If you’re thinking of taking Timidwheeler’s advice and heading Chequers/Risborough way then I could show you some nice stuff between there and Whiteleaf/Bradenham/Golden Ball area. These should allow you to make a nice ride if you start from Wendover side.
As above, I’m tied up for at least the next three or four weeks or whenever the weather turns to shit but I’m happy to show you around. Some of it is a bit cheeky but it helps to join up the (allowed)trails.
If you want I’ll email you when I have a little more time, though I don’t do a lot of weekend riding instead opting for an 11am-ish start on weekdays to avoid meeting walkers.