This is a great route if you are looking to do your first century. Do check the wind direction though, you wouldn’t want a headwind all the way back to Oxford. The route also passes Aston Pottery, in case you want to add a cheeky coffee stop on the leg back.
Who doesn’t like Aston Hill? After climbing the Chilterns for a second time you can reward yourself with a delicious bacon bap at the Barn at Turville Heath. This route has a tricky descend, see the Ride-with-GPS link for more details.
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.
I am a big fan of the Old Shed route on the Cowley Road Condors’ page, however, I prefer not to have to turn back onto myself. This route approached the Old Shed from the opposite direction. Look left, don’t miss it!