you can run the 6mm hexes, i do on some of mine, its obviously good to get the nut onto the nylock, but if you dont its not the end of the world, just check that they are tight each time. also when using the locking hexes, when you put them on, just tighten them a little, then put your wheel and nut on and tighten down, then remove the wheel, and tighten the hex. Its very hard to seat the hex otherwise, if you tighten it down to where you *think* it should be.