I have been experiencing shoulder pain when riding more than 45 minutes straight. I am seeking solutions. I am 5'11" and ride a 2010 Surly Long Haul Trucker. It has a 56 cm frame and 700 c wheels. I have bad knees so I shortened the crank arms to 142 mm. Medically, I have had both rotator cuffs operated on so my shoulder issues are chronic. Last year, I replaced the stock handlebars with wider handlebars. The new bars are Nitto drop bars and measure 17.5 inches across on the inside. This helped but did not resolve the problem.
I would like to raise the handlebars to unload my shoulders when I ride. Unfortunately, the bike mechanics say the headset (correct part?) will not permit any additional elevation. I am not worried about aerodynamics, I just want to be comfortable and take some longer rides. What are my options for improvement?