The Best Explanation of Chain Stretch

[RustySprockets]

Rob Jacob posted this vid earlier today, demonstrating the accumulation of wear that the cycling community has come to know as 'chain stretch.' Old news to many of us, but confusion still seems to rear its head from time-to-time. Chains don't actually stretch, you know...

 

[Karate Chicken Industries]

I've disintegrated rollers.

 

[RustySprockets]

I've disintegrated rollers.

Me too! I'm not proud of it, but I've squeezed every mile out of a chain or two. When a new chain gets shortened at the shop, I've been known to collect the leftover links. Hey--free chain.

 

[Karate Chicken Industries]

FTR, it's only been on 1x1 drivetrains.

"What's that clicking?"

 

[Kevin B]

When I searched for tools like the one in the video the descriptions often mention the tool works for chains on a specific gear range. Does it matter which wear checking tool/gauge you get for a 1/8 x 1/2 single speed chain? To me it seems 1/2" is 1/2" regardless of width.

Here is an example from Amazon -

"BIKEHAND Bicycle Bike Chain Wear Indicator Tool Chain Checker - Compatible with Shimano Sram KMC and All Others 7 to 12 Speed Chains"​

 

[MattiThundrrr]

The difference isn't length, it is plate thickness. 9 speed chains have a thinner outer plate than 7 speed to facilitate more cogs. A 9 chain will fit a 7 train, but it will be weaker, tend to stretch faster.

 

[Kevin B]

The difference isn't length, it is plate thickness. 9 speed chains have a thinner outer plate than 7 speed to facilitate more cogs. A 9 chain will fit a 7 train, but it will be weaker, tend to stretch faster.

Thanks for the clarification. After posting this I discovered some of the tools for thinner chains have tighter tolerances. So what you say makes sense.