Quote:
I know the obvious fix is DON’T LET GO OF THE BARS!
Right, but that is indicative of a problem. I suggest that you get it sorted out ASAP before something bad happens.
Some other possibilities: Headset bearings loose or damaged, front axle bearings, wheel out of true.
I don't know if a bad chain would transmit vibration to the front like that, but check it anyway.
I expect wheel balance or bad tires would be noticeable all the time, but check them too.
Contra todo mal, mezcal; contra todo bien, también
| 
