CVT Physics

[jermwars]

I cant get it out of my head that a stiffer counter spring will cause more friction against the belt/plates and get hotter. Maybe a lot hotter.

Im probably not thinking about it right.

I cant seem to find any stories about people running too stiff a spring and trashing their belt/drive pullies online though, so im probably just making stuff up.

[mousejunks]

I cant get it out of my head that a stiffer counter spring will cause more friction against the belt/plates and get hotter. Maybe a lot hotter.

Im probably not thinking about it right though.

I cant seem to find any stories about people running too stiff a spring and trashing their belt/drive pullies online though, so im probably just making stuff up.

2 types of friction - static and dynamic.

A stiffer spring will grab the belt earlier and harder, but this also means it will slip less. Slipping is dynamic friction and releases more heat than static friction. However the nature of a CVT it is always slipping.

The increase in heat damage is insignificant. If you want a cooler CVT clean the intake filter or remove it completely.

[Ruffus]

As mb says, and
MALOSSI for example  deliver certain drives with 2-3 different counter springs to give you the opportunity to customize the clutch to your likes.

But I did some improvements (pls see pics) on my GD and came down with temperature for around 10° C.
Shorter or bigger CVT air intake and a certain cleanout inside plus some additional airducts to get rid of heat are crucial.
Would not recommend this doing if you drive in very dusty or wet environment.

On the other side I clean out my CVT by putting a garden water hose into this intake grid and rinse it properly through. Then let the water drip out completely, start the scoot, pull rear break, open throttle a little, after 20 seconds the CVT and clutch is clean and dry.

[Stig / Major Tom]

As mb says, and
MALOSSI for example  deliver certain drives with 2-3 different counter springs to give you the opportunity to customize the clutch to your likes.

But I did some improvements (pls see pics) on my GD and came down with temperature for around 10° C.
Shorter or bigger CVT air intake and a certain cleanout inside plus some additional airducts to get rid of heat are crucial.
Would not recommend this doing if you drive in very dusty or wet environment.

On the other side I clean out my CVT by putting a garden water hose into this intake grid and rinse it properly through. Then let the water drip out completely, start the scoot, pull rear break, open throttle a little, after 20 seconds the CVT and clutch is clean and dry.

Ruffus!
"Garden hose into the CVT" !!!
No, I'm not laughing at you - because I know you are a very serious 'tinker'er', with many successful scooter moments in your resume' - and you have not yet starting drilling holes through yourself to increase MPG's, aid cooling and lower wind resistance...but  -

Aren't a few things lubed carefully inside the belt cover.......the clutch assembly?.....and not water friendly?

Nevertheless....one of the neat things about scooters is you can do almost anything to them - and they'll still get you home.

Stig

[Ruffus]

@Stig you are right, there are some lubed parts in there. But, they are protected by o - rings within the clutch. Boss/ sleeve/ rollers / ramp is in most of the cases not lubricated at all.
Rubber belt is happy to feel a shower.
THING IS, not to let it sit in its soup, dry it out immedeately by driving off.
In the industry, when I did not have any other option (huge size not available) I took water lubricated ball bearings, and they last.

[JJJoseph]

Aren't a few things lubed carefully inside the belt cover.......the clutch assembly?.....and not water friendly?

I do something similar to Ruffus whenever I've the belt cover off.  I simply hose it out with a pressure washer, and let it air-dry.  Never had any problems!