Looks like a VERY nice pedal extender to me.
The original rider may have had an injury to ankle or foot, or a congenital
condition that made it necessary for his/her foot to be farther away from
the crank so his/her foot could be angled more and still have heel clearance
to pedal.
There are other more simply made adapters that screwed into the crank and
then your pedal would screw into the extension.
They came/come in a few lengths to accomodate the problem one has.
This one with the bolts holdng it into place looks like a lot of very
accurate work so it keep the foot rotation even and not weaken the crank.
I think that what it is.
Ted Ernst
Palos Verdes Estates
CA USA
> Hi All...
>
> I've never seen a crank that has a pedal end like this one...
>
> What is the function of this design?
>
> http://ebay.com/
>
> Don Williams
> Woodinville Washington U.S.A.