Bad news, the Ribble Valley is quite poor for legal off road riding – i.e. bridleways. It’s mostly farm land, heavy going, lots of huntin’ shootin’ and fishin’ and the few BWs are not joined up like in Calderdale or the Lakes. You have probably already discovered the three BWs that go over the Bowland Fells.
If you head over towards Rossendale or the West Pennines or Calderdale you will find better terrain but that means you will have to drive. Have a look at the website for BAD as they have worked out some decent rides but none of them start or finish in Clitheroe. Good bunch of lads though. http://blackburnbikers.com/
TBH the Ribble Valley and Bowland area is better suited to road riding and for that it’s fantastic because of the huge variety of quiet roads and the fact that you can also head over to the flatlands of the Fylde. There are great cafes in most villages and very little traffic. If you want big hills you can head up through the Trough and places like Settle and Malham are within riding distance. If you happened to be around 6′ with an inside leg around 32″ you’d be welcome to come out for a blast one morning, you could borrow my son’s Roubaix SL3 while he’s snoring in bed, just a shortie to get the feel for road riding in the area. PM me.
Also nip in to the Green Jeresy and have a chat with Richard the owner because he’s got some good deals on CX bikes at the moment, which would be pefect for the area, which is 80% tarmac with a few lanes and BWs thrown in.