How do I decide on what I need?
Don't even know what weight I'm using,just know that it's a Polini variator
What difference do the varying weights have on the performance.
As you all know I always ride sedately so don't need owt o'er quick :biggrin: :biggrin:
Cheers
Roller weights
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coaster
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The variator is a split pulley which is pushed together by the action of a set of roller weights that move outwards at the pulley spins. The closer the sides of the pulley are, the further out on the puley the belts will run. So if you fit light rollers the pulley sides will only move together so far and the belt rides say onlu 3/4 of the way out. Fit heavier roller weights and the pulley sides get pushed together quite early in the rev range and will also force the belt out further thus increaring the gear ratio. It is the same effect as putting a larger front sprocket on a lambrettta engine. The one thing you have to whatch is that the belt doesn't go so far out that it rubs on the outer casing, although mine does and its not really caused any problems.
As I mentioned in your other post, I have a Polini variator in GTS 250, I don't know what weight rollers it had when I bought it but it would do 82mph (according to the TomTom) before the rev counter cut in (it does have a large rear tyre on as well). I changed the rollers to standard (10 grams) and the speed dropped to just over 70 mph and it was hitting the rev limiter all the time. I called SIP and and they suggested I tried 13. something grams or 14. something I bought a set of both but only fitted the 14's. The result is that it's now back up to it's former performance and uses far fewer revs pulling away from standstill.
As I mentioned in your other post, I have a Polini variator in GTS 250, I don't know what weight rollers it had when I bought it but it would do 82mph (according to the TomTom) before the rev counter cut in (it does have a large rear tyre on as well). I changed the rollers to standard (10 grams) and the speed dropped to just over 70 mph and it was hitting the rev limiter all the time. I called SIP and and they suggested I tried 13. something grams or 14. something I bought a set of both but only fitted the 14's. The result is that it's now back up to it's former performance and uses far fewer revs pulling away from standstill.
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red
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Ok mate I'll have a look for some.
Thanks for all the advice
Cheers
Thanks for all the advice
Cheers
I do not try to explain why I ride Lambrettas,
For those who understand, no explanation is necessary,
For those who don't, no explantion is possible.
For those who understand, no explanation is necessary,
For those who don't, no explantion is possible.
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coaster
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Don't know if you're sorted yet but I've just found the box my rollers came in. SIP Part Number 242.166 Polini 20mmx17mm 14.7 grams.
Fitted to a Polini variator with a big rear tyre it pulls away with very low revs, almost no slipping of the variator. the engine has plenty of torque to cope and I still leave all but sports bikes standing (up to 30mph or so). Should be even better in your Scomadi.
Fitted to a Polini variator with a big rear tyre it pulls away with very low revs, almost no slipping of the variator. the engine has plenty of torque to cope and I still leave all but sports bikes standing (up to 30mph or so). Should be even better in your Scomadi.