Coming this autumn is an all-new lightweight eBike motor from Bosch. Weighing a claimed 2 kg, the Bosch Performance Line SX offers a mid-level assist eBike motor suited to Gravel eBikes and Urban eBikes, and of course the rapidly growing segment of lightweight eMTBs.
As compared to the Bosch Performance Line CX and Performance Line CX Race motors that deliver a maximum torque of 85 Nm, the Bosch SX motor offers a less aggressive 55 Nm. That’s not to say it wont in future find a home on more aggressive eMTBs; only that it has a more conservative approach to power consumption, complementing the efforts of the rider in a more gentle rider effort:assist ratio.
Bosch Performance Line SX eBike Motor
Indeed, Bosch says the Performance Line SX motor delivers “a more natural riding sensation” than its more powerful 85 Nm sibling. That said, it has a massive peak power output of 600 Watts. Meanwhile, the TQ-HPR50 – of Trek Fuel EXe fame – boasts a peak power of just 300 Watts. However, the two are equivalent in terms of their rated continuous power output, which comes in at 250 Watts.
The Bosch Performance Line SX system has a claimed weight of 4 kg. The motor itself weighs around 2 kg, and is thus ~750g lighter than the full power Performance Line CX Race offering. The 400 Wh CompactTube battery weighs 2 kg, bringing the system weight up to a claimed 4 kg – that includes the Mini Remote and the System Controller. Despite its lightweight magnesium casing, the motor itself is not quite as light as the TQ-HPR50 which comes in at 1.85 kg.
A new PowerMore 250 Wh battery brings range extension in a package the size of a water bottle. This weighs a claimed 1.6 kg, bringing the weight of the Bosch Performance Line SX system at its maximum 650 Wh capacity to around 5.6 kg.
Of course, as is the law here in Europe, the Bosch Performance Line SX motor stops providing assistance at speeds over 25 km/h. However, key to the claim of its ability to provide a natural riding sensation, this motor offers around 50% less pedaling resistance (or drag) as compared to the Performance Line CX motors.
Likely adding to the more natural ride feel is a narrower Q-Factor. While the full-power Performance Line CX motor offers a wider stance of 175mm, the “new sealing concept” and narrow cranks bring the Q-Factor of the Performance Line SX motor down to 160mm.
While this lighter SX motor was designed with a range of eBikes in mind, from Gravel eBikes, to lightweight eMTBs, as well as Urban eBikes, Bosch has placed a lot of emphasis on what the new system can offer to the drop-bar contingent.
For example, they have designed a new Mini Remote Dropbar Controller with a 31.8mm clamp diameter meant to be operated from the tops only.
Also notable for Gravel eBikes is the addition of a “Sprint” mode, in addition to the tuneable Tour+ and eMTB modes that riders of any Bosch-powered eMTB will be familiar with. This is said to “help eGravel bikers to quickly reach and maintain a high speed. On high-cadence sections the new riding mode supports them disproportionately to their own power: the faster the eBiker pedals, the higher the level of support”.
“Now that most types of bicycle have been electrified, the individual categories are becoming even more diverse. With the new Performance Line SX, we are primarily targeting sporty riders, for whom a low total weight is important for riding fast and experiencing a natural flow. Our goal was to maintain the typical Bosch quality, riding performance and reliability and transfer these to light, agile bikes. With the Performance Line SX, state-of-the-art eBike designs and maximum riding fun can be optimally combined.”Claus Fleischer, CEO of Bosch eBike Systems.
The first models with the Performance Line SX are expected to be available on the market from Autumn 2023.