Question about skip tooth chains

[Rustafari]

Just curious, if there is more than on pitch size? I guess I assumed they were all 1".

The reason I ask is I put a bike together last weekend from some parts I had and noticed that the chain was climbing up on the teeth of the sprocket, binding and making all kinds of popping sounds. I just happened to have another skip tooth chain lying around, so I removed the problem chain from the bike and laid the two out, side by side. I could see that after only 5 of 6 links, the problem chain was way off by comparison to the other one. I put a tape measure next to them and my other chain lined up every inch. But the links on the problem chain were longer. I counted the links in both chains and the problem chain had one link less.

Could a chain actually stretch a full inch over only a 56" length? That's nearly 2%.

BTW, I put the other chain on the bike and now it rides like a dream!

 

[bricycle]

lots of different widths tho...

 

[jpromo]

Yeah, that's the dreaded chain stretch. It certainly can get that bad if it's got a ton of heavily pedaled miles on it; I've had one or two rendered unrideable.

 

[fat tire trader]

Chains do stretch. Like Brian said there were at least 3 different widths of early inch pitch chains.
Praise Jah Rustafari!
Rust is everywhere.
In Rust we Trust.
One Love. Two Wheels.

 

[videoranger]

courtesy of sheldonbrown.com. The late Sheldon Brown was a bike guy that still helps us bike folks out.

http://sheldonbrown.com/chains.html

Chain "Stretch"

Cyclists often speak of chain "stretch", as if the side plates of an old chain were pulled out of shape by the repeated stresses of pedaling. This is not actually how chains elongate. The major cause of chain "stretch" is wearing away of the metal where the rivet 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 rivets by the inside edges of the bushings. With bushingless chains, the inside edge of the side plate hole that rubs against the rivet has a smooth radius instead of a sharp corner. This probably contributes to the greater durability of bushingless chains.
Worn chain pin Worn chain pin
You can see how the rivet of this unusually badly worn chain has been worn away.
Note also how the roller has flopped out of position. The reason the roller flops around is that the "bushing" part of the chain has been eroded away.
No doubt the inner surface of the roller has become enlarged as well.

 

[Rustafari]

Thanks for the help guys. I was thinking the same thing about the side plates stretching and was having a really hard time getting my head around that. Excessive wear and play in the links makes a lot more sense. So I guess that means this chain is junk. I was kinda hoping that it was just for a different kind of bike and maybe I could re-sell it.

Oh well.

In Rust we Trust. Hehehe. I like that.