Chain cleaning tools fall into two camps: the cheap plastic ones that crack after a season, and professional-grade units that actually survive shop use. Park Tool's CM-25 sits firmly in the second category, built around the same cleaning principle as their original chain scrubber but with construction that holds up to daily use. The rotating brush system scrubs all four sides of the chain simultaneously as you backpedal, which means you're actually cleaning the inner plates and rollers where grime does the real damage—not just wiping down the outer surfaces.

The CM-25 uses a magnet-sealed reservoir that contains your cleaning solvent while the chain passes through three rotating brushes. Those brushes spin against the chain's movement, creating the friction needed to break up the paste of old lubricant, road grit, and metal particles that accumulates in the drivetrain. The sealed design keeps solvent from splashing onto your floor or frame, and the reservoir holds enough liquid to run through several cleaning cycles before you need to dump and refresh.

What separates this from the disposable chain cleaners is the replaceable brush cartridge system. When the brushes wear down—and they will, because they're actually doing work—you swap in a fresh GSC-3 cartridge instead of buying an entirely new tool. The handle design gives you enough leverage to hold the unit steady against chain tension, and the body geometry clears most chainstay and chainring configurations without requiring awkward positioning.... Read More