I bought a Givi tank ring as i already own a couple of their bags using the tank lock system. Givi dont list one for the 2015 S1000RR but the a GS one fitted fine. The only problem was that although i fitted the smallest tank bag Givi do it completely affected the riding position. It forced my back to be upright when it should be naturally curved against the tank. It also meant that i was having to lean harder to reach the bars, I am 5'11" so no small fella. Although it appears only a small bag it was so uncomfortable that i had to return home and ditch it after a few miles.