Doing it in September. Have done my first Alp recently (>500m of climbing over 7km), and a couple of long drags in wales, as well as the Mam Rattagan Pass above Loch Duich. I've also done a sustained climb of 20% over 1km in Languedoc, but not at the top of a long climb! Want to really put down a marker, and can't think of a better way than doing the longest climb in Britain. It'll all be at snail's pace, and I'm not kidding myself that I won't need to stop for a rest where it ramps up - but my only rule is never to walk, however many times I have to stop. I'll tell myself I'm the first 20 stoner to do it. As to the hairpins, do you find that traffic coming down gives way to you here, or do you have to grind to a halt while you give way to cars?