We’ve seen top-brand bicycles converted to electric power by using hub motors. But cars? That’s what the German company Sportservice Lorinser is aiming for with the Easybrid, which it says can turn small cars with rear drum brakes into plug-in hybrids — easily — and recently demonstrated the development on a prototype Smart Fortwo at the Essen Motor Show.

Hub motors on cars have actually been toyed with for a while; Michelin made a bit of a stir two years ago with its Active Motor outfitted on a Venturi Volage. But they’ve been perpetually stuck in concept mode. (A MachineDesign.com article explores the technology’s pluses and minuses in great depth.)

Lorinser — in a sometimes awkwardly translated press release — says that in addition to the Smart vehicle, it is considering outfitting the Volkswagen Polo, Renault Twingo and the Fiat 500 with its conversion as it continues testing the technogolgy through mid-2011. At that point, it hopes to be able to equip “customer cars.”

With the Easybrid, Lorinser said cars gain about 30 kilowatts of power for improved acceleration and “final speed outputs,” saving an unscpecified amount of fuel in the process. The company said that motors are powerful enough to reach maximum torque after a single revolution — so going solely electric can be done. Range in that mode is estimated at around 18 miles.

Lorinser gives no firm price for its product, but imagines a scenario under which users wouldn’t have to pay for the lithium ion battery that accompanies the hub system. By forgoing that hefty expense and contracting with charge providers, the system might cost 5,000 Euros, or around $6,600.

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