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
That may be how you think of speed wobble, but the general term refers to the frame going into resonance like happened to the OP. This has been discussed at great length in the research. The resonance can be triggered by all sorts of things. Some bikes resonate easily, and some never do. The on-ride fix is to clamp the top tube with the knees. It changes the resonant frequency of the bike. It was VERY unlikely that a slightly out of true front wheel or a new tire was the fix for this.