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carlfogel@comcast.net
12-31-1969, 08:00 PM
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