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Continuously Variable Planetary Drive Is For Bikes, Not Spaceships

By Evan Ackerman

The Ride

We’ve seen some bicycles recently with automatic transmissions, but a continuously variable transmission is something new. CVTs work without gears, or rather, they provide an infinite number of gears, increasing engine efficiency. In automobiles, CVTs are often pretty complicated, but the NuVinci transmission is simple and efficient, probably owing to the unrivaled genius of it’s original inventor, Leonardo da Vinci. It’s actually a CVP, or continuously variable planetary drive, owing to the rotating spheres that make up the heart of the transmission. Here’s how it works:

The NuVinci CVP is not automatic; you still have a shifter to adjust the bike’s power curve. But “there’s no hesitation, no noise, no waiting for the mechanism to “hunt” for the gear you’ve selected, nothing to synchronize, nothing to guess at, a simple twist of your wrist and you’re at a new ratio.”

You can currently buy bicycles featuring the NuVinci CVP drivetrain from Ellsworth; the base model is a shade under three thousand and the signature model (with some carbon fiber, a headlight, and a belt drive) will set you back another grand. A CVP kit should be available in the second half of 2007.

[ NuVinci ] VIA [ Core77 ]







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  • http://www.iwwebdesign.com/ Ian Weir

    I’ve been waiting for something like this ever since I first learned what a CVT was. The price is still a bit steep though – hopefully it’ll drop down to average-joe-level within a few years.

  • jon

    Fantastic! Very interesting. I’m a little wary of the special fluid though. I bet a leak and fluid top up will cost a lot.

    As for price, don’t expect that to drop. Price is determined by profit. They’ll keep the price as high as possible as long as possible. What’s the point of selling twice as much product if it makes less profit? Price only comes down when a maker is competing for market share. When competing makers are happy with their share, they operate a cartel to keep prices up and profits up.