New chain

[Wasp]

I took my specialized dolce elite into the LBS for a little tweaking today for a shifting issue, and I'm told in addition to fixing the shifting issue the chain needs to be replaced.
The bike was bran new when I bought it in June/12 and its been ridden 4000+ km. Is this normal that a chain wears out within 6 months? Or is the LBS selling me stuff I don't need?. How do you tell when you need to replace the chain?.

[indysteel]

I tend to get more life than that out my chains, but it's not surprising to me that you need a new chain after 4000 km miles. Chain life depends on the chain, how often it was cleaned and lubricated, your riding conditions (wet vs dry, flat vs hilly) and your style of riding. A lot of people change their chain every x number of miles. Some measure the chain for wear before replacing. Regardless, it's a part that you can expect to replace pretty regularly.

[Kiwi Stoker]

The chain also might of been damaged by something (like a stick jamming in it) or have a high degree of rusting due to weather conditions, how much cleaning, storage etc. Maybe you should ask for more info on why the chain needed replacing so you can see if you can improve the chain's life?

[Wasp]

The chain also might of been damaged by something (like a stick jamming in it) or have a high degree of rusting due to weather conditions, how much cleaning, storage etc. Maybe you should ask for more info on why the chain needed replacing so you can see if you can improve the chain's life?

I did ask, and was told the chain was streched. Apparently if you can pull the chain away from the bike in a bow shape, it's time for a new chain. But, I couldn't see the difference between the amount you could move either chain. That's why I was wondering if this was something that was necessary. They also mentioned replacing sprockets after the 3 or 4 time the chain gets replaced.

[Wasp]

If I would "spin" more while riding the chain has less load, and would last longer. Unfortunatley Mastering the art of spinning so far has eluded me....I'm terrible at it.

[OakLeaf]

That's pretty much right at the chain life I get, even when I take good care of them. Much over 2500 miles and I'll be pushing it, and I typically get more miles out of my chains than most of my riding buddies do. 1500-2000 miles isn't uncommon. And yeah, although the tools they sell measure wear along the length of the chain, lateral slop is just as important.

Did they give you the old chain back? Play around with them until you can feel the difference. Set your old chain on the garage floor, plates vertical, and use the finger and thumb of one hand to stretch it taut while you wiggle the middle part side to side. Then wiggle your the top part new chain around (between the cassette and the front derailleur, NOT between the rear derailleur and the chainring, since the RD springs will add to the movement). You should be able to see and feel the difference very easily ... wear will become apparent long before it's actually time to replace a chain, and I can pretty much guarantee a chain with 4000K will have noticeable wear.

The more diligent you are about keeping your chain (1) maintained and (2) replaced when it's worn, the longer your sprockets will last. HOWEVER, you'll need to replace your cassette (rear gearbox) as a unit, even though it'll be likely that only two or three of the sprockets will really need replacement. Back in freewheel days you could buy individual sprockets, but not any more - I'm sure you can find cassette sprockets in odd sizes at swapmeets, but the sizes that will need replacing most often will be the ones in shortest supply. As far as front sprockets, they're called chainrings, and they typically last longer.

Mashing vs. spinning might make some difference, but not nearly as much as maintenance, and honestly although some people here have posted different experiences, I think your chain life has been good.

[Becky]

I wish I was getting that much life out of my chains! Depending on the bike, I get 1000-1500 miles. My commuter is lucky to see 1000 miles per chain, given the crap that I ride through. But I'd rather replace chains frequently than need new chainrings and cassettes because everything starts skipping around.

[Melalvai]

But I'd rather replace chains frequently than need new chainrings and cassettes because everything starts skipping around.
Right, plus a cassette is more expensive and trouble to replace than a chain.
I also get about 1500 miles to a chain, less in the winter, and I clean it often. My mechanic was impressed at how many miles I got out of my cassette given the conditions I ride in.

[Kiwi Stoker]

Invest in a chain measuring tool (it's not expensive). It hooks into the links of the chain and will tell you accurantly about how slack the chain is. I have never heard in any bike shop or bike manual about pullng the chain in a bow shape. Normally you use the tool.

[OakLeaf]

All the mechanics I know check lateral slop as well as linear. Wear on the pins and plates isn't necessarily even in all directions, and either way will tear up your drivetrain.