I just recently bought a 2013 NC700X and love the bike! The previous owner (my Uncle) replaced the rear 43 tooth with a 41 and I can comfortably ride at 75-78 on the interstate. I ride most of my time on the interstate or highways and was thinking of going to a 39 tooth for the rear for passing power at higher speeds. I know the DCT models had a 39 tooth which I am assuming would fit my bike. Has anyone gone with a 39? Opinions? Thanks!