The eCortina could be considered an electric bike, but its builder — Roy Prince — prefers to call it an “eBike hot rod.” With a motor that can take the hard-tail downhill bike up to 45mph and “lift the front wheel almost at will,” it’s easy to see why.
Prince chose the Cortina Triton as a base bike as it is designed to go downhill at speed, and — more importantly — it’s made of steel. This let him weld and clamp the motor and other necessary parts. The motor, by the way, is an Astroflight 3220. It spins up to 10,000rpm, weighs four pounds and needs to be geared way down when used on a bike. If you want one, it’ll cost you $700.
What drew my eye, though, was the two chains on the drive side. One will be familiar: it connects the pedals to the rear wheel just like any other. The second runs from a tiny chainring to a giant rear sprocket. This gear reduction is required because of the high-revving motor.
SOURCE: Wired Magazine