Rob Lee of the Iron Horse Extreme race team is trying to ride all seven of the red-graded 7Stanes trails in the Scottish Borders in one go.
And to make things even more difficult, he'll be riding from trail centre to trail centre too.
Rob set off at 10am today on his Iron Horse MK 111, and he's carrying a SPOT Satellite Messenger so you can track his progress live on Google Earth. He'll be switching to a road bike for the tarmac sections.
This challenge is the second stage of the 7ds (Seven Deadly Spins) project, a UK-based series of long-distance solo challenges aimed at taking mountain biking back into the mountains.
Martin Astley, product manager at UK Iron Horse distributors Jim Walker & Co, said: "As some of the most visited trails centres in the country, the 7ds crew felt that riding all seven red-graded trails, and all the road sections between, made for a modern day challenge that a large proportion of the mountain bike community could relate to.
"Whether it can be done by a soloist within 24 hours remains to be seen, but we hope to be somewhere closer to the answer some time tomorrow morning."
To follow Rob's progress, click here.
