Done a bit of research, the S is higher geared than the R and the GT from what I can make out. Want to keep it that way, planning some tours to euro Gp's. BMW did their usual trick and left a bad design running for way too long (twins had same) , they only fixed this on the 6-cyl and later twins. Problem is that only the inner spindle bearing is in the oil bath, the outer is dry (greased only) and subject to water ingress if the seal fails. My bike only has 28K miles and I've heard they can go that early. In my case its probably not been helped by a daily 60 mile commute which I did in all weathers, all year around. I also hooned a fair bit on bumpy Irish roads chasing mates on more suitable bikes (Tuonos, Panigales, Pikes-Peak Dukes). At 28k miles some of the box wont be worn out (backlash feels ok), so going to stick with lower mileage used boxes (if I could find them) or re-build mine. A K1200 box seems like a retrograde step. If I had time (I don't) would be looking to see if a K1600 box could be adapted, that would be the ideal solution.
By the way Chris, I loved your K1300 Sport, surprised BMW didnt carry that over when upgraded to the K1300 and fixed a lot of legacy issues. Then again, I like mixing and matching BMW stuff, once build for myself an E36 M3 touring. Proper sleeping car that was.
