Honestly I am surprised to hear that yours has a weak detent. While this is usually true of actual hinderer knives the 0560 was actually designed as a flipper only. Even though it has blade stops that can act as a thumbstud the company has been clear that they didnt use them in the 560 for that purpose. Most of these knives came with a considerably strong hold to the detent. Did you purchase this knife new or was it used? The reason I ask is many people tend to tweak the lockbar on knives to adjust the action to their preferences and its possible that could have been done if you bought it second hand. Still I would think as long as you put the knife in your pocket tip up with the blade riding the inside edge of your pocket you have little to worry about. If however you want a stiffer action you can send it in to ZT and see if they can tweak it. Or you could do it yourself.
Another thing to think about is your knife may just not be properly aligned. If you look at the detent area when the knife is closed and see the lockbar is not sitting flush to the blade the ball might not be lined up with the hole. To try and correct this loosen the screws in the handle on both sides as well as the pivot screw. The pivot screw should only be slightly backed off. Then with the knife closed put pressure on the lockbar pushing the detent ball into the blade. While holding it like that tighten the pivot and handle screws back down. Hopefully any tolerance variance would have helped align the parts and allow the detent ball to grab. If not then a slight lockbar tweak is the next option. You would need to disassemble the knife and slightly (and I mean very slightly. Maybe a 1mm increase in bend of the lockbar if that, and this will increase its grip dramatically.
