The walker's path is a steady climb all the way, once you get above the vegetation it gets steeper still - when I did it a few years ago at no point did I think that I'd want to take a bike up there a it would be hike-a-bike almost all the way. The descent is fairly narrow and tight switchbacks - nowhere to really 'run' and you'd be on the brakes most of the way.
I also did some exploring of the forest trails around Glengorm Castle at the north of the island - mainly forest tracks as there's little evidence of any other tracks