Praxis makes these bottom brackets to Shimano's bearing stance for Hollowtech II cranks, including BB30/PF30 conversions that let a Shimano road or MTB crank run in an oversized press-fit frame.

Highlights

• For Shimano Hollowtech II cranks with the 24mm spindle (24mm drive and non-drive bearings)
• Made to Shimano's bearing stance spec
• BSA, T47 external, T47 internal and BB30/PF30 versions
• Enduro 2437 sealed steel bearings; Grade 5 / ABEC 5 ceramic on the BB30/PF30 versions
• Forged and machined heat-treated alloy cups

Threaded versions

The BSA and T47 versions thread in and are tightened to 40Nm, per Praxis's manuals. BSA and T47 external cups take a standard outboard-cup tool with 16 external notches and a 44mm ID. The T47 internal version sits inside the shell and needs Praxis's dedicated T47 I.B. Shimano tool, sold separately. On a 73mm T47 external MTB frame, Praxis's setup chart adds a 1.5mm spacer on the drive-side cup.

BB30/PF30 conversion with the Praxis collet

The BB30/PF30 versions thread together through the shell, and an orange rubber collet expands inside it as the drive cup is tightened. A width-tolerance O-ring takes up frame variance, and a Delrin sleeve is included for PF30 frames. Fitting takes a press plus two 16-notch tools. They are not for Cannondale BB30a or PF30a frames, and the shell must be clear of internal cable guides or screws.

Options

Compatibility & fit

For Shimano Hollowtech II cranks with a 24mm spindle only. They won't take SRAM DUB, M24/GXP or 30mm spindles. Measure your frame first: BSA shells are threaded, T47 shells are threaded with a 47mm bore in 68/73mm external or 85.5mm internal widths, and BB30 and PF30 are 42mm and 46mm press-fit bores. The 68mm BB30/PF30 is for road cranks and the 73mm BB30/PF30 is for MTB cranks. Fitting is a separate workshop service, and the Tune Cycles workshop has the press and cup tools each version needs.