







Box Two/Three P9 X-Wide Multi Shift Groupset
SKUBX-DT23-P9BMXW-KIT
Did you know that you can mix and match Prime 9?
Can't decide between the modern basics of Box Three and the long service life of Box Two? Well, you don't need to! With this pre-configured and pre-tested option, you'll receive a Box Three cassette paired to the durable Box Two derailleur, shifter and chain.
INCLUDES
- Box Two Prime 9 Multi Shift Shifter
- Box Two Prime 9 X-Wide Rear Derailleur
- Box Three Prime 9 11-50T Cassette
- Box Two Prime 9 126L Chain Nickel
- Box One Shift Cable & Housing Kit
Our Box Two tier's mission in life is to deliver performance similar to the Box One but without its exotic (and costly) features. You still get the Tri-Pack (TM) Clutch in our derailleur only it isn't adjustable. The cassette's 11-50T range is equally impressive but we don't cut it out of a single block of steel. The action on the shifter is just as snappy although you don't get the rigid die-cast pull lever. The chain boasts the same unique ability to mate with a wide/narrow chainring except you give up the trick DLC top coat. You're hardly shortchanging yourself with Box Two.
Our Box Three tier delivers many of the same capabilities of its more famous siblings yet it's built upon a simpler platform. Cassettes are accessible at 11-46T and fashioned without spiders. The derailleur exploits our Limited Slip clutch technology without the Tri-pack features. Shift easily with a comparable mechanism, although you'll forgo the hinged clamp and die-cast structure. And lastly, string it all together with a Prime 9 chain but without extravagant coatings. If you're looking to bring your 2/3 by bike into the 21st century, then level up with this group!
SUPPORT MATERIAL
- View Prime 9 Drivetrain Compatibility Manual
- View Prime 9 E-Bike Comparison Chart
- How is the Ebike variant different?
- Why Prime 9?
9 is fine!!!
I love my prime 9! My shifts count, it’s sturdy and durable, and makes climbing a breeze! Way to go Box!!

Some problems, but overall happy
This is quite a good group set. Set up is a bit more finicky than other sets. I’ve had a bit of trouble with derailleur reliability, but Box has been amazing about warranties and my new derailleur is acting very well. Love the concept of fewer gears and bigger steps from a simplicity and longevity perspective, and so far it’s seeming to hold up (I’ve had it for four months or so). My main complaint is that the clutch is not super strong. As a hardtail fanatic, this is a bit annoying as I find myself with more dropped chains than I have with other derailleurs. I love the multi shift shifter feel and the cassette seems to be holding up. If box could further refine the derailleur, especially the clutch (maybe adjustable would be nice…) and the longevity, this set would be awesome and I’d ride it forever. As is, I’m ALMOST sold but not 100%. I think if I had a full sus it would be great, but as a hardtail, 5 day a week rider it’s not quite perfect. Keep going box! Love what you’re doing!

Great first impressions!
Initial impressions are fantastic. Installation and shifting adjustment was straightforward, easy, and fast. Really appreciate the big steps between gears for initial tuning of the shift points. On the trail these gear jumps translated to very noticeable shifts which I prefer to the smaller increments of 12speed Eagle systems. Shift ergonomics are different but easy to adjust to. No complaints. Bottom line: easy set-up, functional and meaningful shifts, great price point. Only thing to vet out is long term durability. No plans to go back to sram/shimano drivetrains.

Box Two/Three P9 X-Wide Multi Shift Groupset
Awesome! I’m very pleased with this purchase. The install took about an hour and the shifting is exact and perfect. I would definitely purchase again.