DT Swiss offers two upgrade kits for the entire range of the DT Swiss Ratchet System rear hubs. While the stock Ratchet System hubs come with a pair of 18T ratchet wheels (which serve up ample performance), DT Swiss has 36T and 54T ratchet wheels, that easily install into any Ratchet System hub for an instant performance bump. Simply put, the more notches, the quicker the engagement. These upgrade kits are compatible with DT Swiss 180, 190, 240S, 350 and 440 rear hubs. They will also upgrade pre-built DT Swiss RR, XR and FR series freehubs

The pitch of the teeth on the 36T ratchets are decreased from 20° to only 10°, which equates to faster and more stable engagement, while the 54T teeth are decreased from 20° to a mere 6.66° for practicality instant engagement. With each step of increased performance, stock 18T to 36T, and then to 54T, comes at a price. Increased the number of ratchet notches makes a more audible sound from the rear hub and requires shorter service intervals. Most feel it's a small price to pay for gears on your cassette to operate more precisely and offer that instant locked in feeling when moving from coasting to under load and torque on the rear hub.