Motor & Software Details
Just before the final EWS-E race in Finale Ligure, Bosch seized the opportunity and officially presented their limited Bosch Performance Line CX Race motor to the press in sunny Italian weather. Not only did we get an opportunity for a first glance of the new CX Race version but were able to take it out for a spin, before mechanics got busy swapping out a bunch of EWS-E racers' motors for the new model ahead of rolling to the start line.
Bosch's commitment to e-bike racing has been a factor since the early beginnings of the e-bike racing movement. Apart from having sponsored and supported many teams and individual athletes in EWS-E-races and other e-bike racing series, they've played an active role in establishing framework conditions for professional e-bike races together with the UCI. Apart from that, Bosch is also campaigning for clean racing, with uniform regulations and active action against tuning.
Therefore, it shouldn't come as a real surprise that Bosch's development team has been working on a race-specific version of the Performance Line CX motor in close cooperation with athletes such as Jérôme Clementz, Tracy Moseley, Joris Ryf and other active racers who, among other things, provided direct feedback on various developments and setups at the annual Bosch development camp or directly at various races. The result is the Bosch Performance Line CX Race Limited Edition and while many elements of the CX Race hardware are very similar or identical to that of the normal CX motor, it's the new additional Race ride mode setup that cranks the performance of the CX series up to eleven.
While the magnesium housing and the structure of the motor itself have remained the same, the clearest visual distinctions are the particularly resistant graphite-grey metal finish and of course the logo badge. 150g of weight has been saved on the innards, bringing the CX Race motor down to a total weight of 2.75kg, although Bosch is quite tight-lipped on how exactly they achieved those weight savings.
While most base numbers like 85 Nm of torque remain the same, the Race mode will provide up to 400 % of rider input instead of the conventional 340 %. The Extended Boost feature has also been integrated into the Race mode (so far was only integrated into the eMTB mode), and the overrun time has also been extended to make it even easier to overcome particularly large obstacles.
Viewed as an overall package, the race setup ensures a more energetic response and faster delivery of maximum power in order to save valuable tenths of a second again and again on the trail, especially in situations such as accelerating out of corners. With races often being decided by small time differences it can make the difference between standing on the top of the podium or just a few steps below. Along with more constant thrust throughout challenging terrain provided by Extended Boost, when only being able to deliver short bursts of pedalling input, the rider basically benefits from the Race setup in all technically demanding sections.
Despite exhausting the technical possibilities, it was important for Bosch to mention that the CX Race version operates within all technical regulations and does not break any rules of the maximum permitted country-specific regulations.
In terms of software, all conventional riding modes from the conventional Performance Line setup are still available, but on top of that, the Race mode – with red color coding – can be selected as an extra option. This mode can also be fine-tuned in its strength of support, dynamic range in plus/minus five levels, maximum speed and maximum torque, using the Bosch eBike Flow app that can connect to the bike via Bluetooth.
Labelling the CX Race as a Limited Edition model isn't just marketing talk. Bosch works closely with bike manufacturers to ensure that the CX Race Limited Edition package is only available in certain quantities to each manufacturer and installed on bikes that technically provide a fitting platform for the product, meeting certain requirements for making a bike suitable for racing, or racing-like applications.
At least for now, Bosch clearly sees their Race adaptation as a special use case application for the racer type of rider and doesn't see the average biker as a target group for the added feature, as they might be overwhelmed by the sensitivity of the settings.
We didn't get a whole lot of time to get in a first ride with the Bosch Performance Line CX Race Limited Edition setup, but fortunately, Finale Ligure provides ingenious testing grounds even within a small area, which can usually only be replicated elsewhere, if at all, under a much greater investment of time.
Apart from that, it is pretty easy to notice the differences between the regular ride modes' behaviours and the Race mode anyway. With every acceleration, the motor pushes quite effortlessly and instantly, to reach its maximum power faster than what could be achieved in Turbo or any of the other modes. It's not as if you'd be sitting on an entirely new product, but it provides a nice punch to Bosch's CX repertoire. Naturally, this becomes particularly helpful when accelerating out of corners or when trying to climb towards the top speed in uphill sections as quickly as possible.
However, in my opinion, it feels like most riders of different skill levels should – at least in theory – not feel too overwhelmed by the extra power delivery. Bosch has by now skillfully mastered the control of the power delivery of its motors to the point that you don't have to worry about the rear wheel spinning wildly even when starting on loose ground (unless you force it to), or that any sort of pedal input would end in uncontrolled forward movement.
In combination with the slightly longer-lasting Extended Boost function, the system can especially play out its full strength when having to navigate sections plastered with bigger rocks or roots with delayed pedal strokes, or when having to overcome boulder-sized obstacles, in order to be able to maintain the rolling speed relatively easily.
In general, the Race mode is also beneficial in case you did not select the matching gear for any given situation or if an unexpected steep section is waiting for you behind a blind corner. It's just a shame that the CX Race motor also rattles like the regular version when idling.
After playing with the Bosch eBike Flow app a bit and varying the dynamics setting of the Race mode from -5 to +5, the behaviour changes in fine steps, adding another noticeable variation of the mode independently of the strength of support, which can also be adjusted. Assuming a standard setting of 0, the reduction has a stronger effect than an increase – as intended by Bosch, since the standard setting of the Race mode already allows for a fairly rapid increase in power.
A quick detour led me to Finale's 'Impossible Climb' – as the locals sometimes affectionately call the e-bike uphill trail Legnino – as it offers quite unique challenging conditions to evaluate extreme climbing capabilities for any kind of motor system. Although line choice seemed to have been widened and made easier with extra options for the last EWS-E event of the season, the original routing over trial-like sections inevitably showed how capable the Race mode was under said conditions. Massive power and yet smooth modulation were a guarantee for maximum traction and forward drive up the rocks. In this respect, too, the new setup deserves top marks.
Personally, only the thought of the limited availability might be a cause for concern. Even if it is not yet clear what price tags will be attached to bike models with the CX Race motor, it can be assumed that you will probably have to dig deep into your pockets to get to enjoy the new Race mode. Racers or not – and let's be honest, it's clear that at least for now the number of non-competing e-bikers still far outnumbers that of active e-bike racers – the Race riding mode is without a doubt a valuable addition to the modes already available on the regular Performance Line CX model. Once you experience the difference, it will most likely be missed on models with the standard CX variant. Time will tell whether only experienced riders will be able to experience both.