To Geoff in England

Dec 26, 2006

If you are experiencing vibration up to 3500 RPM, sounds like you may have excessively hard isolastic rubbers installed. About 15 or so years ago, there was a large quantity of newly built Norton isolastics in which the rubber compound was much too hard. These would dampen the vibration, but only after about 3500 RPM. I ended up with these hard isolastics in a couple of bikes and it nearly drove me crazy trying to figure out why. Problem went away when I replaced them with softer ones. About the only way to know for sure is to take them out a compare them with known good ones. You can tell the difference just pressing on them.