Uneven chain tension

[Zoiders]

Lost me there Zoiders.

Chain wear does not occur on a one to one basis, you aren't getting the tight spot at the same point on every revolution and you arent getting it in one place on each chain.

Rings cause tight spots, not uneven chain quality.

See also Sheldons article about skid stops.

 

[Gerry Attrick]

Exactly. The tight spot positions will appear to change due to different sprocket size. If the tight spot did appear say every time the left crank was horizontal forward, then yes the ring may be suspect, but when the position of the tight spot appears to change in relation to the crank position, the tight spot is chain related.

 

[McrJ64]

The bike has a 42 tooth chainwheel, 16 tooth sprocket, 100+ tooth chain. I think we can agree that the chain will be 'shifting' on the chainwheel and sprocket, i.e any given link in the chain will not consistently meet the same tooth on the chainwheel and/or sprocket. The chain is however tight at the same spot on every revolution of the chainwheel.

I tend to agree that the problem is therefore with either the sprocket or the chainwheel.

The bike has always been like this, even though I have changed the sprocket a couple of times, and regularly change between freewheel (commuting) and fixed (weekend), so I and tending to doubt that chain wear is significant (it may well be contributing).

Thanks for all the thoughts. They are really interesting.

 

[McrJ64]

Apologies to Catrike. Last week he said that the uneven tension was due to chain wear and I doubted him. Well, I changed the chain on Saturday and the tension was much more even. I still don't understand why but I like it. I think I'll have to change it more frequently in future.

 

[Riding in Circles]

Apologies to Catrike. Last week he said that the uneven tension was due to chain wear and I doubted him. Well, I changed the chain on Saturday and the tension was much more even. I still don't understand why but I like it. I think I'll have to change it more frequently in future.

No worries, I am in the trade and have 30 years of experience, so I know fine well that everyone knows better than me until they do what I suggest, glad you have it sorted.

 

[Zoiders]

Catrikes still wrong.

Abritrary answers based on "because I said so" usualy are.

 

[Riding in Circles]

Where is the zombie smilie?

 

[Zoiders]

You have given an answer with no explanation other than "I'm in the trade so I must be right".

It's tosh.

 

[Riding in Circles]

You have given an answer with no explanation other than "I'm in the trade so I must be right".

It's tosh.

You seem to have missed the fact that my answer fixed the issue, go and sit in the corner and argue with yourself, there's a good boy.

I am just happy to have helped the chap, you seem upset that he was helped by someone other than you, perhaps a case for self examination on your part.

My criteria for my hypothesis is not based on being in the trade but rather my experience with pedal cycles and nine times out of ten the issue described has been caused by the chain having stretched in all but a few links, sorry if that is not good enough for you but it is what it is and it is correct.

 

[Zoiders]

Now you are changing your story.

Before you were adamant that it was a chain with a few worn links, suddenly you are saying it's chain that has reached the end of it's life.

On a good condition chain tight spots are caused by ring and spider issues, not the mythical patchy chain wear, everyone else said you were wrong not just me, and you remain wrong.

If you don't know the answer don't make stuff up, 30 years "in the trade" or not.

 

[Riding in Circles]

Ok, I'm wrong, the chap should return his bike to the condition it was and try all your expensive solutions quite clearly, the people who agreed with me are idiots and the damaged chain is obviously damned to hell for disagreeing with you as well.

Your a funny little sausage, I'll give you that.

 

[Zoiders]

x-hundred miles from now there will be the same wear pattern and the same problems because the chain ring is out of true.

It's a common fault and it's a cheap fix compared to endless chain replacement.

"Funny little sausage"?

Go and patronize another member.

 

[mickle]

The only thing that I can think of which could cause uneven chain wear is uneven application of lube. Unless Catrike has any other ideas. Do people really lube one part of a chain and not the other?

 

[Riding in Circles]

The only thing that I can think of which could cause uneven chain wear is uneven application of lube. Unless Catrike has any other ideas. Do people really lube one part of a chain and not the other?

I have seen the issue on motorcycles as well, especially ones that people wheelie, so I suspect it is some sort of issue with shock on the chain and lets face it, bicycle chain is quite light weight considering its application, there is certainly more stress on a chain on a fixie than any other bicycle, of course the ideal is to change chain and sprockets together but sometimes it is possible to just have a wrecked chain.

 

[mickle]

I have seen the issue on motorcycles as well, especially ones that people wheelie, so I suspect it is some sort of issue with shock on the chain and lets face it, bicycle chain is quite light weight considering its application, there is certainly more stress on a chain on a fixie than any other bicycle, of course the ideal is to change chain and sprockets together but sometimes it is possible to just have a wrecked chain.

I disagree entirely that there is more strain on a fixie than any other bicycle. My fixed chains always last longer than those on my geared bikes by virtue of not having to deflect across a block.

On an upright bike the load on the chain is affected by the relative diameters of the sprockets and chain-rings and by the weight of the rider. As you'll no doubt be aware the load on the chain of a recumbent isn't limited by the rider's weight since a rider can exert a force on the pedals in excess of his body weight by pushing back against the seat..

You still haven't explained the mechanism by which bicycle chains wear unevenly.