One-armed bandit: Electrolyte integrates bicycle electrics in lefty fork
By C.C. Weiss
July 10, 2013
We've looked at a surplus of electric bicycle designs over the years, and while we'd be hard-pressed to call any particular design "usual" in this diverse category, a common feature shared by many is a frame-integrated battery pack. German manufacturer Electrolyte dismisses that common element, integrating the battery, motor and controller of its pedelec bikes into a single fork shaft assembly.
What appears a lot like a Cannondale Lefty shock is in fact an entire electric drivetrain housed in a thick, single-arm fork. Inside the arm-integrated drive assembly is a 250-watt motor, 320 Wh battery pack and electrical controller. This combination provides enough momentum for between 60 and 100 km (37 and 62 miles) of commuting. Four drive modes accessible via a handlebar button deliver speeds up to 25 km/h (15 mph).
By integrating all these components into the front arm, Electrolyte claims that the hardware elements are better protected from weather and dirt than exposed components, such as frame-mounted batteries, and require little maintenance. It says that its design is up to 10 kg (22 lb) lighter than other electric bicycles – its lightest bikes with the hardware weigh in at 16 kg (35 lb).
While Electrolyte's solution definitely looks interesting, we'd be curious to know how the bike rides. Other e-bike manufacturers boast about how low down and centered they've managed to keep weight by putting the batteries on the down tube, so this design looks a little front-heavy in comparison. Because all that weight is integrated into a single side, it also seems like it could hinder balance and steering.
Then again, Cannondale has been offering Lefty forks for years, so they can't be that unpopular with riders.
Electrolyte uses the arm-integrated electric drivetrain on three bicycle models: the 2-speed Strassenfeger II and Querschläger II, and the 11-speed Brandstifter II. The models start at €3,999 (US$5,135). Electrolyte will be showcasing its technology at two major European bike shows this summer: ISPO Bike later this month and Eurobike in August.
As those model names indicate, these are second-generation electric bikes. They were preceded by models that used more traditional e-drivetrains with battery packs mounted to the down tubes.