I’m finally return with results…
After my original post I was leaning to the Mustang Sport Touring One-Piece Smooth Seat, No Studs Harley-Davidson® FLHRS Road King. Part Number: 75858. I procrastinate and time goes by, my ass still hurts when riding 60 miles. Apparently, cussing about my ass hurting was easier than dealing with the issue. Then I finally decide to get the 75858 which is made for the FLHRS and I find out that Mustang stopped making it. Discontinued, just Great!
After talking to Mustang and a supplier I learned the Mustang Number: 75486 will fit. The only thing that was different was that the nose of the seat sits over the tank more. The seat was longer than the 75858. This was nice because it cover more of the wiring that’s coming out of the dash at the bottom.
This Mustang Number: 75486 One-piece sport touring seat FITS a FLHRSE3. It nicely covers the wiring at end of the tank and dash. It does move you forward about 1.5” to 2” forward and about 1.5” higher in the seat. That was a wake-up call at first. Everything about the bike seemed different being moved forward and higher some. My head sits slightly higher so I get more breeze over the windshield. It’s a slightly different stance sitting at a light. The ride is much more comfortable NOW!!! This seat just holds your ass in place. Even friends that wanted to try the new seat said the same thing. They liked how the seat just grabs a hold of your ass and keeps it in place. Friends that’s shorter than me, like the bike even more. It wasn’t like the original that sat very low, more back, and you slid around in the seat. When I sat in the old seat it rub on the right side saddle bag lid and side cover on the right. I’m 5’-10” and only weight 185 lbs. Sitting back more was very comfortable, but it’s what I got used to. Plus the seat was way too thin, that why my ass hurt at 60 miles.
Now after 6 months looks like I’m going to keep this new Mustang 75486 seat. I’ve gotten used to the feel of the new ride, because it is comfortable, and especially how it holds your ass in place. Plus, the wife is no longer complaining about the seat when she rides with me. I liked the sport style seat so I’m going to have the old seat custom recovered for a single rider. As you can see in the picture, the factory back rest doesn’t work right anymore. It sits back too far. I’m going to have it custom covered with thicker padding. This new seat is so comfortable that I haven’t really missed the back rest which I used to use all the time.
Hope this helps!