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anyone understand CVTs?

Discussion in 'Scooters' at netrider.net.au started by lolls, Jul 21, 2006.

  1. Hi, I'm interested in scooters, and I'm trying to understand CVTs.

    I know that, as you accelerate, certrifugal force pushes the roller weights outwards, which in turn causes the rear half of the variator to move to the front part. But how exactly does it do this? Why would roller weights moving to the outside of the rear half cause this whole section to move forwards? There are a few sites dedicated to CVTs but none of them explain this part. I'd really appreciate if anyone can offer their viewpoint. I've never seen a real variator, only pictures, which probably doesn't help.

  2. Imagine 2 pulleys with a belt in between when one "drive pulley" spins faster it changes shape and squashes the belt towards the outer perimter. The other pulley has a spring that makes it squash too.
    So baiscally when the the fromt pulley spins slowly, the spring on the rear one is stronger than the force of the front one so the drive pulley has a smaller diameter than the back one and hence you get a big ratio.
    When the "drive" pulley spins faster the force become stronger than the spring on the rear pulley and the "drive" pulley now have a larger diameter than the rear one. That give the small ratio.

    Hope it helps you