I took my Reno into the shop today for a standard tune-up and a few other small things and they called back and said that I needed a new chain already. I have no problem paying the $20 for a new chain, but how long does a chain normally last? I have around 650 miles on my bike and seems odd that I already need a new one, he said it was streched pretty bad and if I did not replace it today I would need to replace it soon.

that seems a little quick. However, there's an objective test to measure the amount of stretch before you need a new one, so you could ask him to show you the amount of stretch on the guage. However, if there's any doubt, I'd put on the new chain. Chains are relatively inexpensive compared to cassettes. I know having prematurely trashed $200 D/A cassettes due to my procastination.

650 smells fishy, I change my chain out at 1500. What type of chain?

It is the chain that came stock on my '06 Reno, so I am guessing it is nothing fancy and could be just a cheap chain.

Lots of chainwear threads if you search. On my road bike i usually change the chain around 1200 miles. I use a cheap Park tool chain wear indicator. If it starts to indicate a lot of wear, i just change it. Still 600 sounds a little early. IN fact there is considerable debate as to whether changing chains frequently on an inexpensive drivetrain is even worth it. Depends on the cost.

Your chain could in fact be indicating needing replacement. Go to the shop and have them show you if you are concerned. It's very easy to measure on your own if you have the tool.

Lots of chainwear threads if you search. On my road bike i usually change the chain around 1200 miles. I use a cheap Park tool chain wear indicator. If it starts to indicate a lot of wear, i just change it. Still 600 sounds a little early. IN fact there is considerable debate as to whether changing chains frequently on an inexpensive drivetrain is even worth it. Depends on the cost.

Your chain could in fact be indicating needing replacement. Go to the shop and have them show you if you are concerned. It's very easy to measure on your own if you have the tool.

I try to change mine at 1200-1500 miles.
Last one I waited too long, 2,000 miles, and had to buy a new cassette.

650 sounds real low. Are you a big guy putting out a lot of power?

LOL I am not a big guy and i doubt that I put out much power at all. I am 6ft and weigh 175lbs, when it comes to power I have no idea how how much I put out. The more that I think of it I am thinkning that it is possible that the chain needs to be changed already. Seeing how this is my first bike I think that I have been pretty ruff on it and have done things that are not neccessarily good for the bike, like shifting while i am really going at it and putting a lot of pressure on the drivetrain. Just one more reason I am glad that I did not go out and buy a $1500 bike for my first bike!

That's a bit soon to replace a chain. My prior chain had approx. 3000 miles on it before it needed to be replaced, and I'm not the smallest of guys (6'00", 185).

Measure from the center of a pin , 12" away your ruler should line up with the center of another pin. I don't recall the ammount of strech before you should replace your chain though.

That seems like too few miles, but, as mentioned above, a chain checker gives you a quick and dirty, objective way of measuring. I have the same tool pictured.

650 is kinda short. If you're concerned about it (as you obviously are) then ask the shop to provide you with a pin-pin measurement for 12 complete links. Exactly 12" is new. It is common for many to replace when you approach or pass 12 1/16". This is an easy measurement that they can do and provide you over the phone. It will also allow you to make the appropriate judgement call based on your own feelings regarding wear.

As a wrench that's been doing this for a lot of years I know that I have recommended early chain swaps to a lot of people before. In my experience I have found that a chain replacement is one of the simplest, least expensive ways to quickly restore shifting performance. I wouldn't fault the wrench for offering up the idea of a chain swap, but technically it is probably not worn out yet.

I understand that if you pedal at a lower/slower cadence, especially if you're mashing uphill, that can take a toll on a chain. And in another thread it was mentioned that it's best to ease up for half a pedal stroke as you shift. Like you mentioned, that might be what happened to wear out your chain early.

A bad chain line (big chainring/big cog or small chainring/small cog) can wear out a chain pretty fast, too.

Where I live the soil is pretty sandy and if you don't keep your drivetrain very clean you will wear out a chain very quickly. I use the Park chain checker and if you change chains soon enough you can get a lot of mileage out of the other "disposable" components.

As usual, Sheldon Brown knows all. In this case, scroll down almost to the bottom of the page and read the section "Measuring Chain Wear".

I have a DA chain on my bike with about 2700 miles on it. It measures to be exactly 12" for 12 links - no stretch at all. Should I replace it anyway? I don't ride it in bad weather much, but it seems like a lot of miles.

Great...now you guys have given me something else to think about and spend money on! I've got about 5000 miles on mine....maybe I should check it this weekend!

Sheldon

2 opinions here (yes opinions):

1. If it measures 12" exactly, shifting performance is "perfect", and you regularly maintain it then keep on riding....

2. If you cringe at the thought of replacing a DA cassette and think your measurement could possibly be 1/16-1/8" off depending on how carefully you lined up the scale to the exact pointon each pin....then spend the $20-$30 and replace it.

Better yet:
1. If you change the oil in your car at 7500 miles or more like your bottle of synthetic oil says to regardless of what the owner's manual says...then keep riding your chain

2. If you change your oil every 2000 miles, even when you use synthetic, just because you feel like it help the engine perform better and last longer...then get a new chain....

Actually, was just reading tonight a comment from a shimano rep in Velonews who says the expected chain life is 1500 to 4000 miles depending on use and conditions, so if it measures ok, and works ok, I think you can keep using it.

12000 km on my set of 2 chains ( i swap weekly). Thats close to 4000 miles each, and still no where near needing replacing. And that includes commuting all winter in the pac north west, so lots of 2 hours a day of rain raiding and no cleanup except swapping chains every 1-2 weeks.

I'd say 650 miles is too short.

Sounds lght to me too, but it depends on how well tuned up your ride is, how clean you keep the drivetrain, and what kind of riding you're doing. I've been getting about 4K miles per chain and 3 chains per cassette. I keep things pretty clean but not spotless, I'm not a big guy, and I'm not a terrible masher. YMMV.

I'll second the chain-wear indicator as an addition to your tool box. Replacing a chain is something pretty much anyone can handle and it'll save you some dough for more exciting bike purchases.

I have 4k on my DA chain with zero stretch.

I clean it about every 200 miles of clean condition riding. Or right away after dirty rides.