martinori

Hello everyone, I'm new to mountain biking. Started last year with my new Norco HT 2.
But today morning when I was just installing and pushing pressure on a new pair of pedals on the ground. My chain brokes... I did not even use a lot of force.

At first, I thought it was some wear caused by impact or crash (I only had one crash). But later today I got a closer look and find out it has multiple links broken.
I just got the bike new at the end of last season. Only less than 200km on the bike. I'm only 160 lbs and I rarely shift under load.
Also, I maintain my drivetrain very well, clean it every 1-2 times of riding. I just don't understand how it can break in so many places.
See the picture attached, there are more than 10 breaking points. on Both sides. I marked them in red circles.

It is s KMC chain 11-speed chain, I suspect that there is something going wrong here. Please any advice or recommendation could be helpful. I don't want to keep breaking chains.

martinori

Sorry just realized I can't post photos yet.

jimc101

Where is the bike kept? anywhere that is close to any chemicals, pool cleaner or similar?, you say you clean it, what with?

Would be trying to identify what caused the issue, multiple links failing suggests something is corroding/eating away the chain, and eliminate this, then replace, as realistically more hassle than it's worth to try and chase any warranty for a relatively cheap consumable item that is used even though it only has a little use, it is as you say more than 4 months old, if not 16 months depending on when you purchased the bike last year.

FBOATSB 

Pic assist for new member @martinori !!!
Welcome aboard!

martinori

It was kept in my living room. So no cold and hot changes...And I used park tool cleaner to clean it. I'm thinking if some drive train parts could cause this. Like cassettes.
And the bike is about 10 months old. Purchased at the start of August.
Thank you by the way!

martinori

Thank you very much!!

FBOATSB 

I have never seen a chain crack up like that, so I can be of no help to you but there is a KMC rep that is a member here that occasionally chimes in (I can't remember their username). Pretty sure they would be interested to see this thread.

FBOATSB 

That's a very nice photograph by the way.

cxwrench

I've never in my life seen a chain fail like that. My guess is counterfeit chain.

jccaclimber

1. That’s a really clear photo.
2. That is not normal.
3. Unless you kept you chain hear a hydrogen source or an acid (which probably would have also rusted it), I doubt this was caused by anything you did.
4. I’m leaning toward a very uncommon manufacturing defect. While I would inform the manufacturer, I would also go buy another chain, change it out, and not worry about it. You might get a free chain from the manufacturer, but the real reason to report it is so they are aware of any potential batch/recall concern. A chain broken without warning can result in injury, just as a chain jumping off the gears can.

Edit: when you clean your chain do you leave it soaking in concentrated cleaner for a long period of time, or do you just clean it quickly, dry, the relubricate? Simple Green is the common villain, but soaking in cleaners that end up acidic will cause problems.

trailangel

Simple Green will do that.

Crankycrank

Papa Ado is the man and the correct spelling although the OP can't contact him through Bike Forums until he gets 10 posts....I think. Anyways, send KMC an email with a photo and see what they say. Could be counterfeit or just a manufacturing fart but KMC is very good with customer service. There was a rash of some KMC chains with this problem a few years ago but not heard any other problems since then.

Camilo

This is an interesting point. I've heard of Simple Green doing this, but I can't remember why. I hope OP responds to this point.

Shimagnolo

Back around 2005 or so, Wippermann had a bad batch of chains with stainless sideplates that cracked like that.

sweeks

I'm interested in how this works. A quick Google search seems to indicate that Simple Green is not particularly corrosive to metals. Even if it *were* corrosive, the links on that chain don't look corroded at all.

Shimagnolo

I've used Simple Green for years with an ultrasonic cleaner, on all kinds of bike parts, (including chains), and I've never had anything crack.

sweeks

The image looks much more consistent with a problem with the metal, irrespective of any chemical exposure. Could the cracks seen in the image have been caused by the insertion of the pins in the side plates? Perhaps the metal was too brittle.

trailangel

Not saying this is what happened to OP's chain, but people have experienced it happening.
https://www.velonews.com/gear/techni...imple-green-2/

sweeks

I appreciate that. However, correlation and causation are different things, and care must be taken not to conflate them.
In order for the Simple Green exposure to cause the failure in this case, it seems to me that would have to make the metal more brittle by a non-corrosive method.
This may be possible if the chain is immersed for long periods, but the OP used a Park Tool cleaner, which would only result in brief exposure.

martinori

That's good to know. I was worried something on my bike was not installed correctly...
And I only used park tool chain cleaner with their degreaser. And never soaked it. Actually, I never took off the chain. Basically, I spay it(not high pressure..), wash it with chain cleaner, and dry it with a mob, wait for drying, relubricate, remove excessive lubricates.

cxwrench

No, it won't. At least not in this case.

79pmooney

My first thought also. Long soakings of high strength steels does exactly that. (Don't know the chemical process. Engineering background but just sophomore metallurgy long before Simple Green.)

jccaclimber

We can debate the concentration and soak time, but the standard Simple Green can cause hydrogen embrittlement in steels, leading to this sort of failure:
https://www.doi.gov/sites/doi.gov/fi...SA_2000-01.pdf

Crankycrank

It may be that soaking in Simple Green can ruin chains, but the OP stated in post #20 that he hasn't used SG or soaked his chain in anything. There is some other issue going on here.

Darth Lefty 

That’s definitely a weird one. My suspicion if something like this turned up at work would be a problem with the batch of steel. It’s hardly your fault. Throw it away and buy a new one and forget about it. Unless you think the effort you were going to put in to get a $20 replacement chain is worth $20.