I am running 15/45 on my L currently for commuting and road riding, etc... I also have the 48 when I do trail riding, and am able to swap them easily without major work. I notice that with 15/45 my bike feels buzzy around 70mph. Is this normal? And if I wanted to go to 15/42 would I need to take a link out of the chain...pain in the ass! Thanks!