Bosch Performance Line CX Gen 5: Market leader or tough competitor? With the new Performance Line CX Gen 5 drive, Bosch want to secure their place at the top. The new motor still features the same 85 Nm of torque and finely-tuned eMTB mode, which delivers that legendary uphill flow. However, how does the CX Gen 5 compare to its predecessor, the CX Gen 4, and can it retain its place at the top?
This review forms part of our big ebike motor comparison test. Here you’ll find an overview of all 15 motors in review, along with lots of exciting background information, and helpful buying advice for your next purchase!
For years, Bosch have been the industry leader in the e-motor segment, and are still widely appreciated for their extensive service network and years of experience. However, times are changing, and new motor manufacturers enter the market with innovative technology, challenging Bosch’s dominant position.
Not backing down, Bosch respond with the new Performance Line CX Gen 5 flagship model. The previous CX Gen 4 motor was a popular choice amongst bike manufacturers and used profusely for eMTBs, trekking bikes, and E-SUVs. In our big E-MTB comparison test, nearly 44% of the test field relied on a Bosch motor, underlining the brand’s dominance. For serious racers, Bosch offer the Performance Line CX Race drive, which delivers a whopping 400% assistance via a software tweak – unleashing its power even faster than the CX, which offers up to 340% assistance. However, it’s yet unclear whether Bosch will also release a Race version of the Gen 5 Line CX. For riders focusing on a light system weight, Bosch offer the SX motor, which delivers less torque and is also slightly more compact.
Bosch’s success isn’t based solely on motor performance; it’s also about their holistic approach. Their cohesive system of motors, batteries, displays, and remotes is supported by a dense service network. In over 100 countries, authorized dealers ensure riders can access Bosch service worldwide. Notably, Bosch use a closed system, meaning that third-party batteries aren’t compatible.
The Bosch Performance Line CX Gen 5 in detail – The all-around eMTB solution?
Redesigned from the ground up with exciting new features, the Bosch Performance Line CX Gen 5 still delivers 85 Nm of torque, 600-watt peak power, and up to 340% assistance. The most striking upgrades are the fewer mounting points, which have been reduced from three to two, and the more compact housing, which both allow to reduce weight by 100g and give engineers more freedom with frame designs. Weighing in at 2.8 kg, the CX Gen 5 sits in the middle of the test field in terms of weight, right next to the Shimano’s EP801 and Panasonic’s GX Ultimate.
The Bosch Drive Unit draws its power from either a 600Wh or 800Wh battery, both of which are seamlessly integrated into the downtube. Unlike Shimano, which allow bike manufacturers to use third-party batteries, Bosch are strict about their battery options, which are usually determined by the bike manufacturers, with limited choices for consumers. The Bosch 800 Wh PowerTube weighs around 3.9 kg and has the highest energy density in Bosch’s portfolio at 205 Wh/kg, securing a top spot for density. Other systems, like DJI’s drive, have batteries with even higher energy densities. The 600Wh Bosch battery, which is nearly 900g lighter than its 800 Wh counterpart at 3.0 kg, uses 2170 cells that ensure increased power and energy storage. Both PowerTube batteries can be used with DualBattery systems, which allow you to use two batteries or a main battery and the 250-Wh PowerMore Range Extender. The Bosch Range Extender mounts to the downtube and offers a significant advantage: it draws power evenly from both the main battery and the extender, unlike other systems like Shimano’s EP801, which depletes the main battery first before tapping the extender. This even power distribution reduces thermal load and stabilizes temperatures, extending the lifespan of both batteries.
The PowerTube 800 and PowerTube 600 share the same length, making it easier for bike manufacturers to integrate the both in the same bike. The only difference is in thickness, meaning that all it takes to swap between the two batteries is either a special battery cover or a thicker downtube.
Using the standard 4A charger, the big battery can be charged to about 50% in around 2.6 hours. Budget models come with a slower 2A charger, which delivers less power and takes more than twice as long to reach 50% capacity. The faster 4A charger is available for purchase in Bosch’s online shop for € 129.
The Bosch motor system can be paired with different controllers, which the bike manufacturer can choose flexibly based on intended use or their preference, provided they’re compatible with Bosch’s Smart System. The wireless Bosch Mini Remote is a popular choice for sportier eMTBs, allowing riders to adjust support levels with plus and minus buttons, as well as activate functions like walk assist, Hill Hold, and the new Hill-Start function (more on that later). Additionally, the integrated System Controller in the top tube doubles as a power switch and displays the support levels in four increments. These are displayed in different colors that offer good readability even in direct sunlight. Bosch also offer other controllers, such as the LED Remote and the Purion 200, which are slightly bulkier yet consistently high-quality and easy to use.
There are several displays to choose from, including the Kiox 300, Kiox 500, and Intuvia 100. For sporty riders, the newly introduced, compact 1.6″ Purion 400 display provides easy access to ride data like speed, battery level, and distance. Those who want to upgrade their e-bike with a new controller or display can choose from models like the LED Remote, Kiox 300, Kiox 500, or the SmartphoneGrip (a smartphone holder). These can be installed by the user and configured through the eBike Flow app or by an authorized Bosch dealer.
The Kiox models also feature a basic navigation function, which can be loaded with routes via the free eBike Flow app and analyzed post-ride. Additionally, the app offers practical features such as eBike Lock to secure the drive unit and eBike Alarm for theft protection. The latter requires the Connect Module and a Flow+ subscription, which costs approximately € 40 per year or around €5 per month after a free 12-month trial.
One very practical feature is the eBike Flow app, which allows you to customize the support modes, including maximum torque, response dynamics, and various display settings. Compared to other systems from Shimano and Specialized, Bosch offer broad customization options, although these lack the finer adjustments of Specialized’s Mission Control app, which allows power micro-adjustments in 10% increments. Shimano’s E-TUBE app also provides a range of customization options and allows for two different riding profiles. However, Bosch’s eBike Flow app still offers extensive customization options, allowing you to fine-tune the motor’s response to suit your needs and different terrains. Additionally, Bosch’s system is compatible with other products like the new ABS Pro and Bosch eShift automatic drivetrain, although these must be installed in advance by the bike manufacturer and are not available for aftermarket installation.
Bosch Performance Line CX Gen 5 in action
The Bosch Performance Line CX Gen 5 has four support modes, ECO, Tour+, eMTB, and Turbo. The ECO mode saves battery on long rides, while Tour+ and eMTB provide dynamic assistance, automatically adjusting to pedal input. Tour+ offers smoother support from 140% to 270%, which is the ideal match for long fire road climbs and gentle trails, while eMTB delivers 140% to 340% assistance for steep technical climbs.
Thanks to the Extended Boost feature, the motor responds precisely to pedal input in eMTB mode, making it easier to negotiate obstacles like roots and rocks: gentle pedaling activates measured support, while stronger input triggers a powerful yet controllable boost. Turbo mode maximizes power with 340% assistance, albeit at the cost of battery life.
On flat tarmac roads and gravel paths, the Bosch Performance Line CX Gen 5 quickly gets you up to speed before cutting out at the 25 km/h limit. However, the support fades out gently rather than stopping abruptly. While the motor accelerates powerfully at lower speeds, it reaches a performance plateau relatively soon. In contrast, the DJI Avinox ramps up its mechanical power to 750 watts, while the Bosch CX’s power curve flattens out just above 500 watts. This difference is noticeable in the lab and, in practice, results in weaker support at higher speeds.
Bosch’s focus is on a natural ride feeling, which the German motor manufacturer promotes with the “Uphill Flow” slogan. The Bosch Performance Line CX Gen 5 indeed works harmoniously uphill, providing powerful support while at the same time adapting to your riding style very intuitively.
In tricky climbing sections, however, it has a clear limitation compared to the DJI Avinox: while the DJI allows a wider cadence range within a gear, the Performance Line CX requires you to maintain a cadence between 70 and 90 rpm for full support. This can be challenging in steep, technical sections, often requiring gear shifts to get the support you need. Here, the DJI Avinox shows its superiority by providing steady assistance even at suboptimal cadence.
Nevertheless, Bosch introduced useful new features that make a positive impact on the trail. For example, while the GIANT SyncDrive Pro2 motor can engage abruptly in power mode when setting off, Bosch’s new Hill-Start function ensures smooth and controlled starts on steep gradients. The walk-assist feature also makes it easier to push the bike up steep inclines, while the Hill-Hold function prevents the bike from rolling backwards.
The new Bosch CX’s also impresses in terms of noise: even at high cadences, the motor hums discreetly in the background, and is almost completely silent in the weaker modes– similar to the DJI Avinox and Shimano EP801. Bosch also improved the motor’s noise levels when riding downhill: the distinct metallic clunking noise of the Bosch CX Gen 4 – which is also an issue with the current Shimano EP801 drive – is finally gone, significantly improving the overall riding experience. Bosch achieved this by separating the internal and external drivetrains, making the motor significantly quieter even on rough trails. Nice!
Conclusions about the Bosch Performance Line CX Gen 5
The Bosch Performance Line CX Gen 5 is a successful evolution of the CX Gen 4, with targeted improvements addressing previous shortcomings. While the suboptimal gearing causes it tostruggle on steep technical climbs, the Bosch Performance CX remains a powerful and reliable motor that offers excellent support. Thanks to the countless customisation options of the Smart System and Bosch’s industry-leading global service network, the CX Gen 5 is our top recommendation for many eMTB riders.
Tops
- Quiet on descents
- Powerful support
- Sensitive response in eMTB mode
- Dense service network
Flops
- Loses performance at suboptimal cadences on technical climbs
For more information visit bosch-ebike.com
The test field
For an overview of our big ebike motor comparison test click here
All ebike motors in test: Bosch Performance Line CX Gen 5 | Bosch Performance Line CX (Click for review) | Bosch Performance Line CX Race (Click for review) | Bosch Performance Line SX (Click for review) | Brose Drive S Mag (Click for review) | DJI Avinox (Click for review) | FAZUA Ride 60 (Click for review) | GIANT SyncDrive Pro2 (Click for review) | Panasonic GX Ultimate (Click for review) | Pinion MGU E1.12 (Click for review) | Shimano EP801 (Click for review) | Specialized SL 1.2 (Click for review) | Specialized 2.2 (Click for review) | TQ HPR 50 (Click for review) | Yamaha PW-X3 (Click for review)
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Words: Benedikt Schmidt Photos: Mike Hunger, Benedikt Schmidt, Manfred Schmitt
