No think I missed the bible! Although think I read a blog about the search for Kona marginal gains before if that’s the same one? (I need to refind that, as I’m currently rereading the aero thread)
Ride Time 11:47
Total Time 13:22
Average power 204W
Normalised power 240W = 3w/kg (Ironman target is ~250-260w; FTP 330)
Climbing Power was typically ~250W, although got sucked into a few laps closer to 270 with friends in the middle.
Avg cadence 60 (36-28 I think).
Avg HR 134, usually topping out at 145 (my max is 181).
2.25km climb at ~10% near constant gradient the entire way, only a few short sections of 12-15% . That was important to me to not have real grindy bits, but keep the total distance to a minimum. That would be my advice in picking a hill, constant gradient at as steep as you can manage without having to go into threshold powers and a safe smooth descent. This hill being picturesque helped mentally 
I estimated 14-15 hours as 3x laps an hour plus an extra 1-1.5 hours for fatigue/setbacks. Lap 22 was the fastest at 16:09, and every lap was under 18 minutes. No cardiac drift or loss in power on later laps.
I’ve had Everest stored away for a while as a challenge I’d like to do one day, and then a few prompts kept bringing it to mind including seeing a UK friend (ex-swimmer, not a competitive cyclist) do it in 18hr. Then it just kinda snowballed after talking with people about how one would theoretically do it, and it kinda turned into a plan when realised only had 1 weekend off work in September, didn’t want to do October November, and then Jan onwards would be too hot.
With 3 weeks to plan I did 3x 3-4hr rides with ~2500m elevation. First week my neck, arms and lower back were worryingly sore after a winter riding indoors, but third week zero soreness.
5 days to go the weather looked ok, so we locked it in just for a group long ride, with me and one other thinking of base camp.
Sunrise 6:00, sunset 1824.
3 of us started at 5 which meant I knew I still had the option of doing a full without too much night riding for that 15hour target. Other people swung by throughout the morning to join for a few laps each and we just had a really pleasant morning, perfect weather to be out on a bike enjoying chatting away. And it was just one of those rare days where everything clicks, and my legs really turned up to play. The other starters cracked badly, which was a surprise, but I just felt the same every rep without accumulating fatigue. It was only when the last person bailed out at 21 laps I decided I’d commit to finishing, meaning another 20 to go. One longer stop of about 20 minutes to have a really good feed and then onwards and upwards. I soon had a lull from 24-30 laps, with onset of fatigue and the realisation that although 25/40 sounded good, I still had a full long ride to go and about 5 hours of riding! 
But I settled into rhythm of 3 laps with a 5 minute break, kept eating and had a caffeine salt tablet. An hour later legs were fixed, but I started wishing I’d read @jaylen advice about taking toilet paper earlier, although disaster averted there too.
Mrs came back at 530pm to “support” into the night, although reality was she just wanted a sunset walk on the top. But that’s fine as it was perfectly timed for me finishing with the extra lap just to get the Garmin above the total, and I really didn’t want to ride home 
Recovery wise, soooo much better than an Ironman without the run impact! One day off, then an easy swim cured the remaining neck and back soreness. Continued with 9 days of easy but daily training, and felt normal by day 7.
