the inner "guard" is a shift assist plate, for lack of an "official" name... i dont know the ref: # - basically helps move the chain across that big 42 > 54 jump...
theres a picture of one separate from a chainwheel set at
http://www.blackbirdsf.org/
-joel
>I came across this on eBay (but, of course), and wondered if anyone 1) had
>seen anything like it before, and 2) would explain the raison d' tre of it:
>
>T A old style triple crank right arm Item # 2172317848
><http://ebay.com/<blah>
>
>If you look closely at the two pictures, you'll see that there is an outer
>chainguard (which is not all that unusual). But look a little closer, and
>there's another(!) "chainguard" on the middle ring.
>
>This setup seems quite odd to me, at least ...but I figure one of the CR
>list experts can/will enlighten me.
>
>In correspondence with the seller, he didn't know what it was for either;
>he'd acquired the crankarm & rings as shown, as part of a lot.
>
>--- brandon davis ---
>-- sacramento, ca --
>_______________________________________________
--
joel metz : magpie@messengers.org : http://www.blackbirdsf.org/
bike messengers worldwide : ifbma : http://www.messengers.org/
po box 191443 san francisco ca 94119-1443 usa
==
i know what innocence looks like - and it wasn't there,
after she got that bicycle...