When I was there last year there was a barrier next to the no entry sign at 4:40 and you had to go down the little dip to the right and up again in order to round that famous bend, just 1/4 mile up the trail.
Ordinarily this would have been quite easy, had it not been snowing for the past hour. I made this short video shortly afterwards.
If you're riding South-to-North then by this point you're pretty much home and dry, just the Col de la Boaire up ahead and down that zig-zag road, the Passo de Tenda. The hardest bits are the previous 2 or 3 miles, specifically heaving the GS over rocks the size of babies heads while riding up a staircase. Scared the carp out of me at the time- I think there's a very brief clip in the vid on this page (and a map of the best bits on this one)
Hehe, cheers. I'd never have gone up there had I known what was in store, the prospect of something going wrong up there made for a proper scary ride. Just goes to show ...
... that some people never learn. Went back there earlier this year, and I'm not sure you'd get a 4x4 along there now. Maybe next year we'll be lucky to make it on foot?