The New World of Bottom Brackets



Here’s a post from our friends at Park Tools.
Yeah, my head hurts too, it’s ok, this is important:

Any mechanic with some history in this industry will recall changes to the headset with the introduction of the 1-1/8″ and 1-1/4″ threadless standards. This caused a bit of a stir at the time, and now we are seeing similar stirrings in the bottom bracket world.

The BB30, so-called “BB86″ or “BB90″, Press Fit 30, and the proprietary designs of various manufacturers should best be thought of as “sideways headsets”. Threadless frame shells hold bearings by either a slip or a mild press fit. The axle system (spindle) will have some sort of pre-load system. These preload systems vary in sophistication from fine threaded adjustments, to compressible rubber washers, steel “wavy” washers, to simply by shoving an arm further along a press fit to load against the bearings. We have of course seen similar attempts at this from older Fisher bottom brackets, Klein, and even BMX standards such as Mid and Spanish.

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