SRAM Eagle Cracked Chain Plates

[ChrisF]

 

BUT... we make key-rings of the excess chain (when shortening it) and then hang them on keys ]

 

 

Off topic ...

 

How do you stop the links from rusting ?

 

 

PS . Nice key ring ????

[RocknRolla]

Keep your keys dry

 

sorry, forgot you guys are by sea.

Edited May 23, 2020 by RocknRolla

[snutkin@gmail.com]

Chains definitely do stretch, the also wear. Two seperate things. I know what I said, and I know how a chain checker works. I used the term "allowable" for lack of a better term, that's why it's in parentheses.

 

Lockdown seems to be getting to people. You're getting way too emotional over a comment made in a bike forum.

 

"Riders often speak of "chain stretch," a technically misleading and incorrect term. Chains do not stretch, in the dictionary sense, by elongating the metal by tension. Chains lengthen because their hinge pins and sleeves wear. Chain wear is caused almost exclusively by road grit that enters the chain when it is oiled. Grit adheres to the outside of chains in the ugly black stuff that can get on one's leg, but external grime has little functional effect, being on the outside where it does the chain no harm."

 

https://www.sheldonbrown.com/brandt/chain-care.html

[Rigardt@Scott]

"Riders often speak of "chain stretch," a technically misleading and incorrect term. Chains do not stretch, in the dictionary sense, by elongating the metal by tension. Chains lengthen because their hinge pins and sleeves wear. Chain wear is caused almost exclusively by road grit that enters the chain when it is oiled. Grit adheres to the outside of chains in the ugly black stuff that can get on one's leg, but external grime has little functional effect, being on the outside where it does the chain no harm."

 

https://www.sheldonbrown.com/brandt/chain-care.html

Chains lengthen because xyz....

 

So they stretch. FFS, now you are just nitpicking.

[Captain Fastbastard Mayhem]

 

Ok, let me explain…. 

 

I am not disputing that a chain tool measures chain stretch as a percentage of overall chain length, and I am not disputing that it is 0,25%, 0.5%, and 0,75%.

 

Some context…. A while back I was going through GX Eagle chains very quickly, and some people on the hub were making big claims about the life span of XX1 chains. I decided to try that, and for curiosity’s sake I wanted to measure how the chain was stretching accurately. So here is what I did, which should explain my initial post a bit better.

 

I replace my chains at 0.75% - that is my “allowable” amount of stretch. To measure I take a vernier calliper, and measure the length from the inside of a roller to the inside of another roller with 10 links in between. For the sake of my explanation let’s say that measurement is 100mm on a new and unused chain. I then took a chain at 0,75% wear and took the same measurement, let’s say for this explanation that this measurement was 110mm, thus giving me an allowable stretch of 10mm. So, if the measurement reads 102,5mm that means I am at 25% of allowable stretch. When it gets to 110mm I am at 100% of allowable stretch, and it is time to replace. Again, I am just using these numbers to explain the concept.

 

As I used my new XX1 chain I take this measurement often, after a considerable amount of km, I am not even at 25% of allowable stretch.

 

Hopefully that clears it up?

 

On the stretch/wear thing. Chains can wear (degradation of the material) and stretch. Bicycle chains generally speaking stretch before the material degrades, and that’s why we measure stretch.

 

Okes really need to relax, this isn’t a foreign policy or religious rights debate. We’re talking about chains.

 

It's a sad indictment that you even needed to type this out, Rig. 

[Captain Fastbastard Mayhem]

"Riders often speak of "chain stretch," a technically misleading and incorrect term. Chains do not stretch, in the dictionary sense, by elongating the metal by tension. Chains lengthen because their hinge pins and sleeves wear. Chain wear is caused almost exclusively by road grit that enters the chain when it is oiled. Grit adheres to the outside of chains in the ugly black stuff that can get on one's leg, but external grime has little functional effect, being on the outside where it does the chain no harm."

 

https://www.sheldonbrown.com/brandt/chain-care.html

The chain's wear results in it stretching its overall length. Therefore, a worn chain can be said to have been stretched, and vice versa.

 

They are both acceptable adjectives to describe a change in the chain's length and life cycle. 

Edited May 23, 2020 by Captain Fastbastard Mayhem

[ChrisF]

Every hung a new chain next to an old chain, to quickly check the number of links for a quick replacement .....

 

 

If the old chain did not "stretch" ... well then they sure as heck made the new chair shorter ....

 

 

 

I even heard an urban rumour that a new chain fits perfectly around a large chain ring .... while an "old' (heaven forbid I use the therm "stretched") chain actually is too long around the long curve, and is loose after the first few teeth .....

 

 

looking at the OP's photos .... "stretching" seems to be the wrong word to use .... rather seems like snap, crackle and pop...

[boesman88]

Indeed snap crackle and pop :-D

[DieselnDust]

 

Ok, let me explain…. 

 

I am not disputing that a chain tool measures chain stretch as a percentage of overall chain length, and I am not disputing that it is 0,25%, 0.5%, and 0,75%.

 

Some context…. A while back I was going through GX Eagle chains very quickly, and some people on the hub were making big claims about the life span of XX1 chains. I decided to try that, and for curiosity’s sake I wanted to measure how the chain was stretching accurately. So here is what I did, which should explain my initial post a bit better.

 

I replace my chains at 0.75% - that is my “allowable” amount of stretch. To measure I take a vernier calliper, and measure the length from the inside of a roller to the inside of another roller with 10 links in between. For the sake of my explanation let’s say that measurement is 100mm on a new and unused chain. I then took a chain at 0,75% wear and took the same measurement, let’s say for this explanation that this measurement was 110mm, thus giving me an allowable stretch of 10mm. So, if the measurement reads 102,5mm that means I am at 25% of allowable stretch. When it gets to 110mm I am at 100% of allowable stretch, and it is time to replace. Again, I am just using these numbers to explain the concept.

 

As I used my new XX1 chain I take this measurement often, after a considerable amount of km, I am not even at 25% of allowable stretch.

 

Hopefully that clears it up?

 

On the stretch/wear thing. Chains can wear (degradation of the material) and stretch. Bicycle chains generally speaking stretch before the material degrades, and that’s why we measure stretch.

 

Okes really need to relax, this isn’t a foreign policy or religious rights debate. We’re talking about chains.

 

 

 

 

People seem to be confusing a reading from a tool with an individuals personal Specification for Wear.

 

A 0.5% reading on a chain checker is a measurement. Its not a specification.

 

"I replace my chain at 25% allowable stretch" is a specification (although not ratified by a standards setting body as far as I know - I've checked the BS, EN and ASME)

 

Trying to get snarky with GM around his specification seems a little juvenile or maybe a bit cabinfeverish. More appropriate to ask what do you mean by jada jada blah blah blah or 

how did you arrive at jada jada jdad blah blah blah.

 

Depending on how the Specification is formulated the degree of wear can be expressed in different ways including change in mass, change in length, or even change in frequency ( higher grade chain wear measurement)

[boesman88]

More here... eish

 

https://singletrackworld.com/forum/topic/12-speed-gx-eagle-chain-woes/

[boesman88]

And here..

 

https://www.mtbr.com/product/drivetrain/chain/sram/gx-eagle-12-sp.html

 

This is clearly a massive problem with these chains. I suggest if you have a GX 12 speed chain on you bike you keep a close eye on it

[Rigardt@Scott]

And here..

 

https://www.mtbr.com/product/drivetrain/chain/sram/gx-eagle-12-sp.html

 

This is clearly a massive problem with these chains. I suggest if you have a GX 12 speed chain on you bike you keep a close eye on it

Another hubber posted on a thread yesterday about his chain doing the same. Not as many links as yours, but the same issue.

 

Personally I wouldn't take money out of my wallet again for one.

[snutkin@gmail.com]

 

Ok, let me explain…. 

 

I am not disputing that a chain tool measures chain stretch as a percentage of overall chain length, and I am not disputing that it is 0,25%, 0.5%, and 0,75%.

 

Some context…. A while back I was going through GX Eagle chains very quickly, and some people on the hub were making big claims about the life span of XX1 chains. I decided to try that, and for curiosity’s sake I wanted to measure how the chain was stretching accurately. So here is what I did, which should explain my initial post a bit better.

 

I replace my chains at 0.75% - that is my “allowable” amount of stretch. To measure I take a vernier calliper, and measure the length from the inside of a roller to the inside of another roller with 10 links in between. For the sake of my explanation let’s say that measurement is 100mm on a new and unused chain. I then took a chain at 0,75% wear and took the same measurement, let’s say for this explanation that this measurement was 110mm, thus giving me an allowable stretch of 10mm. So, if the measurement reads 102,5mm that means I am at 25% of allowable stretch. When it gets to 110mm I am at 100% of allowable stretch, and it is time to replace. Again, I am just using these numbers to explain the concept.

 

As I used my new XX1 chain I take this measurement often, after a considerable amount of km, I am not even at 25% of allowable stretch.

 

Hopefully that clears it up?

 

On the stretch/wear thing. Chains can wear (degradation of the material) and stretch. Bicycle chains generally speaking stretch before the material degrades, and that’s why we measure stretch.

 

Okes really need to relax, this isn’t a foreign policy or religious rights debate. We’re talking about chains.

 

 

Thank you. Understood. Please allow me to withdraw my previous comments.

[boesman88]

This is an update on the outcome of my Snap-Crackle-and-Pop ordeal.

 

 

 

It appears that the problem lies with the GX cassette and NOT the chain.  The cassette has a manufacturers defect - certainly the model I had (2018 stock).  When the chain is running on the 18 tooth cog, there are two adjacent teeth on the 16t cog that interferes with the chain plates running over the 18t ever so slightly.  The interference is caused by the shape of these two teeth and its (mis)alignment with regards to the others, placing it slightly closer to the adjacent cog on a cassette that already has very tight tolerances. This puts a force perpendicular to the chain while under normal pedaling tension which explains the occasional clicking sound at is catches the chain plates. (see my attempt at a picture to explain this)  Over time this causes the chain plates to fail under this undue stress resulting in snap, crackle and pop's.

 

The above is of course my synopsis of the problem - having read up a lot about alignment issues on the GX on other forums, checking out videos of the two mis-aligned teeth and noticing way excessive wear on the said two teeth on my own cassette.  This, plus 1. the agents requesting the chain AND the cassette for inspection (which was a bit puzzling at first), 2. the agents' original response which downplayed the issue from the get go and suggested wear and tear as the cause and 3. upon enquiring about the outcome of their assessment, I was informed by the workshop manager that SRAM was 'not happy with the middle part of the cassette'. 

 

Outcome - full replacement under warrantee. expecting the new bits to arrive tomorrow. 

 

Not quite sure what to make of this whole thing.  I still think SRAM is a great product but it does feel that this defect is being hidden from the general public, hoping people wont notice.  Had I simply replaced my chain with an XX1 without getting to the bottom of it, I would have wasted that money too.  

 

If you are now worried about your own setup and that your warrantee might have expired - some people (I do not recommend this btw) have successfully modified their cassette's by filing the two teeth back ever so slightly (using dremmel or the like) to avoid interference with the chain running on the 18t. proceed with caution please when considering this as its an expensive piece of metal to test your diy skills.   

 

Good luck

Edited June 11, 2020 by boesman88

[madmarc]

Thanks for the feedback and explanation - interesting ! - I will be checking my GX setup for this 

[Rigardt@Scott]

This is an update on the outcome of my Snap-Crackle-and-Pop ordeal.

 

 

 

It appears that the problem lies with the GX cassette and NOT the chain. The cassette has a manufacturers defect - certainly the model I had (2018 stock). When the chain is running on the 18 tooth cog, there are two adjacent teeth on the 16t cog that interferes with the chain plates running over the 18t ever so slightly. The interference is caused by the shape of these two teeth and its (mis)alignment with regards to the others, placing it slightly closer to the adjacent cog on a cassette that already has very tight tolerances. This puts a force perpendicular to the chain while under normal pedaling tension which explains the occasional clicking sound at is catches the chain plates. (see my attempt at a picture to explain this) Over time this causes the chain plates to fail under this undue stress resulting in snap, crackle and pop's.

 

The above is of course my synopsis of the problem - having read up a lot about alignment issues on the GX on other forums, checking out videos of the two mis-aligned teeth and noticing way excessive wear on the said two teeth on my own cassette. This, plus 1. the agents requesting the chain AND the cassette for inspection (which was a bit puzzling at first), 2. the agents' original response which downplayed the issue from the get go and suggested wear and tear as the cause and 3. upon enquiring about the outcome of their assessment, I was informed by the workshop manager that SRAM was 'not happy with the middle part of the cassette'.

 

Outcome - full replacement under warrantee. expecting the new bits to arrive tomorrow.

 

Not quite sure what to make of this whole thing. I still think SRAM is a great product but it does feel that this defect is being hidden from the general public, hoping people wont notice. Had I simply replaced my chain with an XX1 without getting to the bottom of it, I would have wasted that money too.

 

If you are now worried about your own setup and that your warrantee might have expired - some people (I do not recommend this btw) have successfully modified their cassette's by filing the two teeth back ever so slightly (using dremmel or the like) to avoid interference with the chain running on the 18t. proceed with caution please when considering this as its an expensive piece of metal to test your diy skills.

 

Good luck

First time I have heard of this. That is a pretty massive oversight from Sram. I wonder if it is just a few batches, or all of them. Will check on mine tonight (but I'm a couple thousand km in without that issue), hopefully not the case.