Tuesday, May 6, 2008

BB30 - It's not the length, it's the girth

So, Cannondale is pushing a new bottom bracket standard, BB30. Various reasons are given by various sources for the new standard. Narrower stance by FSA and VeloNews (due to the shorter length), enhanced stiffness from Cannondale (due to the larger girth). The only explanation that I buy, however, is the one about durability. Here's my theory - by switching from the tried and true square taper bottom bracket designs to the hollow spindle models (Giga Pipe, etc), manufacturers sacrificed bearing size for spindle stiffness since torsional stiffness increases with diameter and the bearings still had to fit inside the bottom bracket shell. Smaller bearings = more pressure on each ball = shorter life. So then, they went to outboard bearings (Hollowtech, etc), which really screwed things up, because now, you can barely run a triple. Campy, for example, doesn't make an Ultra Torque triple, but still makes a square taper triple. So, the manufacturers painted themselves into a corner with this stuff and couldn't go back to the way things were because it would confuse the hell out of people. "So, you're telling me this expensive road bike doesn't have hollow anything on it? That's so 2004!" Enter, the BB30. All the durability of the old bottom brackets with an increase in stiffness that will go unnoticed to the recreational rider. Tail wagging the dog!

Any tech geeks want to back me up on this? Or maybe just argue about it? Or perhaps just pour one out for the square taper bottom bracket...

images lifted from FSA web site

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