When I go on rides over an hour or two (highways mainly as I don't have any real mountain riding experience), my right shoulder starts getting a little numb and tense. I feel like I'm pretty loose on the bars and consciously try to stay loose. No problems with my left though, just the throttle side. I'm a young, decently fit, guy and I've never had any shoulder injuries. Any thoughts as to what the issue is? Has anyone else had this problem? Any advice would be appreciated. Thanks!