I attempted to take a crank off of a friends bike who had used a pet Gorilla
to install his crank arms. Lucky he had steel crank bolts because it took
my 1/2 inch drive breaker bar and a two foot extension of pipe to get the
bolts free. I almost rounded one. It had not cracked the crank arms but
they had gone way to far on the spindle. When I attempted to put them back
on at the correct torque they worked. A few weeks later he came to me with a
new set of arms. It was just as difficult to take them off the second time -
the taper was destroyed even with correct torque they were history. This is
not as vintage but on my bikes I use aluminum crank bolts. I tighten with a
good sturdy steel bolt and my torque wrench. Then I remove the bolts. I
use red lock tight on my aluminum bolts (one reason they are in a Ti spindle)
and I just snug them in. I have not had to retighten them ever. (they had
aluminum crank bolts in the 70s so this is kind of vintage). When chuck
stated that automotive fasteners are replaced that is due to high torque -
imagine the torque load on a head bolt compared to a bike crank -- imagine
how much fun you would have replacing a headgasket (TWICE) and putting in all
new bolts because you scrimped on head bolts and used the old ones in your
car- How many of us replace the wheel studs every time we take a wheel off of
our cars. I reuse aluminum fasteners on my bikes and have for years never
had a failure. I can't imagine a steel crank bolt breaking because of reuse.
Sam D.