Bosch Performance Line CX
As seen on Canyon and Cannondale bicycles, among others
Popular on gravel bikes such as Canyon’s Grail:on range, Bosch’s Performance Line CX systems also feature on many mountain bikes and hybrids. Thus it’s little wonder that it boasts by far the most torque of the three systems shown here – a huge 85Nm.
Based around a mid-drive design, the Bosch unit fits into a special bottom bracket shell and is a motor, transmission and bottom bracket in one, such that the bottom bracket’s axle is driven when the cranks are turned. Given this and the high power, the components are fairly burly, and Bosch-equipped bikes couldn’t pass as normal road or gravel bikes. Still, the system has shrunk in recent years and this fourth generation is now at least small and light enough to provide a viable option for road and gravel bikes.
‘In terms of weight and power density, a lot has happened in recent years,’ says one Bosch engineer.
‘For example, the size of our Performance Line CX motor has reduced by around half compared to the previous generation and we’ve also been able to reduce the weight by around 25% to 2.9kg. Batteries have also developed in two directions. One: higher-capacity models containing more cells that are larger and heavier but offer increased range. Two: batteries with lower capacities that are lighter and more compact to better integrate into the frame. Both are suitable for e-road and e-gravel.’ Along with higher power, Bosch-equipped bikes are known for having good sensor technology.
‘Sensors measure the rider’s physical power input, cadence and speed and therefore are crucial in adjusting assistance accordingly. Torque, speed and acceleration are measured more than 1,000 times per second, which allows us to precisely determine how much support the rider needs in a respective situation.
‘Moreover, a gearshift detection system ensures smooth shifting and reduced chain wear. We believe this results in the rider benefiting from a particularly natural riding experience.’
Given the vast amount of power on offer this is just as well, and in fact Bosch also offers more pared-back Performance Line products. However, we’ve yet to see anything other than the powerful Line CX featured on a drop-bar bicycle.
It’s a relatively modular system, so be sure to check the size of the removable battery because these range from 400Wh (watt-hours) up to a hefty 750Wh. The size of the system’s various handlebar displays also varies drastically and, although some bikes will connect to a phone via Bluetooth for adjustment and monitoring, it’s worth noting this feature isn’t standard.
‘The size of our motor has reduced by around half compared to the previous generation’