dsbrantjr

+1, I would suggest flexing/bending the rack stay to eliminate the need for the spacer, which is acting as a lever and adding a bending moment. You might need to bend it further up.to bring the end close then bend the end parallel to the dropout. Then the bolt will be loaded in shear and will be much stronger. Use grease as a minimum, anti-corrosion agent like Tef-Gel preferably, on the threads to avoid the bolt seizing. Properly-designed and torqued bolted joints generally should not require use of thread lockers.