I have had no trouble on Continental 4000 Grand Prix Sii tires. However, was just reading tire reviews on Continental 5000 Grand Prix and Gator Skins, and there is recurring pattern of tires blowing sidewalls or beads, while still almost new. Not everybody, but not just one guy either.
The people say they have been riding for years without this happening.
What say you?
Faulty tires a certain percentage of the time?
Hit something they didn't know they hit?
Installed wrong?
There has to be a reason. Is there a best likely guess?