On Tue, 3 Feb 2009 22:15:06 -0600, "KLC Lewis"
wrote:

I'm not asking others to make my decision for me; but why try to reinvent
the wheel ? The idea of newsgroups is to share experience, I assume.


Well, FWIW Harken uses Delrin sheaves in most, if not all, of their midrange
and smaller blocks, and at least many of their Big Boat range as well. I'm
not sure if they use metal sheaves at all any more. I've used their blocks
for the past fifteen years and have never had one fail on me. The delrin
cheeks will discolor over time, going from black to dark grey, but it
doesn't seem to harm them. I like Garhauer for their "all metal" policy, but
I have bought quite a few Harkens over the years and have never regretted
it. You can get them about anywhere there's boats, and there's a lot to be
said for that convenience.

When I was racing on big boats (50+ ft) most of the sheets and guys
had wire tails. With wire a metal sheave is absolutely necessary.