Bosch increases the level of assistance and shaves the weight with the new Performance Line CX Race engine

latest bush electric mountain bike motorThe Performance Line CX Race Limited Edition is claimed to support up to 400 percent of the rider’s strength. It does that, according to Bosch, while flying 250 grams off the claimed weight of 2,900 grams for the standard. CX performance line unit.

Although the new Race version of the Performance Line CX engine has the same 85Nm of torque and 250W nominal constant power as the standard model, that 400% increased assistance is delivered from the initial pedal stroke to the legally required speed limiter.

Further tuning has been made so that the motor now provides usable support “even when [pedalling] Rhythms above 120 RPM”, at which motor assistance normally runs out.

Race mode delivers masses of power very quickly.
Mark Marshall / Bush

Adding to the increased power and extended assist is how quickly the engine grunt is delivered. Motor response times are sped up to the point where Bosch says “only those who have [a] Precision riding technology can control the direct response and power of the race mode.”

The new motor is compatible with the Bosch eBike Flow smartphone app. As with others Intelligent Bosch Engine Systemthe force of the support and how it responds to the passenger’s input, as well as other parameters such as top speed and torque, can be adjusted.

The CX Race engine does not have an Eco mode.
Mark Marshall / Bush

For the CX Race engine, app-based adjustments are limited to the Turbo and Race modes, with Bosch’s impressive eMTB and Tour+ modes adapting to the rider’s inputs remaining non-adjustable. However, the economic setup is over, underlining the “race-focused eMTB” credentials of the new unit.

Another series for the Bosch racing bracket is the reduced unit weight, which is claimed to be 2,750 grams. That’s just 150 grams heavier than Shimano EP-8 And the same PW-X3 from Yamaha, equipped with giant bikes, among other things.

The new engine appears to be the same size and shape as the Performance Line CX.
Mark Marshall / Bush

Bosch claims that this reduction will “improve eMTB handling on challenging trails” and “the drive unit can be perfectly integrated into a sporty, slim frame design, making handling particularly agile.”

To reduce weight, Bosch has “improved” some of the materials of the interior components, although it has not disclosed details.

Cooling fins should maintain performance as expected.
Mark Marshall / Bush

Physically, however, the new Performance Line CX Race has the same size and shape as the Performance Line CX engine.

Aesthetically, the two can be distinguished from each other thanks to the “Metallic Gray Graphite Coating” magnesium cover and “logo and accent colors”.

The new engine is compatible with all components of the current Bosch smart system.
Mark Marshall / Bush

When the “Limited Edition” moniker was tested in the CX Race engine name, Bosch stated that it would “be available in small quantities,” but did not comment on how many units would be produced.

At BikeRadar, we suspect that Bosch will spend all that time and money developing and tuning a limited-running motor, and we think it is likely that the new motor will continue to be produced and specified on bikes in the future.

Electric mountain bikes with a Bosch Performance Line CX Race . motor

Bosch was unable to provide a definitive list of manufacturers and models of bikes equipped with the Performance Line CX Race engine, but did state that “about 20 well-known manufacturers will determine the new drive unit.”

Since Bosch says the engine is “built for race-focused eMTBs,” we think it would be safe to expect to see it installed to the highest standard. Electric mountain bikes From the likes of Trek, Mondraker, Scott, and others.

First ride impressions of Alex Evans’ Bosch Performance Line CX Race engine

Aim and shoot – there is a huge amount of power when you tap.
Mark Marshall / Bush

I tested the new Bosch Performance Line CX Race engine on my home tracks in the Tweed Valley in Scotland before the official launch.

The motor is installed on Trek Rail 9.8 XT Gen 3It is the brand’s newest long-travel enduro electric mountain bike.

Trek claims the average rail 9.8 XT Gen 3 with Performance Line CX engine weighs 23.4 kg (no pedals, tubeless tires). The Rail 9.8 XT Gen 3 I that I used to test the new engine tilted the scales at 23.6kg (medium, no pedals and tubeless tires).

The test drive was installed on the Trek Rail 8.9 XT Gen 3 enduro bike.
Mark Marshall / Bush

Some weight inconsistencies are inevitable, but the weight savings for the CX Race engine weren’t evident with this particular test bike.

Off the road, the race mode definitely ups its ante when it comes to full power.

It is best described as the enhanced Turbo mode; Strength comes stronger, faster and lasts longer.

Race mode made getting on steep technical sections much easier.
Mark Marshall / Bush

However, for people who have ridden the Performance Line CX, there is real knowledge of engine assistance as it mimics the rider’s inputs. The increases in pedaling force equate to a satisfying rise in engine output, but there is now added sharpness.

Adjust the sliders to the right in the Flow eMTB app and that sharpness will increase, as even the lightest touches of the pedal deliver impressively fast power.

Engine input is maintained all the way up to the level Speed ​​Limit Assist With no perceptible slope or flat spots. Claims of increased peak power add up, and Race Mode is sure to fulfill Bosch’s promise of “uncompromising performance” while climbing.

There’s no denying how good the new engine can rise.
Mark Marshall / Bush

Overtaking (the amount of engine assistance and how long it delivers after the rider has stopped pedaling) has also been increased in the CX race.

This feels great on tough technical trails, where handling is easier with rocks, roots or steps as engine power is fed through the rear wheel for longer once the rider stops pedaling.

It’s the same story on flat slopes, where half or even a quarter of the engine’s rotation is interfering. This allowed me to either pick up speed faster or keep it in sections where I wouldn’t normally be able to perform full crank revolutions.

On flat descents, the extra overtaking was helpful, but once the gradients were steep and Alex was on the brakes, it made the balance a little more manageable.
Mark Marshall / Bush

However, as the tracks got steeper with a lot of braking, I found the extended, more sensitive overtaking to be a bit problematic.

Even adjusting the pedal angle by pedaling forward a quarter of a turn—something riders do unconsciously when descending as they enter turns, adjust their balance, or avoid rocks and other obstacles on the ground—use engine assist.

This was a bit of a scenario when I was hard on the brakes, trying to slow down instead of accelerating.

It was better to tackle steep descents in Turbo, eMTB or Tour + modes rather than Race.
Mark Marshall / Bush

Dropping the engine from Race to Turbo fixes this problem because overtaking the Turbo is less aggressive. However, switching modes while riding the technical sections is more than complicated, and it is questionable whether this technology is practical on the road.

Most likely, riders will need to decide if they want more power in Race Mode, Turbo control or less. This, of course, will dictate the terrain they ride on.

Decreased race mode sensitivity also helped in the eMTB Flow app, but this muted upward performance in Race Mode and is probably a compromise that most riders looking to take advantage of the extra power won’t want to make.

How does the new Bosch Performance Line CX Race engine compare to the Bosch Performance Line CX and Shimano EP-8 engines?

The Mondraker Level R is equipped with Bosch’s Performance Line CX engine.
Andy Lloyd / Our Media

Repeated testing against the Performance Line CX engine reveals that the Race Edition is faster.

At a range of 400 metres, a height of 60 metres, the new engine was three seconds faster than the older engine when both engaged in maximum assist modes with the same rider power output and heart rate for the duration of the climb.

In terms of feel, Race mode puts more power at lower rider inputs and is lighter than the CX’s Turbo setup. Towards the upper end of the engine, the difference is less noticeable, but the Race engine is stronger—feeling right up to the rev limiter, compared to the slight rearward feel of the standard version.

Compared to the Shimano EP-8, Bosch has taken utility to the next level. The CX Race feels much more powerful than Shimano when both are set to extreme support levels.

Shimano’s DU-EP800 monitor is in Boost mode.
Ian Linton/Instant Media

After doing several drag races with friends who weigh 30kg, and riding the EP-8 engines, the CX Race was so powerful that I was able to keep up with and exceed these races. Normally, I’m unable to keep up, let alone get past them.

This certainly enhances the CX Race’s outright performance credentials as a class leader, but more time with the engine is needed to get a real handle on its performance.

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