Probably the most explicit and shocking picture that I've ever seen of
block chain on an inch-pitch sprocket.
Not something to click on at work:
http://www.pbase.com/kayakbiker/image/27685419
Note the star markings around the rivets and how the holes go all the
way through the chain-ring.
Here's the whole shocking bicycle, showing its extremely large--er,
size doesn't matter.
http://www.pbase.com/kayakbiker/image/27685415
But if size _did_ matter, that's the equivalent of an 80-tooth modern
half-inch front sprocket on an ancient fixie:
http://i21.tinypic.com/a3m5fo.jpg
With an onscreen protractor, I get 135 degrees for 15 gaps between
teeth, or 9 degrees per tooth and 40 inch-pitch teeth. No wonder the
teeth are out nearly to the pedals.
Cheers,
Carl Fogel