when refurb'ing crankups, I always find the bronze sleeve bearings in
the pulleys are worn and replace them. (along with the cables).
People here have noted the problem with finding the right size to
replace the whole sheave. (McMaster-Carr usually doesn't have it,
although they have the sleeve bearings, and SS retaining pins for the
axle if you need them). I've sometimes seen side wear on the aluminum
sheave, if the bearing was worn, because the sheave then tilts against
the steel housing.
I was searching around and happened to find a place that seems to have
the right smaller sizes, for example 3" O.D. by 1/2" wide with 1/2" bore
for 1/4" wire rope...for not a bad price. (comparatively).
http://www.esheaves.com/pdf/Steel_Cable_Sheaves_Catalog_2009.B2.pdf
top of page 2: Stainless steel with bronze bearing: $29
Now, I've been reading some stuff about nylon sheaves and how their
softness actually contributes to better wire rope life. Got me thinking
about how the softness of the more typically installed aluminum sheaves
might actually be a benefit, and whether SS sheaves might be a little
harder.
But based on the wear and corrosion I've seen on aluminum sheaves, SS
sheaves might make sense.
Has anyone used SS sheaves on a crankup?
-kevin
AD6Z
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