However, general shifting was good and with a positive push of the lever (more on this below) the derailleur didn’t miss any shifts and wasn’t hesitant in its operation. It also happily shifted gears under power. Compatible with HG Freehub Bodies. Compatible with Standard Derailleur Hangers (Non Direct-Mount). Compatible with most 10,11, & 12-speed wide / narrow chain rings. Prime 9 chain must be used. The lever has a lot of travel before a shift is engaged, too, so a fair amount of sustained force was required to change each gear, which didn’t feel particularly natural. Compared to Shimano, pricing for Box One Prime 9’s derailleur and shifter sits in a middle ground between XT and XTR, while the cassette price is similar to Shimano’s SLX-level. My test sample wasn’t supplied with an I-Spec or Matchmaker adaptor, although these are available. Alex Evans

Installation was relatively straightforward and I was particularly thankful for the shifter’s hinged bar clamp, which meant I didn’t need to remove the grips or brake lever from the bar to install it. Box Components provides installation and set up guide videos on its YouTube channel to help with the finer details of getting the drivetrain installed and running smoothly. I followed the instructions to the letter to give the drivetrain the best chance possible of performing as intended.However, it states its system isn’t compatible with 12-speed chainrings or non-narrow-wide offerings. The cable port is vertically positioned. Alex Evans Box Components Box One Prime 9 drivetrain details

General operation was quiet, too, and shifting under power was good – as long as the shift lever was pushed far and hard enough. Compared to SLX M7100 (1,221g), XT M8100 (1,153g), XTR M9100 (996g), and GX Eagle (1,163g) it is significantly heavier. The factory setting for the derailleur’s clutch is stiff, which means its initial movement has a significant resistance peak before the cage is able to smoothly pivot forwards. The maximum jump between gears is eight teeth (consistently between the lowest three gears), with the jumps decreasing as the gears become higher. The consistency of the gaps makes adjusting cadence to a gear change more gradual. Box Components Box One Prime 9 drivetrain compared to SRAM NX Eagle, SRAM GX Eagle and Shimano SLX, XT and XTR The cable-pull lever can shift four gears at once if pushed far enough, but accessing the last shift is virtually impossible while riding because of the amount of travel required to engage the gear.From a pricing perspective, Box Components Box One Prime 9 drivetrain is comparable to SRAM’s GX Eagle level (once you’ve removed the cranks and chainring from the GX groupset). When lower gears were selected and chain length grew, the derailleur’s clutch tension caused the cage to be stiff pivoting forwards, so the cable-pull shifter lever was heavy throughout the lever’s throw. The cable release lever was also quite stiff but felt way more positive. It was only possible to shift one gear at a time, though. Because the derailleur’s cable stop is positioned vertically (similar to Shimano) a large loop of cable is required to avoid a sharp bend that could reduce shifting performance. The cassette uses Shimano’s Hyper Glide (HG) freehub body which is different to SRAM’s XD Driver and Shimano’s Micro Spline system.