Chain Tightening

[scumdog]

It's not tight spots in the chain,it's eccentricity of the sprockets - the chain wears evenly throughout it's length.

At last a sensible answer!! And I doubt the chains physically "stetch", it's wear of the pins and rollers that do it.

[Biff]

It's not tight spots in the chain,it's eccentricity of the sprockets - the chain wears evenly throughout it's length.

Could you please just clarify what you mean here? Do you mean that this is due to the fact that the chain takes an eccentric path from the sprocket, as in an elliptical curvature? That would make sense.

[Motu]

Could you please just clarify what you mean here? Do you mean that this is due to the fact that the chain takes an eccentric path from the sprocket, as in an elliptical curvature? That would make sense.

Um?....the holes aren't in the middle of the sprocket? They are not turning in a true circle like.You could prove or disprove this theory by marking your tight spot,turning the wheel a few times and checking where the tight spot is again.

[Biff]

Um?....the holes aren't in the middle of the sprocket? They are not turning in a true circle like.You could prove or disprove this theory by marking your tight spot,turning the wheel a few times and checking where the tight spot is again.

Right - I think we're both on the same wavelength here. Thanks for clarifying that for me.

[vifferman]

A couple more things.

When you're checking your chain and it's cold, the links sometimes don't pivot easily around the pins, so the chain 'kinks' and tension thus varies. (You can see this, especially when the chain's new, because the links aren't nicely lined up). You also sometimes get the master link being rivetted on a bit tight, so it binds more, thus making the chain tighter on the length that the master link is on.

When the chain and sprockets are a bit worn, the chain doesn't always sit evenly on the sprockets and can ride up the teeth a bit, particularly if the sprockets are eccentric, as Motu said. This can also lead to uneven tension.

I reckon that while in theory a chain wears evenly along its length, in practice this isn't always the case, with the odd 'rogue' link's pins loosening / wearing into the links more than others. This is particularly true for chains that aren't well-maintained or that are made of inferior materials.

Remember: Better to have the chain slightly loose than slightly too tight, as it's easier on the chain and sprockets, even if it does make for slightly sloppier gearchanges.

[jrandom]

Well, I don't know about all this techkernickeral chain-tightening stuff.

I just ride round to vifferman's place every so often, hand him a spanner and an oilcan, and tell him to let loose with the OCD.