Mountain Bike Action Product Test: TRP TR12 12-Speed Drivetrain
The new TR12 system builds from the technologies first seen on the DH7 drivetrain. Features like the Hall lock and Ratchet clutch were carried directly over to the new system. The Hall lock, named after World Cup mechanic John Hall, is a design that locks the derailleur to its upper mount, otherwise known as the B-Knuckle. The Hall lock has an on/off lever designed to lock the derailleur to the hanger and frame and remove unwanted noise. The Hall lock adds stability to the derailleur over rough terrain but can be adjusted to act like a normal derailleur if you desire.
The next key feature is the adjustable Ratchet clutch that also features an on/off switch for ease of wheel removal. This clutch system aids in the reduction of chain noise. Last but not least, the system has some setup features to make installation easier. Two printed indicators allow mechanics to easily check chain length and B-screw adjustments.
The derailleur is said to work with most 12-speed cassettes and has a max range of a 51-tooth. The shifter is designed to work exclusively with the TR12 derailleur and offers a 5-cog sweep for quick shifting. The two components have a combined weight of 402 grams and cost $330.