External cup threaded bottom brackets are quiet, durable, and efficient. These are all reasons we are seeing more standard BSC 68mm threaded bottom bracket shells, which had been overtaken by PressFit options. Wheels Manufacturing offers these Threaded Road AC Bottom Bracket's as solid upgrades to stock options. Wheels only uses Enduro bearings and silicone seals for the most durable and smoothest bottom brackets available, all of which are fully serviceable.

The Angular Contact sealed cartridge bearings have low friction, with long life and are resilient to loads under unequal pressure from each side. The bearings are steel, sealed, and damn reliable. Over time these AC bearing are incredibly cost effective, smooth running and easily (though rarely ever) replaced. The Shimano 24mm version features AC bearings in both left and right cups. Please note that the SRAM stepped 24/22mm GXP option uses a drive side AC bearing, but must have an ABEC-3 bearing on the non-drive side due to engineering requirements for Angular Contact.