start: Oxford, Marston [SP530079]
finish: Oxford, Marston
distance: 41 km
When in France last year, we found these great ice-cream cafes called Amorino. And to my surprise they have a little shop in Bicester as well! Well worth a visit, and this bicycle route takes you there and back. It includes a few hundred metres of very bad road surface (which stops cars using it as a rat run from the A34), and a great gravel road on your way back. Both sections I've marked in red on the map.
Route map:
This route is also published on MapMyRide