chain and sprocket question

[Finesse77]

I just want to know what are the obvious signs when my chain needs to be replace, someone told me that I may as well change the sprocket too.
Is this hard to do, because I am thinking of doing it myself but at the same time I am thinking i might mess it up. What's the average cost for this service.
I would really appreciate all your input.

Ride Safe

 

[kyles here]

look to see how much youve have had to move the chain back, tight spots in certain parts of the chain. and yes you should do your sprockets at the same time otherwise they will both wear out faster. its easy to do if you have the tools. as for the avg cost it depends on size of chain/sprockets. i went -1/+2 with a 520 chain and it cost me almost 200 shipped.

 

[tjdziuba]

+1 for "easy if you have the tools" - you'll need a rivet tool if you install a rivet-type master link, that can go for about a hundred bucks. You'll also need a torque wrench to torque the nuts & bolts to the manufacturer's spec.

A clip-type master link is easier to install (no rivet tool necessary), but they are more likely to fail than the rivet type link. Personally, I run a clip-type link, and just put a but of RTV silicone on it after I installed it, which I inspect every time I lube the chain.

 

[auntiebling]

the depression between sprocket teeth should have a round bottom, matched well to the pins of the chain.

as the sprockets wear, the space between teeth becomes oblong.

granted, this is an extreme example but you get the point

as the teeth wear, they get pointy.

 

[mabbott]

great picture to show the difference! You will also notice and or hear the difference if you chain is bad!

 

[marcg]

I just want to know what are the obvious signs when my chain needs to be replace, ...
Ride Safe

Besides looking for worn sprockets and tight links, you can measure the distance between the pins on your chain to see whether the chain has exceeded its wear limit. Most chain manufacturers recommend replacing the chain once it has "stretched" (worn, really) by more than 1% in length.

Most street bike chains have a 5/8" distance between chain pins. An easy way to check whether the chain has stretched by more than 1% is to put some tension on the lower chain run and measure the distance between the pins 20 links apart. On a new chain, the distance will be 100/8" or 12-1/2". If the distance is more than 101/8" or 12-5/8", it's time to think about a new chain. It's a good idea to do this at a few points along the chain as chains don't wear evenly.

 

[Seesm]

Obviously those sprockets are extreme between new and WAAy worn out...

Btw a sprocket can look good and still not be great... A worn sprocket and or chain will rob HP. If you replace one, replace em all bacuse a worn chain will wear out sprocket's and vice versa... This is the same for mx or RR bikes...