Uh, yes, I was sorta going in that direction. (And by the way, in the podcast, the titanium bike that cracked at the downtube at the shifter bosses, seemingly due to bifurcation, matches another recent thread with that exact same failure mode location, but no mention of any such event.) I had university classes where the prof would just launch into the math of things from day one without any explanation, losing a lot of folks. So in my professional career, where I considered my job as a manager was also to teach, I try to enter a subject slowly, with lots of analogizing in terms that most mechanical engineers would understand, I don't go systems engineer from the get-go. I had worked up to an example of divergent oscillation, but seemingly from a forced input alone. In Hopf, it crosses the boundary to where the system has sufficient undamped elasticity to it, to sustain the oscillation even if forced input is reduced. I knew the problem on bikes but not conclusive causes, nor solutions, other than a steering damper. I did not know the suggestions they made to reduce speed wobble, that's great info. I'm also glad my Cannondale racer, very rigid (to a fault in ride quality), was before top tubes started to get really skinny, and I've topped out the speedo pedaling at max on a mild downgrade, so I think 64 kph (40 mph), no wobble. My current bicycle, 20" wheel folder, in particular has a mild speed wobble that I can steering induce and pull back quickly on fast descents, behavior opposite to what they describe, worse when unseated and thighs not clamped around seat, so perhaps that is not a true speed wobble. I improved stability in general via mass positioning on the bike, easy with front and rear panniers and racks, and a lot of added mass on the handlebars (clip-on-aeros, drink bottle, bar-ends, heavy L brake handles), plus the cheap wheels, tires, and flat liners are especially heavy for their size. However the above (podcast) may call into question the folding joint in the main tube, which has been tightened up considerably via my improvised "Deltech" (Dahon's new thing, I improvised using kevlar line that triangulates the frame). The smaller tires spinning faster, fatter tires, may be more susceptible than my 700c racer.

There's been a great study on bike stability by folks from Delft and Cornell et al, they made an excellent simulation model, but I think it's only valid for basic stability (steering into a fall), and not wobble dynamics. But very good if you can find online, I myself have the PDF but can't really post that without a link.

EDIT: Reading again the above study, I found this: "All known bicycle and motorcycle designs lose self-stability at high speeds because of gyroscopic terms." (Whereas at lower speeds, gyroscopic forces increase stability.)

EDIT: Excellent article:
https://velo.outsideonline.com/road/...-to-stop-them/