Join Date: Jun 2018
Location: Long Island, NY
R's are different than C's. The R's the nuts are part of the seat themselves and are inside the rails, the C's the seat bracket go outside the rails and the threads are part of the rails.
On my 1300R, I drilled through the rails (just opened up the hole), then drilled through the seat bracket threads to 3/8" and ordered the pin.
My suggestion on these R models DO NOT DRILL. Just find a pin that will fit through the rail bracket and the seat threads without drilling, it will just be smaller than 3/8". You can buy a few at home depot then return what doesn't fit.
I did the mod with my factory seat. I ended up getting a new ultimate seat, and drilled through the seat bracket and threads. I had 2 issues, 1 the bracket got so hot that it softened up the seat pan (making it rotate), and 2 one of the welded nuts broke off making it not work on the bike. I had to send my brand new (never used) seat back to Ultimate for a new pan and brackets. I had them pre-drill the brackets to 3/8" BEFORE they installed the bracket on the new pan. So now I have the mod and it works.
Could have all been avoided if I had simply used a smaller pin that fits without drilling.
With the R models, you need the welded nut on the seat bracket, because it is what gives the seat lateral support, without them, the pin will fall out.
Last edited by JPT; 04-11-2019 at 09:55 AM.