I've ridden this circuit when it was frozen a couple of years back and it was pretty good in places.
The Lairig Gartain is a bit of a bog for most of the way so I wouldn't go near it unless it was well frozen or after a very dry spell. The descent from the high point towards Dalness has some nice riding, though it is a bit of a narrow trench in places. From the junction with the Lairig Eilde path you'll be pushing and carrying for much of the way up to the high point but it's worth it for the downhill back to Glencoe – it's a hoot! Make sure you spot the river crossing lower down or you'll end up with a poor finish, but if you cross the river you'll have a good path all the way to the car park. The return to the start point can mostly be done off the A82 by turning into the first lay-by and picking up the track which runs parallel to the road on the N side.
