Interested by this idea of hilly riding causing more chain "stretch". Chains don't stretch, they wear. My understanding is that it's the inner diameter of the bushings that increases due to wear with the chain pins.
So what are the main causes of wear? I guess that the force applied through the links is a minor one but the main one has to be the debris inside the contact points in the chain links
I use KMC chains and live in a very hilly area but try hard to keep chain and sprockets as clean as possible. I get about 2500 miles per chain average
It's less efficient, tires you more. Fine in a race for short term advantage or on a killer sprint you can collapse after. But bad practice. I fairly often see london commuters in too high a gear getting out of the saddle.
Interesting point above about debris possibly being the biggest single cause of wear. Would be interested in more views about this. I definitely don't clean my chains enough. Last time i cleaned one, post clean it failed the chain measurer test but had passed it before. The debris was clearly fooling the park tools measure, reducing the gaps
Indeed, it is wear not stretch. The rate of which for any given chain is down to the strain put on it.
I disagree. My hypothesis is that the main component in wear is debris between moving parts increasing friction. Increased force increases friction but to a lesser degree
It's less efficient, tires you more. Fine in a race for short term advantage or on a killer sprint you can collapse after. But bad practice. I fairly often see london commuters in too high a gear getting out of the saddle.
Interesting point above about debris possibly being the biggest single cause of wear. Would be interested in more views about this. I definitely don't clean my chains enough. Last time i cleaned one, post clean it failed the chain measurer test but had passed it before. The debris was clearly fooling the park tools measure, reducing the gaps
That sounds like a rather daft thing to say, if you wont get up a hill unless you stand, then stand, if you fancy stetching your legs a bit by standing up, then stand.On our group rides, the leader is forever warning everyone not to stand when climbing. Extreme issue, snapping the chain, chronic issue of extra chain wear.
You were the first to use the word 'stretch' in this thread - of course your interest may have been piqued by something else.Interested by this idea of hilly riding causing more chain "stretch". Chains don't stretch, they wear.
Chains do not snap if increased force is applied, unless they are already damaged (hopefully not). The force needed to break an undamaged chain is beyond the heaviest, most powerful rider to produce. @blazed - please post a video. The main reason chains part is because of a messed up change with significant force applied (eg as the road 'unexpectedly' turns sharply up and the rider finds him/herself at the wrong end of the cassette, stands up to exert maximum force to climb and changes at the same time). Sometimes you just have to stall and sort it out when stationary. @Yellow Saddle must be on sabbatical.warning everyone not to stand when climbing
Using the inner (of 2) chainwheels will give a straight chain line when you have the chain on sprocket 4 (of ten, largest is 1).almost always ride this bike on the inner 39T chainring which allows a really straight chain line
When you quoted my post you missed out ' so this may reduce wear?'. I used a question mark because I'm not sure either if a straight chain line reduces wear.You were the first to use the word 'stretch' in this thread - of course your interest may have been piqued by something else.
Chains do not snap if increased force is applied, unless they are already damaged (hopefully not). The force needed to break an undamaged chain is beyond the heaviest, most powerful rider to produce. @blazed - please post a video. The main reason chains part is because of a messed up change with significant force applied (eg as the road 'unexpectedly' turns sharply up and the rider finds him/herself at the wrong end of the cassette, stands up to exert maximum force to climb and changes at the same time). Sometimes you just have to stall and sort it out when stationary. @Yellow Saddle must be on sabbatical.
Standing up is sensible - it is a useful variation of position and brings some other muscle groups into play - so a good climbing regime is mostly sitting and short stretches of standing. Worth dropping down a gear (or two) before standing btw. But if the hill is too steep to sit and spin up, as @Mugshot says, stand up and get up it, or give up and walk.
Using the inner (of 2) chainwheels will give a straight chain line when you have the chain on sprocket 4 (of ten, largest is 1).
Using the outer (of 2) chainwheels will give a straight chain line when you have the chain on sprocket 6 (of ten, largest is 1).
I really don't see how staying on the small chainring will "really" give you a 'straighter' chain line (unless you stay permanently on 39/19(say, 55")).
And there is good science to suggest that cross chaining (eg small/small or large/large) scarcely increases the chain system friction (<0.5%) so by corollary, the additional wear caused by cross chaining is minimal. So optimising chain line doesn't matter that much, though that's not a reason not to (deliberate double negative).
@User9609 - please share your graphs again.
Worth dropping down a gear (or two) before standing btw.
You were the first to use the word 'stretch' in this thread - of course your interest may have been piqued by something else.
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