Travel from Cambridge to Oxford can be a pain. X5 allows bikes, according to someone who has taken their bike on that service.
Else I'd say train to London then Oxford tube bus might be the cheapest way
Jo is driving to Oxford from Cambridge tomorrow morning, her name is Shippey. on here if you want to pm her and see if she can fit you in the car... worth a try but she's working tonight and might not be able to check forum
Jo is driving to Oxford from Cambridge tomorrow morning, her name is Shippey. on here if you want to pm her and see if she can fit you in the car... worth a try but she's working tonight and might not be able to check forum