Well, that's done then. I scooted my way up from pen 7 and got through the start line at about 7.25. I had a relatively slow start but I was pacing myself and my average speed started to climb above 25kmh - not far inside what I needed to avoid the broom wagon, but inside it.
On the ride down towards the lake after about 35km I was really getting in to my stride, moving forward a group at a time and picking up speed and confidence.
Adrian and I had done a recce from Gap to the top of the Isoard, so I knew what to expect and turned off the bridge across the lake knowing that the first sharp - if short - climb was coming. And a third of the way up it I felt something in my calf go pop - the same thing that happened on the Circuit of the Cotswolds. It was excruciating but I knew from the last time that if I backed off a little I could nurse it for at least 50 miles or so.
It just got worse, though, and I really started to struggle. I thought I'd get caught before Embrun, but I made it through with at least 10 minutes to spare. I thought I'd be caught at the feed station, but I made it through there 15 minutes ahead of the broom wagon and there were still hundreds of people there.
The run along the valley from Guillestre to the base of the Isoard is deceptive. It looks downhill, but the altitude data from my Garmin confirms what my legs were telling me - it's uphill almost all the way.
On the run up out of the valley, past the war memorial, a Brit came past at speed encouraging us to speed up because the elimination car was only a couple of minutes behind.
I made the left turn on to the first part of the climb proper knowing that the cut-off time started to creep out beyond Arvieux, if only I could get there in time.
I didn't. By the time I was swept up my average speed had fallen to 21.9kmh and that was that - apart from 7 hours in a coach designed to comply with a statute from the time of Napoleon which requires the leg room to be suitable for Bonaparte - and not a cm more.
There was much consternation on the coach about whether the broom wagon was running ahead of schedule. I heard after the race that it was; someone on the coach was frantically scribbling calculations on a scrap of paper to prove that it was - but my target for Arvieux was 23kmh and I didn't make it.
To be honest, writing this 2 days later and still suffering severe pain from my calf, I don't think it would have mattered much. If I had dragged myself up the Isoard within the time limit I wouldn't have made it up the Lauteret and I certainly wouldn't have made it up the Alpe.
It was still a great experience - and I did manage the descent of the Alpe d'Huez to Bourg d'Oisans, which was awesome.
Would I do it next year? I'm not sure. The rumour is that next year will be in the Pyrenees and I have unfinished business in the Haute Alpes.
What I will do next time is travel out and ride the climbs - one a day - a month or two beforehand because a couple of hundred mile rides in the UK - even the allegedly 'hilly' Circuit of the Cotswolds - is no prepration at all.
For the record, this is how I did...