"Heading into the base of one of the world's biggest faces and onto one of America's most famous climbs was a little daunting with just a day pack to say the least but we managed to top out in 14 hours and 40 minutes. However we benefited from a track up to the first rock band from two Swedish friends before we over took them and we topped out on the Kahiltna Horn (20,000ft), not the summit of Denali proper (20,320ft).
The 15 hour Mugs Stump record from 1991 was also done to the Kahiltna Horn and with a track in the whole way but from the pure ethics side Colin Haley and Bjørn-Eivind Årtun did the Cassin last year to the summit and with no track in 17 hours so they hold the real record.
In today's climbing world it's actually more daunting doing something like this and opening yourself up to a barrage of criticism than actually doing the climb itself so those are the simple facts. In any case Colin Haley and Nil Nielson are up on Denali now set on smashing the Cassin record so by now it's probabaly a done thing!"
The pair accessed the route via the Seattle-Wickwire ramp and started at 8.15pm, topping out on the Kahiltna Horn at 10.55am the next morning.
On the approach to the climb Jon managed to trip over a crevasse and put his mono point crampon straight in to his calf - "not a great start" he laughed.
"The route itself is an awesome line and a really fast scramble type climb. From 14 camp and back we clocked up 9470ft of ascent and descent in 21.55hrs and I could definitely feel it hard in the last hundred metres to the summit- I don't think I've ever felt so completely wiped out in my life.
Our tactics had involved bringing up two freeze dried meals so that we could stop and brew up and eat something half way up the thing but it was so cold that I couldn't get the gas to flow properly resulting in no food and a measly one litre of water each for the entire route!
We had planned on climbing it around the 20 hour mark so left in the evening and climbed through the night meaning that we could top out still with some daylight on us - this ended up being a bit of a bad move as we found ourselves high up on the route freezing cold way before sunrise climbing with every piece of clothing we had on...still a great day out on the South Face and looking forward to next year already."
Will Sim is sponsored by Marmot
Jon Griffith is a professional mountain photographer and regular UKC gear reviewer. He runs the popular blog: Alpine Exposures