Box Three Prime 9 X-Wide Rear Derailleur
The Box Three Rear Derailleur simplifies the features found on the Prime 9 Box One and Two rear derailleurs making for a fully featured wallet friendly rear derailleur. Including a Limited Slip Clutch, Sealed bearing pulleys and a solid construction Box Three Rear derailleurs are compatible with 11-46 and 11-50t derailleurs making it one of the most versatile derailleur offerings for Prime 9.
Good for Less Aggresive Riding
I bought the Box Three derailleur for a budget bike build. After three months of regular XC riding, the clutch came loose rendering the clutch useless and the shifting unusable until the derailleur cage was put back on. The cage screw had a lack of Loctite. Luckily, I discovered this before I hit the trail. I am a XC rider and after shifting under load and hard shifting in general, the limit screws got pushed out of a nylon insert holding the screws in. I contacted Box customer support and they resolved the issue quickly. Their customer service is excellent. I would recommend this for beginning or novice riders. For hard riding XC/trail/enduro guys, I recommend Box One/Two derailleurs.
Excellent Replacement for a Stock Derailleur
This is my replacement for a stock Shimano Altus because I desired an 11-50T cassette. After correcting my derailleur hanger angle with the proper alignment tool (it wouldn’t be fair otherwise), this derailleur shifts crisp and fast. I discovered that I do not need a derailleur hanger extender. There is good clearance on the 50T sprocket.