The belt snapped on the 250 so I had to dig into it. Since I'm in there I might as well tweak something. I've read topic after topic on the subject. Everyone has their opinion. Here's my thinking:

The CVT is basically a lever. The rollers/sliders are balanced against the spring. If you want to hold low gear longer you can either use lighter rollers/sliders or you can use a heavier spring. I know that many folks do both.

That's what I don't understand. It's like a see-saw. Sure you can change what is on both sides if you want to alter it's movement but WHY? Changing only one side SHOULD get the same results.

The crank seal is also leaking so I had to remove the variator. Since I'm already in there, I'll probably do just rollers or sliders. But since I'm known as Curious George, I'm hoping to open a discussion on this cornfuzing subject.

the main spring comtrols the opening and closing rate of the driven pulley ( clutch pulley ) by adding a stiffer main spring it will be delayed on opening thus staying in low gear longer and close quicker making it down shift faster.

I tryed all the springs when I had my 250, and for the type of riding I do the red and white did the best. the blue shifted real quick with real light rollers, the yellow shifted a little later, the red and white shifted alot later.

it all depends on the terrain you will be riding

Eric, I agree with everything you've said.

The actuation of the CVT is controlled by the relationship of the spring rate vs the weight of the rollers at a given RPM, right?

Lighter rollers do the same as a heavier spring and vice versa, right?

What confuses me is why a person might change both. I've read all the posts and posts and posts and I understand what is being said. I guess I just don't believe that both items need to be changed.

It's centrifical force of the rollers vs a spring. You should only have to change one in order to alter how the pulleys move.

Oh well....... no big deal. Just an exercise in theory. I'll order the parts tomorrow.

I would think the rollers would take less force to raise up which would cause the pully to close. So to counter this and give more control of pully movement you use the spring.

In theory I see what you mean. No matter which side cause the pully to move, that in turn makes the other side move. This would be due to the belt only being so wide so when it moves it forces the other to do the same.

See the lighter the roller the faster it moves. So it takes less to start movement and increse the speed. The heavier the spring the longer it will take the rollers to force change through out the spring. The more the spring compresses the stiffer it is till you hit peak rate and at that point the clutch pully moves as determined by the rollers

This may be way off. But after thinking on your question for a while, this is what I got. I'm not that smart

they are darn good mods with the wright roller or sliders plus torque spring.
different springs and roller slider weight to fit your riding style.honestly never thought this belt driven buggy would go places it does.

i thought you had already done your cvt mods gwcrim.


pud

This is the first time the CVT cover has been off. My 13 yr boy was riding it when it broke so I had him take it apart. Ya gotta learn to fix 'em if you're gonna break 'em. He works on his dirt bike too.

thats close, the lighter the roller the stiffer main spring you will need. when I was testing main springs with my 250, I put 11 gram rollers in it, started with the blue main. it shifted into high gear in about 15 ft. the rpms dropped way down.

same rollers with the yellow main shifted in about 18-20 ft, rpms dropped but not as much, red main, shifted 20 feet, the white in about 20-25 feet

with my terrain the 11 gram rollers and white main kept the rpms up and the upshift point closer to where I needed it to be. the down shift was better with the white.

When picturing how the variator works, just remember that the back plate of the variator is what causes the 2 pully halves to close and open.
The weights inside, push this plate. The lighter the rollers, the less it pushes on that plate and the longer the belt will stay at the bottom of the pully (Low end torque). Afer so many rpms, those weights will roll p the ramps and push the plate out, causing the puly halves to close more causing the belt to squeeze to the top of the variator (Top end). A heavier weight will will push that plate a little quicker.
HP and vehicle weight will effect your individual results and is why you need to "play with it" for your needs.
On the clutch side, like Eric said, the main spring changes the when it engages and disengages. The arm springs control when the arms grab the bell.

The rollers and springs do NOT do the same thing. May "feel" like it but they are opposite. Changing springs will not do much for your variator and changing rollers won't do much for your clutch, they are seperate animals. This is why I like to dial in the rollers first then, do the springs. I use the variator for the low end and use the clutch for the top end. One WILL effect the other but not as much as you may think. Now, if you have the "shorty", you'll do the clutch first THEN the variator because this clutch really raises the rpms out of the box.

Get your weights right first by drawing a line down the inside face of your variator and tweek the weights till you erase 95% of that line. Then, move on to the clutch springs.