NCN 4 from London to Bristol is Sustrans’ gold standard route, used by Cycle Orbital for Arc 9, Spoke 6 and Spoke 6-7, and almost throughout this route, apart from a southern alternate below Maidenhead.
We spin off at Dorney lake (a popular triathlon venue as well as Olympic rowing site), over the Thames by cycle bridge, R on Monkey Island Lane to 1.8 Bray , after which NCN4 turns N to take in Maidenhead; Cycle Orbital bypasses the Maidenhead suburbs by using The Causeway, crossing A308 2.3 then L Kimber Rd 2.9, truncated by the A404(M) motorway, so crossed by ramped footbridge 3.1. Regain NCN4 at Highfield Lane 4.2. After suburban winding through Cox Green the route goes off-road to Knowl Hill. Cross the A4 7.7 R - L and you are treated to a substantial off-road climb up and over Bowsey Hill on NCN 4. If you prefer an on-road alternate bear R at Knowl Hill 7.5 and take the road through Warren Row, home of a famous cyclists cafe/workshop, Velo Cafe, which is well worth the visit, or the detour.
At Crazies Hill it’s L for NCN4 towards Reading 9.4, or a train via Twyford link; straight on for the end of the spin-off at a fork in the road; L on Worsleys Lane for Henley avoiding the busy A4130 Remenham Hill, then on into Oxfordshire, or straight on Culham Lane for Aston, where you can cross the Thames at Hambledon Lock, on into the Chilterns.