Modern Vespa

Just passed 1,000 miles on my Liberty 150 and since hitting the break-in mileage I have been cruising on average at 45-50 MPH. The side roads to and from work are 45 MPH speed limit and this really is the safest speed to travel.

My question: will this wear out the CVT belt before the recommended 6,000 mile replacement?

Nope.

Belt wear (and tire wear as well) is accelerated by extended use while fully hot, as it will shed more rubber when hot. This means that you will likely have shorter belt life when you sustain high speeds for extended periods of time. On a Liberty, you’ll not likely be doing extended freeway rides, so it’s probably not an issue.

High speed for short distances or with plenty of cool-off in between is not likely to significantly change belt life.

related Q: what causes flat spots on rollers?

Dunno, actually. I could hazard a guess, but I’d just be speculating.

Don't the flat spots basically come about from the cvt spending more time in one "position" vs another? Which isn't identical to speed, but probably roughly corresponds to spending more time in a certain range than others.

Curious about the answer, if anyone knows

My take:

Rollers don't roll. They slide. One side slides on a flat surface (the backing plate) and one slides on a curved surface (the inside of the variator pulley). The flat surface wear will be slightly greater than the curved wear, as it's all on the same line along the roller. Eventually, a flat land will begin to form on one roller. This makes that roller slightly smaller across, and most wear will transfer to the other rollers. This goes on until all rollers each have a flat spot to varying degrees. This will mean slightly greater acceleration, but a lower top speed, and if the flat spots get more than about 1.5 to 2mm deep from the original circumference will contribute to rapid belt wear as the inner teeth begin to contact the variator bushing. As soon as one of those teeth loses its outer skin, the transverse filling flies out, and before you know it the belt gets stripped of all inner teeth, muckite and kevlar strands get embedded in the clutch, and the show is over.

Moral - change those rollers at the first sign of flats.

I'm somewhat more inclined to believe that much of the physical wear comes from frequent rapid acceleration and deceleration/engine-braking. But that's simply my experience/opinion.

Exactly, for the flat spots. It's the sliding that causes wear. If they were jst in one place there's be no wear at all.

Makes sense - thanks for clarifying

Thanks for the info!