FlyingDodo's route through the Chilterns seems to be good until Banbury. It might be better once you get to the M40 to stay to the north of it rather than take the B4100. (The B4100 is okay-ish, but I'd avoid using it when there's a shift change at the Landrover-Jaguar plant there.)
You can use my HS2 route from HPC.
And you're right after Banbury - but cars weren't the issue as the B4100 was a nice wide road, but it's a crap surface. After 10 miles of it, even on Ti, I was getting a bit bounced around. On the Birmingham ride, I should have stuck with my first route, on the other side of the M40.
Warwick castle, Kenilworth castleThat's a decent 'there and back'. Got any Stonehenge type stuff around there...or other suitable landmark?![]()
I've a nice route to Buckingham I've done before, but not in gpx copy - it's in my head, but I'll try to compile it this weekend using mapometer or one of the others.Phew!
I'll recce ride the London Berkhamstead bit in the coming months. I'll take advice from @FlyingDodo and @CharlieB for the route North to Buckingham.