Jab Derailleur Clutch Types
The Jab derailleur has 2 different clutch types: MTB and gravel. The gravel clutch comes on all gravel configurations, and the MTB clutch comes on all MTB configurations.
Both are adjustable and rebuildable, and the Jab is convertible between the 2.
The clutch applies friction to the pulley cage to help reduce chain vibration, which reduces chain slapping noise, and reduces the chance of a dropped chain.
The gravel clutch is very simple and reliable, applying friction in both rotation directions, which helps calm the chain down whenever the cage is moving. This works like suspension, which has both compression and rebound damping. Most derailleurs apply friction in 1 direction (forward) and no friction in the return direction. This clutch applies about as much friction as a SRAM clutch, and it is adjustable within a narrow range.
The MTB clutch is intended for aggressive MTB riding. The clutch uses a ratchet mechanism applying high friction in 1 direction, while allowing a quick return of the cage. The friction can be adjusted very high - much higher than any other derailleur. This is ideal for the most aggressive riding conditions. It also has a wide adjustment range.
| Gravel Clutch | MTB Clutch | |
| Intended Use | Gravel, road, light MTB | MTB, enduro, DH, eMTB |
| Adjustable | Yes | Yes |
| Adjustment Range | Narrow | Wide |
| Adjustment Method | Add/remove shims | Add/remove shims |
| Rebuildable | Yes | Yes |
| Mechanism | 2-way friction plate | 1-way ratchet with 2 pawls |
| Engagement Angle | Instant | 2 degrees |