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.
Cycle routes in and around Oxfordshire 