I have the 2 up seat with backrest ordered for my new bike, but it's not due in until March. I'm told that the seat is specially made for the backrest, so it won't work on a standard seat...but I'm sure there are enough enterprising lads on this site that can "fix" that or know someone who can, as I'm sure there are adventurous upholsterers out there willing to take on such a challenge.