I think the shimmy is a resonance vibration.
While a certain tire pressure may be the correct fix for one Coupe, on another plane it may take a different tire pressure to keep from having the resonance. Try out the 17 pound nose tire pressure suggested. If it shimmies, then try a different pressure. If a simple pressure doesn't fix the problem, then it's time for some nose gear strut and control maintenance. The humble opinion of a VERY non-mechanic. Ed
