Not sure I can answer your questions, but.................
The one I have was on our tandem when we got it. It's purpose was to connect the child stoker cranks to the regular stoker cranks on the timing chain side. I'm not sure that was the best of all possible ways to solve the problem, and as we don't need a child stoker all that mess got pulled anyway. But if anybody needs one and would like to trade for something more useful there's one available.....................
On Nov 11, 2006, at 1:05 PM, Bob Hanson wrote:
> I noticed an odd item from a current eBay auction (item 300047623057).
> Here is a photo from that auction page:
>
> http://i17.ebayimg.com/
>
> 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
>
Gene Powell
Rad Finishes
Portland, OR
USA