Both lead through the woods up to Winterfold Heath, deep in the Hurtwood Forest set high above Cranleigh.
Mercifully, most of it is accessible on a dense network of footpaths, one of which is an ancient Roman road.
Alderbrook Road offers a steadier incline, replete with a left hand hairpin in the middle section and a long haul through a deeply sunken lane towards the top.
And while Barhatch Lane is steeper, arguably Alderbrook Road is a more classic climb, typical of the short, sharp ascents to be found amongst the Surrey Hills.
Barhatch Lane to Winterfold (Surrey Hills):
Base: 80 m. Top: 230 m. Vertical: 150 m.
Length of climb: 1.5 mile / 2.42 km. Average gradient: 6.2 %. Maximum: 21 %.
Alderbrook Road to Winterfold (Surrey Hills):
Base: 65 m. Top: 188 m. Vertical: 123 m.
Length of climb: 1.0 mile / 1.61 km. Average gradient: 7.6 %. Maximum: c. 14 %.
223. Cycling on Surrey and Sussex hills – from White Down to Ditchling Beacon
153. The green monster – Ditchling Beacon and the London to Brighton bike ride
225. Running on Roman Road 2 – from Stane Street to Guildford
149. In at the deep end – Stratford 220 Sprint Triathlon
155. Le grand départ – the Tour de France in London 2007
113. The Pilgrim’s Progress – Surrey Hills 2