I've been using some heavy string gauges for a while now : .045 - .065 - .085 - .110 - .140. I can't really say it affects the bass neck more, then the standard gauge string that was on first : .045 - .065 - .080 - .100 - .130. I check the neck about three times a week and tweek it when I think I have to. But when does string tension becomes dangerous for the neck? Is it is you have a thin neck like an Ibanez SoundGear with heavy string gauges or if you up tune strings?