2011 Road Glide Ultra FLTRU purchased new and stock. Driving on a road that I have been on many times and at about 60 it felt like I got a blow as I started around a soft curve and ran off the road. A mechanic said this is a problem with these bikes and there is an aftermarket part that can be installed on the swing arm to stop this. First time this has happened to me. Anyone else have this happen? Thank you. RR