If you’re clocking lots of mileage on your eMTB, Box might have your solution with a new e-bike-specific drivetrain that promises long lasting, reliable performance for pedal-assisted trail riders. Their Two-E 9S drivetrain includes an all-new shifter, derailleur, chain & cassette, and to keep those components eMTB tough, Box kept them simple. The Two-E 9S returns to simpler times in a 9-speed setup.

Box Two-E 9S, 9speed eMTB drivetrain

Box Two-E 9S drivetrain, on E-MTB

Despite having only nine gears the Two-E’s cassette spans a wide 11-50T range, which should provide enough range to tackle any trail. In fact, this cassette provides a larger rear cog than many 11-speed drivetrains found on current e-mountain bikes.

Box says with a motor on board, E-bikers don’t need to shift around as much as non-assisted riders. Instead of riding in the tallest gear your legs can handle, E-bikers can pedal at a higher cadence which encourages the motor to kick in and help them up or along the trail. Less shifting also means less wear and tear on your drivetrain components, so if you’re OK with sacrificing a few gear step increments, Box’s Two-E 9S aims to reward you with longevity and less maintenance.

Box Two-E 9S Twin Shifter

Box Two-E 9S shifter

The Two-E 9S shifter is a mix of aluminum and nylon/fiberglass composite, with aluminum & steel hardware. Box says this new shifter features improved ergonomics. And it controls your shifts with a dual-action release lever and a two-piece steel-resin pull lever.  Most importantly for e-bike use, the pull lever is limited to one gear per shift.

The shifter weighs 122g, comes in a Matte Onyx finish, and it is sold on its own for $45 (complete drivetrain pricing below).

Box Two-E 9S Rear Derailleur

Box Two-E 9S rear derailleur

Box’s Two-E 9S rear derailleur is also made from aluminum and nylon/fiberglass composites, featuring 3D forged linkages to resist impact damage.  The cable stay utilizes Box’s impact resistant, spring-loaded Pivot-Tech design. And aluminum & chromoly hardware pins it all together.

For solid chain retention, the derailleur uses Box’s Tri-Pack limited-slip clutch. The Two-E clutch’s tension is pre-set by the factory (not adjustable). The derailleur is compatible with up to 50t cogs, and its pulleys spin on closed bushings. This derailleur is designed for a traditional hanger, not compatible with Shimano’s direct-mount standard hanger.

The Two-E 9S derailleur comes in a Matte Onyx finish, and weighs 290g. It is available on its own for $110.

Box Two-E 9S Cassette

Box Two-E 9S cassette

Even with nine cogs, the Two-E 9S cassette provides a wide 454% gear range with fairly evenly spaced increments top-to-bottom (11-13-15-18-22-28-34-42-50). The 7075-T6 aluminum & hardened steel cassette uses an alloy spider with the cogs pinned in place. Box’s cassettes are compatible with Shimano HG freehubs. The Two-E 9S is finished in ED Black, weighs 650g, and sells for $110.

Box Two-E 9S Chain

Box Two-E 9S chain
photos courtesy Box Components

Intended to handle plenty of torque from your motor, Box’s e-bike specific Two-E 9S chain is built tough. This heat treated alloy steel chain features solid pins, plus solid inner & outer plates for maximum strength. The chain comes with 144 links and weighs 350g. It retails for $25 with a nickel plated finish.

The new Two-E 9S drivetrain is also covered by Box’s “Shift Happens” lifetime warranty program. It doesn’t cover you for regular wear & tear, but if your Box component breaks, cracks, or fails from a manufacturing defect, the company will replace it (see Box site for further details).

Box Two-E 9S complete groupset

Besides, buying components individually, the complete Two-E 9S drivetrain can be purchased for a bundle price of $280. All of the components are available online now, direct from Box.