BB30 Standard Overview

Free International Standard for Bottom Bracket Shells

The bicycle industry works with a number of constraints that can stifle innovation.

BB30 is a free international standard that both frame and component companies can utilize to offer consumers more choice and better performance. The following manufacturers currently use this standard to improve performance.
The BB30 International Standard provides the specifications for an oversized bottom bracket shell for a bike frame. This standard allows for Direct-fit, pressed-in bearings and a 30 mm spindle.

The system saves weight by accepting a 30mm aluminum spindle and eliminating cups that would normally hold the bearings.

The oversized bottom bracket of the frame provides more area to attach larger down tube, seat tube and chain stays to better resist deflection from pedaling forces.

WHAT THE INDUSTRY IS SAYING ABOUT BB30: recently wrote the following summary about the future of BB30. Please visit them online.

Item #2. The truth can be a bit boring, but it’s still important. Here is your official warning: What the bike industry did to the headtube with integrated headsets 7 or 8 ago, they’re about to do again to bottom brackets. It’s not happening in 2008, and it probably won’t happen in 2009, but sooner or later the BB30 standard, as it’s known, will be everywhere.

The BB30 is an open-source (to use software terminology) standard where you essentially press bearings directly into an oversized BB shell. It eliminates the need for external (or internal) BB cups Unlike integrated headsets, the BB30 actually has performance upsides: You get a substantially lighter and stiffer BB. You reduce Q factor. In theory prices should be reasonable since road bikes and mountain bikes will share the same BB design (no more 68 vs 70 vs 73).

The most hyped example of unconventional BB bearings in 2008 was with the new Trek Madone . FYI, theirs is not an example of BB30. Rather, all Trek did was move the cups from outside the BB shell to inside the shell. There was no meaningful weight savings and no consequential reduction in Q-factor. We don’t understand, exactly, why they did this. With BB30 you essentially rid the bike of BB cups. That’s the key. And it’s the future. Ben Delaney of wrote a great summary here, and you ought to check it out.”