For years the Bosch Performance Line CX probably the best-selling e-MTB motor. High reliability, a good ride feel and a long range have made the Swabian drive unit a success. With the new edition of the CX, the question is: How do you make the most popular and probably best e-MTB motor even better? Of course, by addressing the biggest criticisms. And that's exactly what Bosch has done with the new Performance Line CX.
While with the latest new edition of the Performance Line CX While the wait for a "rattle-free" motor was still in vain, the Swabians have achieved exactly that with the latest expansion stage. Just how difficult this supposedly banal goal is to achieve is demonstrated by the fact that most competitor products, from Shimano to Yamaha, also struggle with rattling from the gearbox. This has also been the case at Bosch for years. For the new CX, they have now developed a patented freewheel that does not appear to rely on a classic pawl system and does not make any noise when pedalling backwards. The result: the inside of the motor is completely decoupled from the drivetrain. This means that the transmission is not stimulated by external influences and remains absolutely rattle-free.
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The new Bosch CX motor: More power or significantly lighter?
If you look at the classic key figures of the new Bosch CX motor, however, not much has changed. 2.85 kilos, which is only slightly less than its predecessor. And the volume is also identical - although the "new one" looks slightly different. And the power? 600 watts at peak, 85 Newton metres, maximum 340 percent assistance. Bosch calls this the "magic triad", which already gave the predecessor a very harmonious riding experience. Speaking of the riding experience: Bosch claims to have made additional progress in the modulation and response of the motor through even better interaction between software and hardware.
And the second major point of criticism has also been addressed: the weight of the very heavy batteries, which in the past have usually turned Bosch bikes into real hulks. New are the Powertube 600 and Powertube 800, which have even more capacity than their predecessors thanks to new 21700 cells with a lower weight. More about the new batteries and the range of the new CX below!
The facts about the Bosch Performance Line CX 2025
- Max. Torque: 85 Newton metres
- Peak power: 600 watts
- Support: 340 %
- Weight: 2.83 kg (measured in the BIKE lab)
- Compatible with all components of the smart system
- New automatic mode
- New batteries: Powertube 800, Powertube 600
- New Purion 400 display
The bikes with the new Bosch Performance Line CX
At the same time as the new Bosch motor, many bike manufacturers are presenting their new e-mountainbikes with the new drive. And many more models will follow in the coming weeks and months. We have summarised the new bikes in a large article to give you an overview.
The Bosch Performance Line CX 2025 in the test lab
As usual at BIKE, we do not rely purely on our instincts in our tests. We verify and substantiate the findings from our extensive off-road tests with objectively comparable data and measurements. For this test, we put the new Bosch Performance Line CX on the roller dynamometer in the PT Labs test laboratory and determined the power and torque curves.
At first glance, there are no surprising data. No wonder - Bosch is not promising an explosion in performance. Rather, the picture that emerges is the one we know from the Performance CX. It only develops its full power when the rider pedals a little harder. The motor delivers full throttle from around 180 watts of rider power. When pedalling at a leisurely pace, the motor only pushes off gently, even in turbo mode. This is one reason for the dynamic and harmonious riding feel of the unit. The maximum assistance is 340 per cent. Other motors deliver 400 per cent and more, which can lead to a more powerful thrust feeling when pedalling lightly. The new Bosch CX does not have a shuttle mode for lazy pedallers.
We were unable to prove one of Bosch's advertised updates in the lab: better traction at very high cadences. However, this is not because the newcomer is weak. Rather, the predecessor was already really strong and market-leading here. The new model has similar values and still pushes with full power even at a cadence of 150 rpm. We did not measure any higher cadences. This is because we consider this range to be irrelevant in riding practice.
Top result from the laboratory: The lower pedalling resistance with the assistance switched off is not only noticeable in direct comparison to the predecessor, but is also evident in the laboratory. The motor and drivetrain consume 9.1 watts instead of the 13.8 watts of its predecessor. Anyone pedalling above 25 km/h or cranking without the motor benefits from a freer ride. Bosch says that even a classic bottom bracket has no less resistance. Here, Bosch has orientated itself on the technologies on which the Bosch Performance Line SX light motor is used. Bosch states that both motors can hardly be distinguished from a classic bottom bracket in terms of resistance.
Batteries and range of the Bosch Performance Line CX
The very heavy batteries were always a point of criticism of the Bosch system. The new batteries are now significantly lighter. There is a choice of 800 or 600 watt hours. The 800 battery weighs around 3950 grams, which is around 400 grams less than the well-known Powertube 750 of the previous generation. A big step in the right direction, even if the batteries are still not among the lightest on the market. A remarkable mark is set here, for example the 800cc battery in the new Rotwild R.EXC.
If you want a lighter Bosch bike, go for the Powertube 600 (3080 grams). The batteries are the same length and fit into the same holder. If the bike manufacturer designs the down tube accordingly, they can be used interchangeably without any problems. This is the case with various brands. Another advantage of the new 800: The Powertube 750 was extremely long and very difficult to transport in a rucksack. The format of the 800 makes this much easier. Bosch still excludes batteries from third-party suppliers.
But what happened to the outstanding range of the Bosch batteries? The 750 always scored top marks in our tests. We also subjected the new batteries to our extensive range test. And both versions did not disappoint. The new Cube Stereo Hybrid One44 climbed over 2259 metres in turbo mode with the Powertube 800. These are roughly the values achieved by Shimano bikes with a 900-series battery (Canyon, Norco). There has never been more in our test history!
E-MTBs with Powertube 750 managed an average of 2000 metres in altitude under identical conditions. The Powertube 600 in the Bulls Sonic Evo EN-R climbed over 1700 metres. That's more than its nominally larger predecessor, the Powertube 625 (3600 grams) - with a significantly lower weight!
Side note: The new batteries come in a silver "colour", i.e. without black anodising. This is intended to reduce emissions of harmful chemicals and CO2. As the Powertubes are invisibly installed in the down tube anyway, there is no recognisable visual difference on the bikes.
Purion 400 - the new Bosch display
In the slipstream of the new motor, Bosch has also developed a new display. The Purion 400 is the discreet alternative to the larger Kiox screens. The new Purion with its 1.6-inch screen sits well protected and unobtrusively behind the handlebars. Thanks to its compact dimensions, there is no risk of colliding with your knee. All in all, the Purion 400 is somewhat reminiscent of the long-known Shimano displays and we are tempted to say: "Why not like this?"
By default, the colour screen displays the U-level and the battery level as a percentage. There is also a large field on which data such as kilometres, speed and rider performance can be changed. The good news is that the Purion 400 can be easily retrofitted and can be combined with the system controller or the LED remote. The "brain" of the system is located either in the system controller or the LED remote, not in the Purion. This means that the minimalist combination with just the wireless mini-remote does not work.
More innovations from Bosch
In addition to the new Performance CX, the new batteries and the Purion display, Bosch has also unveiled other innovations. With the ABS Pro, the Swabians also want to make the ABS system interesting for extreme trail riding and professional bikers.
The automatic shifting system, which Bosch has developed in cooperation with TRP, should also really pick up speed with the new CX. Similar to Shimano's Di2 and Sram's Eagle Powertrain, Bosch bikes can now also shift gears fully automatically. It will also be possible to shift gears while rolling, without turning the cranks.
The Bosch Performance Line CX 2025 on the trail
Direct response behaviour and fine modulation in combination with lively acceleration: The newcomer impresses with the skills that already made its predecessor a benchmark. The developers were actually able to go one better in the details. The driving experience has become a touch smoother - without losing any of its dynamism. The drive is now even better attached to the foot and responds very sensitively to the driver's pedalling impulse, even in turbo mode.
The good traction when cranking fast is also still absolutely outstanding. While almost all other drivetrains on the market lose power at very high cadences, the CX provides full thrust even when pedalling extremely fast. A real plus on technical uphills.
Bosch Performance Line CX - the volume
Let's continue with the soft skills: We had different experiences with the noise level of the motor. While the CX in our test bikes from Bulls and Cube pushed significantly quieter than its predecessor, a third test bike with the new unit only showed a minimal improvement from old to new. But on average, the new CX seems to push more quietly. The sound update is even more noticeable downhill. Because all the new CXs we have been able to ride so far are absolutely rattle-free!
The next refinement: the improved modulation is also noticeable when fading in and out around the cut-off limit. With the new version, you can hardly feel whether the engine is pushing or not, the power unit applies and releases its power so smoothly.
However, there was one small thing that bothered us in our detailed old-new comparisons: the extended boost in EMTB mode was negligible on the new motor. Where the predecessor reacted to sharp acceleration with a clear overrun, the new model hardly had any extra boost. This means you no longer get over steps or root carpets as smoothly. According to Bosch, however, the feature should remain as with the predecessor. We hope that it will be just as noticeable again with the next software update at the latest.
What the new Performance Line CX can do better than its predecessor
- No rattling from the gearbox thanks to patented freewheel
- Lighter and larger batteries, Powertube 800 is 400 g lighter than 750s
- Lower pedalling resistance, technology adopted from Perf. SX
- Motor almost 100 grams lighter
- Improved modulation once again
- Slightly quieter drive noise
- New automatic mode
Conclusion on the new Bosch CX motor
Not much has changed in terms of the classic motor characteristics, but the new generation of the Bosch CX is still a really big hit! No more rattling and finally lighter batteries. It's impressive that the new model has topped its already outstanding range figures! - Florentin Vesenbeckh, Deputy Editor-in-Chief BIKE Magazine
Florentin Vesenbeckh
Editor CvD
