CeramicSpeed standard bearings typically have frictional drag of 0.3-0.4 watts per set. That's in the range of a 75% drag reduction compared to standard bottom brackets. That's thanks to balls that are 100% smoother and 15% harder than the ceramic competition. The bearings last at least 3x longer than other bearings.
In The Box:
- 2 threaded cups with bearings installed
- 2 1mm spacers
- 2 0.5mm spacers
- 2 dust covers
- 10ml syringe All Round Grease
- Sticker sheet