How to increase the speed of a scooter without cutting the variator
The first method involves cutting the variator and increasing the maximum speed of the scooter by about 10 km/h. It is not difficult to implement and at first everything seems to be going well.
But then problems begin due to the fact that the rollers lose their anti-friction solid-lubricant coating and try to jump out through the sawed holes.
Also, due to the large amplitude of movement of the rollers, the plastic sliders may break, and the “spider” begins to move along the guides, providing dangerous metal-to-metal contact, leading to rapid wear of the guides.
Despite the relative simplicity of the method under consideration and the achievement of the desired result - an increase in speed, it leads to intense wear of individual places and variator parts, so it is not advisable to use it.
In the second case, you can use sports variator. This method also leads to the desired result - an increase in the speed of the scooter by the same 10 km/h. Moreover, its implementation does not require alterations, adjustments or changes in the design of the variator.
The problem here seems to arise out of nowhere: the nodes in the hole into which the bushing is inserted quickly wear out, probably due to the low mechanical characteristics of the metal, and an unacceptably large backlash is formed. So this method is not promising enough either.
More correct modification of the variator without cutting it yourself
The third approach, related to increasing the speed of the scooter, affects only variator bushing with an internal diameter of 14 mm, an external diameter of 20 mm and a standard height of 38 mm. It is enough to turn a bushing on a lathe with the same diameters, but with a height reduced by 2.5 mm, i.e. equal to 35.5 mm.
When shortening the sleeve, the same effect is achieved as when cutting variator, which, when rotating, comes closer to the overrunning clutch, and at the same engine speed, due to the belt moving to a larger radius, it ensures an increase in the speed of the scooter.
A shortened bushing initially allows the variator with the spider to come closer to the overrunning clutch, but at the same time, washers with a total thickness equal to the shortening of the bushing, i.e. 2.5 mm, must be placed behind the spider. As a result, the speed will increase, because the belt will move to a larger radius.
Next, the variator with a shortened bushing and washers behind the spider is assembled in the usual way. As a result, the speed increases by the same 10 km/hour. Also, this method of upgrading the variator allows the engine to operate at speeds of 45-50 km/h not at maximum speed, but at 60-70% of the maximum. This reduces the noise of the motor and helps increase its service life.
You just need to remember that when assembling a variator with a shortened bushing, at first there are some inconveniences when tightening the coupling nut, becausethe belt does not lie on the bushing, but is located a little higher and seems to interfere with its twisting. There is also a slight loss of power when starting from a stop, since the belt is initially located at a larger radius.
