I have a double crank with the center guard. The guard is ramped (a beveled edge) toward the middle, or in my set the inner ring, and bolts to the "criterium" bolt pattern. It will definitely stop the chain from dropping between the rings. I will bring it to Cirque for show if interested. I thought it was interesting and that's why I have it.
David Stow
Jacksonville Beach, Florida
> 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/
>
> 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 --