[CR]Stronglight 49D to TA cyclotourist... adapter?

(Example: Framebuilding:Brazing Technique)

From: "Bob Hanson" <theonetrueBob@webtv.net>
Date: Sat, 11 Nov 2006 14:05:51 -0700
To: classicrendezvous@bikelist.org
Subject: [CR]Stronglight 49D to TA cyclotourist... adapter?

I noticed an odd item from a current eBay auction (item 300047623057). Here is a photo from that auction page:

http://i17.ebayimg.com/03/i/08/ee/3f/d8_1.JPG

I don't understand the purpose of this device. Why not simply use a TA cyclo outer ring?

Would one use this to combine a TA inner ring with a Stronglight 49D outer ring... possibly by mounting this piece directly onto the "inside" of the crank arm flange?

To do that, you'd also need a special set of longer mounting bolts - or something would surely slip. Plus, you would also need sets of spacers to distance the chainrings appropriately inboard if you intended this as a mount for a third small inner ring. And, I suspect this would also create a VERY tight squeeze between the inside-mounted adapter and the bottom bracket cup if used just to create a hybrid double chainring crankset.

Can someone please explain how this was intended to function? I cannot imagine why this was made.

Bob Hanson, Albuquerque, New Mexico, USA