This is a custom chain tensioner I built from 16mm motion film projector parts. The bolt anchor shaft is 3mm wall steel and ground concave to fit the tube.

I bought the bike last summer for $150, because I liked the frame, spent the time to pull it apart, replace what needed. The bike sits @ $600, is super solid, simple, doesn't screw up, and there are not enough o's in smoooooth to describe the ride.

I did o.k. And I did most of it myself, with a little BF members good advice.
Thanks guys.