There ought to be a standard way to judge when a nylon strap or fabric has been "sun rotted." Something like will a 1 kilogram lead weight dropped from a height of 1 meter crash through the fabric or bounce back.
Does anyone know about how many days a silnylon fabric can be left in the sun before the UV does an important amount of damage? I guess that the direct Arizona desert sun would do the job quickly, while semi-shady areas under tree canopies in West Virginia would require more time to ruin the material.
But in both cases: how long? Days? Weeks?
I remember how a plastic bottle that used to be resiliant suddenly shattered into shards when I accidently kicked it. It had been sun rotted as it stood on my porch.