The rollers on your John Deere Tractor are part of the tensioning system, not to mention that the belt is twisting in every direction, your belt on your bike is already on tension with the back wheel and is straight in line with each other. The use of a belt DAMPENER, is to take out some of the vibrations of the belt, is this needed, well this is a long-time discussion on here that will never be solved, it like oil, tires, seats, it's a personal thing, and only your butt will tell you whether it's right for you! The one thing I will say is that if you drink the Kool-Aid, you have just given yourself another thing to watch and maintain. Good Luck! P.S This post was from back in 2022hyea::bdh:
Correct, one pulley on my tractor moves on a spring to keep constant tension on the belt, because if one blade spins slower then others or change in terrain will cause slack in the belt which is bad. Same thing is true for spider, the static adjustment on rear tire takes inherited slack out of the belt, but does not account for acceleration, changes in suspension do to weight or road conditions that can cause unnecessary vibrations and possibly excessive belt wear. which is why a tensioner is needed to keep load on the belt when hits those condition that cause slack in the belt outside of set tension.
I see people claim spiders belt is over built or over tighten and fine as it, but then see reports of people belts snapping at very low mileage with no other cause. Imo if you are casual rider and cruising around maybe fine which could be why canam didnt engineer a better solution. But me, I push my spyder to limit. I rode mine the other day with the panels off before i installed tensioner arm and my belt was bouncing at least top frame rail. With it installed seems keep it contained.