A variation on a theme this one. The loop starts off from Aithrey Loch, the same as the previous route, but this time it takes you up past the entrance to Mine Woods. Instead of the descent down to Bridge of Allan you keep riding up and round Cocksburn Resevoir until you reach the gate for accessing the local hill, Dumyat.
Contouring round lower Dumyat you first come to a viewpoint providing amazing views over the Forth Valley before launching your bike down the rapid and fairly technical Witches Craig descent. Be aware of the cliff top drops as you come to the end of the first descent through the trees. Next up is the dark and rooty Rhododendron tunnel which will shoot you out and down to an access gate crossing the powerline construction road.
Once across you're pointing down again through fast and steep singletrack until you reach the 'Hole in the Wall'. From here you can loop back up to the University Woods on the road and then enjoy a final blast back down to Airthrey Loch.