E-MTB / Test: With the Bosch CX Race, the e-bike pioneer from southern Germany is expanding its portfolio with a new motor. We've already been able to test it on the trails in Finale Ligure and reveal what makes the new powerhouse so special.
At least since this year's Eurobike there has been a lot of rumor about a new motor from Bosch. Now the cat is out of the bag - it goes by the name Bosch Performance Line CX Race Limited Edition - we will only call it Bosch CX Race in the future. However, its full name is not entirely unimportant and the suffix 'Limited Edition' in particular may raise eyebrows. In this context, limited means that every bicycle manufacturer who buys the new motor from Bosch will only receive a very limited number of units. In this way, Bosch wants to ensure that the new powerhouse is only used in suitable bikes. In this context, suitable means – suitable for racing!
Same torque, less weight
As the name already suggests, the new Bosch CX Race motor is also based on the well-known and proven 4th generation CX motor. Accordingly, the basic performance data has also remained unchanged: The new Race motor also delivers a maximum of 85 Nm torque and the maximum power (more on this in our Bosch CX test) has remained unchanged.
Of course, there would be no need for a new variant of the engine if everything stayed the same. The Bosch CX Race delivers up to 400% support performance (vs. 340% with the regular CX) - a considerable and noticeable increase. There are also differences in weight: the new CX Race weighs 150 g less, which now stands at 2,75 kg for the bare drive unit. This puts it on the same level as the Yamaha PW-X3, clearly undercuts the Brose Drive S Mag and is only just beaten by the Shimano EP8 (2,6 kg) on this front. Even if one is inclined to suspect the weight savings here in view of the new, gray case color, this took place on the inside. However, Bosch is silent on the exact details. However, durability, heat development and background noise should not be affected.
Support level Race with 400% support and enhanced Extended Boost
However, the biggest innovations are hidden in the new race mode, which supplements the previous support levels "upwards" and will be available exclusively for the Bosch CX Race. In addition to the mentioned increase in the maximum support performance to a whopping 400%, the response behavior has also been fine-tuned. For this (as for the entire development) we worked closely with the athletes who ride Bosch E-MTBs - such as Jérôme Clementz, Tracy Moseley or Flo Espiñeira. Drive support is immediately available in Race mode, anytime; even brief pauses for thought or a minimal start-up are no longer there. For example, you can accelerate out of corners much more quickly in order to tease out relevant tenths of a second in competition.
The developers have also lent a hand to the already well-known Extended Boost. Behind this is a feature introduced with the eMTB mode: A short impulse on the cranks is enough to get an extra boost from the drive without having to pedal for it. What sounds like unwanted "pushing along" has relevant advantages in E-MTB practice: overcoming large obstacles is much easier, since it is often not possible to pedal without getting caught with the crank or pedal. This boost has now been significantly extended in race mode. As far as the corresponding UCI standard for competition use just allows. Last but not least, the motor now delivers more power even at extremely high cadences of up to 120 or more.
Impressions from practice: The Bosch CX Race wants to be tamed!
To get a first feeling for the new Bosch CX Race, Bosch had invited to Finale Ligure. As the venue for EWS and EWS E and one of the destinations for enduro bikers from all over the world, the choice could hardly have been better. Before the first technical uphill section, the Bosch employees warned us: we should be careful with the race mode and definitely keep our fingers on the rear brake – just in case. And they should be right!
The extremely direct response, paired with the higher support performance and the extended Extended Boost, offers the potential for new top times on climbs, but it really demands everything from the rider. At first I flew over the trail more like a disoriented bouncy ball because I couldn't keep up with the motor or the bike - which was due to the lack of familiarization as well as my rather average riding technique. However, the former came with every meter on the trail and especially the extended Extended Boost was an enormous help in blocked passages in order not to lose speed here. The Flow app, with which you can customize the new race mode - like all support levels - was also helpful. If you reduce the dynamics, you lose some directness, but you also take away the nervousness of the engine.
After some time, the new mode feels significantly better and more controllable. Nevertheless: It requires maximum concentration, appropriate driving technique and the terrain in order to be able to take advantage of the advantages.
Conclusion Bosch CX Race: A brave step
The Bosch CX Race is a bold move from Bosch. This brings a very special product to the market for a (still?) very small target group. However, one is aware of this and one would like to commit to this still young development in the E-MTB area. Racing series such as the EWS E or the in-house eMTB Challenge will become more and more popular in the future, it's only a matter of time - as will other drives, especially for this segment. In any case, Bosch has presented and we are curious to see if and when the competitors will follow suit.