BSA comes from British Standard Cycle, aka English threading. English threading on road bikes means 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 thru-axle cranks, like those from Rotor, to fit in the tight space of this 34mm spindle.
Choose between two bearings 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.
In The Box
English threading is easy to work with and the drive side cup, thanks to being reverse-threaded, stays in place without any extra effort. The threaded extension is thin, as they need to fit a 30mm spindle inside the cups.
The spindle increases efficiency, as is the CeramicSpeed system.
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.
Race Day Grease, All Round, and Long Life are three greases CS designed to help the bearings roll smoothly. The first is the least drag, the last is the most durable. All Round comes with. You can change the grease to tune performance.