Die-cast A380 aluminum is not a typical material for chain cleaning tools, and that's the point. Park Tool's CM-25 Professional Chain Scrubber exists because plastic chain scrubbers have a finite lifespan in any environment where they see regular use. The hinges fatigue, the latches weaken, and eventually the housing fails. The CM-25 replaces all of that with a die-cast aluminum body and handle, stainless steel hinge pins on the locking cover, and a cartridge-based internal system where every wear component can be swapped without replacing the tool itself.

Inside the housing, rotating brushes scrub all 4 sides of each chain link as you backpedal, while dual-sided sponges and wicking pads catch excess solvent before it drips onto your floor or workstand. The 4-stage cleaning system is more contained than the typical plastic scrubber, which helps keep degreaser where it belongs rather than running down your chainstay. Park Tool recommends their CB-4 Bio ChainBrite as the cleaning solvent, though any bike-specific degreaser works in the reservoir. You can choose between drip or immersion fluid application methods depending on how dirty the chain is and how much solvent you want to use.

The CM-25 works with all multi-speed chains from 5-speed through 12-speed, plus some single-speed setups. The handle is removable and secures with a 1.5mm hex bolt, so it stores flat if you need to tuck it into a toolbox or drawer. When the brushes and sponges wear down, the RBS-25 replacement cartridge clicks in and out of the body as a single unit. You don't need to individually position each brush and sponge. If only the sponges and wicking pads need replacing, the 2336K kit covers those separately. That modularity is where the cost math works out over time. You're buying replacement internals instead of replacement tools.... Read More