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[Closed] Are lighter chains a false economy?

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For a while now I have been using the KMC chains which have the holes in the side links. I have just measured the one on the MTB and the chain gauge says "replace me". I then started thinking about whether I am better off sacrificing the extra weight for a links that do not have a piece missing. Surely, this must make the chains stretch more quickly as there is less material?


 
Posted : 05/06/2015 7:11 pm
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The chain links don't stretch


 
Posted : 05/06/2015 7:12 pm
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Lighter chains? I just buy the cheapest!

I think Scotroutes is correct though. Chains do not stretch per se. They just wear around the rollers. The links shouldn't make a difference.


 
Posted : 05/06/2015 7:15 pm
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As noted they wear they dont stretch


 
Posted : 05/06/2015 7:19 pm
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They are already more expensive so they cant be a false economy... but that said it gets worse 🙂 Assuming that you use 6 chains over the life of a bike (you're replacing the bike every couple of years) then you'd pay in the region of £100 over those chains to save around 20g. Whereas you could use a cheaper, heavier and stronger chain (I find the hollow pin chains a bit fragile) and use that £100 to buy something more useful, like a nice set of carbon bars for example, which would save a lot more than 20g & improve your ride!


 
Posted : 05/06/2015 7:22 pm
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"The chain links don't stretch " - So if they don't stretch is it the rollers that wear?


 
Posted : 05/06/2015 7:31 pm
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Good excuse to quote from Sheldon's website: 🙂

The major cause of chain "stretch" is wearing away of the metal where the link pin rotates inside of the bushing (or the "bushing" part of the inside plate) as the chain links flex and straighten as the chain goes onto and off of the sprockets. If you take apart an old, worn-out chain, you can easily see the little notches worn into the sides of the link pins by the inside edges of the bushings.

[url= http://sheldonbrown.com/chains.html ]sheldonbrown.com -chains[/url]


 
Posted : 05/06/2015 7:35 pm
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£/g the worst place to save weight on a bike.


 
Posted : 05/06/2015 7:37 pm
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I had a wee foray into posh chains, main issue I found is that they bend easily if they chainsuck- I had my drivetrain basically explode on a muddy 10UTB lap, I ended up taking the chain off and straightening out a bunch of links at the side of the trail to get it going again

(on the plus side, they were easy to straighten too)

So I put the cheapo KMCs on everything now. Takes away any temptation to make them last too long, as well.


 
Posted : 05/06/2015 7:37 pm
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If you want to make your chain last then following Sheldon Brown's chain maintenance regime is vital.

[url= http://sheldonbrown.com/chainclean.html ]Do this once per week, or after a wet ride.[/url]


 
Posted : 05/06/2015 7:46 pm
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i did 15,000km on a KMC X10 DLC - cost me 70 quid,

seems like good value to me


 
Posted : 05/06/2015 7:52 pm
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If you want to make your chain last then following Sheldon Brown's chain maintenance regime is vital.

Brilliant!


 
Posted : 05/06/2015 7:53 pm
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Having a "light" bike is more a mind set rather than what makes economic sense. 20gms of your chain becomes part of the whole. All those little weight savings add up.


 
Posted : 05/06/2015 7:54 pm
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If you're a serious gram saver then there are grams to be saved on the chain... but since it's a consumable item perhaps not the most sensible place to sink money if you're not a serious weight-weenie.

...but like your wheels, there is more to the weight of the chain than what it contributes to the overall bike weight. There's something interesting to think about... 😀


 
Posted : 05/06/2015 7:58 pm
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The chain does stretch. I have just put the new sram against the old KMC chain and over the whole length of the chain the KMC for the same number of links is ~ 6-8mm longer than the new chain. If it was just the rollers that wore then the chains would be equal length.

I remember this was also the case when I replaced the kmc chain on the road bike with a new kmc chain. The old chain was slightly longer for the same number of links.


 
Posted : 06/06/2015 10:09 am
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The chain links don't stretch.

It's the inside surfaces of the rollers you've got to think about, not how the side plates are manufactured


 
Posted : 06/06/2015 10:17 am
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The metal of the links doesn't stretch, it's the pivots/bushings that loosen and the resulting play makes the chain longer under tension.


 
Posted : 06/06/2015 10:18 am
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flanagaj - Member
The chain does stretch. I have just put the new sram against the old KMC chain and over the whole length of the chain the KMC for the same number of links is ~ 6-8mm longer than the new chain. If it was just the rollers that wore then the chains would be equal length.

the chain isn't the same as the links though, you should find if you line up one ink against another, edge to edge is the same,do exactly the same with each link and they will al be the same, the chain as a whole will be "stretched though" as the pins/rollers wear, allowing the joints to elongate.

Side note though-how often do you end up changing chains? i gave up a number of years bak when i realised i was spending more on chain than anything else changing them five or six times a year - got about 3 months average in summer but well below two often closer to one in winter. A new XT cassette, chain rings (36 every time, 24 every other swap) and chain costs me about 90 every 18 -24 months vs 15-20 a chain, 8-10 times in the same.


 
Posted : 06/06/2015 10:23 am
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cheapo KMCs

I've seen new ones measure 0.5% worn!

I used to go cheap but there's something nice, psychologically at least, about a plated one that rusts less.

I'd love to read a proper thorough article about differences in cleaning, lubing, wear etc, I don't think anyone has done a comprehensive test.


 
Posted : 06/06/2015 10:49 am
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£/g the worst place to save weight on a bike

Carbon stems must be a strong contender


 
Posted : 06/06/2015 12:04 pm
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[quote=cynic-al ]I'd love to read a proper thorough article about differences in cleaning, lubing, wear etc, I don't think anyone has done a comprehensive test.I'm pretty lax with the chains on my own bikes but the ones at work get ruthlessly cleaned and re-lubed after every ride. It makes the bike look more presentable for the customer but I'm not convinced there's much difference in chain life as a result. We also change cassettes every second chain and rings every second cassette (though very few bikes get that amount of wear). What we're missing is data on how far each customer cycles.


 
Posted : 06/06/2015 12:13 pm
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£/g the worst place to save weight on a bike.

Not even close!

I've always used lightweight chains - XX1, X10SL, X9SL, PC89-Rs, all have been fine. SRAM claim their hollow pins are tougher, and as noted the plates themselves don't stretch.

More importantly, expensive/light chains are plated, so they stay looking shiny when you clean them!


 
Posted : 06/06/2015 2:40 pm
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I've seen new ones measure 0.5% worn!
I think you maybe right there! I think that is why I have been replacing them so often. Went with a SRAM chain today and the chain gauge only just squeezes in when set to zero.


 
Posted : 06/06/2015 6:49 pm
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The hollow pins fill up with dirt, or if you use dry lube, they fill up with dry lube.


 
Posted : 06/06/2015 8:50 pm