I have been big on the urethane ride for a number of years. I at work have used a lot of urethane casters. And strangely enough on a number of occasions, we will come into the shop and roll a piece of equipment that is maybe 8? years old, and within 10 mins all four caster urethane treads will crumble and fall off. Hard to explain how all four will destruct almost at the same time without warning. Urethane might a great idea, but seems to have a very limited and abrupt lifespan.

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.