A bike riding/artist friend of mine made this movie which shows me doing some 3rd gear wheelies. The only way I can get them up at this stage in 3rd is to slip the clutch while cresting a rise in the road. The ones that show the bike coming towards the camera from far away are the 3rd gear ones. You'll notice in some of them the bike seems to drift to the side with the camber (and bumps) of the road. The hardest thing I find with longer 3rd gear wheelies is steering them. Easier to balance...harder to steer! More practice needed I guess.
This video is almost 3 minutes long. Just wanted to warn those on dial up!