Just info. I have the Saturn aluminum seat base. I also have the Wise seat that 99 shows. The seat sits very close to the tube and after you run awhile the base shifts and you can't swivel the seat as it is to close to the tube. I purchased a different Wise seat that has the same cushion area but doesn't have the plastic base sticking out. Leaves a lot more room for the seat to swivel. With the other set up I had to air down the tubes and shift it over. Haven't tried the new seat but sure I won't have that problem.