Dave Lowell said:And we can continue this thread when you need to put cranks back on the
unicycle. That should be a much more lively discussion (the hammer vs.
torque wrench camps can, um, hammer it out).
Good point. I used to be in the hammer camp but converted to the
torque wrench camp. My advice for mounting cotterless cranks:
Put grease on the crank arm and/or square tapers, and also put grease
on the threads. That makes sure that as much as possible of the force
you're applying goes into tightening the cranks. I.e. less wear and
more reproducible.
Tapping with a hammer? WARNING!! Only very light taps are OK. But as
soon as the nut engages enough of the thread, don't use the hammer any
more. The sudden force of a hammer blow is likely to cause haircracks
to arise near the four corners of the crank hole, and once this
begins, the cracks tend to grow due to the forces of riding and even
of tightening. It is the beginning of the end for your crank!
The crank nut is not easily overtightened. For most systems, the best
tightening torque is around 40 lbs.ft. If you don't have a torque
wrench, you can use a normal wrench of 1 foot long and lean on the end
with a weight of 40 lbs. Or a half foot long wrench and lean with 80
lbs, etc. This is probably not easy to do exactly, but it gives an
idea about how tight the nut should be. Alternatively, you can put the
uni on a bathroom scale. Use a non-digital one, because most digital
scales need a stable weight to display a value at all. Then orient the
wheel such that you push down vertically on the wrench. Don't push or
pull on the uni while tightening. Subtract the weight of the uni +
half the weight of the wrench for extra precision...
Klaas Bil - Newsgroup Addict
--
"Deflating pi does not reduce calories, it just concentrates them. - billham"