Picking up a used frame or building around a closeout deal sometimes means inheriting a bottom bracket standard you didn't choose. The 386EVO standard shows up on frames from several manufacturers, using a wider shell than PF30 and bearings designed for 30mm spindle cranksets. If you already own Shimano cranks—or prefer Shimano's shifting integration, pricing, or parts availability—the 386EVO Adapter from Wheels Manufacturing lets you run your 24mm spindle crankset in that 386EVO frame without replacing the entire bottom bracket.

The adapter works by reducing the inner diameter of the 6806 bearings from 30mm down to 24mm, matching the spindle size of Shimano HollowTech II and similar cranksets from FSA and other manufacturers. Wheels Manufacturing machines these adapters from engineering-grade Delrin, which provides the dimensional stability needed to maintain bearing preload while self-lubricating against the spinning spindle. The material also dampens vibration transfer between the spindle and bearing races, which can reduce drivetrain noise in some installations.

Installation involves tapping the adapters into the existing 6806 bearings with a soft mallet. The adapters seat against the inner race of each bearing, creating a new interface sized for your 24mm crankset. Eight 0.7mm spacers come included in the kit for chainline adjustment and eliminating lateral play once the crankset is installed. Stack spacers on either side of the bottom bracket as needed to center the chainrings relative to your rear cassette or to take up any side-to-side movement in the crank arms.... Read More