(image: SAE)

What We’re Driving: Bosch eBike demonstrator

Spending two-wheeled time on a human-electric hybrid.
Bosch does not make electric-assist bicycles (ebikes), but is a key supplier in the growing segment. Its electrifying components feature on more than 70 cycling marques, including Bianchi, Cannondale, Fuji, Mondraker, Scott and Trek. It recently loaned us a demonstration bike fitted with some of its latest offerings, which include on-board computers/controllers, battery packs, and drive units. As one of the major suppliers in the space, Bosch competes with similar components from cycling stalwart Shimano, as well as establish industry players including Brose and Yamaha.
The Tiffany-colored loaner was one of the more entertaining press loans in recent memory, as ebikes have a way of generating bouts of childish joy by tapping into the primal wonder of propulsion. Our loaner featured a Bosch Purion on-board computer, PowerPack 400 battery and Active Line drive unit, which worked together in near silence to seamlessly add thrust to the comfy urban cruiser.
The new Active Line drive unit is the heart of the system, providing a pedaling boost at speeds up 20 mph (32 kph). Weighing in at only 6.4 pounds (2.9 kg), this latest version of Bosch’s smallest e-bike motor has shrunk 25% compared to its previous iteration, and will provide a maximum of 29.5 lb·ft (40 N·m) of assist. Supplied by the removeable/lockable 5.5 lb (2.5 kg), frame-mounted 36V PowerPack 400, the lithium-ion battery features a convenient carry handle, a 400Wh content rating and will recharge in 3.5 hours with the standard (110V) charger.
Directing the system on our loaner was a Bosch Purion handlebar-mounted computer, which lets you select between the different assist modes (from least to most assist: Eco, Tour, Sport, Turbo), and provides battery status, speed, trip distance, estimated range, lighting toggle and a convenient push-button Walk mode (up to 3.7 mph/6 kph) for loading or other low-speed bike-wrangling duties.
On the road 
For the uninitiated, the hallmarks of a well-sorted ebike component setup include an intuitive nature to the power delivery (adding boost swiftly and smoothly when you apply more power to the pedals, and adding none when you stop pedaling), quiet operation and overall system friction/efficiency. The provided Bosch setup fared well on all these counts, and those who have yet to get on an ebike may be surprised how refined the supporting electronics in the field have already become.
On multiple rides on Michigan’s admittedly non-extreme terrain, the Bosch system provides an almost eerie and remarkably natural delivery of power. Beyond simply pedaling like you would on a regular bicycle, there’s nothing to do. When engaged, the Bosch e-assist setup provides a barely noticeable whir with each pedal stroke, and overall system friction with assist off was undetectably low.
The least-boosting Eco mode is all most folk who spend frequent time on a bicycle will crave, with Tour and Sport simply further reducing pedaling effort. Turbo mode will make any ebike a truly swift errand runner around town, putting you quickly onto the 20-mph limiter, and other drive units in the Bosch lineup boost top-speed to 28 mph (45 kph).
Range varies depending on mode, speed, rider weight, conditions and terrain, but on a flat-ish 28-mile Saturday ride with non-assisted cyclists (mostly in Eco mode), the battery still showed over 60 percent available charge at the end of the loop. More notably, almost everyone who sampled the e-machine asked where they could get one, and it will certainly be the saddest my wife has ever been to see a press vehicle returned. Continue reading »