Confused

Ya'll take it easy on me, but I think I just confused myself on sheaves and grease. I read Firefighter's small list of stock parts JBS keeps and it said greaseless sliders and od's, but then I see the video on greasing the sheave? Should I be greasing my stock sheave? Is the greaseless set up only on a machined one? I thought I had it figured out....

Whether its greaseless sliders or rollers you can run with out grease. But you can get better performance out of them by greasing them.

The slider is what is on the sides of the cam plate and the rollers are what moves out with rpm which push the cam plate out, right?

Yes. The new weights that you can get are not rollers though. With the new machined sheaves a greaseless sliding weight is used to push the primary sheave halves together.

Ok, that helps. This may be a dumb question, can I use any other slider/weights without a machined sheave? I will get a JBS sheave soon, but until that time can I do anything else with my stocker?

Hey Willy, I think You can use OD weights and grease less sliders in a stock sheave. And You can do it with or without grease. I'm not the authority on this, but let me see if I can explain a little bit.

Stock sheave has sliders that require grease and round weights. The stock setup is not as fast and has what is called "roller flop". This is a point in the sheave where if feels like it shifts. In other words You get a little performance then a "shift", then a little more performance.

Then came OD weights and grease less sliders. OD weights are overdrive weights that perform better then round weights and don't have the shift point or "roller flop". The grease less sliders are sliders that go on the camplate and are built for use without grease. With OD weights and grease less sliders, You can go grease less and get better performance.

Then came the "machined sheave". Many people machined them differently. But the machining was done to increase the low end and / or top speed.

Now it gets confusing ! James Hotrod Davis found that some people were getting water in there CVT's pretty regular. This causes a couple of things. First if You get Your belt wet and try to run it, it will cause extreme wear REAL fast. Second. If You are running grease less and get water in the CVT it causes the dust to set up real hard and causes the OD's to not go all the way in or out. Dr. James came up with the idea of running grease in the grease less setup for the guys who run in a lot of water. The grease fixed the problem of dirt and water gumming up the sheave. It also allows the sheave to work smother.

Then comes the Improved 2013 JBS sheave ! I get in to that later.....

For Your stock sheave, I think You can run the OD weights and grease less sliders with or without grease. I think it will give You a little more top end and You will not have the roller flop.

Man I hope I am correct on all this. And I hope this helps on the confusion. It is very complicated, but Dr James can explain it very well.

Thanks for taking the time to explain all of that. I might get in touch with James and see what he recommends. Like I said before, I will get his machined sheave in the future, but in the mean time I would like to try and squeeze everything out of my stock one. I am very happy with the way it runs now (cdi helped a whole lot!), but maybe with little investment I could be even happier. Again thanks for explaining, I catch myself reading too much and just get confused, LOL! One more thing, I actually took it out this weekend to a local riding park and had a blast. The very first hill I started up (wasn't that steep) the belt slipped, but it never slipped again? Any thoughts?

AH the belt slip ! That is where the secondary spring comes in. An after market secondary spring will put more tension on the belt to prevent the slip.

When You talk to Dr Hotrod, ask Him about putting a shim in your sheave for quick fix until You get a Hotrod Sheave.

foyota86 wrote:

Ok, that helps. This may be a dumb question, can I use any other slider/weights without a machined sheave? I will get a JBS sheave soon, but until that time can I do anything else with my stocker?

I think that this describes the evolutionary path of the Yamaha CVT upgrades:

First there was the bone stock Yamaha setup. Round cylindrical weights with thin plastic coverings. Reqiured huge gobs of special (expensive, Yamaha only source) grease. The grease had a limited useful life due to caking and contamination with dust.

Then came the first attempt at increasing the range of gearing. The sheaves were machined on the outer perimeter to increase the sheave travel, enabled by the same roller weights being able to be flung further outward. This gave the CVT an effectively higher gearing at that extreme. Problems with the transition between the old and new travel ranges. Commonly called roller flop, a noticeable transition into the newly machined area. Some of these were later marketed with shims to space the primary sheaves a bit further apart to increase the low end gearing. However going too thick with the shim caused the spline in the sheave to drop off the end of the spline on the shaft. This was a risky thing, in that if there was not enough engagement of the splines the splines would strip out under load.

Next came the OD (Over Drive) weights. These were not simple cylindrical shapes, but rather shaped such that they were narrower in the direction of travel within the sheave. This allowed a longer stroke to effectively achieve a higher gearing at the maximum stroke end, without sacrificing the low end gearing. These had much thicker plastic bodies enclosing the actual metal weight. This plastic was selected to withstand the wear involved without using grease. These were originally designed to provide about the same gearing range as the original machined sheaves, but using the standard stock unmodified sheave.

The next big innovation was to machine the inside area of the sheave to effectively increase the inward travel of the OD weights. This safely lowered the low end gearing. This is useful up to a point where belt travel is limited by other issues. The most notable is that the belt can move ony so far outward on the secondary pulley without rubbing on the enclosure surrounding the CVT This approach was pioneered by our HotRod James, and has been copied by others (but apparently not perfectly).

Please do feel free to make any corrections or to add to this, as I am certainly not the Guru on this subject. Actually, I am sure there are a lot of subtle in-between stories here.

Again thanks for the explanations, I spoke with James. I am going to do an orange spring and OD weights. You can't get better service and advice than just picking up the phone and within 4 mins had it figured out. It is obvious the man knows what he is talking about, from real world experience. That means a lot. Now I will be set up when I get his machined sheave.

Yep, you won't have to buy twice! Some vendors may have tried to pull a fast one on ya but not hot rod

Unless you wear it out riding like hell.

you will love it

Cool

CustomizedRhino13 wrote:

Yep, you won't have to buy twice! Some vendors may have tried to pull a fast one on ya but not hot rod

haha the buying twice deal

still haven't got to that point yet. but getting closer

how are you liking it..