BikeFit Surrey offers fun, social and relaxed led cycle rides of between one to two hours around SE Surrey, using a combination of quiet roads and bridlepaths.
Dorking Cycling Club (website not working as at March 2018) organises rides starting from Dorking Sports Centre at 9am on Sundays - see https://www.facebook.com/dorkingcyclingclub/
Love to Ride runs free (members only) rides in the Mole Valley area on Tuesday evenings through out the year and Thursday evenings in the summer months (BST).
Rides start from Nirvana Cycles of Westcott at weekends and on some weekdays.
Leith Hill Music Festival is running a sponsored cycle ride on 24th June - more details here