Since its launch in 2015, the Bosch CX motor has been the ultimate reference point amongst E-MTBs, but the competition certainly haven’t rested on their laurels, with a number of viable rivals tugging for pole position these days. Yet Bosch are confident that their latest release – a new eMTB mode for the Performance CX motor – will reiterate their supremacy via one free software update.

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Can a software update boost performance?

E-MTB motors are taking a similar route to smartphones, with increasingly frequent software updates that leverage new or revised functions to current systems. This latest news will come to satisfaction of Bosch CX motor owners, as the all-new eMTB mode can be acquired through a simple update carried out by retailers. There’s no need for any new hardware in this case.

The eMTB mode in detail

The eMTB mode essentially replaces the current Sport mode, and is capable of adapting itself to the rider and the route on-the-fly. The easiest way to explain its approach is to compare it to a car that drives in automatic: the eMTB mode independently switches between Tour, Sport and Turbo depending on how much force the rider exerts on the pedals. Instead of the former Sport pedal-assist that resulted in 210% of the rider’s exertion, this can now vary between 120% and 300%.

This progressive motor support shouldn’t just render manual switching between the modes unnecessary, it’s also reputed to be more similar to a natural riding sensation. Previously, riding off-road on an E-MTB often meant you had to compromise in terms of pedal-assist: the more forceful modes were often unmanageable; the weaker ones were too feeble. The eMTB mode should make pushing off much easier and more stable, as the motor won’t surge directly with full power. If you push down hard onto the pedals, the motor will expend the same power as in Turbo mode, which sees it therefore covering a broad scope.

The ride

We’ve already had the opportunity to trial the brand new eMTB mode off-road. From the initial start-up, it’s evident that the Bosch motor is significantly gentler when powering up, feeling much like the former Tour mode. From approximately 125 watts of personal power input upwards, the motor delivers the full extent of its powerful support of 300% (the same as you’d have got in Turbo mode) – a value you reach easily as a fairly in-shape rider. As the pedal-assist now progressively adjusts as you’re riding, the Bosch CX motor does deliver a more natural sensation, distributing its power in a more mellow manner rather than lurching forward at the first touch of the pedals.

On technical off-road climbs the eMTB mode generates more control and demonstrates better capability at modulating the power. However, this is primarily an asset on really technical sections with steps, big obstacles or other hurdles that most E-MTB riders will only rarely encounter on their trail rides. On more mellow uphill gradients, the eMTB mode isn’t noticeably different to the Turbo mode, as even the eMTB mode tends to provide full pedal-assist in such situations anyway. This makes the Turbo mode somewhat redundant, as the eMTB mode offers the same maximum power with better modulation.

Does the new eMTB mode have an affect on the range?

This predominantly depends on your preferred riding mode. If you’re used to Turbo, this progressive approach to pedal-assist will extend the range you’ve previously had. For riders that usually opt for Tour or Sport while riding, you’ll probably encounter the opposite. The eMTB mode eradicates the former Sport mode, which was a level of pedal-assist we enjoyed using for riding off-road. If you don’t want to use the maximum support in order to save battery life, then you’ll only be left with the Tour mode once you’ve carried out the update – this mode is frequently too weak for off-road riding. Consequently, we’d like to see a second progressive mode, which could alternate between Eco, Tour and Sport (50% – 210% support).

Certainly a welcome development, we’d recommend the eMTB mode update for riders with a Bosch CX motor – providing you’re willing to sacrifice the conventional Sport mode. Interestingly, we didn’t notice any glaring benefits while testing the eMTB mode, and concluded there were just marginal gains to be gleaned. The notable criticisms relating to Bosch motors – like the bulky size and the transmission that requires additional power above 25 km/h – are still present after the update, so Bosch fans will still need to practise some patience on those fronts.


The update is available from the 1st of July 2017.

Our thoughts

The new eMTB mode marks a successful attempt to rejuvenate the market’s most popular E-MTB motor, shortening the gap to the competition. However, this software update does not result in a brand new motor, and the benefits are perhaps not as significant as one may have expected. But as it’s a free update, we’d certainly recommend that riders with CX motors give it a shot.

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Words: Moritz Dittmar Photos: Bosch, Christoph Bayer, Valentin Rühl

About the author

Moritz Dittmar

My job is to make sure you guys get access to the hottest news, the best reviews and the most inspiring stories from the world of mountain biking. Just like my work, I’m not keen on putting a label on my favourite type of riding - as long as I’m having fun then I don’t care if I’m grinding my way up a thankless climb or knocking off vertical metres in minutes on a gnarly descent.