In reply to gammarus:
Can't remember, I remember that there was a strong headwind as evidenced by the waves on the loch but we also rode round the forest a bit so it wasn't a straight out and back. The route is in the Scottish Wild Trails book BTW so that will have timings. There possibly a hundred metres where you couldn't be in the big ring, really very easy riding.
I do remember that about ten minutes after we had got back and were just heading to the cafe that the heavens opened, very lucky timing.