OK, here's one from the H&M Trails but not motorcycle related. We were coming down the last stretch of trailhead into town after a day with no cell signal and I decided to check my e-mail instead of paying attention to the trail. Got two wheels up on the bank and over we went. Naturally I told my wife, "You stay right there. I'm going to crawl out the front window and get a picture."
When I was a kid in the 70's we'd camp for 2 weeks every Spring at a small primitive campground just before you got to the store at Smoke Hole, about half way between Upper Tract and Big Bend Campground. The campground got washed away in a flood some time in the 80's.
The river must have changed course during the flood because several times over the years I've tried to find the spot where the campground used to be with no success. I did a combined riding/fishing trip in the area last year and caught a shitload of nice smallmouth in that river.