Originally Posted by LarrySellerz

I think of speed wobbles as being caused by out of true wheels, and they normally aren't very large. What you described sounds more like a slight imbalance that quickly oscillates out of control, which can be super sketchy and annoying. I doubt a speed wobble would have affected you the way it did, and I doubt trueing the wheel will fix the problem; When this happens to me I clamp the top tube with my knees. Never happened to me at that speed, personally I would just find another bicycle if mine did that to me. Its really not worth crashing at that speed