The cat’s out of the bag! Bosch have finally introduced their brand-new Performance Line CX 2020 motor. But how good is the new drive compared to its predecessor? And is it worth snapping up a bargain bike fitted with an old Bosch motor or are you better off waiting for bike models with the new 2020 Performance Line CX drive?

Before we get into the review, we would like to tell you about our latest print edition. The E-MOUNTAINBIKE Print Edition 2020 is our third annual edition and ultimate test bible, with which we aim to help you choose the perfect eMTB. More than 250 pages of extensive buyers advice, tons of eMTB know-how as well as reviews of the 35 most exciting eMTBs and the 7 best motors. You’ll also find many helpful tips and a guide to the most exciting eMTB trends – all of this is wrapped in a high quality print format. Click here for more information or order it directly in our shop!

The difference in size is massive: The new Bosch Motor is roughly have the size of it's predecessor

Bosch Performance CX 2020: small but impressive

½ vs. 1

The new Bosch Performance Line CX is almost half the size of its predecessor. But the engineers didn’t just limit themselves to shrinking down the old motor, and instead redesigned the new one from scratch. For example, the drive shaft no longer sits in the middle of the housing and has now moved further back and upwards. As a result, bike manufacturers are given more freedom to develop and implement frame designs with shorter chainstays and more efficient rear ends. The result? A new generation of exciting eMTBs with better handling qualities and increased fun factor! The new FOCUS JAM², which we’ve already tested for you, is a good example.

Hardly any compromises
With its compact dimensions, the new Bosch motor is easier to implement into individual suspension concepts
Necessary evil

With the old bulky version of the Performance Line CX, engineers struggled to keep the chainstays a reasonable length

Bosch Performance CX 2020: smaller equals lighter

2.79 kg vs. 4.09 kg

In this context, we could use a simple equation to describe the new Performance Line CX 2020 drive: less material = less weight. Bosch’s development team put its high-end motor through a strict diet and trimmed its weight by a whopping 1.3 kg. Thanks to this significant weight reduction, bike manufacturers will be able to use larger batteries without affecting the overall system weight. Comparatively, a new bike with a 625 Wh battery will now be lighter than its equivalent with an old Performance CX motor and 500 Wh battery. In other words, manufacturers will soon be able to build lighter eMTBs, without affecting their performance or durability. We’re looking forward to a new exciting generation of Bosch-powered bikes!

The Bosch Performance Line CX 2020 is approximatley 1.3 kg lighter than the older bosch-motor

The torque remains the same.

340 % vs. 300 %

Both the old and new Bosch Performance Line CX models bring a torque of 75 Nm. But not all else is equal. Whilst the old model provides up to 300% assistance in Turbo-mode, the newer version goes up to an impressive 340%. All other assistance levels have been revised too. The support level of Tour mode has been increased from 120% to 140%. These changes are also reflected in eMTB mode. Bosch’s new progressive mode modulates dynamically between Tour and Turbo and adjusts the support according to the riding scenario and the amount of pressure you put on the pedals – respectively from 140% to 340% with the new motor and 120% to 300% with the old Bosch Performance CX.

Nothing new on the display front

Or at least not for the sporty eMTBer. Together with the new Performance Line CX 2020, Bosch have also released the new SmartphoneHub. Unfortunately, the new connectivity interface isn’t aimed at eMTBers. Moreover, neither of the Bosch motors includes a minimalist display solution for the trail. In this respect, other connectivity solutions from Shimano or Brose/Specialized are clearly ahead.

It’s not always about numbers. Trail performance is what really matters

In a nutshell, the latest rendition of the Bosch Performance Line CX does pretty much everything better than its predecessor. Despite generating the same torque, the new Bosch provides 40% more support and steams past its older brother at full power. Especially on steep climbs, the peak performance of the Turbo mode has been improved noticeably. On top of this, the mode is now easier to control on startup and when pedalling cautiously on technical terrain. Whereas the “old” motor delivers its power abruptly and vigorously, the new version is a lot more sensitive and predictable, yet never fails to provide enough power.

While it’s true that the eMTB mode of the old version impressed us right up until the end, once we tried the reconfigured eMTB mode in the new Performance CX 2020, we realized how much more potential for improvement there is in all other available progressive modes on the market. The new eMTB mode is incredibly accurate, smooth and easy to control and always delivers enough power. Simply superb! Even the transition at the 25 km/h threshold is a lot smoother than with the previous model. The internal pedal resistance of the old Bosch drive has always been so strong that it feels like you’re hitting a wall whenever the motor stops providing support. It’s almost imperceptible with the new model.

Finally, even though the noise of a motor strongly depends on the actual frame of the bike – which often acts as a resonator – neither of the Performance CX motors excels in this respect. While the older model generates a loud electronic humming noise, which is perceivable especially under full load, the new Bosch Performance Line CX has a problem with the freewheel clutch of the chainring. Whenever the suspension compresses, the chain is tensioned quickly and repeatedly, causing the chainring to rotate a little and the freewheel connecting the chainring to the motor to engage. In turn, this makes a loud, metallic clunking noise. The sound reminds us of a chain slapping on an unprotected chainstay. Regrettably, this means that all bikes with a 2020 Bosch motor will be loud on rough descents.

Conclusion

As far as performance goes, the new Bosch CX 2020 surpasses its predecessor in every respect. To put it simply, the old motor is simply outdated. Of course we are not implying, in any way, that bikes with an old Bosch-drive are now obsolete, but are heralding a new exciting generation of more efficient eMTBs. If you’re not concerned about the high internal resistance beyond the 25km/h threshold and if you’re not necessarily looking for an ultra-light or super-playful bike, you might be able to snap up a real bargain with the old motor. However, if you’re an enthusiastic, sporty eMTBer we suggest you wait for new bike models fitted with the newest Bosch Performance Line CX 2020 motor.


Check our Bosch-overview for even more info on the new Performance Line CX 2020.

More info at: bosch-ebike.com


It's finally here: The E-MOUNTAINBIKE Print Edition 2020 is our third annual edition and ultimate test bible, with which we aim to help you choose the perfect eMTB. More than 250 pages of extensive buyers advice, tons of eMTB know-how as well as reviews of the 35 most exciting eMTBs and the 7 best motors. You’ll also find many helpful tips and a guide to the most exciting eMTB trends – all of this is wrapped in a high quality print format. Click here for more information or order it directly in our shop!

Words: Felix Stix Photos: Diverse

About the author

Felix Stix

Felix is chief of testing and undoubtedly one of the best test riders in the world. With a degree in sports engineering, excellent mountain bike skills, his love of technology and as a certified bike guide, Felix has everything it takes to make comprehensive and fair assessments of bikes. His legendary group tests are internationally known and feared, though they tend to be a bit longer due to his love of detail and technical deep dives. Every year, he reviews around 100 bikes, specialising in the subject of tires, motors and suspension, before putting on his skis come winter! His know-how is incorporated into each of our reviews, ensuring the quality of our work stays high!