My CC129 still has the original tires on it - front and rear and they have a lot of tread left. The PO had said that this particular unit was used for a long time at his home in Maine and then it was brought here to New Brunswick and used at the cottage. Storage was essentially under the deck and the tires were exposed to the weather a lot. However very little cracking or sun damage to the rubber. There are inflation issues but I think it is more valve/stem problems than anything physically wrong with the rubber itself.
My Craftsman aka Roper Deluxe circa 1990 or so still has it's original rubber and it was used hard - almost to the point of abuse. Yes .. I admit it...

My JD L-111 on the other hand is about 5 years old, has 320 hours on the clock and the front tires are worn out

So .. what should be the normal life span for tires on essentially a Lawn and Garden equipment be it a Cub Cadet or some other brand? And what brand would y'all recommend. Course .. will have to find them up here above the 49th, but that is a different story.