I own a K1300GT and a R1200GS Rallye, so I have both inline four and boxer twin engines. Never heard of nor never experienced a right side lean due to a shaft drive??? You would have to be spinning that shaft at incredibly high RPM's (much higher than a K Bike can generate) to torque a bike off it's center line, but I'm no engineer, just a rider with 30 + years of riding experience on every style made, chain, shaft, inline, v twin, boxer.... By the way, if you are looking for a nice bike to buy, my K1300GT is looking for a new home. :-)