My rear krylion eventual started getting p'tures at 5000 or 6000miles, got 3 in a row and replaced it, I think though it could have lasted longer. The front Krylion replaced the rear and a Pro4 Endurance went on the front. I cant fault the Pro 4, it looks well, rolls well, grips well and has yet to p'ture. (I would add the disclaimer thats for me and I'm not the heaviest of riders and touchwood don't p'ture often with any tyre). About March/April I got summer wheels though and they had GP4000s on them but I'll have no hesitation puting Pro4 Endance tyres on there when the GP's wear out.