I have previously tried and failed on Sgurr Mor from Strathan and thought it was a hideous bog trot. I was curious about whether you could reach the hill from Glen Garry by bike since the paths look fine on the map.
I am pleased to report that not only is it doable it is also a wonderful route - long, committing and wild but you can cycle from Poulary to within a mile of the east ridge of Sgurr an Fhuarain with decent front forks. You could probably get to the bridge under the hill but it does become a game of diminishing returns as the path starts to climb. It also does deteriorate beyond the ruin at Lochan. This part of the route was probably greatly improved by the recent dry spell and I am sure you would get a real soaking under normal conditions. Sgurr Mor itself is an exceptional viewpoint and a lovely hill.
A peach of a day and strongly recommended.