Here's my 1985 FXWG with a Mustang Regal Duke seat. It's very comfortable on long trips, my wife loves it. I usually put the stock seat on when I'm just boppin' around solo, because it sits lower.

 

Ingenuity at it's best! So, in other words...if it doesn't quite fit, MAKE it fit!
We've got a "Gunfighter" (I think that's what it's called) seat on that DH thinks is comfortable and we both love the way it looks; but my bum doesn't care for it much after an hour of riding...in fact my bum goes quite numb in protest! (Then I walk funny for awhile, scares children, quite embarassing)
We also have what could be the stock seat that looks like a tufted grandma couch...and like I said, I don't want to ruin our beautiful girl's sleek lines with, well, a couch! (Maybe a divan, but NEVER a couch ).
Plan for now is to wait until riding season is finished (and hunting season starts, maybe November) and then try various seats. I'm glad to know that some FX seats will work with slight modifications.
Once again, "Thank You!" to all you wonderful gents for taking the time to help my bum...gotta love Evo dudes!

 

That does look comfy! So, more likely than not, if it's any FX__ from '85 it can be made to fit our FXSB?! THAT makes a difference in searching for a seat!
Thanks!~

 

Not sure if you ever found a good cure for your "bum" problem.
I can make a recommendation but you will have to post some "bum" pictures for my recommendation to be valid.
The "ButtyBuddy" device may be the way to go. http://www.buttybuddy.com/

 

Thanks cromagnon- just so we're clear -
NO pics of my bum will be forthcoming!

Have been riding on the "gunslinger" seat without a sissy bar all season. Either my tuckus has waved the white flag and has decided to complain is futile, or I have lost all feeling in my bum. I can ride much longer now. Am still thinking about sending the seat out once riding season is over to have it worked on. But....(butt) what if there's a REALLY nice day in February?
Have I mentioned lately how great this forum is- how awesome all the EVO Dudes?
One more time then...

 

Seriously though, a friend of mine has a V-Rod and his wife was complaining about her sore rump. He purchased a ButtBuddy for her. Now I must say she has a fine derriere ... oh wait I was getting off track ... anyway she is enjoying the longer rides now.

 

I've seen the buttbuddy advertised here on the forum - I would really like to see it in person. Will check to see if anyone carries them locally. Thanks cromagnon - you only got a little sidetracked!

 

I have an 88 FXRS with a mustang wide regal touring seat we do long trips with no sore butt either me or the wife on the back

 

My Mustang Regal Touring Seat RULES! With the rider backrest, it's like a La-Z-Boy on wheels!

 

On the underneath of my seat,,,,"#6-F85 3WN/75463 fits 85 FX models and 85 and 86 FXWG w/ solid mount engines" of which the FXSB would be one of. Again, the best seat I've had, yet the Musang for an 07 EG I had was so so at best.
Good Luck