Description
Polini Torque Spring Evo Slider +34% Yamaha T-Max 500 - 530cc - harder than original spring (+ 34%).
Many riders underestimate to what degree engine performance can be improved by exchanging the original torque (or contra) spring with a softer or harder one. The torque spring puts pressure on the torque drive and influences the shifting characteristics of the CVT which in turn has a considerable impact on acceleration and top speed. Keep in mind that it may be necessary to replace the variator weights as well.
The spring comes with the low-friction Evo Slider spring seat for torsion-free movement which leads to smoother shifting characteristics and reduced loss of power which can instead be used on the rear wheel.
Suitable for Yamaha T-Max 500 - 530cc. Recommended for tuned set-ups.
- length: 128mm
- inner diameter: 58mm
- wire diameter: 6.2mm
- coils: 5.5
- OEM spring rate: 65 / 70 mm/kg
- Polini spring rate: 65 / 94 mm/kg
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 +34% Yamaha Tmax 500 - 530cc | |
|---|---|
| Article no. | U243.099 |
| EAN | 8054705079290 |
| Weight | 0,50 kg |
| Series | Evolution |
| Brand | Polini |
| Product type | Torque spring |
| Range | Standard |
