You might remember my Race Face X-Type rant on outboard bottom bracket (BB) bearings. In a nutshell I don’t think the additional stiffness of outboard bearings is worth the maintenance headache. The problem is the smaller balls used in the current outboard BB’s (especially the x-type) are more prone to seize from exposure to the elements. Which is what happened to my X-type after the Tom Brown Park XC. I won’t even go into the problems with chainline and q-factor. When I started wrenching, Shimano cartridge BB’s were on the scene so the idea of maintaining the BB is completely foreign to me. I’ve now learned that you have to keep an eye on the outboard bearing BB’s.

While most folks have been putting band-aids on BB flex issue with outboard bearings some folks (Cannondale) have been working on a solution. Putting the bearings back in the BB shell to begin with, but also making the BB shell bigger allowing for bigger balls and a bigger spindle. It is the BB30 spec and it seems to be gaining steam. With two major bicycles manufacturers, several major component manufacturers and many smaller frame builders jumping on board; it seems like it will stick.

BB spindle pr0n.

The problem is Shimano has also addressed this issue with their spec. So there will certainly be some adoption problems. Shimano has the muscle to force their spec on the large manufacturers. Sram gaining market share could help in that department, but that’s a topic for another day.

I’m jumping on the BB30 bandwagon because I figure if you’re gonna change the BB size you may as well go whole hog and use a 30mm spindle as opposed to the 24mm in Shimano’s spec. I figure if you’ve got component manufacturers such as FSA and SRAM saying things like BB30 systems are “38 percent stiffer than their 24mm counterparts” and “FSA’s push in to the BB30 bottom bracket and cranks is due largely to rider feedback” then that’s the way to go.