For all of the Cannondale riders, this is not new information because your bikes have been running this system for awhile. The BB30 standard (Cannondale calls it SI – System Integrated) integrates the bottom bracket bearings into the frame via a press fit.
According to the BB30 Standard website:
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.
CompetitiveCyclist.com is quoted as saying:
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 velonews.com wrote a great summary here, and you ought to check it out.
BB30 also claims that SRAM and FSA are now also on board.
198’S THOUGHTS
This is actually one of the Cannondale proprietary items that I actually agree with (probably the only one). This is the solution that solves the square taper vs. x-type argument that I addressed last week. This is also a very similar setup to the one found in the custom Wolfhound build. This system provides the thicker 30mm axles for greater stiffness but with internal bearings. To me, this seems like the best of both worlds. All it really takes is the frame manufacturers jumping on board, and the system would be in place.
Pictures from Singletrackworld.com’s coverage of Sea Otter:
