My weak link on my rides of (25 to 40+ miles) is a little muscle between my elbow and shoulder, kind of on the outside of the arm. I change my grip as I ride, but I think I would have a hard time finishing a 50 + ride. I have not been riding long, I just have one ride over 40 mile. Will this muscle get stronger or is their a chance I have my handle bars setup wrong? I have just been riding a new to me 2007 Trek 2100; 58cm for about two weeks, before I had an old mt. bike longest ride on it was 26 mile no problem. I’m 6’ 198 bought the trek from a rider that was 6’2” I’ve lowered the seat but left the handle bars the same.