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My buddy got me thinking, your opinions?

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I was sitting down talking it up with my buddy the other day, I was in my garage adjusting chain slack. I said something along the lines of "Damn this chain keeps stretching." He then got a puzzled look on his face and said "Wait, if chains stretch then how do they still fit in the sprockets. Wouldn't they not line up with the teeth."

He said this and my mind basically exploded :jawdrop:

He makes a point, where does this slack come from?

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As the chain stretches, it also wears the teeth on the sprockets. The chain stretches just a little per link and it adds up with a lot of links.

That is why you always replace chain and sprockets as a pair.

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Chains do not stretch, they wear. The rollers on the pins elongate, making the gap between rollers increase. This is compensated by the teeth wearing to 'fit' the now wider gap. If a chain never wore, the sprocket teeth would only get deeper, not 'hooked'.

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I believe that the links of the chain do not stretch at all, but rather the rollers and pins wear out.

The cumulative effect is a loose chain.

If the sprockets look good, I just throw a new chain on the old sprockets -never had a problem doing this.

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The chains wears and the sprockets go round.

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Chains do not stretch, they wear. The rollers on the pins elongate, making the gap between rollers increase. This is compensated by the teeth wearing to 'fit' the now wider gap. If a chain never wore, the sprocket teeth would only get deeper, not 'hooked'.

a worn chain is longer than the same link size brand new chain. chains do stretch

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a worn chain is longer than the same link size brand new chain. chains do stretch

No they do not stretch. They wear. The rollers wear inside, that enables the link pins to be looser.

A new roller has a ID like this : o A worn roller is like this:O The distance from the center to the inside of the roller increased. Making the over all length of the chain longer.

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No they do not stretch. They wear. The rollers wear inside, that enables the link pins to be looser.

A new roller has a ID like this : o A worn roller is like this:O The distance from the center to the inside of the roller increased. Making the over all length of the chain longer.

He's right^ but the act of the chain wearing makes it longer thus stretching. Like when you stretch, your muscles and ligaments get longer allowing you to put your leg behind your head. As does the chain, get longer. It's just like a kind of saying. Like every scientist will tell you there's no such thing as suction. Only different air pressure zones. But no one is going to call suction cups, different air pressure cups. People are just going to say their chain stretched. You are completely correct. But you don't need me to tell you that.

Edited by Yz4481f

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No they do not stretch. They wear. The rollers wear inside, that enables the link pins to be looser.

A new roller has a ID like this : o A worn roller is like this:O The distance from the center to the inside of the roller increased. Making the over all length of the chain longer.

I am now a convert. Jeez William, why didn't you explain it that way in the first place?

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Chains do not stretch, they wear. The rollers on the pins elongate, making the gap between rollers increase. This is compensated by the teeth wearing to 'fit' the now wider gap. If a chain never wore, the sprocket teeth would only get deeper, not 'hooked'.

That would explain why my old chain is eating through sprockets :banghead: :banghead: :banghead:

Thanks for that pointer

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I was sitting down talking it up with my buddy the other day, I was in my garage adjusting chain slack. I said something along the lines of "Damn this chain keeps stretching." He then got a puzzled look on his face and said "Wait, if chains stretch then how do they still fit in the sprockets. Wouldn't they not line up with the teeth."

He said this and my mind basically exploded :jawdrop:

He makes a point, where does this slack come from?

All these posts are accurate. I've had the frustration of, "Damn this chain keeps stretching." My experience is that a loose chain is far better than a tight chain. A tight chain on my old Gas Gas hooked a brand new countershaft sprocket after one race, not to mention wear on the countershaft bearings. My chain clacking loose is better than this alternative.

To get the chain adjusted, I removed the shock so the swingarm would travel freely. I found the "tightest" point of the chain while the swingarm travels up and down, then adjusted the chain so it has no slack at this tightest point travel. This is the tightest I ever adjust my chain, and I just make a precide mental note of how this adjustment is measured while on the bike stand (3 middle fingers, no glove on).

Since adjusting the chain this way, I rarely have to mess with the chain because it's not overtightened, thus not stretching out, thus not needing more adjustment. Run a good chain with Ironman Sprockets and you can get literally hundreds of hours out of chains and sprockets, even riding nasty terrain in the woods (mud, sand, etc).

Maybe this is a little off topic, but it's my experience with chain wear. Keeping fresh, quality equipment installed is pivotal.

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No they do not stretch. They wear. The rollers wear inside, that enables the link pins to be looser.

A new roller has a ID like this : o A worn roller is like this:O The distance from the center to the inside of the roller increased. Making the over all length of the chain longer.

Chain wear is called "stretch", even though the chain is not literally stretching.

Edited by CamP

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Chain wear is called "stretch", even though the chain is not literally stretching.

Like being a 'Youthful 80 years old', it is a misnomer and promotes incorrect understanding. If people would say 'chain wear' (less letters too) there'd be a better understanding of what is going on. Stretch is the very last thing a chain does before it snaps and holes the cases. It is akin to people thinking race gas (non O2) will make them faster when in fact it merely enables a worked engine to survive. Wives tales and bad explanations promotes a lack of knowledge and understanding. Re-read the thread here and see how people literally think a chain is 'stretching like a rubber band'.

Chain wear makes it eaiser for people to understand why an over tightened chain wears excessively. It also explains to them why the sprocket teeth wear like they do.

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Like being a 'Youthful 80 years old', it is a misnomer and promotes incorrect understanding. If people would say 'chain wear' (less letters too) there'd be a better understanding of what is going on. Stretch is the very last thing a chain does before it snaps and holes the cases. It is akin to people thinking race gas (non O2) will make them faster when in fact it merely enables a worked engine to survive. Wives tales and bad explanations promotes a lack of knowledge and understanding. Re-read the thread here and see how people literally think a chain is 'stretching like a rubber band'.

Chain wear makes it eaiser for people to understand why an over tightened chain wears excessively. It also explains to them why the sprocket teeth wear like they do.

Even the chain manufacturers call chain wear "stretch". It's the accepted term to describe the lengthening of the chain as it wears.

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Even the chain manufacturers call chain wear "stretch". It's the accepted term to describe the lengthening of the chain as it wears.

That does not make it correct. It is an old wives term. A heart attack is not an attack on the heart, it is a severe muscle cramp. Beating on it releases the spasm and permits regular beating to resume. An attack is more related to a viral infection. The point being is the more poor verbiage is used, the longer people will not understand what is really going on and instead, jump to incorrect guesses/conclusions..

When I was young and heard the term, I could not fathom how a chain stretched. I did research on tensile strength and even some physics lab tests. No stretch, just catastrophic snapping. I spoke to the people at Duckworth (still in business???) and they gave me the skinny, which made perfect sense. A brand new chain squeezes the lube, so the first mile or two, the chain lengthens. Then there is a little more lengthening over the next hour or so of run time as the pins bed in the bushings. At this point, there should be no further changes in chain length until the chain is worn out, often a sudden lengthening due to exhaustion of the lubrication and sudden wear. This will normally happen prior to any significant wear on the sprockets (assuming a lubed exterior and an non-abrasive environment). As soon as a chain it technically worn out, it should be replaced. Though few do, they wait until the sprockets are ruined too.

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That does not make it correct. It is an old wives term. A heart attack is not an attack on the heart, it is a severe muscle cramp. Beating on it releases the spasm and permits regular beating to resume. An attack is more related to a viral infection. The point being is the more poor verbiage is used, the longer people will not understand what is really going on and instead, jump to incorrect guesses/conclusions..

When I was young and heard the term, I could not fathom how a chain stretched. I did research on tensile strength and even some physics lab tests. No stretch, just catastrophic snapping. I spoke to the people at Duckworth (still in business???) and they gave me the skinny, which made perfect sense. A brand new chain squeezes the lube, so the first mile or two, the chain lengthens. Then there is a little more lengthening over the next hour or so of run time as the pins bed in the bushings. At this point, there should be no further changes in chain length until the chain is worn out, often a sudden lengthening due to exhaustion of the lubrication and sudden wear. This will normally happen prior to any significant wear on the sprockets (assuming a lubed exterior and an non-abrasive environment). As soon as a chain it technically worn out, it should be replaced. Though few do, they wait until the sprockets are ruined too.

Maybe you should petition the chain manufacturers to stop using the term "stretch". LOL

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