I’m opening this discussion to bounce a few thought around the membership to discuss what really needs to be known to determine ‘How Much’ is ‘Too Much’, ‘What kind of wear is bad’ and what is really going on under the C.V.T. cover. (Like which came first? The Chicken or the Egg.)
First, I decided to start this thread from a recent thread about belt wear on a very new machine, and the dealer replaced the belt when it looked like new, probably just to sell parts and service.
First of all ask;
How would a worn belt affect C.V.T. performance?, and is all belt wear bad?
When the machine is brand new, with near a 2.5 to 1 ratio, (remember I always recommend knowing ‘your’ actual stock ratio to understand future performance). The belt is not riding out of the secondary, which means it is riding high the primary. (Not near the collar the movable sheave sides across)
If the belt wears (narrows) 2 mm’s, it still doesn’t ride out of the secondary and does not bottom out in the primary, so if it doesn’t slip, what is wrong?
Many members add shim to widen the primary to raise the ratio which causes the belt to ride out of the secondary and lower in the primary. I say adding shim is like running a narrow belt, so in effect a worn belt is a good thing as long it isn’t slipping.
On top of that, some Grizzly owners machine material off the movable primary sheave which widens the gap between the sheaves the belt runs in, causing the belt to ride lower in the primary, higher in the secondary, like a worn belt.
Additionally, some members combine shim and machining, but still the belt does not slip. Then going to another level, I played with narrowing my belt while adding shim and using machining for max ratio and still the belt did not slip.
It is my thought;
Not all belt wear is bad!
Yes if you run aggressive C.V.T. mods it takes less narrowing of the belt to cause the belt to ride on the collar causing belt slip. Generally the belt rubs the C.V.T. cover long before the belt rides on the primary collar. I do know of one member that experiments with C.V.T. mods, for racing applications, that experienced the belt riding on the collar, but that was a very rare situation.
I feel most members need to be concerned about the belt failing from cracks in the material more than from narrowing of the belt.
Those that need to watch for belt narrowing are the ones running C.V.T. mods with the belt rubbing into the cover. Any additional belt narrowing causes more cover rubbing which eventually causes a hole in the cover.
I say ‘If it Ain’t Slip’in, it’s O.K.’
And if it is slip’in, find out why.
Is the belt bottomed out or is the ratio too high for the secondary spring.
If you want to know the difference between two different belt, install each and count the ratio with each. A worn belt will produce a higher ratio, but again if the belt is not slipping, what’s wrong with the belt?
Post your personal finding and lets see where this goes:)
