Why a worn cassette cannot damage a new chain

[Yellow Saddle]

if pedaling force is a minor than articulation factor then that would also imply that a slow cadence (low gear) inflicts less wear on a chain?

I'm not quite sure what you are saying, but pedaling force and articulation both play a role and wear is a factor of both. In other words force amplifies articulation and articulation amplifies force.
Cadence makes no difference whatsoever.

 

[silva]

I'm not quite sure what you are saying, but pedaling force and articulation both play a role and wear is a factor of both. In other words force amplifies articulation and articulation amplifies force.
Cadence makes no difference whatsoever.

Because you stated: "Firstly, we need to understand why a chain wears and what happens when it wears. It does not wear from the tension induced into the chain by pedaling forces."
which I interpreted as that the articulation of the links around the cogs/teeth were the major/dominant factor in the chains wear.

 

[Ian H]

An excellent explanation of what I generally refer to, colloquially, as chain-stretch.

 

[Ajax Bay]

if pedaling force is a minor than articulation factor then that would also imply that a slow cadence (low gear) inflicts less wear on a chain?

Chain wear will be related to power, which might be low gear or high gear, high or low cadence.
For a given power, tension will be lower at higher cadence, but the rate of articulations will be higher (obv).
Tension of the chain (directly related to pedaling force) will only cause (and affect the extent of) wear during the chain's two points of articulation under tension.

 

[silva]

Chain wear will be related to power, which might be low gear or high gear, high or low cadence.
For a given power, tension will be lower at higher cadence, but the rate of articulations will be higher (obv).
Tension of the chain (directly related to pedaling force) will only cause (and affect the extent of) wear during the chain's two points of articulation under tension.

1) force as a cause of wear
2) movement as a cause of wear
wear is a thus function of both, but does the formula give one of both a bigger weight than the other?
Because if yes, a lower, or higher cadence would result in more, or less wear.
That was what I was after.

 

[Dogtrousers]

Good grief man, two extra washers on every stay? Think about the added weight!

And cost. Do you have more money than sense?

 

[Ming the Merciless]

Misread this as a warm cassette. I then wondered if this was the next big thing, heated cassettes to improve drivetrain efficiency and chain life.

 

[Yellow Saddle]

1) force as a cause of wear
2) movement as a cause of wear
wear is a thus function of both, but does the formula give one of both a bigger weight than the other?
Because if yes, a lower, or higher cadence would result in more, or less wear.
That was what I was after.

Force without articulation cannot wear a chain. That's why I said that the piece of chain that's in transit from rear to front, doesn't wear, even though it is under tension (force). Articulation without force doesn't cause wear. That's why I said that the chicanes and other bits of articulation in the non-tension run doesn't wear.

There is no formula, because contaminants also play a role and you cannot quantify contaminants. However, if there was a formula, it would be a factor situation, as I stated. Something lime Force x Articulation x Somesortofcoefficient plus Z Contamination.

Don't overthink it.

 

[silva]

Yes, wear (removal of material) is due to friction and friction requires force and relative (between the mating surfaces) movement, but my question was if one doubles the force at a same relative movement, or one doubles to relative movement at a same force, if both situations would end in the same amount material removed / wear? For simplification ignoring other influences (probably what you name "contaminants")

 

[Mark pallister]

I've looked at this today and adjusted the derailleur, will see how I get on tomorrow.

Here are before and after shots. I've never adjusted a B screw before but this derailleur had clearly got out of alignment.
View attachment 496696

Jockey wheels 😂

 

[Yellow Saddle]

Yes, wear (removal of material) is due to friction and friction requires force and relative (between the mating surfaces) movement, but my question was if one doubles the force at a same relative movement, or one doubles to relative movement at a same force, if both situations would end in the same amount material removed / wear? For simplification ignoring other influences (probably what you name "contaminants")

I have answered the question. Don't overthink this.

 

[silva]

I can't help (over)thinking it. It's clear that the chain is the drivetrain component that is by far the most wearing part and also the major cause of wear of the other components.
Imagine a chain wouldn't become longer under tension, sprockets would last forever.
So if I see a promising hole I jump in it to see if there's something in it to benefit from. :P

 

[Ajax Bay]

Thought about this while riding today, without 'overthinking' it - more as an HR control measure.
Less power will result in less wear. At a given power the product of tension and cadence will be the same in any gear. So for you and your (fixed) promising hole, @silva , the variable available to you is the size of your sprocket. You will get less chain wear the larger the sprocket (implies a larger chainring which will also mean less wear). The articulation at the chainring is much less so the wear caused there is proportionately less (tension the same).

 

[gbb]

To use YS's own words if i may, drink a beer, ride your bike...and I'd follow that advice and not worry too much about chain wear or the reason ...or not, for that wear. Been there, done that, measured, checked, assessed mileages against specific chains, adapted very regular lubrication regimes, very regular cleaning regimes etc etc etc....and non of it made any noticeable difference to mileage achieved, whatever chain I used.
Check your chain moderately regularly, wipe and oil it as necessary....and ride your bike, that's the best bit, dont get hooked up in extreme and accept the inevitable, you'll replace a chain once In a while...its not going to break the bank.

In simple terms, just buy a chain and stop trying to eke out every last speculated mile out of them.

Edited to say,not aimed at anyone in particular, just accept chains and components wear, the reasons why may be interesting, maybe, but it wont change the simple fact they wear...JMO.

 

[Ajax Bay]

Just trying to give @silva treasure at the bottom of his 'promising' hole, as opposed to a pig in a poke.