The Park Tool BBT-19.2 handles installation and removal of 16-notch external bearing bottom brackets, the style found on most modern road and mountain bikes running Shimano Hollowtech II, SRAM GXP, Campagnolo, and similar systems. The tool fits bottom bracket cups with a 44-45mm major diameter and 42.7mm minor diameter across the notch pattern, which covers the vast majority of external bearing bottom brackets on the market.

Park Tool machines the BBT-19.2 from hardened chromoly steel for durability under the torque loads involved in bottom bracket work. The compact socket design seats fully into the cup notches, reducing the risk of slippage that can damage both tool and component. A 3/8" drive fitting accepts torque wrenches, ratchets, or breaker bars, while 1" wrench flats provide an alternative drive method when clearance allows.

The compatibility list reads like a catalog of the industry's external bearing systems: Shimano BB80, BB5700, XT BB70, BB51 and earlier outboard bearing cups, plus equivalents from Campagnolo, Chris King, FSA MegaExo, Hope, Race Face X-type, Surly, Wheels Manufacturing, and Fulcrum. The tool also fits 16-notch lockrings on Bafang BBSH and BBS02 mid-drive e-bike motors, which share the same interface. This cross-compatibility means one tool covers bottom bracket service across multiple bikes in a home fleet or shop workload.... Read More