HMK 561: Electric bike turns brake energy into go-go juice

Have a gander, friends, at the HMK 561 -- a prototype electric bike that's so sexy, it'll make you want to cycle the streets naked, singing I Touch Myself and smearing treacle all over yourself.

The brainchild of German designer Ralf Kittmann, the HMK 561 is more than just a pretty piece of design -- it's also extremely clever. It doesn't use batteries or cables, for a start. The entire frame is made of carbon fibre. In addition to being outrageously light, it stores energy during braking and conducts it to the bike's front and rear motors under acceleration -- like a massive, bike-shaped capacitor.

It's all very clever, we'll admit, but Herr Kittmann appears to have forgotten a couple of crucial additions no bike should be without: pedals and brakes. How are you meant to stop this thing? And how are you supposed to make it go once all the juice runs out? And how ridiculous will you look with your legs up by your ears using that foot rest?

The HMK 561 is only a prototype at this stage, so we expect all these little niggles can be ironed out if and when Ralf gets around to releasing a consumer version. In the meantime, have a butchers' at the pictures in our photo gallery, then go read the review of the Ultra Motor A2B electric bike we tested last year. It's a little less sexy, but at least you can buy it right now.