Box Two Prime 9 X-Wide 11-50T Cassette
Box Two Prime 9 X-Wide 11-50T Cassette
Box Two Prime 9 X-Wide 11-50T Cassette

Box Two Prime 9 X-Wide 11-50T Cassette

$109.99 Sale Save
5 reviews
Size 11-50T
Color Black

Only 0 left in stock


The Box Two cassette was where Prime 9 started. Originally conceived as an E-MTB product to deliver long service life and extra range over fewer gears, we quickly grew to enjoy its abilities on unpowered MTBs. All cogs are stamped from steel and subsequently, the larger ones are pinned to alloy spiders. Due to its provenance, this is, without doubt, the most durable cassette in the range.

Please see 
page 6 of our guide for notes regarding the 2 HG drivers.

Our Most Durable Cassette
Steel Stamped Cogs
Lightweight Alloy Spiders
Ultra-Wide Ratio with Consistent Progression

Box One Prime 9 Chain 126L DLC Black
Box Two Prime 9 126 Link Chain Nickel
Box Three Prime 9 126 Link Chain Polished
Box One Prime 9 Rear Derailleur
Box Two Prime 9 X-Wide Rear Derailleur Black
Box Three Prime 9 X-Wide Rear Derailleur Black
Box One Prime 9 Shifter Black
Box Two Prime 9 Shifter Black
Box Three Prime 9 Shifter Black

• Cogs: Stamped / Hardened Steel
• Spider: CNC / 6061-T6 Aluminum
• Lockring: CNC / 6061-T6 Aluminum
Finish: ED Black
Speeds: 9
Gear: 11 - 13 - 15 - 18 - 22 - 28 - 34 - 42 - 50
• Platform
• Non-Ebike
• Driver: HG Freehub Body
• Chain:
• Box One Prime 9
• Box Two Prime 9
• Box Three Prime 9
Weight: 645g/22.7oz

Q: What is the difference between the Wide and X-Wide?
A: The Wide cassette offers an 11-46T range while the X-Wide offers an 11-50T range.

Will the Box Two Prime 9 Cassette fit on an wheel with a Sram XD Driver?
No this will only work with a HG splined Shimano 9-10-11 speed freehub body

Is the Box Two Prime 9 Cassette compatible with other 9 speed drivetrains?
No, The Box Two Prime 9 Cassette is optimized for Box Prime 9 drivetrains and running other component variations can result in poor performance.

How should I clean my Two Prime 9 Cassette?
We suggest removing the cassette from the wheel and using a soft bristle brush with soapy water or a mild de-greaser. We do not recommend pressure washing, strong solvents or de-greasers as they could degrade the surface coating.

Will Box be making cassettes compatible with XD or Microspline driver bodies?
At this time our cassettes are only compatible with HG style MTB 8/9/10 speed or road 11 speed driver bodies. Most hub manufacturers offer the different

Customer Reviews
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Filter Reviews:
Brian K.
United States United States

Great cassette!!

Love my Prime 9 setup!!

Isaac P.
United States United States

Another excellent component

I own many BOX Prime 9 systems. 1, box One Two system, 1, box Two system, 1, box Two Three system and 1, box Three system. This purchase was to complete a new BOX Two system for a 2019 Trek Marlin 4 that's been so upgraded it's now better than a 2022 Trek Roscoe 8, and part of that is a complete BOX Prime 9 Two system. Keep making great components.

Robert A.
United States United States

Best performance/value cassette

5 star operation. I am completely sold on Prime 9

Manuel F.
Germany Germany

Heavy but still the best cassette range for 1-by conversions

This was used for a 1-by conversion of my 2009er Haibike Edition hardtail and it was the best upgrade since I've gone tubeless on this bike. Two important lessons learned: 1. Make sure your rear derailleur has enough capacity to serve a 50T cassette. I had to order the Box Two Prime 9 XL-cage derailleur (and Box One Prime 9 shifter) since my existing derailleur couldn't handle anything bigger than a 34T cassette. Both the shifter and derailleur are excellent, but keep the additional cost in mind. 2. Pay attention to your chainline - bigger rings in the front might need more spacers / offset than you expect. I ended up using 9.1 mm(!) spacers to get the chain line and noise in check using a 34T ring on a 104 BCD crankset. For an every-day MTB, my recommendation would be to pair this cassette with a 34T oval chain ring in the front, which will give you marginally improved climbing without loosing too much top speed when compared to the classic 3-by system (44/32/22 rings with an 11-32 cassette). If you're bikepacking, consider a 30T oval chain ring to get even better climbing. In my experience the oval chain ring will provide you with a wider usable cadence range (when compared to round chain rings), which compensates nicely for the loss in granularity by dropping 18 gears. So far, I've put around 900 miles on the cassette in six months on my bikepacking commuter. Shifting is still great, surface wear appears nominal. I like the old-school construction cogs hardest five gears, because this is where most of the wear and tear accumulates. Since shipping from the US to Germany is crazy expensive due to ~30 % import tax I hope to be able to replace the smaller cogs with locally sourced parts instead of ordering a complete replacement cassette once this ones worn out. My only complaint would concern the weight of the cassette, which comes in around 645 g on my scale. It's not exactly a drag, but you definitely feel the weight of your drivetrain with this piece.

Kevin G.
United States United States

Box 2 cassette is tough a light for Pisgah

Super tuff, long lasting and sharp