By Alex Boyce

Bosch has now been present in the bike motor market for 10 years, but despite their pioneering effort in the world of e-bike powerplants, of late Bosch has fallen a bit behind in the spectrum of new product offerings for the quickly changing e-bike marketplace. 

Recently, the global German brand invited journalists to their Stuttgart headquarters for the launch of their new Performance CX e-bike motor. The Performance CX is available in five different versions and has 75 N/m of motor torque, and the new Powertube battery jumps to a headline-grabbing 625 Wh. 


Hitting the scale at 2.9 kilos, the new CX motor is around 1 kilo lighter than its previous version and has a housing made of magnesium and is 50 percent smaller than the previous generation. These changes allow for a greater range of bike construction styles and design flexibility, which will affect bicycle performance. 

Bosch’s brand-new, 50-percent-smaller Performance Line CX motor provides the same power and torque in a smaller form factor.


Bosch has focused a lot of energy on improving riding sensation, creating a more natural feel and a normal-sized 104mm chainring. With 340-percent support, the Bosch Performance CX also includes some software upgrades that improve the ride experience. The most notable technical change is the almost total decouple of the motor from rider when passing 15.5 mph or riding with the motor switched off. 


Bosch has also diversified their range of motors this year with a motor for every type of pedal-assist bicycle use.

CX Speed: A 28-mph version of the Performance CX designed for speed pedelec e-bikes that require lights and number plates.

CX Cargo: A Performance CX motor that provides up to 400 percent of support and designed for transporting loads that total up to 550 pounds, including bike and rider in a cargo bike.

CX Cargo Speed: A Performance CX Speed motor that is designed for cargo bikes that can reach speeds of 28 mph and have a system weight of up to 550 pounds. 


The press launch was an Apple-style launch with the world’s bike press invited to a special event with a dynamic presentation. Some bikes were available for testing, but unfortunately only in a restricted area. We still managed a short time on the Performance CX-powered mountain bike, plus some time on a speed pedelec Performance CX. Our main impressions come from the Performance CX MTB test we did. 

The Cargo Line motor provides up to 400 percent of support and designed for transporting loads that total up to 550 pounds, including bike and rider in a cargo bike.


Despite the small-scale test loop, what we did find was a new motor that feels like a big step up from the previous generation. First, it is a lot smoother and the sensation is more natural, with a power support that is strong but does not give a mechanical boost sensation in use. The motor reaches 12.5 mph very quickly in Turbo mode, but doesn’t hit you with the power in one big jump. We noticed the acceleration tapers off after 12.5 mph, and after passing 15.5 mph on our short test, we noticed it was imperceptible that we had ridden through the limit. The old Bosch motor was like running into a wall at 15.5 mph, which displeased many riders and was a consequence of the multiplication gearbox. 

The motor now uses a standard chainring and chain layout with a one-to-one ratio on pedaling. All this will please bike designers, as it will give a better ride feel and also more flexibility for chainstay design. 

We didn’t spend enough time on the motor to judge its torque performance and e-MTB mode, which is dynamic according to rider input pressure on the pedals. For what we could understand, its feeling has been improved compared to the old version. However, Turbo mode has been improved, which e-MTB mode was originally designed to supplant, as it mitigated the old-power “thump” that the Turbo mode had. Now Turbo mode is as sweet and powerful as e-MTB mode was. At the end it’s another option, which is good and probably will improve over time as Bosch launches software updates.


The torque feeling of the new motor is different from the older one. There is plenty of power, but we didn’t have enough time to find the sweet spot when cadence and power meet perfectly. The most notable sensation was an improvement in smoothness on smooth surfaces, and we will be interested to see how that translates to the trail. Bosch now also uses metal gears inside the case, which allows for a stronger gearbox, but does cause some mechanical whine. We would say it is similar to a Shimano sound but different in tone and slightly quieter, but not silent like a Brose, which uses a belt drive.


This was a problem on the old motor when compared to the competition, but no longer. The new motor is 50-percent smaller and a lot lighter. This gives bike makers the ability to better integrate the motor into the frames they design. The Bosch visual look has been retained, which is an important part of their marketing and sales influence. The motor is less of an obvious monster and more of a hidden power source. Previous Bosch-equipped bikes were defined by the motor more than new Bosch bikes will be, which is important and hands back to bike makers the power of making bikes that sell. 


Bosch had on display for our preview launch a Kiox-based display and controller and a Cobi display and controller. Both aim to connect the rider to the internet better and give more data channels than before. The Kiox display we have used before. It also acts as a digital lock—take it off and the bike is rendered unusable. This is similar to what Greyp introduced earlier in the year, and we think it’s a good idea. 

“Now Turbo mode is as sweet and powerful as e-MTB mode was.” 

However, we really aren’t fans of the display sitting in the middle of the handlebar sticking out. It is vulnerable to damage, and not everyone likes the display. Making it optional would have been a better option. The Bosch product manager commented that he understood our concern about this. We actually wondered why they have done this. The only idea we can come up with is maybe it is down to development cycles. The motor has been a huge undertaking and is actually a year late of its original launch schedule. So, we can assume they have focused all energy on the motor and will introduce a display update on the next product cycle. Other high-end bike makers make displays an option or at least are better positioned.


The Cobi.Bike app was added to the motor control system and acts as a smartphone hub. It’s designed to hold your smartphone and then give you all kinds of controls, including navigation, incoming call and music control, plus many other digital possibilities. This is obviously a feature for use in a more urban setting than on the trails. We did not get to try this system, and will hopefully do a feature on it in the future to see how digital connectivity affects mobility. 


This was on the horizon, and Bosch is the first company to release an integrated motor and suspension system. Technically, it means any Fox Live Valve shocks or forks that are connected to the motor will work together to switch damping modes based on not just the terrain but also the motor inputs from the rider. Pedal hard and the suspension locks out or slows down—clever stuff—and we look forward to trying a bike with this feature. Probably an expensive option, though. 

Bosch adds 25 percent to the capacity of their PowerTube batteries by offering this 625 Wh battery, which can be charged to 50 percent in 1.5 hours.



Bosch has repackaged the PowerTube design into a slightly longer form and increased its power to 625 Wh while weighing only 3.1 kilograms. That’s an extra 125 Wh, which with a more efficient motor is going to mean more range. It is always hard to measure this, as there are many factors that affect range. Charge times have been decreased, with batteries now recharging 50 percent in 1.5 hours. To increase charge times significantly, high voltages would have to be used. Bosch has chosen to stay with the standard 36 volts, but does now have a 6-amp charger, whereas before most charges were 3–4 amps. Better battery-control circuitry and improved cells are the main developments here. 


The CX Speed motor is designed for Urban use, with bikes having to be registered and insured. In reality the motor seems to be the same but it has a different software tune. On the road the motor is fast and powerful and gets you to 28 mph very quickly. We rode around Stuttgart a bit and found ourselves moving through the traffic at a quick pace. This type of system is going to be appreciated in cities. The motor’s ability to react quickly and smoothly was improved compared to the older system. Our rider weight is around 187 pounds, and even lighter riders are going to be really happy with this performance on Urban bikes.

Performance CX Specs

—2.9 kilos 

—Magnesium casing

—75 N/m torque

—Size reduction of 50 percent

—360 percent of support

—Dynamic power adjust 

—Electronic suspension control and dynamic adjust with Fox Live Valve systems

—Kiox display

—New smart-hub Cobi control system option

—Electronic locking of motor via display

—New PowerTube 600 battery with 625 Wh of power weighing 7.7 pounds 

—Improved charging times 50 percent in 1.5 hours

—New variants, CX Speed, CX cargo and CX Speed Cargo


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