I blame BMW for selecting that model of tire for the RT.
But delaminating ply’s On that Conti is troublesome for sure, excessive heat and pressures comes to mind, but maybe just a defective tire?
Good point MBevans, re selecting that tire for RT.
Besides PR4GT I tried Z8, Angel GT and Conti RA3 and I'm on my 3rd set of those right now. Bad batches happen (just think about poorly hardened cam lobes in wetheads happening over many years) and my guess is that's exactly what's happened here. Or perhaps the tire sat out in the sun and cooked on top of being ridden in high heat conditions repeatedly. One bad story can be all it takes to take down something like this, and really as you point out, we don't really know if this is more of a one-batch-off issue, or something pervasive--very doubtful else we'd (and Conti) would already have heard about it. When these tires go I will buy another set because in all areas the tire beats the other 3 handily and especially in turn-in the tire matches the RT's and my body weight and riding practices perfectly, no noise, best dry traction and likely fine in wet I just don't ride in wet much, resistance to squaring perhaps a little better, best in linear grooved pavement, bridge surfaces etc, and minimal cupping by EOL at BMW recommended pressures, and 100% traction from initial install with no break-in required. Haven't tried the newer Michelins but a while back I concluded the tire is vastly overrated at least for this bike and decided when their solution was to overinflate the tire I didn't want to endorse that any further. My guess is that tire cups seconary to its ornate siping, where as RA3 has large bold channels.