Faq Technical Area - Transmissions
See AnswerHow can I calibrate the clutch?
The clutch is very important because it represents the pickup when starting: it's the acceleration. The Polini clutches, all but the EVOLUTION ones, are delivered with a coupling range calibrated for the original scooters. In the adjustable clutches it is possible to modify the pick up time at your choice But be careful not to over exaggerate this adjustment or you run the risk of burning the clutch out after only a few starts.
See AnswerHow can I calibrate the transmission?
When setting up your scooter the last operation to make is the transmission calibration. First of all, you have to check that the engine is not defective. If you want to set up a scooter the best thing to do is to buy a POLINI variator. If you have already assembled a standard Polini muffler it is enough to modify the rollers calibration and change with a lighter serie. If you also fit a power unit we suggest adding the gears that let you a better set up of the transmission. If you decide to fit an EVOLUTION cylinder kit it is necessary to fit the corresponding EVOLUTION transmission you find in the POLINI catalogue.
See AnswerHow much is the speed increase if I change the primary or the secondary gear?
The speed increases according to the teeth of the gear and to the engine power. If you increases the gear too much it must be adequate to the engine power. An Evolution gear on a standard scooter will only worsen the acceleration.
See AnswerI have to choose the gears for my bike: how can I find them in the catalogue?
The schedules are divided according to the scooter brand and model and Polini suggests a specific gear for them. Attention: for Piaggio models see the dedicated schedule.
See AnswerWhat is the compression spring for?
The compression spring is for a better calibration of the transmission. The stiffer spring helps the spring to transmit the power of the scooter to the wheel. In this way the variator too can give the best power.
See AnswerWhat will happen if I change the inclination of the cam of a torque calibrator?
The torque calibrator is indicated for the tuned-up scooters that need to increase the number of revolution of the variator, as for example the EVOLUTION engines. The more inclined cams oppose to the belt opening, increasing the number of revolutions of the transmission.
See AnswerWhat will happen if I fit lighter or heavier rollers?
People think that the lighter rollers are for the pickup and the heavier ones for the speed. This is not completely true. Rollers of different grams are to calibrate your scooter according to the engine set up. The rollers aim is to match as much as is possible the speed range to the engine rev at the maximum power. In this way you achieve the best acceleration and the best speed that your scooter can generate.
See AnswerWhat's the difference between primary gear and secondary gear? Which ones better to achieve more speed?
There is no difference between primary and secondary gear. In the Polini catalogue you can find a schedule indicating the number of teeth of each POLINI gear and that can help you to find the fastest one.
See AnswerWhat's the variator performance?
All the Polini variators have been studied and tested on all the scooters brands and models. They have been all tested on the original engine without the power unit. The main feature of all the Polini variator is the increase of the variator range. Usually it is possible to modify the pulley ratio on the belt obtaining in this way a short gear for the starting and a longer gear exploit the maximum speed of your scooter.
See AnswerWhen have I to change the rollers weights of my variator?
Rollers must be changed as part of the normal service of your scooter. Please look at your use and maintenance manual.