Velogical shrinks the rim drive to "world's lightest" e-bike drive

http://www.gizmag.com/velological-worlds-lightest-e-bike-drive/31976/ / friction drive Rubbee lighter simpler transform bicycle ebike e-bike Velogical Velospeeder friction drive light lighter compact edrive e-drive weight weighs assist manual riding lightest smallest bicycle Cologne Velogical builds build rim dynamo power powered powering bike lights small sized down 600 watts of power torque 3.5 lb 1.6 kg lighter kit lithium-polymer battery spare swap dual Velospeeder motor seat stays traditional bicycle frame transfer power rear rim polyurethane rings toothless drive system smooth metal rim slip slippage dual swing axle drive keeps optimal contact efficient efficiently apply pressure power wheel braking wear weight bike manual pedaling easy to switch between manual and electric-assist riding prototype Spezialradmesse Velospeeder equipped test bike wear rim optimizing bicycle manufacturers installation bike shops retrofitting consumers video yet noise level /