@IWRATS: Ta, I'll take that offer! Especially as I managed 2hrs47 on the way home, which I'm even more stoked with!
@Beano, twq: The route I take goes over the bridge, around Dunfermline then down to Alloa o on the old railway path. My GPS reports it as 76.2km, so a total of 94.7 miles return. Total time was 5hrs33, so an average of just over 17mph - that was on my road bike and was going for it, though. Fuel for the way out was a breakfast of an Apple and a banana, a Clif bar after an hour and then dried apricots and jelly-babies, with one sugary-drink bottle and with water and dioralyte. Fuel on the way back was clearly not so well managed because I met The Man With The Hammer climbing of the Dalmeny...