A set of Polini centrifugal rollers — they are critical parts for tuning your scooter's performance. This particular set includes 6 rollers measuring 25x21,8 millimetres and weighing 14,2 grams each. TECHNICAL ADVICE Depending on how much each of these rollers weighs, they affect performance. By changing the weight from the manufacturer's grams we achieve, in the most economical way, a different performance and behaviour from the scooter. (WE NEVER CHANGE THE DIMENSIONS - HEIGHT & DIAMETER) SUGGESTION 1 Heavier than specified. A PARTIAL INCREASE IN TOP SPEED (Suggested for scooters with increased capacity, for riding at lower revs) SUGGESTION 2 The same weight as specified. NORMAL BEHAVIOUR - MAINTENANCE (Suggested for scooters with wear on the rollers already in use) SUGGESTION 3 Half the rollers the same weight as specified and half lighter, fitting them alternately inside the variator. SPORT RIDING (Suggested for knowledgeable riders) SUGGESTION 4 Lighter than the specified weight. RACING RIDING - MORE ACCELERATION (Suggested for demanding riders) SUGGESTION 5 REPLACE THE WHOLE VARIATOR WITH A MALOSSI Scooters are built at the factory to change 3 automatic gears. The variator is the main reason that happens. malossi variators are designed to improve a scooter's performance in a simple way, with no bodges, and to change 5 gears instead of 3. They add one gear at the start and one at the end, making the action smoother.