BOX Two Prime 9 Speed X-Wide Derailleur

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BOX shook up the drivetrain market last year with the release of their wide range 9-speed drivetrains. The prime 9 components are optimised for 11-50t cassettes without all the headaches of adjusting 12 gears. The Box Two Prime 9 rear derailleur is BOX's middle of the range Prime 9 offering. It includes many of the awesome features from the Box One derailleur but forgoes the adjustable clutch and uses bushing pulleys to be more wallet-friendly. 

Who's this item for: Any shredders running a Box Prime 9 speed drivetrain or those looking to upgrade to Box's innovative wide-range 9-speed drivetrain offering.

E-bike friendly: Yes, The Box Two Prime 9 components are suitable for use on e-bikes when used with the single-release shifter. 

Number of gears: This is a 9-speed derailleur

Weight: 290g

Materials: Constructed from both hardened alloy steel and stainless steel with a matte onyx finish

Chain and cassette compatibility: This derailleur is designed to pair up with the rest of the Box Two Prime 9 drivetrain components. However, it will also perform flawlessly with any other Box Prime 9 components.

Max cassette range
  • Minimum sprocket size: 11T
  • Maximum sprocket size: 50T
  • Total capacity: 39T
Clutch style: The Box Two uses the non-adjustable version of the Tri-pack limited-slip clutch.

Cage length: A forged inner and outer long cage provides excellent strength and the length to accommodate the wide range cassette.

Pros: 11-50T range at a 9-speed, easy on the wallet price point.

Cons: Non-adjustable clutch.
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9 Speed
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9sp all the way!


Loving the 9sp set up. Had to replace this as I bent the other but really there has been no issues what so ever.

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9sp all the way!


Loving the 9sp set up. Had to replace this as I bent the other but really there has been no issues what so ever.


BOX Two Prime 9 Speed X-Wide DerailleurBX2PRM9DER
9 Speed639266097273

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