This is a good reminder to give the tires a visual once-over before a ride. Though who's to say when yours got cut like that. Did you go back and take a look for debris that might have caused the cut?
I do appreciate all the good wishes and concern from everyone :thumbup:
I guess when you say the bikes been down 6 times it does give a bad impression hah.
The BT-16's had ~8.5k miles. I know it wasn't there less than 2 weeks ago when I lubed the chain. If it was there before the ride it was where I couldn't see it. I always check the pressure either with a good firm squeeze or a actual tire gauge. No idea what it was. It was dark and I wasn't going to stand around in the street looking. On the way home the next morning there was a van with a blown out tire in the exact same spot, so whatever it was got someone else too.