Bicycle Mechanics - How often should you change your chain?

How many miles should you put on your chain before changing it out?

My MTB racer friend says he changes his chain every month because supposedly worn chains accelerate chainring and cog wear. I think that's a bit excessive, so I'm trying to get a feel of a more conventional replacement interval...

When it has worn down a little, but before the extra length can wear out your cogs. The rate of wear depends on lube, dirt, rain etc. so is pretty variable.
See
http://www.sheldonbrown.com/chains.html

For everything there is to know about chains.

conditions affect chain life, get a park chain checker and replace the chain when the indicator says to. this will help you save money by not prematurely replacing a good chain.

i like sachs chains myself, and i change 1-2 months (most of the time) it is a little overkill but it does lengthen the life of your drive train and besides think of all the cool mnt bike jewelery you can make!

wow ... that's fast ... I've been told 1 year at the least ... usually just check the chain length with a 12-inch ruler. If the 1 and the 12 don't land on the rivet centers by less than 1/16" difference, then replace the chain.

I agree with Chi on the method of checking and on how much some of you replace your chains. My chains for the last 30 years or way over 120,000 miles have averaged 20,000 miles before replacement. My current bike now has over 80,000 miles on it, I have replaced the chain 5 times in 18 years. During that time I only replaced the freewheel once and that was AFTER it had over 70,000 miles on it and I have never replaced the front rings. So to say replacing your chain every month or two to prevent the cogs from wearing out seems way out of line-at least in my experience and others I know where I live that ride and have had the same results as me.

well i have to admit to having changed my chain too infrequently the past few years - an average of about every 11 months... and since i ride about 10,000km/yr (and last year 65,000 meters vertical so a lot of force) and that's just too infrequently

not surprizingly i have pretty much replaced the whole drivetrain once a year (this year new small and middle chainrings and new cassette so the big ring was the only the that wasn't toasted from using my chain too long)

i plan to buy a chain-stretch measuring tool and hopefully my drivetrains will last a little longer...

I was wondering if the frequent chain replacement is more of a mtb thing or does it translate to the road also? It would seem to me that a mtb chain is stressed more than a road chain. Generally what is the "life expectancy" of a road vs mtb chain?

I try to change my chain once every three months... simply because I do a *lot* of trail riding, mud riding, and getting things in general.... nasty.

I did the same on my previous bike.. and never once had a problem with a skipping chain, or thrashed cogs... because I kept fresh chains on it.

I usually just buy 2 or 3 of them at a time from Mail Order... and then "stock" the other ones on my shelf.

I've averaged about 750-1000 miles per chain... so not too bad for offroad abuse, hucking, and powering up some mad hills.

My new bike (only 4 months old now) hasn't received a new chain yet, but will before I go to Utah & Colorado.

The only way to go is a chain checker IMO. I don't have one though, I jsut use the one at the shop.

I think it is most definatly a mnt bike thing!? most road bikes well are very well kept, dont see mud or dirt and probably never ride through deep muc puddles the shifting on a road bike is not under the same stresses dont get me wrong roadies you guys ride hard and long but your shifts are nice and not under as much torque as a mnt bike

the park chain checker is a pretty cool little tool, and it is very easy to use but the guy who was talking about the ruler well the ruler is great and everyone has a ruler (or can get one from work)

It depends on use, how dirty/clean it stays, etc. Best practice is to measure the elongation--either with the park tool or a steel rule. Using a steel ruler, 12 links of a new chain will measure exactly 12 inches. Once 12 links wears to 12 and 1/8, it's time to change. (Actually, 1/8 is a little on the too much side, I start thinking of changing when I can detect that the chain has worn past the 12 and 1/16th mark.

Dave

when there is a lot of play in your chain then change.Or otherwise you could ruin your chainrings and your rear cogs.Then everything will be wore and in need of replacement