Last year, Bosch updated the Performance Line CX and set off an avalanche of new eMTBs designed around the powerful and compact motor. One year later, the German tech giant has released a software update which brings a whole bunch of new features, including a newly tuned eMTB mode and an extra 10 Nm of torque. With a low system weight, 85 Nm of torque and a battery capacity of up to 1,250 Wh, the revamped version of Bosch’s classic eBike drive provides some exciting data – at least on paper. But is the hype around the fourth-generation Performance Line CX justified?

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!

Click here to find out what it takes to be the best eMTB motor.

One year after launching the revamped version of their Performance Line CX motor, Bosch release a new software update – find all details in our “old” VS “new” article. Not only does the update increase the torque to a total of 85 Nm, but also improves the overall handling of the bike. With up to 340 % maximum support, even on steep climbs it keeps up with the more powerful Brose Drive S Mag without breaking a sweat. However, the key highlight of the 2,79 kg motor is not its power but the eMTB mode, which is tuned even finer after the latest update. The progressive mode modulates dynamically between the Tour (140 %) and Turbo (340 %) modes and adjusts the support according to the riding scenario and the amount of pedal pressure applied. The new mode is incredibly accurate, smooth and easy to control and always delivers enough power. As a result of the increased torque, however, light riders might find that the factory setting delivers the power too abruptly when riding flat trails. Here, it would be great to be able to individualise the setting using the app, an option that other systems from Brose and Shimano offer. Thanks to Extended Boost, the eMTB mode detects and anticipates steps, big obstacles and other hurdles on technical trails and supports the rider with a particularly long hysteresis. In other words, no other motor in the test field feels as effortless and controlled on technical uphills as the Bosch Performance Line CX 2020! The transition at the 25 km/h threshold is smooth and silky. But what about the notorious pedal resistance though? Well, there isn’t any! However, the new Bosch does have a bit of a noise problem – not the typical noise of the motor humming under full load, but the coarse-toothed freewheel-clutch that produces a clunky metallic sound when it engages, sounding almost like a clattering chain on rough downhills or when the rear-end compresses.

Ready for any adventure
The DualBattery system offers up a 1,250 Wh capacity. The frame has to be designed specifically for that purpose though.

In typical Bosch fashion, the Performance CX comes as a closed system and requires bike manufacturers to use Bosch’s in-house remotes, displays, motor software, batteries and standard motor tuning. The DualBattery system combines an internal PowerTube and external PowerPack battery and allows for a battery capacity of up to 1,125 Wh – with two PowerTube batteries even 1,250 Wh! Despite five potential display options, the Purion and Kiox are the only reasonable options for sporty eMTBing. However, the latter is hard to read on the trail and the standard mount on the stem is not ideal for sporty eMTBers either. With an additional software update for the display, the Kiox will be able to display the navigation-commands from your smartphone (available from summer 2020). The minimalist Purion display has an integrated remote, is easy to use and provides the most important riding info. That being said, compared to more compact solutions like from Shimano for example, it looks outdated and clunky. Individual tuning of the support levels is possible neither end users via app nor for dealers or bike manufacturers. You only have the option to adjust the eMTB mode to the crank length.

Exposed
The standard mount places the Kiox display on the stem, where it’s exposed to damage. That’s why most bike manufacturers have developed their own solutions here.
Functional favourite
The Purion display is our favoured choice for sporty use on the trail. It’s easy to read and use, though in terms of its functionality, is a little clunky.

As far as weight and size go, the new Performance CX is top notch. Light and compact, Bosch’s new eMTB motor hits the nail on the head. While the new shape gives bike manufacturers lots of freedom for new rear-end designs, its distinctive bend in the front creates new challenges in terms of optical integration, at least on designs without a cover. Unfortunately, the new Bosch motor still features the same flimsy spoke magnet which, like the charging port, has pushed some manufacturers into finding their own, more reliable solution.

Our conclusion

In terms of performance, the Bosch Performance Line CX 2020 plays in the top league of eMTB drives! The latest software update makes the already superb eMTB mode even better and consolidates its status as the best progressive mode available on the market. Due to the increased torque, it would be great to have the option of customising the support levels – very light riders would be grateful for this. Remotes, displays and sensors are usually difficult to integrate into the bike and cast a cloud over the positive impression just as much as the distinctive rattling noise.

Tops

  • compact and lightweight
  • phenomenal eMTB mode
  • simultaneously powerful and easy to modulate

Flops

  • clunking of the internal gears
  • challenging integration (display, remote, sensor)
  • no custom support modes

For more information head to bosch-ebike.com

All motors in this comparison: Brose Drive S Mag | Bosch Performance Line CX | FAZUA Evation Firmware 2.0 | Yamaha PW-X2 | Shimano STEPS E8000 | TQ HPR 120S | Specialized SL 1.1


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: E-MOUNTAINBIKE team

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!