tou can still use your own, built in, human windshear detection system. The criteria are actually given in the Fcom somewhere as to what a winshear looks like. If you've passes 100kts and are having big jumps in wind speed and speedtrend and the likes, you are rotally in a windshear scenario. Captain's judgement and worth balancing with the risks of a high energy STOP. but that's what you're payed for.