He's got the only kashimax saddle with bikini lines in england!
Seriosuly though, a sunbed does geenrate uv rays, but the intensity to require a tan, porbably means it generates heat too, which is probably not the best for structural integrity. If nylon expands at a different rate to aluminium, then you might generate all sorts of forces in the wheel and destroy it. Nylon is pretty resistant to uv itself however.