A New Bottom Bracket Standard
If there's one thing I would change about the Stooge MK5, it's the eccentric bottom bracket. With a 1x12 drivetrain, I simply don't need it. I acknowledge that there are benefits to having one. For one, the MK5 can be set up single-speed or geared. As such, it has a wider appeal, and should I ever part with it, the circle of potential buyers would be considerably larger. My experiences with the two EBB-equipped bikes I've owned, however, were more bad than good. My Niner One9, for instance, had a setscrew EBB. The setscrews quickly ate themselves into the EBB, and the BB shell ovalized over time, leaving a wide gap between the shell and the EBB. The gap filled with dirt, and the whole setup was creaking more often than not. My Air9 Carbon came with Niner's own Bio-Centric bottom bracket, a design that clamps to the outside faces of the EBB shell. In theory, this seemed great. Machine a precise cylindrical BB shell with parallel outside faces and clamp two eccentric cups against those faces. In practice, it was pretty shitty, to say the least. For one, machining tolerances were such that a Bio-Centric cup would more easily turn on one side of the shell than on the other. But much worse was that Niner designed large cutouts into the shell so that shifter cables could be routed internally. This dramatically weakened the shell to the point that the proper tightening torque of the Bio-Centric was enough to crush it. It was an extremely troublesome design that creaked a lot as well.
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