There are an whole number of links in one foot. That means if you lay a ruler so Zero is at the center of one rivet, the one foot mark should also fall in the center of a rivet. If you were stretched by exactly one inch, you were probably not stretched at all- just measuring incorrectly. How many links did you have in your 13 inch measurement? If I recall, there should be 24 links in 1 foot.

When you hear about a chain being elongated an eighth of an inch, the reference is to this "whole number of links per foot". Generally this equals about 1%. So a ruler is actually not a bad way to measure wear.

Other methods require a bit of money such as buying a new chain and compare them (never hurts to have a spare chain around) or a chain wear gauge. Park also has a chain wear gauge for about $25 with a "consumer model" coming out later this year for less than $10 (or so it says on www.biketoolsetc.com).

If you were really stretched a full inch, then a new chain would have almost certainly skipped on the cogs you have.

Unless of course, you knew that and you were just kidding with me <aw shucks>.

- Jeff