Here's my version:
http://youtu.be/XB0U1pJ5QRg
I bolted a cog from an old cassette to a v-belt pulley that was the right size for my drive bar on the mill. Then ran an extra long chain from the cranks on the bike. The bike has long since lost any wheels, so I had to make a stand for it.
Love it. Great pic. So great. I'm in awe of your ingenuity.