I have a 92 FXR and a major vibration problem when I back off the throttle.I did not have this problem untilI installed Vance HInes Big Radius pipes. Even went back to the old pipes to try it and it went away.Could this besome sort of a back pressure problem?Ive replaced the front rubberengine mount and the stabilizer links, and re aligned the bike. Still have the problem. If Itightenthe front link (take the engine out of alignment) the vibration isnt as badbut the belt is then out of alignment.Im at a loss with this thing. PLease help!

 

I have an fxr rubber mount style pro street, an when I had shorter pipes on it, (short shots), it vibrated a bit more. When you think about it, the engine/trans assemble pivots on the swingarm bolt thru the trans as it vibrates. The longer your pipes are, the more of a counterweight (dampening) effect they have. That being said, what type of mount do the big radius pipes have? Are they tied to the trans, or the chassis?