During the last week of August 2010 I stayed in Cheticamp and rode the mountains of the Cabot Trail on alternate days (more level roads on the between days). My bike computer has an honest-to-God slope measurement device on it, not subject to the calculation errors inherent in GPS devices. The following graphs all show exactly 10km of road. although the climbs are somewhat shorter than that. Statistics for the blue shaded portion are given below each profile thumbnail. The brown shape is the elevation profile, the red shape is the slope data.
Clearly the eastbound side of North Mountain (ie Cabot Trail loop in clockwise direction) is the hardest in terms of pure slope and the distance during which it is above 10%, but the westbound side is longer in duration so if one goes too hard on the first bit one may well suffer more. And on any given day the wind may have the final say in which climb is the worst, or should I say more challenging!
Distance 5.6km, climbing 396m, average slope 7.13% (min 0.6, max 10.8)
Note the two little legbreakers before it!
Distance 4.3km, climbing 317m, average slope 7.45% (min -0.6, max 12.9)
North Mountain, eastbound.
Distance 3.9km, climbing 378m, average slope 9.85% (min 0.1, max 14.3)
North Mountain, westbound.
Distance 5.4km, climbing 386m, average slope 7.31% (min -3.1, max 14.2)