There are probably some things you can do with tires, tire inflation, tire balance etc… Some frequency related to road imperfections, tire rotation sped, and/or hitting some bump is causing the frame to oscillate. It’s related to control theory way to complicated and math heavy to discuss here, but you need to change the frequency response of the frame.

One key place to look would be using a wider tire at a lower pressure. This could have the effect of adding considerable damping to the system and preventing some of the frequency input from the road in terms of repetitive imperfections in the surface or filtering out some of the higher frequencies from a pot hole hit from getting to the frame.

Avoiding impulse hits like potholes is key because, in the frequency world, this is like a square wave. Any sharp edge like that is comprised of the sum of many sinusoidal frequencies at high frequency. If any of those component waveforms are at the resonant frequency of the frame in sufficient amplitude, the frame will be coerced into oscillation. When you get an impulse hit like that, you’re injecting lots of different frequency inputs to the bike all at one time which can invoke a very complex and unpredictable response.

The problem with trying to figure that out is you risk more crashes until you find it. I’d hate to suggest it, but if it were me, I’d ditch the bike and look for another that was probably a little stiffer and maybe a bit beefier.

The Domane frame is a much more complex case when you look at the elastic couplers it has for adjusting ride quality. That sort of changes the frequency response and makes it a lot more complex.

So my suggestion would be to either ditch the frame, play with the tires and inflation as a starting point, and avoid impulse response type road imperfections (pot holes are a good example) like the plague.

You didn’t mention any injuries from the crash so I’m hoping that’s the case. Hope you’re ok.