Yesterday I pulled my rear Michelin X11 Trials tire off the XR650R. That was the tire I was concerned about during the Saddle Mt. ride cause there was a split the entire width of the tread. We thought we couldn't see the innertube so assumed that it did not go all the way through. Boy was I blessed that day, I never got a flat. The split did go all the way through and there was a 3 inch split though which I could see daylight. The innertub actually had a brown line on it the color of the soil we were riding on. That tire has been like this for two different rides. The tire went flat and we replaced the tube in the tire when we rode the Green Dots 2 weeks ago. We didn't see the split in the tire that day. I also noticed that the X11 is a directional tire and that I had mounted it in the wrong direction. I put about 500 miles on the tire, when Roy gave the tire to me he said he had put 800 miles on it. Now I'm wondering if I had paid attention to the fact that it is a directional tire, would it have lasted longer? (I realize 1300 miles isn't bad) Does anyone know anything about directional tires and what it does to them to mount them in the wrong direction? Inquiring minds need to know.