January 6th, 2012.
I do believe that the military Dnepr/Ural bikes descended from the BMW R75 or R65 of the pre WWII German Army, and back in the seventies or early eighties they would max out at 51 or 61 on the road. The problem then was with valves, springs and rings as those almost always had to be replaced at day one to get them to run. USSR can weigh in here as he is a lot closer to the source, so to speak. The drive on the sidecar wheel can apparently be disengaged, and apparently like the German bike they are descended from, fairly ferocious off road bikes, considering they are burdened with a side car and a small (comparatively speaking) engine.
Still, the guy in the blizzard has trash can sized kahunas, given the temperature, the slipperyness of the road and the poor visibility, if they can rear end a deuce or a tractor trailer under those conditions, a motorcycle might be taken for a bump or pothole.... I'm more curious how he kept the drum brakes from freezing up or the fuel line ditto, as when I used to ride the dirt bike at -20*F, the snow would melt into the brake drums and when you stopped, freeze them solid, or the fuel line would ice up..... (You have to be a lazy hillbilly to do this, but I figured I could ride the bike up and down the hills, and made cash towing sleds & riders up to the top)....

Now mind you, I don't claim any sanity for back then, and probably less now.....