The Bosch Performance Line SX Motor Is a Year Old—What Does It Tell Us About the Future?

During the summer of 2023 Bosch introduced a new motor, the Performance Line SX. This is Bosch’s lightest drive unit to date, weighing only 2.0kg (4.4 lbs.). What makes the Bosch Performance Line SX so special isn’t just that it is light; it is also powerful. At peak power output it produces 600W.

Light is good for performance-oriented e-bikes such as eMTBs, road and gravel e-bikes, but light only gets us so far. There are other lightweight motors out there. The Brose-made Specialized SL 1.2 motor weighs just 1.95kg (4.3 lbs.) and produces 320W at peak. The TQ HPR 50 weighs a tiny bit less than the Specialized, at 1.85kg (4.1 lbs.) and produces nearly as much wattage at peak: 300. The Fazua Ride 60 improves on both of those by running in the same neighborhood weight-wise (1.96kg), but producing a more muscular 450W.

The difference in weight between the Bosch Performance Line SX and the Fazua Ride 60 is 40g, or about 1.4 oz., which is roughly the weight of a slice of bread, or $1.75 in quarters. The difference between the Bosch and the TQ is about ⅓ of a one-pound box of pasta or a bit more than two Clif bars that you might bring along on a long ride. We’re talking very small amounts of weight … but a big difference in power.

It’s easy to see that the Bosch Performance Line SX motor offers nearly double the power-to-weight ratio of both the Specialized and TQ motors and roughly 33 percent more than the Fazua Ride 60. This is what makes the Bosch motor so exciting. Even compared to Bosch’s coveted Performance Line CX motor it shaves almost a third of the weight while producing the same peak wattage. It does give up some torque, though—55Nm for the SX compared to 85Nm for the CX.

E-bike manufacturers making high-end eMTBs have been racing to launch eMTBs using the motor. Because the Performance Line SX motor is essentially housing-less, it uses a different mount, which means that manufacturers can’t simply decide to swap out the Performance Line SX motor for the Performance Line CX motor. Brands must design an eMTB or other e-bike with the motor’s mount integrated in the design.

Because a manufacturer can spend two years designing a new model or revising an existing one, and because the Performance Line SX motor is only one year old, most companies have yet to begin offering an e-bike equipped with this motor.

That’s not to say you can’t find it out there. There have been plenty of early adopters. It can be found in Canyon’s Neuron:ONfly, the E-Lyte from Whyte Bikes, Norco’s Fluid VLT, Orange’s Phase EVO, the E-Troy Lite from Devinci, Mondraker’s Dune, the KTM Macina Race and Macina Scarp, M1-Sporttechnik’s 400 variants, and the Sonic EVO and Sonic EVA from Bulls.

In bike racing the absolute measure of a cyclist’s fitness is gauged by how many watts they can generate per kilogram of body weight. It’s the same for motors; the Bosch Performance Line SX generates 300W/kg and that number is the one that competitors like Shimano and Yamaha will be aiming to match.