Yamaha persists in the e-bike market. The Japanese manufacturer has thus presented a new version of its mid-range engine, called PW S2 and replacing the PW ST launched in 2018. Much more than a slight update, the PW S2 brings its share of new features and targets the Sports-oriented VAE. This motorization should land with the ranges of electric bikes of 2023.
The PW S2 is a central engine that takes place at the level of the pedals. This position implies an adaptation of the frames, and therefore specific constraints for bicycle manufacturers. Yamaha therefore set out to make their unit more compact for greater latitude in frame development. The volume of the PW S2 is reduced by 20% compared to the previous generation, aka the PW ST. All this is logically accompanied by a 16% weight gain, the new Japanese engine now weighing 2.85 kg on the scale.
Interesting torque/weight ratio
This puts the S2 quite close to Yamaha’s top model, the PW X3. The latter weighs only 2.75 kg, but develops 85 Nm. The PW S2 displays 75 Nm of torque, a slight improvement over its predecessor (70 Nm). Interesting, because on these points it puts the new Yamaha engine ahead of that of competitors like Bosch. The German offers a Performance Line engine developing 75 Nm, but weighing 3.2 kg.
Bosch, however, retains a major advantage over its Japanese competitor: its intelligent system. Indeed, Bosch motors offer a large number of features related to the manufacturer’s technology, as well as advanced connectivity. Here, Yamaha nevertheless promises some features already crossed on the other engines of its range, in particular the automatic mode which varies the level of assistance in a transparent way for the cyclist. The Zero Cadence function, for its part, optimizes engine performance at start-up and when pedaling.
Display B: a new 3-inch screen
This engine is not the only novelty launched by Yamaha. The Japanese also unveiled a new screen, Display B, a 3-inch black and white display with complete information: instantaneous speed, distance traveled, pedaling rate, battery level or even a clock. This screen is removable to avoid the risk of theft or damage due to bad weather. The controls are remote on a box with five buttons to control the electric bike.
Yamaha also promises memorization of the assistance mode and the position of the lights used last. Finally, the Display B ignores Bluetooth technology at first sight, unlike its big brother the Display C. On the other hand, the screen has a USB connector delivering 1 A to recharge a smartphone, for example.
This engine being mainly intended for the European market, Yamaha has chosen to manufacture it there. Cock-a-doodle Doo ! France was chosen for the production of the PW S2, and more particularly the MBK factory in Saint-Quentin (Aisne). The desire is to necessarily limit the costs related to logistics, as well as the environmental impacts caused by transport from Japan to Europe.