Description
Torque Spring Polini Evo-Slider 4,6 +28% Piaggio
Torque springs play an important role when adjusting the CVT. They regulate the pressure on the rear pulley and maintain the tension on the V-belt. This has an effect on how fast the pulley can move to the outside, which in turn affects gear shifting. If the spring is too soft or worn out, the belt will start to slip and performance will deteriorate despite lighter variator weights. We recommend to also readjust the variator when using a new/harder contra spring.
Contra spring
The contra spring, or torque spring is part of all scooters and mopeds with CVT transmissions.
function of torque spring
The contra spring is located between the torque driver and the clutch. As soon as you accelerate and the engine revs up, the spring is released by centrifugal force. This causes the torque drive to open, which in turn causes the V-belt to move outward on the CVT front pulley. The transmission ratio changes in favor of higherspeed. When the scooter slows down and the engine speed is reduced, the torque spring is compressed again and the V-belt returns to a lower position on the front pulley.
soft or hard contra spring?
The choice of torque spring depends on different engine components, you need to find the right balance here.
- A spring that is too hard cannot fully expand. Acceleration is improved, but the V-belt cannot move outward to the maxi and top speed will be lowered.
- A spring that is too soft will relax too quickly, affecting the pull of your scooter.
Tip: To determine whether the V-belt can move to its maximum achievable position, you can mark the maximum position with a felt-tip pen on the CVT. If the mark disappears, this indicates that the belt actually moves up to the max position, i.e. the spring is not too hard.
How to change the torque spring ?
| Torque Spring Polini Evo-Slider 4,6 +28% Piaggio | |
|---|---|
| Article no. | P243.105 |
| EAN | 8054705079351 |
| Weight | 0,18 kg |
| Series | Evolution |
| Brand | Polini |
| Product type | Torque spring |