The max lvl is lvl 115 with 50 transcendence lvls. These transcendence lvls increase your equipment carrying level so the max equipment carrying level is 165.

Having said that you can safely lvl refine to -32 (get to 29 and do a -3 refine). So your lvl 140 crossbow can be equipped at lvl 108 but it would cost a lot more than just lvling up.