OK Folks - I'm a St noob, but already got my own story. Bought "Candy" ('93 standard model) a few weeks ago off eBay. I've ridden a little over a thousand mostly highway miles on what looked to be pretty new Avon Storm Ultra 2's. Noticed a little vibration, but thought maybe the bike, maybe a slight imbalance,but nothing worth fretting over. Today, however, when turning in to work, I noticed a LOT of vibration- especially around 45 MPH. On the return home, I damn near had my teeth shaken out - thankfully, they're still my own. My first thought was the internal belting was separating on either the front or rear tire. Stopped and did a pressure/visual/tactile check and found nothing really obvious, so continued the remaining 60 miles home - on side roads,just in case. At one juncture, the sun was positioned so that I could see the shadow of the rear end of the bike, and Good Golly Miss Molly! Candy's rear end jiggling would have made a pole dancer proud!
Made it home, pulled into the garage, put her up on the center stand, and with some good light and time to more carefully examine, there was evidence of some magnificent cupping.
Now to be honest, I have no idea how many miles were on the tire - front looks perfect, BTW- and the previous owner was not much of a bike person, from what I could tell. He had allegedly ridden the bike 50 miles in the last two years, so there may have been some age issues, as well as UV damage from being stored outdoors.In Tennesee.
All told, It may well be different lots of Avons wear better than others and may be adversely affected by negative factors, especially age.
I know from my previous riding experience to expect to go through 2 rears and 1 front tire per year, so I'd say most of us would never see 2-3 years go by with the same tires mounted.
I'll say "You're Welcome" in advance for muddying the water further.