@phil_hg_uk will probably be your best bet.
Getting out to Pateley Bridge on the B6165 from Ripley would not be too bad but it can be a busy road depending on the time of day.
Getting out of the town up Cornwall Road past Valley Gardens, to Penny Pot Lane and past the Army barracks will get you nicely warmed up and will take you onto the B6451 and across the A59. You can turn left and go round the back of Menwith Hill Base where you can turn right towards the top of Greenhow Hill and then down into Pateley Bridge. (returning by the same route UP Greenhow Hill could be considered 'character building'.
Any roads around Hampsthwaite and Summer Bridge are good to cycle on though.
The A59 would probably be best avoided at any time of the night or day.