Originally Posted by
jonwvara
I seem to recall Jobst Brandt or someone sternly (he was stern about almost everything) advising against that. The idea was that the proper amount of torque at the initial tightening would push the arm onto the taper as far as as safe, and that further tightening later risked expanding it too much and causing it to crack at the corners of the opening.
Does anyone else remember that? Maybe I dreamed it.
But I think that loctite is probably a good idea.
I believe this is where you saw the Brandt admonishment.
Installing Cranks by Jobst Brandt
Back in the day, aluminum crank bolts used to be popular with the weight weenies. You would use the steel bolt to tighten the arm onto the spindle. Then you would remove the steel bolt and replace it with the lighter aluminum version, though torqued to a far lesser amount. I don't recall a deluge of loose or failed crankarms, despite the "loss" of pre-load caused by the lower installation torque of then aluminum bolt.