"I felt pretty confident until about 1pm. It was super-hot and the tar melted. The road had recently been resealed. The sticky tar picked up loose chip and kept jamming my rear wheel. I had to get off every 2km and use a stick to free it up.
"I thought I might have to pull the pin but on the next repeat, the sun had moved. There was a small strip of seal that was in shade and I was able to ride on that."
At 11pm, Walter dismounted back in Ohakune - nine summits, 334km and 9200m of climb had cemented his place in the Everest Hall of Fame.
"Initially I wanted to do 10 repeats to hit 10,000m of vert but on the last repeat, my lights ran out. It was bitterly cold - I was wearing every layer I had and was still freezing. It wouldn't have been smart to go back up there as fatigued as I was. And I didn't need to," he says.
This weekend, Walter is on his bike again, tackling the WEMBO 24 Hour Solo Mountainbike Championships in Rotorua.
Event details
Everest Cycle Challenge
What: 8848m of vertical climb cycle challenge
For more information: www.everesting.cc