Starting at the unrestricted sign on the abandoned road that Cycle Orbital uses heading south for Penn Woods on Arc 10, the spin-off ends at the start of the Phoenix Trail, running on old railway track straight as a die to Thame, and on to Oxford.
After a lovely climb up Penfold Lane, the section through Holmer Green 1.5 and Great Kingshill 3.5 is rural-suburban. L and R on Missenden Road 3.6 and then down Hatches Lane to Hampden Road 4.5. Bryant’s Bottom Rd is a great ascent (and descent) of the High Chilterns, steadily graded, fairly quiet and well-surfaced. At the crossroads 7.5 you can take NCN57 signs straight on to Kop Hill and then through Princes Risborough. Spinoff 10 turns L, reaching the scarp edge at 8.0 Parslow’s Hillock, 235m.
Descend Pink Hill, straight on at the hairpin 8.4 and R on Woodway 8.9, R and L over A4010 9.6, then picking up NCN57 at the railway bridge above Princes Risborough 10.3. There is a lovely final run down Horsenden Lane, crossing the heritage Icknield Line to the start of the Phoenix Trail for a straight 7-mile rail track run to Thame - a very popular family cycle outing at weekends.