Geez... I have seen this shimmy issue talked about ad nauseum and, in the end, I surmise that no one knows what the heck the answer is. Jobst Brandt's typically absolutist pronouncement doesn't wash with my 30 years experience either! (Which is pretty much the same with at least half of what I read from Herr Brandt! Sorry!)
I see seemingly perfect bikes every once in a while develop a shimmy, who knows why?
I had that happen on a bike I built for a friend..It was straight arrow solid, no shimmy for two years, then out the blue it developed a head shake....I tried everything, new wheels, other forks with different offsets, frame & fork alignment, head set replacement, different riders of different sizes, etc., etc... All to no avail. We hung it up in disgrace for about 4 years. Then, as a what-the-heck, we took it off the hook, built it with hang-around-the-shop components, and viola!, the shake was gone! Figure that one out!!
We just had a customer/CR member/ friend Gary Kling have his older Waterford built oversized Paramount do exactly the same thing. It rode great for who knows how many years, then start shimmying.. We went through the entire rigmarole, finally sent it back to Waterford to be checked & it came out clean!
So I don't believe ANY of you! :)
Dale Brown
cycles de ORO, Inc.
1410 Mill Street
Greensboro, NC 27408
336-274-5959
fax 336-274-6360
http://www.cyclesdeoro.com
http://www.classicrendezvous.com