This ride starts from Horsford Village Hall (NR10 3DN) and runs north towards Roughton, then west to Holt, south to Saxthorpe before returning to Horsford. There are lots of start times available, between 8:30 and 9:30, with expected ride times between 3 and 4 hours. Slower riders should opt for an earlier start time. More info on the EACC events page.
Here is the GPX file for the EACC 50-mile reliability ride.