Thanks to the Performance Line CX for that ‘uphill flow’
More than ten years ago, eMTBs were still largely unknown – something new. Yet Bosch eBike Systems was already firmly convinced of the concept back then and, in 2015, launched the Performance Line CX, the first drive system designed specifically for e-mountain bikes.
This gave the market a real boost. As a result, more and more manufacturers adapted their designs and strategies, added eMTBs to their ranges and enabled ever more cyclists to experience this unique riding sensation. Initial doubts gave way to fascination, taking mountain biking to a whole new level. The eMTB has transformed the entire community. For competitive mountain bikers and trail riders alike, e-mountain biking has become an integral part of the sport today.
The idea back then was that anything which wasn’t fun without an ‘e’ should be turned into an experience. This included steep climbs, peppered with obstacles, sections with roots or steps. ‘Uphill Flow’ led to a new phase in the development of mountain biking, one in which the overall experience takes centre stage rather than just the descent.
Even long climbs in a group became more sociable; suddenly, it was easier to ride together whilst chatting. At the same time, long alpine cycling adventures became possible without the need for a shuttle or a lift. This concept, together with the first Performance Line CX, laid the foundations for numerous further product developments, cycling infrastructure projects in tourist regions and new competition formats.
From the first generation to a smart system
Since its launch in 2015, the Performance Line CX has undergone several stages of development and continues to set new standards in terms of riding feel and motor performance. The pioneering, progressive-dynamic eMTB mode, the refined eMTB+ mode for the most challenging terrain, the customisable Extended Boost for overcoming obstacles, and many other technical developments complement the Drive Unit.
Since 2022, the Performance Line CX has been fully integrated into the smart system. Regular over-the-air updates keep it up to date and continually introduce new features. The Drive Unit does not operate in isolation: the motor, battery, display and eBike Flow app all work together as a single, interconnected system.
Developments over the past eleven years clearly demonstrate how consistently Bosch has continued to refine the Performance Line CX. What began as the first drive system designed specifically for e-mountain bikes has evolved into a technically sophisticated powerhouse that adapts individually to different riding conditions.
Power meets control
The fifth generation of the Performance Line CX promises even more dynamism on the climb, greater agility on the trail and a smoother ride on long tours. With its perfectly tuned motor software, the Drive Unit allows sporty e-bikers to experience unique riding dynamics for the perfect eMTB experience, whether it’s a delicate start on steep trails or powerful, perfectly controlled acceleration out of bends.
The power of the current Performance Line CX is delivered dynamically and precisely tailored to each riding manoeuvre, whilst responding exactly to pedal input. This is made possible by the advanced sensor technology. Several high-performance sensors precisely measure pedal input more than 1,000 times per second. These include, amongst others, a high-resolution cadence sensor and precise torque measurement technology. Inertial sensors, known as IMUs, also measure acceleration and rotational rates in six dimensions. They detect gradient and tilt angles as well as vibrations. This means the eMTB ‘knows’ how steep the climb is and whether the rider is on a forest track or a root-covered trail.
The drive unit reacts with great sensitivity to changes in acceleration, the rider’s own power output and current speed. Thanks to the refined sensor signals, e-bike riders always receive just the right amount of motor power – responsive, controlled and immediate. Or, alternatively, smooth, restrained and reliable for long rides. The current generation of the Performance Line CX is a true all-rounder.
More power, more control: the Performance Upgrade 2.0
One of the key benefits of the current generation of bikes is that eMTB enthusiasts can customise the riding modes on their Performance Line CX via the eBike Flow app and tailor them to their own personal setup.
The eMTB+ mode, introduced in 2025, unleashes the power of the drive unit with responsive precision exactly when the rider needs it. This enables even more controlled riding on challenging uphill terrain.
Bosch also offers the option to increase performance metrics such as torque, power and assistance. This makes the Performance Line CX and the Performance Line CX-R – also launched in 2025 – even more customisable and powerful for the most demanding trail riding.
Whether you’re riding on steep trails, negotiating high steps or pedalling through tight, twisty bends, Bosch’s smart system – featuring the Performance Upgrade 2.0 – will provide even more torque and assistance from summer 2026 onwards.
Using the eBike Flow app, sporty riders can increase the torque of the Performance Line CX and Performance Line CX-R to up to 120 Nm in any riding mode. The maximum setting can be defined by the respective bicycle manufacturer. Starting from the default setting of 85 Nm, this provides a wide range of adjustment for personalised tuning.
In addition, the maximum assistance level can be increased. In certain riding situations, assistance of up to 600 per cent is now available at speeds of up to 15 km/h. What this means on the trail: whether it’s a long stretch of roots, a challenging exit from a hairpin bend or a sudden steep drop after crossing a stream – it is precisely at these key points that the intelligent riding software makes the full power available, delivered very precisely and in a context-sensitive manner. This requires the rider to apply dynamic effort to the pedals. Anyone who briefly increases their input receives a decisive boost of power from the system and is rewarded with a new sense of achievement. Immediately afterwards, the system reverts to an efficient level of assistance.
This intelligent power management reduces wear and tear on components – particularly the chain, cassette and freehub – and maximises range. Riders can decide for themselves via the eBike Flow app whether and to what extent they wish to use this short-term boost.
More than the sum of its parts
This means that the current Performance Line CX is now at the heart of Bosch’s eMTB ecosystem. Built around the drive unit, Bosch eBike Systems presents a sporty range of products that takes the e-mountain biking experience to a whole new level. This includes high-performance batteries for long ranges, a lightweight range extender, compact displays, eBike ABS Pro and the eBike Flow app with a host of features. The Performance Line CX is therefore now much more than just a drive unit. It forms the technological heart of a connected system that combines power, control, safety and personalisation.
Motor profile: Bosch Performance Line CX 2015
- Rated continuous power: 250 watts
- Maximum torque: 75 Nm
- Maximum peak power: 600 watts
- Maximum support: 300 per cent
- Weight: approximately 4.0 kilograms
- Support levels: Eco, Tour, Sport, Turbo
When Bosch unveiled the Performance Line CX in 2015, cycling traditionalists were sceptical: an e-drive designed specifically for mountain bikes? Yet the initial scepticism quickly gave way to enthusiasm for this new way of mountain biking. With 75 Nm, 300 per cent assistance and three-sensor technology, the Performance Line CX transformed pure thrust into a natural riding experience. Responsive handling, dynamic power delivery and improved cadence support suddenly made even the most rugged, steep climbs rideable. Riding uphill became a new and enjoyable discipline for mountain bikers, and the concept of ‘uphill flow’ was born.
Motor profile: Bosch Performance Line CX 2026
- Rated continuous power: 250 W
- Maximum torque: 120 Nm
- Maximum peak power: 750 W
- Maximum support: 600 per cent
- Weight: 2.8 kilogrammes
- Support levels: Eco, Tour, eMTB, eMTB+, Turbo
The past eleven years have impressively demonstrated the continuous innovation Bosch has achieved with the CX series. Compared to the original CX, which weighed four kilograms, the current powerhouse has shed a substantial 1.2 kilograms whilst significantly improving its performance: 120 Nm of torque, 750 watts of peak power and up to 600 per cent assistance. At the technological heart of the CX Gen5 is a multi-sensor system that detects incline, acceleration and terrain, and measures pedal input more than 1,000 times per second. The result is pinpoint power delivery – gentle one moment, explosive the next – yet always intuitive and controllable.
Performance Line CX: A comparison of 2015 and 2026
| Characteristic | Performance Line CX 2015 | Performance Line CX 2026 |
| Maximum torque | 75 Nm | up to 120 Nm |
| Maximum engine power | 600 watts peak power | up to 750 watts |
| Maximum support | 300 per cent | up to 600 per cent |
| Sensors | 3-sensor technology | Multi-sensor concept with more than 1,000 measurements per second |
| System | Classic e-bike drive system | A fully connected smart system |
| Personalisation | Pre-set driving modes | Customisable driving modes and performance settings |
From 75 Nm in 2015 to 120 Nm in 2026, from three sensors to intelligent multi-sensor technology: the Performance Line CX represents a development that has continually refined the uphill flow.