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How to Buy a Press-Fit Bottom Bracket

So you've followed Step 1 of our how to buy a bottom bracket article, and you've determined you needed a press-fit bottom bracket. The good news is that you're only one step away from determining what press-fit bottom bracket standard you need.

 

Step 2: Selecting the press-fit standard required

Press-fit bottom brackets are relatively new to the industry when compared to the threaded interface of internal or external bottom brackets that has been around for many decades. Instead of using threads, the bearings are pressed directly into the bottom bracket shell. Because the fit relies on precise dimensioning of the shell, every different press-fit standard is designed to work with a slightly different bottom bracket shell. Below are the current different press-fit standards. The proper press-fit standard that the frame was designed for must be.

BB30

BB30.png

The most common press-fit standard.
Shell width of 68mm (road) or 73mm (MTB).
Shell inner diameter of 42mm.
Crankset spindle of 30mm (BB30 cranksets).
Bearings are press fitted directly in the frame.



   

PressFit 30
(PF30)

 PF30.png

Shell width of 68mm (road) or 73mm (MTB).
Shell inner diameter of 46mm.
Bearings same as BB30, but contained in a cup which are press fitted in the frame.
Crankset spindle of 30mm (BB30 cranksets).



   

 BB86 / BB91

 BB86-BB91.png

Shell width of 86.5mm (road) or 91.5mm (MTB).
Shell inner diameter of 41mm.
Bearings contained in a cup which are press fitted in the frame.
Crankset spindle of 24mm (Hollowtech, GXP).



   

 BB90 / BB95

 BB90-BB95.png

Shell width of 90.5mm (road) or 95.5mm (MTB).
Shell inner diameter of 37mm.
Bearings are press fitted directly in the frame.
Crankset spindle of 24mm (Hollowtech, GXP).

 

 

   

 BBright

 BBright.png

Only used on Cervelo road bikes.
Shell width of 79mm (road only).
Shell inner diameter can be 42mm (uses BB30 bearings) or 46mm (uses PF30 bearings).
Crankset spindle of 30mm.
Shell is 11mm offset to non-drive side which requires a BBright specific crankset.



   

 386 EVO

 BB386EVO.png

Shell width of 46mm (road only).
Same as PF30 with wider shell which requires a 386 EVO crankset

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    Tony Montana

    Very informative!

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