I have another post similar to this "buried" in another thread, but have re-posted here for better "exposure" and with added information.
I had a Dunlap E-3 ("regular", bias, front tire) which remained on the bike when converted from 2 to 3 wheels. It performed perfectly. Recently, with the tread down a little, I thought I'd treat myself to a new Bridgestone BT-45 (bias, rear, sized for front). Almost immediately I encountered an occasional front wheel shimmy in the 55-70 speed range. It doesn't do it all the time, it seems if I hit a slight bump, or have a cross wind condition, something "sets it off". Sometimes it's slight and brief - sometimes severe enough to require a quick slowdown to stop the shimmy. Since the new tire is the only thing that changed and it never did it before, it is reasonable to blame the tire. Anyway, this just started in the last week or so since I changed the tire. Maybe I should have stuck with the "old" E-3 while it still had some life in it - but who knew?
Other than purchasing another new tire (of a different brand), does anyone have any other thoughts or suggestions? The bike is a '95 GL1500 with a "superbrace" (had for years) and the new tire is balanced with "CounterAct" beads (similar to Dyna beads).
Front tire pressure at 41 lbs (rears, 22). I thought the BT-45 was one of the "top shelf" brands.