Bosch has today launched the latest incarnation of the Performance Line CX, its sportiest mid-motor which is primarily intended for electric mountain bikes. As well as reductions in noise and weight, the brand has made a number of tweaks to its sensor technology, and now claims the system “knows” how steep an ascent you’re on and whether you’re riding on a forest path or a root-covered trail.

The Performance Line CX was first launched in 2015, having been specifically designed for eMTBs. It’s had a number of updates since then, becoming something of a fixture in the world of mountain biking – as evidenced by the number of times it features in our guide to the best electric mountain bikes.
 

New for 2025

The motor offers up to 85Nm of torque, peak power of 600W and up to 340 per cent support. (‘Continuous rated’ power is obviously the usual 250W.)

The reduction in weight for the 2025 model is not colossal – just 100g – but the reduction in noise might be more noticeable. Bosch has tweaked the gearbox so that when riding downhill, the external drivetrain (the chain, chainring and cassette) is decoupled from the internal drivetrain (the freewheel, gearbox and motor).

Changes to the sensor tech may also prove to have a significant impact on ride feel.

Bosch says its combination of sensors now measure pedal input more than 1,000 times per second. This includes a high-resolution cadence sensor and torque measurement technology, as well as inertial sensors to measure acceleration and rotation speeds and to recognise inclination and tilt angles, as well as vibrations.

One product of this is a new hill start assist feature, which apparently means, “riders can tackle challenging uphill terrain in a controlled manner and with full traction.”

According to Bosch: “The drive unit is highly sensitive, responding to changes in acceleration, rider’s pedal power and current speed. Thanks to the newly interpreted sensor signals, eBikers always receive the right motor power – sensitive, controlled and immediate, or gentle, restrained and reliable for long rides.”
 

Battery, display and ABS

Other updates to the Bosch ‘ecosystem’ include the introduction of an 800Wh battery – the PowerTube 800 – which will be Bosch’s largest, and a new Purion 400 display.

The brand’s anti-lock braking system (ABS) also sees a few changes with the arrival of two new braking modes: ABS Trail Pro for performance-led mountain bikers and ABS Race for enduro racers.

Bosch has been testing the tech in eMTB racing and says the new modes allow, “late and powerful braking without the front wheel slipping.”

> Bosch e-bikes to be compatible with ABS from rival Blubrake