5 weeks until Henley

So, less than five weeks to go until Challenge Henley. My longest bike has been 137km, my longest run has been 26km and I'm unlikely to do anything longer now. At least I've done a 4km swim, although not in open water.

My target times remain a little uncertain - I don't actually know what the ascent on the bike is like, particularly now they've changed the course. The elevation estimates vary from barometric altitude from the bike to the GPS course plotting estimates of e.g. ridewithgps.

Rough back of an envelope calculations from recent long hilly rides suggest each 10m of climbing adds about a minute, so I can expect to be 30 minutes slower than IM Switzerland if the ascent is 1500m. (This is demonstrably not actual science as that would mean a pancake flat course would take me 4 hours, at 45kph - which is faster than I can maintain for one hour on the rollers, which doesn't have wind resistance. I'd probably need to solve a non-linear simultaneous equation to get a better model). That would assume I had no bike improvements in a year, however, so I'd hope to do better than that.

Also, we can assume that I did Woodcote at pretty much IM race pace - add a third again and you get 7 hours, but from my test ride Challenge Henley has fewer horrific hills.

So, to predictions:
Swim + T1: 1h30
Bike + T2: 6h45
Run: 4h

This would make 12:15, two minutes faster than IMCH on a hillier course (I am assuming I can run ok after the bike there).