>>2003731When ridden loose, or, after multiple installs, the taper of the hole on your crank arm will deform. Eventually cranks simply wear out. You can visually inspect this.
What can then happen is that after it's installed, the crank walks further up the spindle, and that causes the bolt to lose preload.
After you install square taper crank arms, you should check the bolts are snug after 2-3 rides. Don't try to re-torque it, just check they're snug with minimal torque.
People don't understand why the bolt looses preload, and so, will try to retighten it, or, consider threadlocker, but it's actually the crank arm walking away from the bolt, not the bolt loosening, so neither of those will work.
The other key is, when you install the crank, thoroughly clean the mating surfaces and very lightly grease the mating surfaces on the axle taper and the thread of the bolt. With a non-teflon grease.
This will allow it to be installed much more thoroughly. If the taper is damaged, a reinstall, which uses a lot of torque, can usually reestablish the taper.
You then want to just use 'a lot' of torque. It's basically as hard as you can with the relatively short lever of a 3/8 ratchet or a 8mm allen key. I don't think you need a torque wrench. It's not a torque wrench application for many mechs.
Lastly you may find a better fit with the arms in different orientations, so experiment with that a little if they sit loose before install.
>>2003731>just tighten moreawful advice.
Clean. Grease. Tighten.
