Box Two Prime 9 Derailleur (Black) (9 Speed) (Clutch)

Price: $141.99
Discontinued Online
This item is discontinued and no longer available for purchase. You may want to search our site for a similar item.

While everyone else keeps adding more and more gears, the Box Two Prime 9 Groupset takes a different approach. The engineers at Box decided that sometimes simple is better so they developed a groupset with a wide ratio range over only 9 cogs. The benefit is that fewer gears reduce the chain angle on the low end; making the chainline more direct across the whole range; improving component longevity and power transfer. The rear derailleur boasts a limited-slip clutch with instant engagement and constant torque which prevents dropped chains and minimizes chain slap.


  • Prime 9 Technology for less derailleur travel and better chainline, less wear, and improved lifespan
  • Tri-Pack limited slip clutch 
  • Forged inner and outer cage 
  • Pivot-Tech cable stay
  • Sealed bushing pulleys
  • 3D forged linkages
  • Not compatible with Shimano direct mount derailleur hangers (requires traditional derailleur hanger)

Speed: 9 Speed
Shifter Compatibility: Box Prime 9
Shift Mechanism: Cable Actuated
Max. Tooth: 50T (X-Wide Cage)
Min. Tooth: 11T
Chain Wrap Capacity: 39T
Cage Material: Forged Steel
Chain Retention: Clutch
Color: Black
Weight: 290g (X-Wide Cage)

This product was added to our catalog on December 1, 2020

Box Prime 9 Model Comparison