I have an 09 Piaggio Fly 150. I picked up a Polini Maxi Hi Speed variator a couple of years ago. At the time I installed front hub parts, with the heavy rollers. The kit had two sets of rollers, yellow and blue ones. I believe the blue ones are 5.8gr. Kit uses 9 rollers. Scooter is stock, except the front hub parts. The kit also has a big blue spring for the rear hub that I did not install.
Scooter had to sit for a couple of years due to illness, but, I am back to riding it this year. I am what I consider to be normal size(6'1, 270lbs). I put a tach on the scooter the other day, and currently here is what the scooter does.
From a standing start, apply about half throttle, the tach jumps to 2700 and stays there for a bit. I can feel the clutch come in, and can notice it engaging fully within a couple of seconds. If I go wide open throttle, the rpm's never go passed 3400prm. Scooter tops out at about 95 km/h, at which time I can roll back the throttle to about 3/4 to 7/8, with rpm dropping to 3300.
According to the specs I can find online, max torque number is up around 6000 rpm and max hp at around 7750rpm. My background is about entirely automotive repair, with about another 10 or 15% of motorcycle repair. CVT transmissions are completely new to me. For such a simple design, it is very complex. I understand that the lighter rollers will let the engine rev higher, and on the surface that sounds like what I am after. I also have the big blue spring for the rear hub, and cannot find any information that is understandable to in regards to the effect of changing this spring. Most articles/blogs/guides are written with the idea the reader already has a good understanding of this transmission system. In other words, not written for my knowledge level.
What would happen if I changed just that rear spring that came in the kit? Kit part number is 241-666. What would happen if I swapped out the rollers for the lighter 5.8gr rollers? And, what if both items were changed?
My goal is to get the scooter closer to its most performance level. I am expecting to do the piston/cylinder swap over the winter as well, but that is for another post, at another time.