Praxis Works BB30/PF30 68mm SRAM GXP/ISIS2 Conversion Bottom Bracket

Insightful Design
The patented Praxis Works Collet design keeps the cartridge bearings outboard of the frame right on spec for greater rigidity and free of frame/c-clip tolerance issues that other systems deal with. This design also uses a compressible O-ring on the non-drive side cup to compensate for frame shell width discrepancies. What makes this converter so clever is the fact that it doesn't just clamp the shell from the outside, but thanks to the threaded Collet, the middle expands slightly to grip the inside of the frame where the bearings normally sit and holds itself captive with an expansive force too.

Easy To Install
Simply press in the longer Non Drive Cup, then the shorter drive cup threads into it. As the Drive cup threads in, the trademark Praxis Works Collet system expands to a precise machined limit evenly dispersing pressure for a super-tight fit. With both cups connected and the Praxis Collet set exactly to spec, there is no chance the bearings can come out of alignment or walk out of the frame.

Disadvantages of Band-Aid/Spacer Adaptors
Why put up with a higher chance of creaks and noises from a bad fit when you settle for band-aid/spacer adaptors. They don't handle heavy pedal loads well. They're subject to more frame/spindle tolerance issues, and separate L & R adaptors can really make trouble for you when they wiggle/walk out of frames.

The Praxis Works Patented Collet
This greatly reduces the chances for creaking and other unwanted noises associated with the lesser "Band Aid/Spacer" type adaptors on the market. The cartridge bearings included are high quality steel with shield type quad-ring seals. This 68mm version for Road Bike is the most rock-solid Conversion BB available.