According to international standards ISO-9633, The length between 2 pins will be the main part for judging the chain’s stretch.

In some cases, some of the tools are measuring the length between 2 rollers. However, this may make a huge difference when you want to detect the chain still working or not. 

So what do we do? 

Method 1

Analogy- Using a Ruler for testing

All type of chain is using “Inch” as a basic unit. Each link length is 1 inch (length of 3 Chain bolt) and the length between the two Chain bolt is 0.5 inches.

The basic of the testing location is the middle of Chain bolt and we usually choosing 6 inches of chain to test the extension.

If 1% of the tensile rate will be over the standard, the chain needs to be replaced
If the length of stretching is more than 1/16 inches, this chain should be replaced as well.
If the length of stretching is more than 1/8 inches, we highly recommend that not only the chain but also the flywheel should be removed together.

Method 2

Transfer the chain to the outermost wheel then pull up from the middle of the tooth plate

If you can pull up the link, this chain or gear should be over scathing. In this condition, the gear and the flywheel group may also have been damaged, Both of them should be changed.

Please note that TAYA’s safe margin of chain stretch is between 0.4 to 0.8 percentage via park tool.

With good measurements can make the chain life longer. The longer the chain life maintains, the more joy of your riding could remain.