Bosch Performance Upgrade 2.0: Free Firmware Pushes CX and CX-R to 120Nm

Bosch is rolling out a free firmware update called Performance Upgrade 2.0 that turns every existing Performance Line CX and CX-R motor into a meaningfully more powerful machine — no hardware swap required. Starting May 4, riders can pull the update through the Bosch eBike Flow app and immediately unlock 120Nm of maximum torque, up from the 85Nm those motors shipped with and the 100Nm ceiling set by last year's software revision. Peak power stays at 750W, but maximum rider support climbs from 400% to 600%, available at speeds up to 15 kph in Race, Turbo, eMTB+, Cargo, and Auto modes.

The numbers tell the story of how quickly the eMTB motor segment has moved. When the current Smart System CX platform launched, 85Nm was competitive; a software update in 2025 pushed that to 100Nm. Now, 120Nm matches the outgoing Avinox M1 motor spec. The 600% support figure deserves some context: if a rider is putting out 100W of pedal power, the motor can add up to 600W of assistance, though the system caps total output at 750W and backs down immediately after the demanding section. Above 15 kph the system steps down — Turbo and Auto modes hold at 340%, while Race, eMTB+, and Cargo hold at 400%.PinkBikeSingletracksBikeRumor

The most technically interesting piece of the update is a feature Bosch calls the Drivetrain Tensioner. On any pedal-assist bike there is a brief dead zone between the moment a rider starts pedalling after coasting and the instant drive actually reaches the rear wheel — caused by chain slack and the time it takes the rear freehub to engage. Bosch's solution is software: the system closes the internal freewheel in the motor and slightly pre-rotates the chainring, keeping the drivetrain in a primed state. The result, according to Bosch, is near-instantaneous traction when the rider reapplies input, which matters most on low-speed technical climbs where restarting on steep grades is common. The Drivetrain Tensioner will be available in eMTB+ and Race modes when it rolls out in mid-2026. A second refinement, Extended Boost, has also been made adjustable: riders can now set the length of the motor's post-pedal-stroke overrun — up to two metres — via a slider in the eBike Flow app for each individual ride mode.SingletracksBikeRumorBikeRadar MTB

The update reaches riders as a free over-the-air download through the Bosch eBike Flow app beginning May 4. Compatibility covers the BDU38 Performance Line CX and CX-R motors — the entire current Smart System generation — and no service appointment or hardware change is required. Riders can tune their torque ceiling up to the 120Nm maximum in any ride mode, subject to whatever limits a specific bike manufacturer has set, and the app's slider gives granular control so riders who prefer a more natural feel can dial things back. Alongside the firmware, Bosch is also announcing a new Live Data Interface that pushes real-time battery level, motor output, and cadence to select Garmin Edge head units, bringing the ecosystem in line with what Avinox already offered.PinkBikeBikeMagBikeRumorRoad.cc

The strategic backdrop matters here. DJI's Avinox M2S motor — the catalyst that prompted this update — offers 150Nm and bursts to 1,500W, well beyond any legal Class 1 e-bike ceiling in the US or Europe. Bosch has been deliberate about holding at 750W, and brand ambassador Hans Rey publicly called for legislation capping Class 1 eMTBs at that figure in April. The 120Nm torque target is not arbitrary: it matches the Avinox M1 that was the class benchmark before the M2S arrived, and Bosch argues that 750W is a sensible ceiling that keeps eMTBs trail-legal and mechanically realistic. For riders who already own a CX or CX-R bike, the calculus is simple — a motor that launched at 85Nm effectively becomes a 120Nm motor at zero cost on May 4, with a GaN-based 12A fast charger (500W, 3x the speed of the old 4A unit) available as an optional hardware add-on later in 2026.BikeRadar MTBSingletracksBikeMagPinkBike