Park Tool GearClean Brush (GSC-1)

The curved toothed end really digs into the tight spaces between my cassette cogs, making deep grime easy to scrub out. It’s so much more effective than an old rag or toothbrush, and the whole job takes half the time now.

This brush’s curved, toothed-end makes it so much easier to dig grime out from between cassette cogs without shredding my fingers. The handle is comfortable even after scrubbing for a while, and it really gets the deep dirt that builds up on a dirty chain.

The handle is nicely padded and comfortable to grip, even with greasy hands. It really digs into the cassette to get the grime out, though I wish the bristles were just a touch stiffer for really caked-on drivetrains.