Box Two Prime 9 drivetrain

25/01/24 23:20 Filed in: Gear

Close to 20 years ago now I bought my first 29r. A titanium hardtail with XT bits providing the gears and stopping. That was my race bike until I got a full-suspension bike for that role and the hardtail was modified to be a singlespeed. Then about 3 years ago I bought a new singlespeed and the titanium bike went in storage. It came back out just before Christmas to become my son's new bike. But he needed some gears.
Box is a company that was known for making high-end BMX gear. They decided to get into MTB and eventually released four levels of related drivetrain components that are all 1x9 (Prime 9 = 1 x 9). The top one is quite expensive and called Box One. The cheapest one is not very nice looking and is called Box Four. The Box Two pieces aren't quite as flashy as the Box One, but much lighter and nicer than the Box Three level stuff. Seems like Box Two hits the sweet spot. Especially when it is on sale when you need it!

One small box contained the derailleur, the shift lever, the chain, the cassette (11-46 range), some cable housing and a shift cable. Instructions were provided online either written or YouTube. It all went together really easily. It did require a lot more B-tension than I expected to keep the upper jockey wheel from hitting the low gear teeth on the cassette. And when I was finished it was not shifting nicely into the second-lowest gear when coming from a higher gear (but it was fine from the lowest gear). No adjusting could quite get rid of that.

I checked the derailleur hanger and it was not perfectly lined up with where it should have been. Once that was fixed, then the shifting was perfect.

In use, the Box Two items work really well. I did find that the amount of pressure required on the shift lever reflected the gear the bike was in - some strange relationship between cable tension and lever effort that suggests Box hasn't nailed every last aspect of their design philosophy quite yet.

It was also my first exposure to anything in the CUES line from Shimano. I put new cranks on the bike because the new owner didn't need my old 180 mm cranks but by remaining in the Shimano brand I didn't have to change bottom brackets. The CUES crank preloads like a SRAM DUB crank, except there is no locking mechanism for the preload collar.

Only having 9 steps for most of the SRAM Eagle gear range means the steps are wider. In use, that seems OK. Especially for a fun bike. XC racing might benefit from more options, and any decent downhill slope (whether XC or Enduro or anything) would benefit from the 10T high sprocket the Box cassette lacks. But for a fun bike, it's great and you pretty much know what gear you need to be in at any time. Given that the entire box-set (pun intended) cost about the same as an XT cassette, it can't be just as refined and light as Shimano's second tier offering.

I like this brand. I'll be curious to see how it fares with use. I'm betting OK.

Michael Hanslip Coaching

If you want to go faster, you have to pedal harder

Box Two Prime 9 drivetrain