Just thought I'd put this up... a mate is going to the Himalayas in July next year for a few days, riding an Enfield up the Gata Loops to Leh with a tour group.
Looks like a good ride, but at 4,000 - 5,200metres it might get a little on the chilly side.
http://youtu.be/2bieVIciGuE
And hard to breathe.
A good mate did it a few years ago and had a ball.