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THE PRAXIS CONVERSION BOTTOM BRACKET

Our conversion BB is designed to be a proper BB for Shimano™ Hollowtech cranks in either BB30, PF30, or Specialized's OSBB frames. Our patent pending design keeps the cartridge bearings outboard of the frame right on Shimano™ spec for greater rigidity and free of frame/c-clip tolerance issues that other systems deal with. Simply press in the longer non-drive-cup, then the shorter drive cup threads into it. As the drive cup threads in, our trademark Collet system expands to a precise limit evenly dispersing pressure for a super tight fit. With both cups connected and our collet set exactly to spec, there is no chance the bearings can come out of alignment or wiggle/walk out of the frame. This design also uses a compressible o-ring on the non-drive side cup to compensate for frame shell width discrepancies.

"WELL THAT'S SMART!"

Exploded view of the conversion kit.

As the drive cup threads down into the non-drive cup, our Collet expands to a precise limit dispersing pressure inside your frame for a super tight fit.

Drive cup
threads in
Non-Drive
Cup Pressed

Our unique collet system also greatly reduces the chances for creaking and other unwanted noises associated with the lesser "Band Aid/Spacer" type adaptors in the market. The cartridge bearings are high quality steel with shield-type quad-ring seals. Available in either 68mm or 73mm widths, the Praxis Works Conversion BB is the most rock-solid BB for Shimano™ cranks on BB/PF30 frames.

SAY NO TO "BAND AID/SPACER" ADAPTORS

  • Separate L & R adaptors can wiggle/walk/fall out of frames.
  • Subject to more frame/spindle tolerance issues.
  • Don't handle heavy pedal loads well.
  • Higher chance of creaks and noises from bad fit.
bikeradar

"Praxis Works showed what we feel is the most thoroughly designed BB/PF30-to-24mm bottom bracket adapter currently on the market. The bottom bracket uses a collet system that wedges itself tightly inside the shell with even pressure throughout." —James Huang, Bike Radar

  • MFG: Forged & machined heat-treated 7075 T6 Aluminum
  • BEARING: Cartridge with steel ball, high-grade grease and fill
  • SIZE & USE: 68mm Road / 73mm Mountain
  • FRAME SPEC: For BB30, PF30, and now Specialized OSBB!
  • COMPATIBILITY: For Shimano™ Hollowtech cranks only.
  • Patent Pending Design
  • "Collet" style non-drive cup expansion for wiggle-free press
  • Compression/Spacer O-Ring compensates for frame width discrepancies.
  • 68mm can only be used with road cranks. Cannot be spaced.
  • New "Wiring windows" only for the BB30 version
  • Not compatible with SRAM/GXP or Campy/Ultra Torque cranks
  • Felt F1/F2/Z1 custom BB30 shell cannot accept the Conversion BB.
  • Not made for BBRight or BB386EVO frames.
Say NO to Band-Aid type adaptors.
PATENT PENDING
In depth at the UK Core bike show