At what % chain stretch do you replace your chain?

[Louis]

A while back I bought a Park CC-3 chain wear indicator. I’m approaching a decision point because soon my Shimano 9-spd chain will reach the 0.75% stretch mark. Park says the following:

“A worn chain shifts poorly and wears sprockets at an accelerated rate. The CC-3 is a "go, no go" gauge designed to accurately indicate when a chain reaches .75% and 1% wear, the points at which most chain manufacturers suggest replacement.”

For those of you who use this tool or something similar, when do you replace the chain, 0.75% or 1%?

Thanks
Louis

[palincss]

Chains are much cheaper than cassettes. I believe if you replace the chain at the first "no-go" indicator the cassette will last longer & stand a better chance of avoiding wear than if you want until it reaches the 2nd "no-go" indicator.

[gasman]

I change at .75%, chains are cheaper than cassettes.

[Lincoln]

I always prefer to err on the early side.

[toaster]

One percent wear when chain is measured over 12 inches is .1200"

1/8" as a decimal equivalent is .1250"

75 percent wear is .0900 or about 1/11th"

The go no-go guage is a simple and easy way to go. I'd replace at 75% because I've let my chain on a mountain bike get to one percent and it was pretty sloppy.

On my Campy chains I use a dial caliper and replace according to Campagnolo's own specs which are more conservative than the the Park tool's 75%.

[toaster]

BTW, I got thinking today about cleaning a chain in an ultrasound machine that you can find for small parts cleaning and came up with a alternative that works for me instead of buying another device.

I already own a vibratory cleaner used for cleaning rifle and pistol brass with corn or walnut media. I put a Rubbermaid plastic container with the dirty chain and solvent in it pop on the lid and place it in the machine amongst the media and turn it on. No leakage and it works great.

[Dave]

by Campy. That's 1/16 inch per foot or 1/4 inch in four feet.

Any of the chain checker tools that measures over a short 5-6 inch length and includes the rollers at each end in the measurement will be LESS accurate than a good 12 inch scale. Lay the scale on the edge of a pin. The pin at the opposite end will be completely covered when the chain is new. When 1/2 of this pin is exposed, you're slightly beyond the 1/16" per foot recommended length.

For those willing to expend a little extra maintenance effort, it is possible for a 10 speed chain to easily last 5-10,000 miles.

[Ti Designs]

In season I change my chain about once a month, 6 weeks on the outside. Given the cost of an Ultegra 9-speed chain, the amount of time it takes to clean it and the amount of chain wear, it just makes sense. I have a set of cassettes from 11-21 to 12-25 which I know will keep working and I never have to worry about shifting performance due to chain wear.

In the winter months I ride a fixed gear with an 1/8" chain, I change that when it stops working or when the cog's teeth turn to points and start snapping off.

[pdxmech13]

.75 is the way to go.
I agree with Ti on chain
replacement and less cleaning :D :D