I am working on getting an 883R this Spring and doing a Buell Headed 1200 conversion. I have been doing as much research as possible since this is to be my first HD. Question I have is.....In all the road test I have read on Sportsters is that the vibrate horribly over 70mph. I read on other threads that they will vibrate so bad that the mirrors break off. Is this true? I'm not looking for a touring bike, But I would like to think I could go on an ocassional 3-4 hour hwy trip without loosing any fillings. How fast can you cruise for extended periods of time?????