I did it back in 2013. I think gearing would be my tip. I was quite good at hills at the time and 39/25 had got me up Scotlands Alp D'huez but I was quite glad I changed for a 34/29 for the real one
When I done it I think there was only one descent that was neutralised but that still didn't stop a nasty crash on it.
A light weight long sleeved windproof and mitts was good enough for me and also for the folk who had done it before. I don't think I'd want the extra bulk of a full boil in the bag waterproof and long fingered gloves. You'll know yourself how much heat you generate/ how you feel the cold
One thing that I can remember the multiple tunnels can be very dark when you speed into them with shades; I'm glad I had reactolites
Above it all though, enjoy
