First Look: Bosch Takes It To The Next Level


With help from the newest Bosch Performance Line Speed motor, getting dropped from the group ride is no longer a problem.
Photo: Pat Carrigan


As the e-bike market has continued to expand, the days when all e-bikes are defined solely by either city or mountain bike versions is no more. Drop-bar e-bikes, whether they be gravel or road bikes, have gained in popularity as of late. Some of the earlier ones that came out a few years ago featured Class 1 (20-mph) motors, and we were unimpressed. 

Unlike mountain bikes, road bikes tend to go faster than 20 mph (without hardly trying), and some motors offer significant drag above their rated electric-assist speeds. All that, combined with the added weight, makes riding an e-road bike a tough choice for anyone looking for a truly performance-oriented experience. 

Following in the tire tracks of the Class 3 Specialized Creo Turbo, we’re finally starting to see more drop-bar bikes with Class 3 (28-mph) motors, which makes much more sense. Bosch has been making Class 3 motors for a decade, and they came out with their fourth generation of the venerable Performance Line Speed motor last year. It improves on previous models in a number of ways.

First off, it’s lighter with a smaller form factor. The new motor weighs in at a mere 7.1 pounds versus the third generation’s 8.8 pounds. That’s a weight savings of 1.7 pounds! Some of this is thanks to a magnesium shell, which helps in cooling as well. Torque is now 85 N/m versus the third generation’s 63 N/m. Maximum support is up to 340 percent now. Actually, when the fourth generation first came out, it was rated at 75 N/m, but a firmware update offered an extra 10 N/m over that.


There are quite a few options for batteries—from a 400 W/h external battery to a 625 W/h internal version, and on some bikes they can be doubled up for more range. 

There are also plenty of choices for displays, including the Purion, Intuvia, Kiox, Nyon and SmartphoneHub. We love the Kiox and SmartphoneHub because they allow for all kinds of extra features—from maps to heart-rate monitors and more, plus you get cadence and a power meter display.


“The new Bosch G4 motor weighs almost 2 pounds less than its G3 predecessor.”


Available assist modes include Eco (60 percent), Tour (140 percent), Sport (240 percent) and Turbo (340 percent). In all modes it supports up to 28 mph and 120-rpm cadence. You can feel the difference from previous motors. Several modes have slightly higher assist percentages, and the overall bike can be lighter. 

Of course, for some, the one downside of the Bosch motor is that unlike bikes that use either the Fazua motor that is integrated into the downtube or the eBikemotion rear hub motor, the mid-mount Bosch bikes will still maintain that “e-bike” look that many roadies eschew. 

While e-road bikes with Class 1 power have already proven popular and capable for the intended user, thanks to the added power of the new Line Speed motor from Bosch, the pavement playground will definitely start to get more crowded—and that’s a good thing. 

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