Hello Lister's! Got several parts that seem to be chain tensioners with Simplex jockey wheels. Here's pictures:
http://www.wooljersey.com/
Not sure how they mount, or what the application is. If you mount it in a derailleur hanger, the jockey wheel will be too far outboard to line up with a cog. Anyone know how this is used?
John Siemsen San Luis Obispo, CA