Performance Line CX-R

Bosch's 2022 race-only twist on the Gen 4 CX platform: the same 85 Nm and 600 W as the standard motor, but with an exclusive Race mode dialling support to 400% and pushing usable power to far higher cadences. Built for UCI E-MTB starting grids, not extra torque.

Builds quickly to a broad ~600 W plateau around 75-90 rpm, then, unlike the standard CX, Race mode keeps it pulling strongly past 110 rpm before tapering. No dyno exists for the CX-R itself; as a real-world anchor, independent tests of the standard Gen 4 CX it's based on have measured a peak in the 600 W region, in line with Bosch's claim, which is the curve replicated here with the Race-mode high-cadence extension added.

The verdict

Bosch Performance Line CX-R is best understood as what it officially was at launch in September 2022: the Performance Line CX Race Limited Edition (motor code BDU376Y), a tuned variant of the familiar Gen 4 CX hardware aimed squarely at competition. The headline figures don't change from the standard unit, 85 Nm of torque and 600 W of peak power, because the differences live in the firmware and the trim, not the gearbox.

What you actually get is an exclusive Race mode that lifts support from the standard 340% to 400%, removes the gentle start-up ramp for an instant hit of assistance, and keeps power on tap at extreme cadences, up to 120 rpm or more, where the regular CX has begun to back off. Extended Boost is pushed as far as UCI rules allow, so the motor keeps shoving for a beat after you stop pedalling. Bosch also shaved roughly 150 g from the casing, quoting a bare drive-unit weight of 2.75 kg, and added red accents and remote LEDs so you know Race mode is live.

Honest caveat: there is no independent dyno of the CX-R specifically, ebike-lab never logged this variant, so the 600 W here is Bosch's own peak-power claim and the curve below is the well-documented Gen 4 CX shape with the Race-mode high-cadence extension layered on. If you want more torque or more peak watts, this isn't it. That story belongs to the 2025 Gen 5 CX-R, and it's worth being precise about what that is: the Gen 5 CX-R launched in May 2025 at 100 Nm / 750 W, and crucially it is the same Gen 5 CX hardware in race trim, not a wholly different engine. Bosch made the point itself by pushing standard Gen 5 CX motors to that same 100 Nm / 750 W through a free over-the-air update a couple of months later. The 120 Nm figure people now quote for the family is a separate, later step (Performance Upgrade 2.0, May 2026), which lifts torque to 120 Nm and support to 600% while peak power stays at 750 W. That is exactly the firmware-not-hardware logic this 2022 motor lives by, one generation on. This Gen 4 unit is the same engine as the standard Gen 4 CX, with the gloves off.

“Same 85 Nm, same 600 W as the standard Gen 4 CX, gloves off: Race mode is firmware, not a bigger motor.”

Character

Rider input

Race mode runs 400% support (vs 340% on the standard Gen 4 CX) and drops the start-up ramp, so a modest pedal input releases near-full assistance immediately.

On the trail

Sharper and more eager than the standard CX thanks to the no-ramp Race mode and high-cadence reach, it rewards spinning a fast cadence rather than grinding, with Extended Boost smoothing the gaps between pedal strokes.

Noise

No lab dBA figure exists for the CX-R specifically, so we won't invent one. Subjectively it carries the full Gen 4 CX soundtrack, and that's the honest knock: the Gen 4 CX is notably louder than its newer rivals, a penetrating high-frequency gearbox whirr under load (most audible in Turbo and Race) plus the familiar coast rattle on rough descents when the chain loads the freewheeling gear. Reviewers rate the Shimano EP801 and DJI's Avinox as quieter and lower-pitched, and Bosch's own Gen 5 CX is a clear step quieter again. If near-silence matters to you, this isn't the motor.

Efficiency

It inherits the standard Gen 4 CX's efficiency, which Bosch and several group tests rate as strong for a full-power trail motor: the Race tune trades a sharper, higher-cadence delivery for the same underlying drivetrain, so on a steady effort it draws much like the standard CX rather than a lightweight assist motor. There is no published per-kilometre energy figure for the CX-R specifically, so treat range as broadly the same as a standard Gen 4 CX on the same battery, with Race and Turbo unsurprisingly the thirstiest modes.

The case for and against

Strengths

Instant, ramp-free Race-mode assistance
400% support vs 340% on standard CX
Holds power to very high cadences (120+ rpm)
Thermally stable on sustained climbs; holds full output where lighter motors de-rate
Lighter than standard CX at a claimed 2.75 kg
Generous, UCI-legal Extended Boost

Compromises

No extra torque or peak power over standard CX (85 Nm / 600 W)
Race-only limited edition, hard to find
Loud: full Gen 4 CX whirr and coast rattle, noisier than EP801/Avinox
No independent dyno of this exact variant; 600 W is a Bosch claim
Name clashes with the newer, stronger Gen 5 CX-R

How it stacks up

On paper it matches the standard Bosch CX Gen 4 (85 Nm, 600 W, ~2.9 kg) and trades only firmware and trim. Against named rivals: Shimano's EP801 is line-ball on output (85 Nm, ~600 W) and a touch lighter (~2.7 kg) but feels softer off the mark; the CX-R's no-ramp Race mode hits harder and holds power higher into the rev range. Specialized's 2.2 has more torque (90 Nm) but a similar peak (~565 W) and is heavier (~2.98 kg). The outlier is DJI's Avinox M1, which is in a different power class, 105 Nm and ~850 W (up to 120 Nm / ~1,000 W in Boost) at just ~2.52 kg, so on raw grunt the CX-R can't live with it. And it is comfortably out-muscled by Bosch's own Gen 5 CX-R, which launched at 100 Nm / 750 W (now 120 Nm / 750 W after Performance Upgrade 2.0) on the newer Gen 5 hardware. The CX-R's case was never peak numbers; it's the instant, high-cadence, UCI-legal delivery on a proven, thermally stable Gen 4 platform.

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Sources: Bosch eBike - Performance Line CX Race Limited Edition (official) · Velomotion - Bosch CX Race test (2022) · Velomotion - E-MTB motors 2022, Bosch Smart System · NSMB - Bosch unlocks 750W/100Nm for Gen 5 CX (May 2025) · Pinkbike - Bosch firmware update: more torque, higher assistance · Singletrack - Bosch CX to 120Nm (Performance Upgrade 2.0, May 2026).