Originally Posted by
terrymorse
I doubt temperature is going to degrade rubber or plastic on a bicycle by any significant amount.
Consider a car’s passenger compartment, filled with rubber and plastic components, sitting for thousands of hours in the sun over its lifetime. It gets quite hot in the passenger compartment, yet the parts don’t fall apart. The dashboard may crack, but I submit that’s due to UV from direct sunlight, not high temperature.
Perhaps, it's the combination of heat and ozone. Our attic is well ventilated and we live in the city. Ozone can definitely get in there. I suppose if ozone pollution is negligible, a shed would work just fine.
I've noticed in cars that's been mostly used in a city vs a car in the countryside, the city car has more cracks in the tires even if the same age as the tires on the countryside car.