Overtravel is a characteristic that has always been the subject of debate within the EMTB test team when assessing new motors. Some say that it gives the e-bike motor a life of its own and makes it more difficult to control for the uninitiated. Others say that the short boost after the pedals come to a standstill helps in tricky passages over the one or other key section. The fact is that so far no Motor on e-mountainbikes had an intentionally built in, controllable overrun. That is why the "Extended Boost" in the new software update from Bosch an absolute novelty in the motor market. The sophisticated sensor system decides, depending on pedalling intensity and pedal pressure, whether and for how long the motor should continue to run after the cranks have come to a standstill. The root passage or the thick boulder that would otherwise inevitably cause the pedals to touch down should thus lose their terror. This is because the motor provides the decisive boost even without pedalling. However, the "Extended Boost" is only available in the E-MTB mode of Bosch motors for use. All other support levels function as before in terms of coasting. However, Bosch engineers have also refined the sensor technology of the E-MTB mode apart from the coasting. For example, the dynamic mode should have a smoother start-up behaviour and better traction control.
More torque for E-MTB and turbo mode
The improvements in modulation are not only, but also accompanied by an increase in torque. 85 instead of the previous 75 Newton metres will be available on the Bosch Performance CX in future. This increase in power should have a particular effect in the lower cadence ranges. You should be able to accelerate more dynamically out of tight bends and push the bike better over crests in high gears. As with the combustion engine, where a larger displacement leads to more power at low engine speeds, this feature also benefits e-MTB riders who are lazy to change gears and those who simply prefer higher gears. The extra torque comes into play in both E-MTB and turbo mode.
The software update is installed by the Bosch dealer and is available for all Generation 4 Performance CX versions possible. Bosch has not yet given an exact date for availability. The update should be available in the summer.
How the Bosch motor rides with the software update
You only realise how powerful the Bosch update really is when you switch back to the previous version. And so we quickly got used to the new features. The "Extended Boost" function is particularly impressive. Lovers of tricky uphill sections will no longer want to do without the deliberate coasting in E-MTB mode. It works intuitively, and although the motor pushes on without active pedalling, there is never a feeling of loss of control. The "Extended Boost" provides the decisive boost in passages that you can't pedal up without a pedal touchdown. Steps, root passages and scree fields are mastered with ease. It's like an invisible hand that gently lifts you over obstacles when needed. But even apart from the coasting, we were impressed by the Bosch CX's advanced sensor technology. Starting off, accelerating, throttling - all riding situations merge smoothly and without jerking. The higher torque in the lower speed range provides additional support and helps you out of some stuck situations. The elasticity of the drive improves significantly.
Test summary of the Bosch software update
Even before the update, the Bosch Performance CX was already setting the benchmark in terms of off-road uphill performance. With the new software update, however, Bosch has gone one better. The intentional coasting is a new feature that no e-bike motor has ever had before. Bosch is thus taking on a pioneering role that others will follow in the future. The increase in torque in the lower speed range is good for the system and extends the range of applications. Not only lazy shifting and riders who want to make less effort will appreciate the extra power. Pedalling with higher gears simply gives you more room for manoeuvre on technical terrain. If you don't install this update, it's your own fault.
You can read more about the Bosch software update and many other exciting stories about e-mountain biking in EMTB issue 4/20 - in stores from 18 August!
