Old racer with 44 x 10 skip tooth gear
 

Someone with a better computer screen can get the true count but I think I am close.
About 118 inch gear. Not all that big, but thats a heck of a chainring.

http://www.ebay.com/itm/RACYCLE-MIAM...ht_7182wt_1025

The ad says (and I quote) the sprocket size is 13" and 40th which is a bit difficult to interpret, but maybe he means 40t x 13t?

Racycles were many decades ahead of their time, with cotterless cranks attached to a bottom bracket with a design is very similar to the current Campy design. This one is in pretty poor condition. There was one on my local craigslist a few years ago, which was complete and in virtually ridable condition (the tires held air) but I didn't go see it; the seller was using CL as an auction site and it gave me a bad taste in the mouth.

I think he means that the chainring is about 13 inches in diameter and 40 teeth? The rear cog is about a 9 or a 10 (I can't tell for sure which).

I'll guess 9, so 40/9 x 28 = 124-inch gear. Yowsah.

^Yeah, that makes a whole lot more sense than my theory. Nice.

A lot of Racycle advertisement copy is preserved; you see it on ebay and various bits are on the web. Somewhere I read that the large chain ring was intended to reduce the inefficiency of the chain; they were worried about the friction of the plates of the chain rubbing against one another, and the larger the chain ring, the less they rub. I know, that's kinda crazy. They were beautifully made bikes, though.

Here's that one I mentioned before. I'm kinda sorry I never went to look at the thing....