Chain failure advice ?

Stringybark

Likes Bikes
Relatively new Scott Spark 740 XT equipped 2x11...broke chain at less than 300ks
Relatively new Scott Spark 900 Sram XO1 equipped 1x12...broke chain at less than 400ks
Chains lubed approx every 2hrs, never ridden in wet or mud, rider's an old dude.
What the hell is going on !!
Any advice with regards to replacement chains etc would be greatly appreciated.
 
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Stringybark

Likes Bikes
Thanks for the reply creaky & Ackland,
I purchased the bikes new so the chains were original equipment.
All the riding with these two particular bikes has been on my local 25k singletrack.
I've ridden it 100's of times & know it intimately so there's no shifts underload.
I have other bikes in the shed with 3,000-5,000ks & still with the original chain.
However, these older bikes are 3x9 & 3x10 so I suspect that the newer narrower chains are just not 'up to the job'
The chain side plates have broken near the pin on one side & half way along on the other.
The chains have broken while riding slowly up hill (not when shifting)
On a practically new $6000 bike you wouldn't think a 70yr old could break a chain if he tried :)
 

Flow-Rider

Wheel size expert
A couple good pedal strikes can spread the links and then cause the chain to split when it's under load.
Some of the OEM chains can be a bit dodgy too I've found.
 

rowdyflat

chez le médecin
As chains get narrower there is no way they will be as durable . 5 and 6 speed chains lasted for ever.
The 10-12 speed chains have narrower plates.
The manufacturing must have closer tolerances and the pins are much harder to push out than 9 speed.
Chains generally break with a side load but this shouldnt happen with yours and the 1x 12 doesnt have a front derailleur.
I guess it just must be dodgy OEM chains that Scott puts on bikes to save a dollar ?
Do you have problems with ghost shifting where the chain moves onto a smaller cog at the back due to suspension travel altering cable tension?
 

Daniel Hale

Likes Dirt
yep had problems with near new st 11 spd chain myself, broke it twice in 2 months, went back to 10 spd, may have just got a bad one?
 

Oddjob

Eats Squid
Sram chains are shit. I haven't had much luck with Shimano either. Wipperman Connex for my lard ass with Kmc a close second.

Sent from my SM-G900I using Tapatalk
 

wkkie

Eats Squid
Been using kmc on my bikes and the mates bikes that I look after too and had zero issues. Good value, quiet and long lasting.
 

ozzybmx

Likes Bikes and Dirt
I've broke a few, KMC are prob my favourite, to be honest, broken chains vs stretch are blah blah. I have broken more chains on singlespeed than geared so shit shifting may be out of the question, I broke the most when I started riding so technique is definitely a factor, I have not broken a chain in the last 5 years but I am absolutely anal about changing at 0.75. In that time I have ridden mostly sub $10, Sram 1011 chains before the Geo-blocking took that away from us.
 

Nambra

Postmeridian
I have to say, I hope I’m still capable of riding, let alone breaking chains at 70 - I salute you @Stringybark!

In my limited experience with Eagle, it’s the cassette that’s the weaker element, psticularly the GX (50t cog is made of cheese). X01 isn’t cheap, but it’s streets ahead in terms of performance. I’ve not broken the OEM chain, but has Scott specified OEM chains on your bikes or an aftermarket brand like KMC?

I’d even be tempted to make a warranty claim, if there were no specific events contributing to the broken chains. It sort of sounds like manufacturing defects, as @Daniel Hale suggests.

Side note, SRAM looks to be releasing SX Eagle soon, at a lower price point than NX, and 200g heavier. Lots of lower spec new bikes will end up with it I’d imagine.
 

ForkinGreat

Random Krishna
Thanks for the reply creaky & Ackland,
I purchased the bikes new so the chains were original equipment.
All the riding with these two particular bikes has been on my local 25k singletrack.
I've ridden it 100's of times & know it intimately so there's no shifts under load.
I have other bikes in the shed with 3,000-5,000ks & still with the original chain.
However, these older bikes are 3x9 & 3x10 so I suspect that the newer narrower chains are just not 'up to the job'
The chain side plates have broken near the pin on one side & half way along on the other.
The chains have broken while riding slowly up hill (not when shifting)
On a practically new $6000 bike you wouldn't think a 70yr old could break a chain if he tried :)
Do you have a quicklink on your chains or do you have to use a chainbreaker to take the chain off?

both bikes are Scotts, did you buy them from the same dealer? if so, maybe they were in a hurry slapping the bikes together, or it was the work experience kid installing the chains. eg too short or didn't istall the pin properly (if not using a quicklink)

another recommendation for KMC chains, got 11spd ones on both 1x11 bikes.
 

Flow-Rider

Wheel size expert
The Scott Spark 740 XT has a KMC chain from new AFAIK. I've seen two of the OME KMC chains split randomly but never an after market one.
 

Stringybark

Likes Bikes
As chains get narrower there is no way they will be as durable . 5 and 6 speed chains lasted for ever.
The 10-12 speed chains have narrower plates.
The manufacturing must have closer tolerances and the pins are much harder to push out than 9 speed.
Chains generally break with a side load but this shouldnt happen with yours and the 1x 12 doesnt have a front derailleur.
I guess it just must be dodgy OEM chains that Scott puts on bikes to save a dollar ?
Do you have problems with ghost shifting where the chain moves onto a smaller cog at the back due to suspension travel altering cable tension?
 

Stringybark

Likes Bikes
No ghost shifting, both bikes shift flawlessly & to date there's been no stick, stone or roo carcass bone caught up in the drivechain componentry.
ForkinGreat….bikes were from different dealers, quicklinks, have not been off bikes (until they broke)
With regards to bike assembly, the biggest mistake I make when buying a new bike is to ask them to double check everything twice as I live a 5hr drive from the bikeshop. This pretty much guarantees something will have dropped off it before I get home.
 
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Stringybark

Likes Bikes
I have to say, I hope I’m still capable of riding, let alone breaking chains at 70 - I salute you @Stringybark!

In my limited experience with Eagle, it’s the cassette that’s the weaker element, psticularly the GX (50t cog is made of cheese). X01 isn’t cheap, but it’s streets ahead in terms of performance. I’ve not broken the OEM chain, but has Scott specified OEM chains on your bikes or an aftermarket brand like KMC?

I’d even be tempted to make a warranty claim, if there were no specific events contributing to the broken chains. It sort of sounds like manufacturing defects, as @Daniel Hale suggests.

Side note, SRAM looks to be releasing SX Eagle soon, at a lower price point than NX, and 200g heavier. Lots of lower spec new bikes will end up with it I’d imagine.
It's a pity the 50t cog is NOT made of cheese, then at least you could eat the bastard...what is its purpose ? I thought it may have been put there for 70yr olds but mine's never had the chain on it...buggered if I know ?
 
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