Belt age on shelf

[ute]

I know there was a thread a few years ago about this but can't find it .........so

How come its ok to put new belts on that have say been sitting on a shelf at the dealership for say 2-3 years ( or longer )

when the ones on the bike are the same age ( with lets say very minimal mileage during the 2 years  )

Is it a stress thing on the ones on the bike or is it because they are under tension ? ..its not a sunlight thing

Just curious trying to wrap my head around it ( a group on Facebook ( Ducati Monsters) went 13 years ...in fact so many response's of 10 years ....and I do understand playing with fire and the valve hit if it breaks

[koko64]

I remember that thread.
Small pulleys (sharp bend), belt tension, heat cycles, safety margin, pre kevlar belts. There was a link on storage and shelf life, iirc non kinked, cool dry place, etc. I cant recall the storage time. Get some Exactfit belts and you're good to go.

[Speeddog]

I'd hope the belts at a dealership turn over faster than 2-3 years!

Storage? Cool, dark, dry, totally free not folded in the paper sleeve.

Heat from the engine and from transmitting the power I'd say are biggest enemies.
They get baked by the IR.

Seized tensioner rollers are a big threat, bike will run for a while but eventually it wears through the belt and shit gets broken.

[ute]

Ok makes sense

Do any of you follow that group on FaceBook ( Its in Italian but hit the translate button )  ...just crazy 13 years ...can't even imagine pushing your luck that long  ....  and more than one guy