Originally Posted by
larsalan
I hardly think that my cranks are loosening. A third turn is quite a small amount and I believe I have over torqued the bolts. How the hell would I measure torque on a #8 hex?
I am really bearing down to tighten them that bit as they are newly installed and I am fiddling w/ them.
You can accurately torque anything that you can buy a socket for, and you can buy a socket for an 8mm allen head bolt.
If you over-torque the cranks then you will 'stretch' the inside of the crank taper, which is as bad as riding with the cranks loose. Check the back of the spindle-hole in the crankarm to see if it is flat, or if the spindle has caused the edges to flare outward a bit. If the back of the hole is not completely flat then you have damaged the cranks.
In extreme cases, overtorquing can stretch the taper so much that the crank bolt will bottom out on the bb spindle before actually securing the crank.
Greasing the spindle or crank taper makes damage from over-torquing much more likely.