Description
Wave spring for Polini clutch For Race
Replacement spring for the For Race clutch from Polini for Piaggio Ape / Vespa 50 / 125 2-stroke.
Polini For Race
The For Race series from Polini includes exhausts as well as crankshafts and clutches for scooters, 50cc supermotos and Vespas. Although the name sounds like ultra-high-quality and high-performance racing parts, this is not quite true.
The exhausts are not road-legal and are theoretically only intended for use on the race track, but due to their performance, which focuses mainly in the lower and medium RPM range, they are more suitable for sports / entry level tuning setups, which are appreciated for their balanced ratio of performance and reliability for everyday use.
The crankshafts are also suitable for sports cylinders, as are the few For Race clutches.
Polini fans looking for maximum power for the racetrack should therefore opt for the Evolution or even the P.R.E. series.
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 rear pulley and the clutch. As soon as you accelerate and the engine revs up, the spring is released by centrifugal force. This causes the front pulley 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 ?
| Clutch Spring Polini For Race & Evolution Vespa | |
|---|---|
| Article no. | P228.0104 |
| EAN | 8054705118074 |
| Weight | 0,10 kg |
| Series | Evolution, For Race |
| Brand | Polini |
| Product type | Torque spring |
