I have an original superfly and have been having a terrible time with my rear skewer. I am just starting to notice this now since I am riding 10 times more. I have gone through bontrager, salsa, and now hope skewers. If I ride anything over 10 miles my rear skewer will losen up to the point that my wheel become lose. Is this all due to frame flex? I am a bigger rider at 6'6" and 205 lbs. I thought each skewer was defective now I am thinking it may be the frame?