Since the Drone specialist DJI with the Avinox motor has entered the e-bike market with a loud bang, the well-known motor manufacturers seem to have fallen behind somewhat. In terms of power and weight, the Chinese have pulverised the existing products. At the start of the Bike Festival in Riva del Garda, Bosch is following up with the new CX-R. This means that the race version of the Performance CX is getting its long-awaited successor. And the newcomer should not only impress with watts and Newton metres - but also with its special engine tuning.
In addition to increased performance, the developers of the grey noble engine have also fine-tuned the weight. The classic CX also has the powder-coated magnesium housing, but the corrosion-resistant titanium crankshaft and high-quality ceramic ball bearings reduce the weight of the CX-R to just 2.7 kilograms. This is roughly the same weight as the Shimano EP801 and around 100 grams less than its "little" brother, the Performance CX. A comparison with DJI: the Avinox is even lighter at just under 2.6 kilograms.
The housing and hardware are otherwise very similar to the current fifth-generation Performance CX. The form factor, mounting points and the gearbox inside are identical to the classic. This means that the two motors fit into the same bikes again. And that also makes one thing clear: unlike the old Race CX, the new CX-R no longer rattles on the descent.
More power than ever before
750 watts of peak power, 100 Newton metres of torque and 400 percent support are the new key figures that Bosch has specified for the CX-R. A Bosch motor for e-bikes has never had so much power. The current Performance CX before the announced power update is specified with 600 watts, 85 Newton metres and 340%. The race predecessor CX-R had 600 watts, 85 Newton metres and 400% support. With the Power-Plus, the Swabians are still some way off the fabulous values of the DJI motor (850 watts in normal operation, 1000 watts at the peak) - but closer than before. In terms of performance, Bosch should be roughly on a par with the new Specialised S-Works engine However, at over 3.1 kilos, it is significantly heavier.
What the Bosch Performance Line CX-R can do
- Thanks to exclusive materials such as a titanium crankshaft, the CX-R is lighter than the classic CX. However, the gain is manageable: according to the manufacturer, the race unit weighs 2.7 kilos, compared to 2.8 kilos for the classic model.
- The CX-R has more power than any Bosch e-MTB motor before it. It is said to deliver up to 750 watts (previously 600 W), 100 Newton metres of maximum torque (previously 85 Nm) and up to 400 percent assistance.
- Race mode is exclusive to the new CX-R. The focus here is on direct engagement, strong acceleration and full thrust right up to the switch-off limit. The mode can be customised in the app.
- The new E-MTB+ mode is intended to lie between the familiar E-MTB mode and the aggressive Race mode. It reacts strongly to the rider's input and is intended to release up to 400 per cent support. Bosch wants to switch between fine modulation and extreme thrust with long coasting depending on the situation.
- Bosch has announced that the first bikes with the new CX-R motor will be available in autumn 2025. At the very least, the models will not be available from specialist dealers until then.
More power for the Performance CX motor too
The best news for many Bosch riders: The majority of the new features are not just exclusive to the new CX-R. The latest version of the classic Performance CX (Gen. 5 / BDU 38) also gets more power and new modes via a free update. All information about the major software update for the Performance CX can be found here in the link!
Full thrust, long overrun: Race mode for steep climbs
The more aggressive Race mode is exclusive to the CX-R. This works extremely directly and offers even more support than the turbo mode in many situations - for maximum acceleration. It also continues to push at full thrust right up to the switch-off limit. Extended Boost has been extended again compared to its predecessor and is designed to help you over root passages and steps even more playfully. This means that Race mode remains a special tool for really nasty climbs and E-MTB races. If you want to adapt the mode to your personal preferences, you can customise the various performance parameters in the E-Bike Flow app.
New E-MTB+ mode
In addition to pure power, Bosch has also further tuned its hobbyhorse: the tuning of the motor is said to have moved up another level. To this end, there is a new mode, E-MTB+, which is designed to work particularly dynamically and adapt even better to the conditions on the trail. The E-MTB+ mode provides up to 400 per cent support and, in the right situations, the maximum overtravel of the Race mode. A sensitive race mode, so to speak. Compared to the classic E-MTB mode, the "Plus" is therefore stronger and more geared towards trail fun. With Tour+, E-MTB, E-MTB+ and Race, the new Bosch Performance CX-R has four dynamic modes to choose from, which can also be fine-tuned in the app.
New Kiox 400C display
It had long been clear that Bosch was launching a new display. Many new Bosch bikes had a hole in the top tube that was too large for the system controller. Now it's here: the Kiox 400C, which fills the superfluous space perfectly. The idea: all important riding data on an inconspicuous, well-protected screen in the top tube. It's not revolutionary, but it's a success.
Special: Data such as power, cadence, heart rate or altitude can be displayed dynamically, without manual intervention by the rider. This means that you can always keep your hands on the handlebars, as the data changes automatically depending on the riding situation. For example: uphill, the altitude metres are in view, downhill the speed. The classic display pages can also be customised and sorted in the E-Bike Flow app.
The tactile buttons on the Kiox 400C can be used to scroll through the pages manually. Theoretically, the entire motor can be completely controlled using these buttons, meaning that there is no need for an extra remote control on the handlebars. For technology fans, the new Kiox 400C has a waterproof USB-C port for charging your sat nav or mobile phone. The screen automatically adjusts its brightness and also has a navigation display on board. Hardly any other top tube display can do this.
Already tested: The Bosch Performance Line CX-R on the trail
If you have activated Race mode, you can feel it immediately. When you put your foot on the pedal, the engine can twitch nervously like a wild racehorse. The engine then responds to the driver's input without delay and with strong acceleration. If you want to tackle steep gradients with vigour and as much speed as possible, Race mode provides maximum support.
The extra power compared to its predecessor, the CX-Race, is clearly noticeable. When pedalling slowly, the motor pushes more powerfully and therefore helps you over steps and steep sections more easily - even if the ideal gear is not engaged. And the motor is also very powerful at the top, so you never get the feeling that the drive could run out of breath.
The Race mode thus retains its character. It pushes unwaveringly and clearly prioritises acceleration and speed over modulation and controllability. The special trail, the Extended Boost, is very distinctive and creates a whole new playing field for experienced bikers. Even on steep steps, it allows you to move forward with just short pedal kicks. A fine tool for rough terrain.
If you have to be particularly controlled, the extreme overrun and aggressive thrust can easily throw you off track. Especially in exposed hairpin bends, you always need to have one finger on the brake - or you should choose a different mode. In the other modes, the CX-R behaves in the same way as the CX with power update. In other words, it is as cultivated and lively as ever. The EMTB+ mode delivers a whole new level of dynamics. If you want to find out more, you should take a closer look at our driving report on the Performance CX with power update.
BIKE summary of the Bosch Performance Line CX-R
The new CX-R is the most powerful motor Bosch has ever built - and the lightest to boot! An exclusive combination for racers and demanding e-bikers. However, Bosch has the biggest competition in-house, as the classic CX is extremely close to the CX-R thanks to the software update. With the new E-MTB+ mode, both drives raise riding dynamics and control on difficult uphills to a new level. - Florentin Vesenbeckh, Deputy Editor-in-Chief BIKE Magazine
Bikes with the new Bosch CX-R drive
According to Bosch, the first e-MTBs with the new motor should be in shops in autumn 2025. Presumably, some manufacturers will be keen to show their new high-end speedsters to the public in advance. One thing is clear: the more expensive CX-R is more likely to be fitted to high-priced models. At the Bosch test event, bikes from Mondraker and Orbea were equipped with the CX-R. Two brands that are closely associated with racing.
Florentin Vesenbeckh
Editor CvD
