From:Joe McWilliams Electronic:jmcwilliams -A-
Subject:How much slack in the primary cahain? Date:Sat Nov 27 19:40:59 2010
My primary chain seems to have excess play. Not enough to come off the sprockets, but enough slack to make me worry about undue wear and sloppiness in the drive.

The up & down play measures about 1/2" half way between the sprockets.