BoxThree Prime 9 Multi Shift Non E-Bike and Single Shift E-Bike Cycling Groupset 9 Speed 1x Drivetrain Shifter, Rear Derailleur, Freehub Bike Cassette, Chain | Box Components

The Box Three Prime 9 groupset is installed on an custom built mid-drive electric bike with a 1000 watt motor. I was a little hesitant to try such a wide range cassette because the 12 to 50 tooth spread over 9 cogs seemed aggressive but was willing to give it a try. I'm glad I did. The shifts are positive under a load with no issues.

Works awesome... Highly recommend

An upgraded I’ve wanted to do for a while now was to switch to a one by system from my 3x9. I found box a while ago and waited for more reviews before purchasing. It came brand new in packaging with everything you need to install (excluding tools). If you’re doing as I have, you will also need to purchase a narrow wide front chain ring, with teeth count of your choice + short chainring bolts. Overall, I love the look of it on my bike and as far as performance, I strongly recommend you get hold of someone who knows their bike mechanics.The install didn’t take too long, but the Ty int process took me a while to figure out. When I set the tension, it would shift perfectly in the high gears range, but then would experience crazy chain jumping around the larger, low gear ranges. For me, I managed to fix the issue with some derailleur hanger alignment changes and B screw adjustments. Personally, I recommend you start with backing (loosening) out the b screw almost all the way as a start. From there I adjusted the H + L limit screws and cable tension. Afterwards, I played around with the B screw and cable tension simultaneously until I was able to get the gears to sit in place with minimal chain jumping. 👌works great for me so far and I’m sure it’ll last a while-the derailleur tension is quite strong-there’s a little play in the cassette-there’s a little play between the derailleur and hanger-had to grind down my crank arms a little bit to fit single narrow wide chain ring (silver spots in crank arm photo)-would recommend if you want your bike to feel lighter/easier to ride-32 tooth single narrow/wide chain ring

I saw this on YouTube and was curious to try it, so I did. To my surprise this group set are really good. It was a little stiff at the beginning but eventually it softens and shifted really quick. I would definitely recommend it to anyone out there that wanted to make their old 9 speed cassette converted to 1x9. Try it you will never regret it!

Great set for the price. The cassette is all steel

It's supposed a clutch derailleur, but it's not. It's incredibly stiff and hard to work with. This was by far the most difficult groupset I've ever attempted to tune. I say attempted because I spent three hours trying adjust it, then took it to my local bike shop and they couldn't get it to shift correctly. This groupset is junk. I should've ordered a Sram or Shimano groupset and saved myself the frustration.

Swapped out the stock 7 speed factory crap and put a breath of life into my bike.Can climb better and has a higher top speed no. This groupset has a great range!Haven't had one dropped chain since I've swapped!

Could never get it tuned brand new derailleur hanger and everything. Bought the scram eagle NX yeah it cost a bit more but it works perfectly.

Setup was so easy we assumed Murphy was around the corner. Used a race face 32T and it basically matched my old XT 3x9 range Have ridden it a handful of times on relatively easy trails and it is flawless. I am truly astonished. It shifts with authority and is so quiet with the clutched derailleur. Only flaw is the shifter levers feels a little cheap, but the mechanism inside feels solid.