In reply to Russell Lovett:
The walk-in to Lochnagar from the Glen Muick car-park is my least favourite walk-in of all. For some reason I've had more blisters on that walk-in than on any other. And too much of it is up that crappy bulldozer path of Prince Charles's. And I think it plays a psychological trick on you: because the terrain doesn't change that fast en route, you remember every section of it as briefer than it actually is. And I usually get annoyed if I find myself walking something that I could have cycled. And when I'm walking in to a climb, I'm nearly always in a hurry, and thinking about the climb, not the walk-in... no doubt I should be more zen about this.
Obviously this depends on conditions too, but it's not always impossible, even in winter, to use a mountain-bike for some of this approach. This is especially true late season, when it's snowier up high and less snowy lower down. (In summer conditions, I've cycled, or otherwise moved, a mountain bike right from the top of Lochnagar.) Certainly the first mile across the strath can quite often be cycled. And then up Prince Charles's eco-bulldozer-track (did I mention I hate the bulldozer-tracks on the Balmoral estate?) to the first col, that isn't always snowy either. You might even get somewhere on the way to the second col, though that is less likely to be snow-free, and is rougher. If you're interested in saving some time downhill on the return, it's worth lugging the bike uphill a bit on the outward leg.
And how much time would this save? Piece of string question. Some. Compute walking speed vs cycling speed, factoring in conditions.
Two other approaches-- (1) go via Glas-Allt Shiel, which is absolutely beautiful, but certainly not quicker. (2) Wait till it really snows up, and ski it.
Post edited at 09:51