Hi Andy, all. The internal ring is to make shifts smoother and keep the chain from jamming between the rings. Schwinn Sports Tourers came w/ these on their TA and i believe on the Nervar cranks as well so it might be a Schwinn proprietary part; not sure. Cheers. Billy Ketchum; Chicago, IL; USA.
----- Original Message -----
From: aruland1@tx.rr.com
To: classicrendezvous@bikelist.org
Sent: Friday, January 21, 2011 10:10:24 AM
Subject: [CR] Curious about this part
The part is a TA Pro 5 Vis ( cyclo-touriste) chain ring set (54,40) with an outer chain guard and another alloy ring between the toothed chain rings. Pictures: http://www.flickr.com/photos/andyruland/5375088153/in/set-72157625748841959/ I have used TA cranks in the past but have never seen this configuration nor can I find any reference to it at several sites. Perhaps someone in the group can shed some light. Thanks Andy Ruland