Tony, Don't know how helpful this might be but I was experiencing shimmy on my 60cm saluki, I tried a number of things to fix it, including a needlebearing headset (which helped i think). But the biggest change was when i swapped out the cockpit from a 90mm stem to a 100mm stem. Shifting a bit of my weight (240lbs) forward over the front wheel reduced the hands on shimmy more than anything else. With a load in the front basket and hands off, there is still a bit of wagging from the handlebars, but more like the wagging of a dog getting petted, than oone being taken outside for a walk.
Sky in New west On Tuesday, August 23, 2016 at 9:46:05 AM UTC-7, Trenker wrote: > > > > Last summer I was on a short bike trip thinking to myself, during that > time on the bike when you have lots of time to think, that I have never > been bothered by shimmy on any bike that I could remember. The same morning > I kept hearing a knocking sound while pedaling or gliding at low speed, > which went away when I put both hands lightly on the handlebar. I gradually > figured out it was the fender knocking against the tire, and I realized > that I had always experienced shimmy, but never realized it or been > bothered much by it. This is on a 66 cm Toyo Atlantis with rear panniers > and a front basket. The same morning I was having the prolonged impression > of how much I liked this bike for touring. > > > During that trip I had enough time to experiment and ponder the shimmy, > and I realized that it only happened at low speed, and that at higher > speeds, eg. descending on asphalt or gravel, the bike was rock solid. Which > is a nice concession. > > > I think shimmy can be finely tuned in or out of a bike. Going to a > slightly narrower tire can improve things, as can pumping up the front tire > to the same adequate pressure as the back; it isn’t written in stone that > the front tire has to be at a lower pressure. > > > Even the road surface can affect or initiate shimmy: it looks flat but > there are subtle undulations caused by car tires; they are a lot more > obvious on gravel roads, before or after intersections. > > > If you are tweaking your setup to reduce shimmy, you can test it at home > by standing beside the bike and rapping the side of the handlebar with the > heel of your hand: you will be able to see if the vibrations focus on the > front end ( shimmy ) or condense around the back end of the bike ( ideal, > which I now have with a small basket on front and saddlebag tied to a small > home-made rear rack.) Tomorrow morning I head out on another short trip and > I’ll have plenty of time to see how I like this setup. > > > I suspect that tall riders on big bikes probably always experience a > certain amount of shimmy, as well as a certain amount of frame flex, but we > are used to it and don’t know any different. I wonder what size your > Atlantis is? > > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
