# Snapped Another Chain.



## BigSwede (Aug 25, 2009)

Hi everyone,
I'm new here on the forum,and was wondering how to solve the issue of snapping chains.I've been running a standard Shimano 9-speed chain on my 2005 Kona Coiler.I have snapped chains in the past,and in each instance,this has caused a nice crash!Can anyone recommend a good chain,or is it just me,that is the issue?Last time it happened was about three weeks ago,and I did a nice 20ft. nose wheelie before going over the bars.I'm a decent sized Clyde at 6'7" 280lbs.Any suggestions?Any Gorilla proof chains out there?


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## CaveGiant (Aug 21, 2007)

The clyde proof chain is the KMC-x9

I have used kmc x9l silver and gold and kmc x9sl gold. never snapped one.
I occasionally balk at the price of th kmc and go back to SRAM, I broke my last sram chain 3 times in a few weeks then bought an KMC-x9l and worn it out with no breaks.


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## tenbsmith (Dec 31, 2004)

I use the inexpensive SRAM 9-speed chains, haven't tried the KCMs.

Last time I went on a spell of chain breaking--broke several chains in a row--it was because other parts of my drive train had started to wear out.


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## watermoccasin (Jan 28, 2004)

My choice is the Shimano Dura-Ace/XTR CN-7701. Been running it for years with no breaks, after breaking several cheaper Shimanos and multiple SRAM power links.


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## mtnbiker72 (Jan 22, 2007)

You don't mention which Shimano Chain and if the appropriate replacement pin is used...but the HG93 (XT) or CN 7701 (XTR) chains are quite strong. And you can use a SRAM, KMC, or Connex connector with them eliminating the replacement pin issue. I would also second the KMC X9 as a great chain. All of these use center punched pins which have a much higher pull strength than the SRAM pins (350 kilo's vs 200 kilo's) on their PC 951 and PC 971.


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## drewdoeboy (Apr 29, 2008)

I use the SRAM 991 Cross step.


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## BigSwede (Aug 25, 2009)

mtnbiker72 said:


> You don't mention which Shimano Chain and if the appropriate replacement pin is used...but the HG93 (XT) or CN 7701 (XTR) chains are quite strong. And you can use a SRAM, KMC, or Connex connector with them eliminating the replacement pin issue. I would also second the KMC X9 as a great chain. All of these use center punched pins which have a much higher pull strength than the SRAM pins (350 kilo's vs 200 kilo's) on their PC 951 and PC 971.


Good point.Your right I didn't mention which Shimano chain.It is the Shimano CN-HG53 to be exact.I've never used a replacement pin,just put the existing pin back in place.Come to think of it,I have used KMC chains in the past,and can't say I've ever had an issue with one.Looks like I need to pick one up.Thanks


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## mtnbiker72 (Jan 22, 2007)

BigSwede said:


> I've never used a replacement pin,just put the existing pin back in place.


You just determined the problem...never ever reuse a pin on ANY 9 speed chain:nono:

I'd be willing to bet that is the EXACT point of failure. Either use the replaceable pins for Shimano chains or use a quick link. Carry an extra quick link on the trail, if you break a chain on the trail use the quick link to repair. Two quick links in a chain is still better than reusing a a pin.

:thumbsup:


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## jerjon7 (Jun 16, 2009)

i snapped my first one today, boy was i not happy haha


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## BigSwede (Aug 25, 2009)

mtnbiker72 said:


> You just determined the problem...never ever reuse a pin on ANY 9 speed chain:nono:
> 
> I'd be willing to bet that is the EXACT point of failure. Either use the replaceable pins for Shimano chains or use a quick link. Carry an extra quick link on the trail, if you break a chain on the trail use the quick link to repair. Two quick links in a chain is still better than reusing a a pin.
> 
> :thumbsup:


Okay,thanks for the info.I didn't clarify the fact that this was the first time I snapped this particular chain.So It might be hard for me to determine which link is the bad one now. After reading your reply,I think I will get a new chain for safeties sake though.I just want to stay wheels down.LOL!


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## BigSwede (Aug 25, 2009)

jerjon7 said:


> i snapped my first one today, boy was i not happy haha


Yeah it does suck.Hope you didn't wipe out like I do most of the time when this happens.


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## mtnbiker72 (Jan 22, 2007)

BigSwede said:


> Okay,thanks for the info.I didn't clarify the fact that this was the first time I snapped this particular chain.So It might be hard for me to determine which link is the bad one now. After reading your reply,I think I will get a new chain for safeties sake though.I just want to stay wheels down.LOL!


FYI-I just picked up an X9 from Cambria Bike for cheap a couple weeks ago

http://www.cambriabike.com/shopexd.asp?id=39100&page=KMC+X9+CHAIN


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## tenbsmith (Dec 31, 2004)

mtnbiker72 said:


> ...All of these use center punched pins which have a much higher pull strength than the SRAM pins (350 kilo's vs 200 kilo's) on their PC 951 and PC 971.


So you're saying the Shimano HG93/CN7701 and KMC chains all have greater pull strength than the SRAM 951/971? Or does that just apply to the Shimano? I've heard people say Shimano were stronger, but this is more than just opinion. Thanks.

Even the full retail price listed for that KMC chain seems lower than that of 971s and LX's.

I've got new 951 at home I'm gonna swap soon, but I'll be lookin' for one of the above mentioned chains next time around.


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## mtnbiker72 (Jan 22, 2007)

tenbsmith said:


> So you're saying the Shimano HG93/CN7701 and KMC chains all have greater pull strength than the SRAM 951/971? Or does that just apply to the Shimano? I've heard people say Shimano were stronger, but this is more than just opinion. Thanks.
> 
> Even the full retail price listed for that KMC chain seems lower than that of 971s and LX's.
> 
> I've got new 951 at home I'm gonna swap soon, but I'll be lookin' for one of the above mentioned chains next time around.


Yes...not only do the Shimano HG93 and CN 7701 chains have a higher pull strength...but so do the HG 53 and HG 73 (both of which are made by KMC) and all of the KMC 9 speed chains. The center punch pins have a higher pull strength than all the SRAM chains, including the PC 991 Cross Step. Sram is using the same pin type as they (and Shimano) do on their 8 speed chains. The problem is the 9 speed chains have thinner outer plates so while this pin type is sufficient for 8 speed, it is a weaker interface in 9 speed chains.

And I'm not a SRAM basher...look at my bike spec in my signature...its full of SRAM. But their 9 speed chains suck...I saw it when I worked on bikes and I've only broken two 9 speed chains and they were both SRAM PC-69 (now PC 971) chains. Yes, both were with less than perfect shifts but those happen occasionally and I've never had a Shimano or KMC chain break under those conditions.

:thumbsup:


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## WTF-IDK (Feb 23, 2009)

I snapped a Shimano HG93 chain earlier this year. 
I installed a HG73 in it's place because my friend had a new one on hand.
The 73 has out lasted the 93 so far.

I was thinking of getting two new chains and swapping them every other month or so.
Does anyone do this?

Will it make the drive train last longer?
Isn't most drive train ware caused from a worn out chain?
Two chains will last twice as long right?


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## tenbsmith (Dec 31, 2004)

That's all great info. I snapped chains a few times before I had much technical knowledge, so not sure which brand.

Being a man of 1,000 questions I have to ask:

Can describe or point me to a description of how the pins differ or explain a "center punch pin" and what SRAM uses?

I did a little googling and couldn't find it.


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## mtnbiker72 (Jan 22, 2007)

*Some pictures to help*



tenbsmith said:


> That's all great info. I snapped chains a few times before I had much technical knowledge, so not sure which brand.
> 
> Being a man of 1,000 questions I have to ask:
> 
> ...


OK, lets start off with SRAM. They use a pin system that came from their aquisition of the bicycle division of Sachs. It works very well with the thick side plates of 7 and 8 speed chains. However, 9 speed chains have the same internal width but have to be narrower so the side plates are what got thinner. Pin strength is now extremely important. Their standard pins are rated to 200 kilo's pull strength. Plenty for standard conditions under standard riders...but combine bigger riders and the occasion ill timed shift and IME, they're not up to par. Look at the picture, the strength of the pin is perpendicular with the chainline, but not uniform around the entire pin. I've actually taken several chains apart and the SRAM is only gripping the plate on each side of the center ridge.








Knowing this shortcoming, SRAM makes the PC 991 CrossStep (which offers no other performance benefits to the PC 951, 971, or standard 991). This increases the pin pull strength to 250 kilo's but its still not uniform strength around the entire pin.









Now look at the KMC X9 and the Shimano HG73 (made by KMC), the pin is center punched and flared evenly around the entire pin. This make the strength of the pin uniform and gives it a pull strength of 350 kilo's

















The weakness is if you push a pin out and then push it back in, you've flared the side plate and you have a weak spot. This is what the OP did on his HG53 and probably the spot it failed. I don't even like to use the Shimano supplied pin, I use a quick link. I've used a SRAM, KMC (which looks identical to SRAM's) and Connex (probably the strongest) link with Shimano and KMC chains with no issue. KMC chains come with their quick link so if you go that route your covered. I also recommend carrying an extra quick link so if you do break a chain on the trail, repairing with a quick link is stronger than re-using a pin.

I'm not advocating you go an ditch a new SRAM chain, and as mentioned before I am a big SRAM user on other parts of my bike. But if your going to spend money on a new chain, don't you want the strongest one for your money...especially if your a Clyde?

:thumbsup:

Edit 8/28...not sure why the pictures keep disappearing but I have continued this conversation on my blog if your interested with the pictures.


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## tenbsmith (Dec 31, 2004)

mtnbiker72 that was an outstanding post. Thanks.

WTF-IDK, I'm not expert, but I don't see how that would make your drive train last longer. The key seems to be removing the chain(s) when they get to a certain amount of stretch (designated as .75 on my chain measurement tool). If you add swapping you will still be running each chain until it gets to the level of stretch.


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## [email protected] (Dec 3, 2008)

hey, cheers for this, was looking at getting a new sram chain when i upgrade to sram x9 drive, but think i'll go for a kmc now
but whats the difference between these kmc chains? (apart from colour)
http://www.chainreactioncycles.com/Models.aspx?ModelID=25423
http://www.chainreactioncycles.com/Models.aspx?ModelID=12756
http://www.chainreactioncycles.com/Models.aspx?ModelID=25421
in particular the last one is an extra £10, is one worth any than the other?
cheers


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## mtnbiker72 (Jan 22, 2007)

[email protected] said:


> hey, cheers for this, was looking at getting a new sram chain when i upgrade to sram x9 drive, but think i'll go for a kmc now
> but whats the difference between these kmc chains? (apart from colour)
> http://www.chainreactioncycles.com/Models.aspx?ModelID=25423
> http://www.chainreactioncycles.com/Models.aspx?ModelID=12756
> ...


The last one has machined out inner links, making it lighter. Durability wise, they will all probably last about the same amount.

The other two just comes down to looks...if you like the silver color or not.


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## Nubster (May 15, 2009)

With the KMC having center punched pins, can you break the chain if needed with a standard chain tool?


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## rinseflow (Sep 18, 2007)

YBN heavy duty chain could be a good choice too if you can find one. CRC is all sold out on it:
http://www.chainreactioncycles.com/Models.aspx?ModelID=12073

Slightly heavier than your regular chains but I'm so far impressed by it. Used a KMC quick link to connect it and no problems with that. Maybe one of you bigger boys could dish out some real punishment on one of these chains so we'd really know if they're up to it. :thumbsup:


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## mtnbiker72 (Jan 22, 2007)

Nubster said:


> With the KMC having center punched pins, can you break the chain if needed with a standard chain tool?


Yes, but I would make sure you have a good one...the $5.99 special is not the best choice.


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