Well I installed my new 4 inch Rineharts on Thursday and put about 500 miles on them in the last couple of days.First I will say they sound great but my first impression was they were not very loud.After putting some miles on them I decided they were loud enough but not to loud.I installed them on my completely stock 2010 Ultra Classic.One concern I had was how little of clearance there was to the axle nuts.I decided to play it safe and replaced the 1/2 inch bolts with 1 inch and then used 4 small lock washers on each one.By doing this it moved the mufflers a 1/2 inch away from the axle nuts and everything seems to be fine.I will contact Rinehart at the first of the week and see what they say.I rode with 3 of my buddies that have the standard size Rineharts and couldn't tell any noticeable difference in the sound.My buddies said they liked the look of the 4 inch and that they sounded really good from behind.Overall I'm happy with my choice which was between these and Vance & Hines.

 

I too noticed the clearance issue, but I'm living with it. The crease, or dent that is put in for the nut clearance is half the length of the stock muffler. and if I would have put them on far enough for the axle nut to be in the crease, there was no more clearance to attach the rear mounts.

Other wise they look and sound great.

 

did you have to do the ecm calibration after you put them on