The main role in tuning a variomatic scooter is the weight. Rule of thumb: The lighter your roller set, the more revolutions are required to push outward rolls through the centrifugal motion to set gear shifting on the go. Heavier rollers need to lower the rpm to start this process. This means that if your scooter is lighter it rolls it will need higher revs to start moving. Heavier rollers allow you to start moving at low rpm. Each driver will have to find out which level of laps is right for them. A lot of factors in this decision: the degree of tuning, the weight of the drivers, what weight (of rolls) are optimal, etc. Knowing the overabundance of inadequate material on the market, we can only recommend various rolls from renowned POLINI studios and MALOSSI. Their products are manufactured to the highest standards, are of the highest quality, and are durable - and still affordable! Here are the most common formats: Engine type: MINARELLI 15x12, MORINI 17x12 / KYMCO / PEUGEOT / HONDA / PIAGGIO / GILERA -> `98 16x13, PIAGGIO / GILERA` 98 -> 19x15, 5 Sport variators: POLINI / MALOSSI 16x13, 15x12 HEBO PERFORMANCE 17x12 / TOP SIP-TIP! By changing variator rollers, each scooter can be tuned exactly to its engine performance or driving conditions. What you should note: The more aggressive your engine is tuned, the more sensitive it reacts to weight changes in the lists. Be careful not to work with weights that are too different! Remember: vario exact tuning is really necessary so that the engine doesn't waste its performance under unnecessary revs (weights too light) or through gear changes too early (weights too heavy), which won't get you any acceleration.