Charlbury and the White Horse Century

Distance: 162km, altitude: 1323m.

https://ridewithgps.com/routes/29739312

When you are planning a (imperial) century, but want to go to the Old Shed, so have to loop-round just to make sure your cafe legs don’t kick in too early.
This ride includes one of my favourite hills out of Charlbury (twice) and the hill I hate most (Dragon Hill/White Horse). At least I managed to get to the top without touching the floor last time.

Cog Cafe and Phoenix Trail

Distance: 133km, altitude: 1277m.

https://ridewithgps.com/routes/29624905

This route takes in Brill, to warm you of for some more bumps on the way to the Chilterns. The return journey follows the Phoenix Trail, an abandoned train track, which is partially paved, and partially crushed limestone. When riding it early April, it was absolutely fine on a road bike. It may proof more of a challenge in the winter.

It’s Christmas (Common) all the time

Distance: 126km, altitude: 1376m.

https://ridewithgps.com/routes/27654394

Fancy taking in some hills? This goes one better than hill-reps. If I am not mistaken, this does not follow the same stretch of road twice (at least not in the same direction), but does tackle the Christmas Common from all directions.
This route includes a tricky descent, see Ride-with-GPS for details.