Bicycle Mechanics - How Long Will A Cassette Last If The Chain Is Replaced Regularly?

I'm not sure if this has been covered elsewhere, but I had a question about cassette replacement: Some bike mechanics have told me that a quality cassette will last almost indefinitely with diligent chain replacement. The reasoning is this: A chain doesn't start to wear down other drive-train components until it is more than 50% worn. So if you replace the chain reguarly (at or before 50%), they cassette will last almost indefinitely. Is this true?

What's the definition of a 50% worn chain?

I don't know about 'almost indefinitely' - but yeah, a very long time - several years if you're diligent about your chains. Longer if you periodically replace the little gears which wear faster.

I'd rather like a 12-27 to replace my 12-25, but I'd have a hard time rationalising it when the 12-25 is still in good spec.

See this thread. (http://www.bikeforums.net/showthread.php?t=282161&highlight=cassette+wearing+out)

There are a lot of variables.

There are a lot of variables.

Exactly. Since the OP is in Seattle, I think "indefinitely" is a little optimistic. All the PNW rain mixes with road grit and gets on your drivetrain to make it wear faster. Even with dilligent chain cleaning, lubing and replacement, you'll still need to replace cassettes. In my experience, if I'm very dilligent I can get 3-4 chains per cassette. Normal use for is 2-3 chains per cassette. Of course, that's with commuting year round. If you're a fair weather cyclist it might last indefinitely (esp. since fair weather cyclists don't ride too many months around here :) ).

I don't know about 'almost indefinitely' - but yeah, a very long time - several years if you're diligent about your chains. Longer if you periodically replace the little gears which wear faster.

I'd rather like a 12-27 to replace my 12-25, but I'd have a hard time rationalising it when the 12-25 is still in good spec.


i think there are too many variables to generalize. no doubt that a cassette will last longer if you diligently clean your drivetrain and replace chains earlier than later.

the shimano HG cassettes i use (lower end) cost about the same as the upper end Sram chains that i use so one way or the other its probably a wash.

ed rader

http://www.fototime.com/9D345A9E91B798E/orig.jpg

You also need to realize that a "quality cassette" means different things to different people. The real high end stuff tends to focus more on being lightweight than durable so don't assume that more money buys you a more durable cassette. A lot also depends on where you ride and what kind of nasties are getting in your chain and gears. Where I ride in the midwest, my chains and cassettes last years, but i'm sure there are places with more abrasive stuff blowing around that will wear out parts much more quickly.

My experience with road bikes (8-9sd) is the cassette is good for two chains, if you try the third chain
something will skip. Chainwheels seem to last at least 3 chains, sometimes 4 chains. Typical chain
exchange for me is at 5-7 kmi. This would be on paved roads, dry weather, rare rain exposure.
Chains are cleaned when I think of it and have time, typically 3-4x during their lifetime, and lubed
about 2-3x as often.

You also need to realize that a "quality cassette" means different things to different people. The real high end stuff tends to focus more on being lightweight than durable so don't assume that more money buys you a more durable cassette.

Golden words of wisdom!

Thanx for all the responses - lots of helpfull, constructive info :)

The cassette I have is about 2-3 years old - I can't remember exactly what model it is, but it's a Shimano 11-32. I'm on about my 4th chain, and since I replaced the cassette I've been diligent about lubing the chain and replacing it before it get's too worn. As far as I can tell the cassette still seems to work just fine. It almost never skips, and when does it's only during occasional erratic shifting (which I try to avoid).

So is there an easy way to determine if/when the casette needs replacing? A couple months ago when I went my LBS to have the chain checked he said, 'the cassette looks fine'. So can you tell just by checking visually, or does it require more precise measures?

Thanx for all the responses - lots of helpfull, constructive info :)

The cassette I have is about 2-3 years old - I can't remember exactly what model it is, but it's a Shimano 11-32. I'm on about my 4th chain, and since I replaced the cassette I've been diligent about lubing the chain and replacing it before it get's too worn. As far as I can tell the cassette still seems to work just fine. It almost never skips, and when does it's only during occasional erratic shifting (which I try to avoid).

So is there an easy way to determine if/when the casette needs replacing? A couple months ago when I went my LBS to have the chain checked he said, 'the cassette looks fine'. So can you tell just by checking visually, or does it require more precise measures?


I suppose you can tell if the cassette is severely hosed, but I doubt if anyone can tell by looking if it will skip.

I suppose you can tell if the cassette is severely hosed, but I doubt if anyone can tell by looking if it will skip.

i know a bad cog when i see one or one that's close enough to be considered bad.

ed rader

So is there an easy way to determine if/when the casette needs replacing? A couple months ago when I went my LBS to have the chain checked he said, 'the cassette looks fine'. So can you tell just by checking visually, or does it require more precise measures?

I found the Rohloff tool:

http://www.rohloff.de/en/products/hgigcheck/index.html

a good investment. There is some subtlety in its application and it is correspondingly worthwhile to have some new cogs around that can serve as a reference.

In my riding experience, the middle cogs wear out fastest. From time to time, I replace one or two, maybe at the same pace now as the chain, but not the same cogs each time.

I found the Rohloff tool:

http://www.rohloff.de/en/products/hgigcheck/index.html

a good investment. There is some subtlety in its application and it is correspondingly worthwhile to have some new cogs around that can serve as a reference.


I have that. Indispensible for me, as I just can't trust my eyes to determine anything. This tool just removes the human factor out of the equation, as much as possible.

With just a little bit of experience, one can use it to determine the state of the chainrings, too.

"I'm not sure if this has been covered elsewhere..." try the search function, hint it has been.

Riding styles more than miles dictate wear on drivetrain parts. Good guestimate is 3 chains per cassette for the average.i

Another style consideration is if you use just one or 2 gears all the time, your cassette will not last as long as if you use several gears.

Steve Snowling, who was a mechanic for several European pro teams in the 70s and 80s, once wrote of knowing a fellow mechanic who changed chains every two weeks. Said that made the freewheels last an entire season, which is an accomplishment for a bike that sees 500 miles a week in all weather.

Of course, that didn't even make financial sense in the days of $5 Sedisport chains, let alone now that you can easily spend $50 on a good chain.

How many licks does it take to get to the Tootsie Roll center of a Tootsie Pop?

For me, about 3 chains... I suck.