Slipping after chain replacement

[Racing roadkill]

I replaced the chain on my 9 speed Sora after 2500 miles and get the occasional slip on the middle sprocket, by that I mean about half a dozen times in 24 miles. It is not always under load conditions. It did not do it before the chain change and was changed because of wear and no other problems. The cassette has done slightly less than the chain. The way I see it is that I have three options :
1, Buy a new cassette
2, Refit the old chain and then replace together
3, Wait and see what happens
I have read somewhere that the slipping might settle down after a while. I`d just like to know what you guys think or would do. Thanking you in anticipation.

You can’t teach an old cog new links, as you’ve just discovered. It will settle down once the new chain meshes with the old sprockets, however, the chain will be damaged / prematurely aged in the process. It’s best practice to change chains and cassettes in unison, though not strictly necessary, until you’re into high end, lightweight, relatively expensive 11 or 12+ speed set ups.

 

[Gunk]

With motorcycles you always change chains and sprockets together. A 9 speed cassette isn’t expensive, just fit a new one

 

[overmind]

You can't do that with a cassette sprocket. They only fit in one position.

Yes, your are right, I made a mistake. I thought the poster meant the chainset when they meant the cassette.

 

[faster]

Replace the cassette with a new one now, then in a 1,000 miles or so, swap back to the old cassette, which won't slip on the now old chain.

The next time you need to change the chain (after another 1,000 or so miles), use the new cassette again and repeat.

That way, new chains will always run on a new cassette (which will hardly wear at all, as most of the wear occurs when the chain has stretched), and older chains will always run on older cassette (which will wear a bit, but won't slip for an eternity, as it will never be presented with a new chain).

You won't need to buy a cassette for a very long time.

Old cassettes don't cause any additional wear to new chains in my opinion (unless they are actually slipping). Old chains on the other hand, will knacker a new cassette enough that it will slip with a new chain in just a few miles.

 

[Shearwater Missile]

Replace the cassette with a new one now, then in a 1,000 miles or so, swap back to the old cassette, which won't slip on the now old chain.

The next time you need to change the chain (after another 1,000 or so miles), use the new cassette again and repeat.

That way, new chains will always run on a new cassette (which will hardly wear at all, as most of the wear occurs when the chain has stretched), and older chains will always run on older cassette (which will wear a bit, but won't slip for an eternity, as it will never be presented with a new chain).

You won't need to buy a cassette for a very long time.

Old cassettes don't cause any additional wear to new chains in my opinion (unless they are actually slipping). Old chains on the other hand, will knacker a new cassette enough that it will slip with a new chain in just a few miles.

That sounds like a good idea. Thank you.

 

[Yellow Saddle]

With motorcycles you always change chains and sprockets together. A 9 speed cassette isn’t expensive, just fit a new one

The analogy doesn't hold water. On a motorcycle you have a tension run on top and and a semi-slack run at the bottom. On a bicycle with a derailer, you have a tension run on top and a slack run at the bottom. The spring in the derailer allows the chain to ride up on the sprocket whereas on a motorcycle or single-speed bike, there is no slack to be had from a tensioner.
The mechanism by which these two wears and subsequently fails is completely different. There is no need to fit a new cassette, as I've mentioned.

 

[Yellow Saddle]

You can’t teach an old cog new links, as you’ve just discovered. It will settle down once the new chain meshes with the old sprockets, however, the chain will be damaged / prematurely aged in the process. It’s best practice to change chains and cassettes in unison, though not strictly necessary, until you’re into high end, lightweight, relatively expensive 11 or 12+ speed set ups.

Would you care to explain by what mechanism the chain will be damaged and or aged in this particular scenario?

 

[Racing roadkill]

Would you care to explain by what mechanism the chain will be damaged and or aged in this particular scenario?

Every time the chain jumps, it undergoes an elastic deformation, which it wouldn’t do if it didn’t jump. This will lead to a premature degree of stretch, it wouldn’t see, if it didn’t jump.

 

[Yellow Saddle]

Every time the chain jumps, it undergoes an elastic deformation, which it wouldn’t do if it didn’t jump. This will lead to a premature degree of stretch, it wouldn’t see, if it didn’t jump.

No.

Firstly, repeated elastic deformation in steel does not lead to plastic deformation. Go read up on fatigue limits in steel. That's why car springs don't sag, watch springs work for many millions of cycles and spokes last very long, especially when stress-relieved.

Secondly, a chain undergoes elastic deformation with every single pedal stroke, not when it jumps. In fact, when it jumps, it is the only time that elastic deformation is smaller than during normal use.

You make these things up as you go along.

 

[Racing roadkill]

No.

Firstly, repeated elastic deformation in steel does not lead to plastic deformation. Go read up on fatigue limits in steel. That's why car springs don't sag, watch springs work for many millions of cycles and spokes last very long, especially when stress-relieved.

Secondly, a chain undergoes elastic deformation with every single pedal stroke, not when it jumps. In fact, when it jumps, it is the only time that elastic deformation is smaller than during normal use.

You make these things up as you go along.

My 30 years experience of ( and degrees in )material science, not to mention many hundreds of thousands of miles of riding, over 35+ years tell me you’re wrong, not only this time, but many times. You really need to know what you’re talking about, before challenging those with far superior knowledge and experience of a subject, or you may end up looking a bit daft ( like you just have ).

^^This very well may be the last time anyone was as wrong about something, as what you just said.

 

[Shearwater Missile]

I have ordered a new cassette and will fit this and leave for a few hundred miles and swap back as @faster has said. Thank you for all the replies, much appreciated.

 

[Racing roadkill]

I have ordered a new cassette and will fit this and leave for a few hundred miles and swap back as @faster has said. Thank you for all the replies, much appreciated.

That should work

 

[Stompier]

My 30 years experience of ( and degrees in )material science, not to mention many hundreds of thousands of miles of riding, over 35+ years tell me you’re wrong, not only this time, but many times. You really need to know what you’re talking about, before challenging those with far superior knowledge and experience of a subject, or you may end up looking a bit daft ( like you just have ).

Yellow Saddle is absolutely correct - and you're absolutely wrong, I'm sorry to say. His interpretation of plastic deformation is technically accurate, so your attempts to contradict it with an appeal to 'authority' is a bit daft. If you genuinely do have a degree in material science (in which case prove it or bottle it), then I'd sue for a refund. The evidence suggests that you don't have said degree, or if you do, you've clearly forgotten what you studied.

 

[Yellow Saddle]

Yellow Saddle is absolutely correct - and you're absolutely wrong, I'm sorry to say. His interpretation of plastic deformation is technically accurate, so your attempts to contradict it with an appeal to 'authority' is a bit daft. If you genuinely do have a degree in material science (in which case prove it or bottle it), then I'd sue for a refund. The evidence suggests that you don't have said degree, or if you do, you've clearly forgotten what you studied.

You can't fight bluster with philosophy and fallacies. It has been tried on said individual before to no avail.

 

[Ajax Bay]

Every time the chain jumps, it undergoes an elastic deformation, which it wouldn’t do if it didn’t jump. This will lead to a premature degree of stretch,

Every time a chain experienced tension (ie normally pedalling) it "undergoes an elastic deformation". But this does not "lead to a premature degree of stretch". It's not elastic deformation that leads to the elongation of a chain with use.
How can "an elastic deformation . . . lead to a premature degree of stretch"? The deformation is elastic ie the dimension of the material is the same after the applied force as it was before. Therefore no long term stretch occurs.
Rather than suggesting that one who disagrees is "wrong" and 'daft', why not make an effort to explain why your colocutor is 'wrong' and/or what you really meant, drawing as necessary on your extraordinary cycling experience and multiple materials science degrees. [Your normal response to being asked to explain more clearly a doubtful assertion/explanation is that 'you (materials science) plebians wouldn't understand'. Go on: break the mould!]