Lighter Bosch Active Line Plus motor debuts on Trek Marlin+

Bosch has refreshed one of its most widely used e-bike motors, and Trek is first in line to use it in North America. The new generation of the Bosch Active Line Plus (model BDU344Y) is more powerful, smaller and lighter than the drive unit it replaces, and it now powers Trek's updated Marlin+ 6 Gen 2 electric mountain bike.

What's new in the motor

According to Bosch's announcement, the updated Active Line Plus offers:

• up to 60 Nm of torque, 600 W of maximum power and up to 340% support on top of your own pedalling;
• a new two-stage gearbox that makes the unit 17% smaller in volume;
• a weight of about 2.7 kg (6 lb), roughly 0.5 kg (1.1 lb) lighter than before;
• improved seals and bearings intended for riding in all weather;
• smoother response from updated sensors and software, and specially machined gears that Bosch says make it "virtually silent";
• compatibility with Bosch's eShift automatic gear shifting and, on suitable city bikes, a backpedal (coaster) brake.

Bosch's European spec sheet lists a rated continuous output of 250 W and assistance up to 25 km/h, in line with EU pedelec rules. In the US, the motor assists up to 20 mph as a Class 1, pedal-only e-bike. Bosch also says around 40% recycled aluminium in the housing cuts nearly half of the CO₂ emissions compared with conventional aluminium.

The first bike: Trek Marlin+ 6 Gen 2

Trek's Marlin+ is a hardtail e-MTB aimed at riders who want trail ability without paying for a high-end electric mountain bike. Trek's product page lists the Marlin+ 6 Gen 2 at $2,999.99 with:

• Bosch Active Line Plus motor and a 400 Wh CompactTube battery;
• Purion 200 display, Class 1, 20 mph assist;
• 120 mm SR Suntour XCM 34 fork and 9-speed Shimano CUES drivetrain;
• Tektro hydraulic brakes, and a listed weight of 22.10 kg (48.73 lb) in size M.

If you're used to car batteries, 400 Wh sounds tiny, but it is a typical size for a lighter e-bike. Our power bank guide explains how watt-hours work, and the same rules for keeping a battery healthy, like avoiding heat and long periods at 100%, apply here as they do in our EV battery care guide.

More Bosch updates

Electrek notes that Bosch has also introduced an Intuvia 200 display with a 2.4-inch screen, a smaller LED Controller with USB-C, an updated ConnectModule for tracking stolen bikes, and a PowerTube 720 battery. Trek hasn't said which of these, if any, will come on the Marlin+. Because Bosch supplies drive systems to many e-bike brands, expect the new Active Line Plus to appear on other city, trekking and entry-level trail bikes over the coming months.