I'm sure this has been explained here before, and I may have even read it and then forgot about it, but it occurred to me the other day that checking chain wear with a ruler is really, really easy.

Here's the deal: the rivet on a Shimano 10-speed chain is 3/16" in diameter, or 6/32nds of an inch. That means half the diameter is 3/32nds which, interestingly enough, is generally considered the maximum amount of acceptable "stretch" or wear a chain should have before it needs to be replaced.

So, if you take a steel 12-inch ruler and lay the first mark down the middle of a rivet, the position of the last mark on the other end of the ruler will fall somewhere between the left edge and the center of the corresponding rivet at the 12-inch mark. If the mark is anywhere to the right of the edge of the rivet, your chain is still good, as shown in the accompanying photograph. The yellow zone, in other words, is the "safe" zone.

This being the 41, we can and no doubt will argue vigorously whether or not the acceptable amount of stretch is actually 3/32 or 1/16. Moot point. Either one is easy enough to determine using this method.

Uh is there another way of checking? I thought this was just how it was done.

This works just fine and you don't need to buy an expensive tool.

If you want the expensive tool follow the link in my sig and I will source a really expensive tool for you.


Heck you may even have to fly here and foot the bill for hookers and blow. Wink.

The revelation to me was the size of the rivet and using it as a guide. I'd always eyeball the ruler and try to guestimate the amount of stretch, not realizing that the "zone" is obvious.

Is the measurement of the rivet the same as a Shimano 9 speed?

When I lived in Taipei in the mid '70s there were plenty of hookers, but no blow. Lots of pills, but apparently those didn't count as drugs. I think they executed an American for selling heroin around that time.

I don't have a steel ruler. What's Plan B?

Come'on kids - 12" from the center of one pin to the center of another. 1/16 of an inch outside of this and it's time to go shopping.

It ain't rocket surgery.

I always thought it was easier to line the ruler up with the edge of the pin rather than the center.

They still would.

Pills are still the rule.

They like speedy stuff here (like they need it!) or horse tranquilizers so they can drool on themselves.

Bin Lan is still king.

Tom-EH-to tom-AH-to.

Nice how-to post.

Oh, and you need to wash your hands.

Piejo
Long Life's
Taiwan Rum
Romilar
Normanox
"Green Pea" diet pills

We used to go down to Shimanding and load up on beetle nut for a little variety.

Taiwan beer is swill (like bud's any better!)
I don't smoke.
I like white liquors or tequila
?
?
New game in town.

Bin Lan is nasty and gives you cancer. No thanks.

I prefer green tea and a pick n, fry of ducks blood and chicken a-holes.

Borrow mine.
Drilled a hole in the ruler.
Clean then hang the chain.

So when the chain is new the rivets should be exactly 12" apart? Thats a nice coincidence.

The red bean popsicles were pretty good. I agree that the rest of it was pretty rank, but being teenagers, we really didn't know any better.

Nice use of gravity, TW. Looks like that chain's shot, by the way.

Hard to mess up with this and you don't need to take off the chain. Don't need to store 12" of ruler either.

Two nails side-by-side on garage wall,

Hang used chain on one, new on other. check the chain over its entire length.

I concur, the Park tool is a snap to use, costs $10, keeps things clean.

I like the metric system, what do I do now?

But, I already have a 12" ruler. So, I don't need to store another measuring device or spend $10.

If the background is skin then he needs more than soap and water. He needs an embalmer.

Garage would cost me $25,000

And doesn't require a wall...

Move to Russia, or join a commune?

Ruler, chain-checker, tape measure --- which one is in easier reach?