This is probably my favourite one day ride from Lewes. It heads north out of the town towards Cooksbridge and then runs under the northern ridge of the downs, largely along quiet lanes, with a few off road stretches which are easily managed on a road bike. There are lots of places to stop for refreshments and lots of places you can stop and just admire the view.
The total distance is 44 kilometres (27.5 miles). You could shorten it by about five miles by taking the train to Plumpton and cycling south past the racecourse to meet the route. There are a few short hills but most of the route as far as Bramber is gently rolling countryside. After Bramber the route is flat.
Do be aware that you cannot take bikes on trains leaving Brighton between 4pm and 7pm Monday to Friday. Coming back from Shoreham you need to change at Brighton, so be careful with your timings.
There are four sections to the ride. Click on the icons on the left for the maps
1) Lewes (detail) (you may not need this section if you know Lewes well)