+1
It's simple to get two hose clamps, a short length of pipe plus a male pneumatic quick release coupling to create a new hitch right on the chainstay, I prolly spent more money getting a piece of hose fitted to the female quick release than on the brass parts. If your hardware store doesn't have thick enough hose to press onto the female quick release, wrap some cut-down spokes in electrical tape and place them into the hitch hose to increase stiffness/reduce trailer oscillation.



Pneumatic hitch post
Pneumatic hose wear post
Pneumatic hitch fix post