Doug,
Should you remove the "pants guard" you will discover that the piece does indeed serve a useful purpose. As you mentioned, there is a large difference in size between the 2 chain rings. The central, toothless ring helps guide the chain through that large gap and also prevents if from becomming jammed between the 2 toothed, chainrings.
Good luck,
Fred Rednor - Arlington, Virginia (USA)
> From: Doug Van Cleve <dvancleve@gmail.com>
\r?\n> Subject: [CR]What is up with these Nervar chainrings?
\r?\n> To: "Classic Rendezvous" <classicrendezvous@bikelist.org>
\r?\n> Date: Friday, August 1, 2008, 6:26 PM
\r?\n> Howdy folks.
\r?\n>
\r?\n> I just bought a Nervar crank, really for the arms as I want
\r?\n> to do a TA
\r?\n> chainringed triple. The chainrings on it, that I am pretty
\r?\n> sure are
\r?\n> original, are strange. Here is a picture:
\r?\n> <http://tinypic.com/view.php?pic=9bcebm&s=4>.
\r?\n> The big ring is a 54
\r?\n> (!) and the small ring a 40, an odd combo. The weird part,
\r?\n> in case
\r?\n> you can't see it very well, is that there is what looks
\r?\n> like a pants
\r?\n> guard for the small ring sandwiched between the big ring
\r?\n> and the small
\r?\n> ring. It (of course) serves no purpose whatsoever in
\r?\n> there. Anybody
\r?\n> know what is going on with this? Is it mis assembled?
\r?\n>
\r?\n> Doug Van Cleve
\r?\n> Chandler, AZ USA