Box Four 8 Speed Wide/Narrow Chainring
SKUBX-CR4N10432-BK
The Box Four Wide/Narrow chainring completes that package for the 1x8 system. It is the first 8 speed specific chainring designed to optimize chain retention when using 8 speed chains. The tooth profile and thicknesses are tailored to match the inside geometry of the unique Box Four chain.
SUPPORT MATERIAL
- View Prime 9 Drivetrain Compatibility Manual
- How is the Ebike variant different?
- View Prime 9 Comparison Chart
- Why Prime 9?

Haven't lost a chain yet
I converted my old Cannondale to an ebike using a TSDZ2. On the first ride using the original Shimano XT 9-speed, I dropped the chain on a bumpy downhill section. I upgrade to the Box 8-speed with this chainring and haven't lost a chain since. Its very robust and I can shift under power even with the motor putting out about 750W.

Good addition to the 8speed drivetrain but you can't use the master link
Inexpensive. Holds your chain snuggly when running a clutch derailleur, I am running the Box 8speed. Overall I am definitely pleased with the 8 speed and this narrow wide chain ring. My one complaint is that I can't use the 8speed master link when using this chainring. The master link is not compatible due to the link width being to narrow.