how do you know when your chain is going bad?

[se7enty7]

Is there a proper technique to cleaning and lubing a chain?  how do you know when it's going bad?  I bought some spray-on chain lube...  and use it but I dunno... should I clean the chain or anything?

[mp183]

I never really clean mine completely.
I just wipe off the major crud off of it with a rag slightyl soaked in WD40.
The same holds for the rear sprocket.
At 18,000 miles mine showed some links that started to kink.
Just spray it after you ride it every 600 miles.
I used a chainwax which does not fly off.  I'm going to use
a liquid type on my next chain just to see the difference.
There are different ways to tell if the chain is gone.
The best way is to look at it as you spin the rear wheel with your hand
with the engine off.  If it turns looks smooth it's probably ok.

[Rema1000]

If the chain is too loose, then you need to take-up slack in the chain.  For example, if you walk the bike backwards in neutral, a loose chain produces a "tink tink tink" sound.  As the chain wears, you have to do add tension several times.  Finally, you're left at the end of the chain tension adjustment, and you can't get it any tighter; so it's time to get a new chain.

Also, when you clean the chain, check that all the links pivot smoothly.  If there are any links which don't pivot smoothly, and cleaning doesn't fix them, then it's time to get a new chain.

When you change the chain, you should also change the front gear, and many people also change the back gear.  Otherwise, your new chain will wear-out quickly.

[sprint_9]

You can push up on the bottom of the chain and if it stays in that position it is time for a new one, the links will bind up and not rotate back to there normal position.  Also if you tighten it up good but after a few days of riding it needs retightening it might also be time for another chain,  You should have around 1 inch of slack in the middle of the chain.

[johncam4]

for about 1000 miles i kept hearing this sqeeking noise, i thought it was my key chain but then i realized i hadn't oiled the chain in a while.  It was bone dry. D'oh

[Dom]

Count out 21 pins on the chain(20 pitches) and measure the distance between the two points.  If the distance exceeds 319.4mm(12.57 inches), the chain must be replaced.