For his latest challenge, ultra-endurance mountain bike specialist Rob Lee is aiming to ride the length of Britain off-road in less than two weeks.
The 1,200-mile X1 route from Land's End to John O'Groats takes most riders up to 23 days to complete, but Rob reckons he can do it in as few as 10.
The ride will be the final challenge in his Seven Deadly Spins project, which has previously seen him tackle the West Highland Way Double, the Welsh Coast-to-Coast and all of Scotland's 7stanes red routes in one hit.
"I'll be trying to complete the route within the window of 10 to 14 days, although I acknowledge that this may be pushing the limits of my riding ability to their extreme," said Rob. "To put the attempt into context, it's the equivalent of attempting to ride the Montane Kielder 100 repeatedly for 10 straight days!"
Rob, manager of Team Syncros Endurance, set off yesterday, to coincide with the release of cycling film Find, which features his second 7ds ride. You can watch a clip below:
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He's been keeping supporters updated via Twitter, where he initially sounded pretty chipper, writing: "Fun day in the saddle so far. Rode a sweet bit of singletrack in middle of nowhere! Feel good." However, after reaching the finish in Truro, Cornwall, 162 miles later, he Tweeted: "Later start today. I'm a tad sore."
Rob is hoping to raise £1,200 for the charity Let's Hike or Bike for Children – visit his JustGiving page if you wish to contribute. You can view Rob's route here, and follow his progress via live tracker, Twitter and his daily blog.