Is it resonance or a Hopf Bifurcation? :)

I wouldn't call it "preventing" anything if you have to realize something is wrong before you respond. I've never had it happen to me, but my prevention would be selling the damn bike. I've seen enough of it close up to know I want no part of it.

I have tested that too and in my case it didn't solve the problem. I literally sessioned (repeats) a major mountain where I did trial and error with every one off suggestion to fix a high speed wobble, and none of them worked. Sell the bike!

Of course, preventing means doing it beforehand. So what I do is keep putting power down, or leg to the top tube when I coast above 35-40 mph, depending on what the road calls for. Nobody ever had a speed wobble when putting power down. All of my bikes have had wobbles when I coast somewhere between 40 and 60 mph, depending on frames and wheels combinations, so I just act preemptively as wobbles are some of the scariest things I've ever experienced.

Ermagerd. I don't think I could put up with that.