Chain replacement = cassette replacement ?
#26
Really Old Senior Member
#27
Senior Member
It isn't a "bad chain" that wears cassettes, it's using the cassette that wears cassettes. Same for the chain. It will last forever in a box but once you put it on the bike, it is subject to wear. Lubrication and cleanliness probably don't have much to do with how long a chain lasts either. It may shorten the life of the chain but only slightly. As I've said in another thread, I wish I had the courage to ride an unlubricated chain and see how long it will last. I may do it yet...
Your method of pulling the chain up on the teeth of the crank may have been a good...well, not good but somewhat acceptable... indicator of wear 25 to 30 years ago but chains are very different and a lot more is being asked of them today. Either measure it or use a chain checker but don't depend on the "pull it off the teeth method".
As for cassette wear, there are simply too many factors to consider as to when you'll need to replace the cassette. Generally speaking, if you change the chain when it shows 0.75% chain elongation, your cassette will outlast a few chains. If you go much past that, the teeth on the cassette will start to mate to the chain's wear and a new, tighter chain won't mesh properly and will skip.
In my experience, you are probably only going to get 3 or, possibly, 4 chains per cassette even if you are religious about checking the chain and/or lubricating the chain. The ramps on the cogs that help with shifting don't leave much room for wear. Chainrings, on the other hand, last roughly forever.
Your method of pulling the chain up on the teeth of the crank may have been a good...well, not good but somewhat acceptable... indicator of wear 25 to 30 years ago but chains are very different and a lot more is being asked of them today. Either measure it or use a chain checker but don't depend on the "pull it off the teeth method".
As for cassette wear, there are simply too many factors to consider as to when you'll need to replace the cassette. Generally speaking, if you change the chain when it shows 0.75% chain elongation, your cassette will outlast a few chains. If you go much past that, the teeth on the cassette will start to mate to the chain's wear and a new, tighter chain won't mesh properly and will skip.
In my experience, you are probably only going to get 3 or, possibly, 4 chains per cassette even if you are religious about checking the chain and/or lubricating the chain. The ramps on the cogs that help with shifting don't leave much room for wear. Chainrings, on the other hand, last roughly forever.
I have found that cleanliness does make a chain last longer. I don't mind spending the time necessary to clean my chain and drive train.
#28
Senior Member
Brad
#29
Senior Member
#30
Senior Member
...Yep, partly.
It's not about how the trough of the tooth wears on a cassette...it doesn't wear much. It's how the points of the teeth wear. Most specifically how the edge of the points wear. As the chain contacts the cassette teeth, the cassette tooth grabs onto the chain and puts pressure on the chain. It needs to maintain that pressure over all of the teeth that are engaged on the chain. If the point of tooth is worn, a new chain will roll up and over the edge of the tooth so that the chain loses contact and skips. The wear that is needed is minimal and mostly invisible. You can't really look at a cassette cog and see if it is worn like you can with a chainwheel.
It's not about how the trough of the tooth wears on a cassette...it doesn't wear much. It's how the points of the teeth wear. Most specifically how the edge of the points wear. As the chain contacts the cassette teeth, the cassette tooth grabs onto the chain and puts pressure on the chain. It needs to maintain that pressure over all of the teeth that are engaged on the chain. If the point of tooth is worn, a new chain will roll up and over the edge of the tooth so that the chain loses contact and skips. The wear that is needed is minimal and mostly invisible. You can't really look at a cassette cog and see if it is worn like you can with a chainwheel.
Brad
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