FIRST RIDE REVIEW

BOSCH MY25 PERFORMANCE LINE CX AND ABS PRO

Already one of the leaders in the eMTB market, Bosch eBike systems are not resting on their laurels, and have developed a new Performance Line CX drive unit for MY25 in addition to new batteries, display and ABS system. We had the chance to visit Bosch, learn all about them, and put them to the test for a first ride review, and it’s time to share our thoughts.

ABOUT THE BOSCH PERFORMANCE LINE CX MY25 (BDU38)

Bosch already had a very good thing going with their “Gen 4” or BDU37 Performance Line CX drive unit, but felt the pressure to release a new model with refinements throughout. Enter the new Bosch Performance Line CX MY25 (BDU38), which is likely to be known as “Gen 5” to most.

For the new drive unit, Bosch has remained with the 85Nm of Torque and 600W peak power of the previous generation system. They claim this to be the “ideal balance of power, efficiency and range”, citing that increased power comes with higher demands on the battery and more wear to the drivetrain and tires of the bike.

So, what has changed? Bosch has managed to shave 100g from the weight of the drive unit through a new magnesium housing, which will be appreciated by the gram counters. Within the drive unit, there are new sensors including inertial sensors, which help to feed information into the brain of the eBike motor. The new pedal sensors feed information into the system over one thousand times per second. The result is an increase to the sensitivity and intelligence of the BDU38 Performance Line CX drive unit, allowing it to deliver a more natural assist with increased control.

Bosch has also worked on the noise of the new drive unit. Not only did they target a reduction in the maximum noise level output when the motor was working, but they also worked to make the noise a tone that was kinder on the ears. By decoupling the freewheel when coasting, they’ve also removed the rattle of the freewheel mechanism on the way down the hill.

For the times when the terrain isn’t rideable, Bosch worked on an improved walk assist function with improved sensitivity to prevent the bike from “running away”. The new Hill Start Assist means that once you reach some pedal-able terrain following use of the walk mode, you can simply hop onto the bike and remain in place until you pedal away.

Now available is the eShift, in collaboration with both TRP and Shimano. This features automatic shifting and the possibility to shift while freewheeling, adding to the autonomy of the ride.

ABOUT THE BOSCH POWERTUBE 600 AND POWERTUBE 800 BATTERIES

To power the new Performance Line CX drive unit, Bosch has released two new battery options with improved energy density. This means reduction in system weight and in some cases an increase in range.

The new PowerTube 600 and Powertube 800 batteries are the same length, making switching between the two easier than ever. The PowerTube 800 packs an improved 205Wh/kg energy density within its aluminum shell, making it the most energy dense battery Bosch has yet to make. These are both still compatible with the PowerMore Range extender to boost by a further 250Wh, and can even be doubled up to deliver up to 1600Wh if the manufacturer desires.

With environmental impact in mind, Bosch has also worked to use partially recycled materials in the battery casing. They reduced the amount of material required in their production too, and will ship it without the black coating to make it more easily recyclable and less impactful to produce.

ABOUT THE BOSCH PURION 400 DISPLAY

The new Bosch Purion 400 display aims to offer a minimalistic unit that displays the key information on the handlebar, protected by its positioning tucked away next to the stem. With a 1.6-inch color display, the Purion 400 is stripped back to offer sporty riders with a tailored display option.

ABOUT THE BOSCH ABS PRO

The original Bosch ABS system was produced from a purely safety perspective, aiming to limit the likelihood of less experienced riders from locking up the front wheel or going over the handlebars. The new Bosch ABS Pro system is designed to maximize performance on the downhills.

eBike ABS Pro was produced through racing applications, and features two modes – ABS Trail Pro and ABS Race – to tailor the level of stability and braking performance the rider desires. Compatible with high performance brakes such as the TRP DH-R EVO and the Magura MT7, the ABS Pro system is less obtrusive than the system of the past and is designed to allow riders to brake harder and later without risking lock-up.

BOSCH TARGETS STANDARDIZED CHARGING

Finally, Bosch eBike Systems has made a commitment to support Charge2Bike in their pursuit of implementing an industry-wide, standardized charging solution. This would mean that eBike riders around the world would have readily accessible fast charging stations compatible with their electric bike, which is something that we’re sure just about everyone could get on board with.

RIDING THE BOSCH PERFORMANCE LINE CX MY25 (BDU38)

I’ve managed to log around 8 rides on the new Bosch Performance Line CX drive unit, on a few different bikes that will be launching imminently.

On the face of it, this is very much a Bosch Performance Line CX drive unit, and I’m not mad about that. It was already somewhat of a benchmark for eMTB performance, after all. The remotes are familiar, the top-end power is the same. But there are some notable, welcome improvements.

The first thing that’ll hit you, whether you’re on the bike or riding with someone on the new system, is the reduction in noise both up and down the hill. It’s still audible on the way up, but it’s quieter and a nicer tone. On the way down, there’s no sign of the drive unit rattle from the previous generation drive unit, which is very welcome and helps the bike to feel more dialed all round.

The increased sensitivity is awesome. It’s been a well controlled system in the past, but the new Gen 5 (BDU38) drive unit takes another big leap forward. It feels extremely natural and reactive, letting you control the traction on the rear end effectively. From being able to do small kicks of power to get up and over an obstacle, to being able to ease off the power as you make your way up and over a slippy root or rock, it is now exceptionally well controlled on technical climbs. For regular fireroad pedaling it’s not going to make any difference, but once things get technical and slippery, the extra control is notable.

The updated Walk Mode is much easier to control, and the new Hill Start function works fairly well. Sometimes it has a little lag before it realizes you want to go, but I guess this is preferable to it taking off without you. It makes the tricky task of remounting the bike on a technical climb a bit safer and easier.

The new battery options are welcome, with the increased energy density dropping weights a little and helping to push towards high power eBikes with lower weights. With a 0.5kg drop in weight for either of the new batteries, it’s going to make a notable difference to weight figures.

Overall, it’s not like the previous generation Bosch Performance Line CX system is completely obsolete now that this drive unit is on the market. But Bosch has made some very welcome improvements, and has made the user experience even more enjoyable. Hopping back on the previous system has highlighted the improvements that Bosch has made, and makes me excited for more bikes to be released with it over time.

RIDING THE BOSCH ABS PRO SYSTEM

Bosch developed the ABS Pro system for more aggressive riding, and aggressive riding is what we love here at The Loam Wolf. It targets improved braking power, but still crucially prevents a front wheel lockup when braking hard in slick terrain. They’ve updated the valving inside and changed the algorithms to make a more reactive system. It focuses on acting on the first braking phase, where the initial slip would occur and reaction times may not allow for the hardest braking possible.

So far I’ve only had one ride on the ABS Pro system in very challenging conditions. During this time I was actively trying to use the ABS system in the Race mode. Over the course of a ride in ultra-slick conditions, I had 11 activations. I think this would have been less if I hadn’t been actively pulling the brake as hard as possible.

It’s deeply ingrained in my brain to modulate a front brake and prevent it from locking up, so the chances are that I’m not yet making the best use of the system. With time, I could potentially learn to trust the ABS Pro system more and pull the brake harder, potentially obtaining shorter stopping distances than I could do myself.

The ABS Pro system in ABS Race mode doesn’t change the riding experience until it kicks in now. So, you get the feeling in your finger of a normal Magura MT7 brake. From that perspective it could be worth it, but I’m conflicted about whether or not it’s worth the extra complexity, weight and cost. Time will tell, and Bosch is confident that the system is going to become readily used on eBikes in the near future.

The Wolf’s First Impression

Overall, it seems that Bosch has done an excellent job with their updated 2025 system. It’s been a joy to ride so far, and I’m excited to get on more new bikes with it fitted.

Particular highlights for me are the reduced motor noise and the impressive extra sensitivity it has. A quieter and easier to control bike is very welcome, and Bosch’s new system has delivered on that with great success.

As for the Bosch ABS Pro system, it’s also vastly improved over the previous generation ABS system. I’m going to maintain an open mind and see if I can be convinced by its worth in future tests, but for now I’m not sure.

Website: Bosch-ebike.com