A bit off course, but a thought about Jack's observation why the gut/poly hybrid offers the least coefficient of friction:
Some would call this sliding/slipping situation a plain bearing. Plain bearings work best when one material is hard (poly?) and one is soft (gut?). When both are hard or both are soft, seizing or other bad things are likely to occur.
Wikipedia's article on "Plain Bearing" sez: "Often the bearing is made up of at least two constituents, where one is soft and the other is hard. The hard constituent supports the load while the soft constituent supports the hard constituent."
Perhaps one of the earliest successful plain bearings using soft/hard were early wheels with metal axles with wood hubs. Farm equipment and lots of other early machinery used this combo well into the 20th century.
So maybe hard poly and soft gut really do make a good combo for known reasons?
Last edited by WileyCoyote; 01-15-2013 at 06:12 AM.