Lexus unveil electric prototype bike

Car manufacturers have a long and (in)glorious history of knocking out the odd bike to lend a bit of green credence to their otherwise planet-mangling output. This one from Lexus is more of a design exercise than a brand addition since there are no plans to put it into production – only two exist, one of which is now in the UK – but it's an interesting beast nonetheless.

Built around what looks like a 20" wheelset and a cruciform frame the bike it's most reminiscent of at first glance is the Giant Mini series, but the similarities end with the shape. The Lexus is a full carbon beast for a start, featuring 'L-Finesse design language' apparently, and nestling near the bottom bracket is a 26v Lithium Ion battery that powers a 240W motor in the front hub. Lexus claim the bike has 'All wheel drive by means of a belt system' but unless there's something really clever going on inside that frame we'll take that to mean that you can pedal the bike as well.

Most interestingly of all, the Lexus claims to have 'an electric eight-speed Shimano internal gear system, which references the sophisticated eight-speed shift-by-wire automatic transmission of Lexus’s LS 600h limousine'. What that means in practice is that Lexus appear to have managed to marry Shimano's Di2 levers with some manner of electric shifter for a rear hub gear. The hub in question looks like an Alfine unit in natty anodised blue. Whether this mash-up is something that could spawn a production electric shifting system isn't clear - we don't think we've seen an electrically operated Shimano hub since the four-speed Auto-D back in the late '90s.

Weight wise the Lexus is okay rather than special at 17kg, and we don't know how far the battery – which Lexus claim takes just 2 hours to charge – will propel you. There's energy capture from the braking system to eke a bit more life out of it, anyway. The bike was first seen in 2009 at the Tokyo motor show but Lexus are planning to show it off over here as part of their sponsorship of the Great British Bike Ride (http://www.greatbritishbikeride.com), a four-day sponsored ride from Land's End to Twickenham in aid of Rugby charities the RPA Benevolent Fund and the RFU Injured Players Foundation, as well as Help for Heroes.