On Thu, 08 Nov 2007 13:18:24 -0600, in rec.bicycles.tech A Muzi
wrote:

9/16" is highly unlikely. More probably 1" x 3/16". Either
locate/finance/acquire a chain or count on changing the cog. A standard
1/2" x 1/8" track cog fits most. Which brand/model hub is it?

It's a Bendix red band hub from the '50s or so.

I have a piece of 1/2" X 3/16" drive chain and it's not meshing!

Jones