when will our pomelons[som-o] be ready.

after over 7yrs.we have a load of fruit for the first time.its my favourite just like a grapefruit.do they fall when ready,at the moment they are as big as a lump of elephant dung.but hanging well,so we have had to support those with 3-5 fruits on a branch.we do have a lemon tree whose fruit are as big as footballs,but they drop when ready,they make a fantastic lemon/lime drink.yet the pomelons are the best.