The relatively gentle relief of the Wey and Thames valleys ends abruptly with a short but steep climb up onto the fluvio-glacial Taplow Terraces, which are at their most spectacular and landscaped at Cliveden 2.4 (NT - cyclists can pick up a £1 voucher as carbon offset bonus to use at the café).
The long Spoke 8N joins 3.2 as the Arc turns L Sheepcote Lane. To take a break from a fairly busy Wooburn Common Rd, 4.3 turn sharp R on Green Common Lane and L Lillyfee Farm Lane. A brief section of the A40 (caution - there is a dangerous rut on the approach run-in from Broad Lane) and a stretch of Beaconsfield suburbs is soon over; there is unbroken countryside riding now until Chesham.
A refreshment stop hard to pass by is the magnificent Royal Standard of England 7.6 at Forty Green. After a stiff climb to Penn church 8.6 (possible potholes), down to Penn Bottom (more potholes) and back up to Penn Woods 10.6. Follow the line of the timber stack for the correct direct path, which is cycleable slowly, negotiating roots and puddles – but do not be tempted by the road detour as the A404 is busy with 50mph traffic - better to walk your bike and enjoy the woods.
There follows 1.5 miles of a Cycle Orbital discovery 11.3; Beamond End Road is a disused metalled road, gated at its centre. Look back at the comedy road sign 12.7 (yes, it's on the Welcome page of this website) as you rejoin the road entering pretty Little Missenden. This is also where Spin-off 10 begins its Chilterns journey towards Oxford. Cross A413 with care 13.3 and engage low gear for the final climb of a long arc up to Hyde Heath 14. Chesham is arc’s end, but the level run back on Copperkins Lane 14.7, the link to Amersham, will provide a more frequent rail service.