Daft idea I know, but has anyone ridden Land's End to John O'Groats using green lanes as much as possible whilst still trying to keep a relatively straight line there.
I've done it on a trail bike! However, it was a big BMW GS and I used a lot of motorways and no dirt.
But to do it properly... I recall a couple of women doing it a few years ago using local TRF members to act as guides in their areas. It was featured in Trail Bike Magazine so I may be able to find it.