Chain lifespan

[andrew_s]

They last longer because of both the straight chainline and the thicker sprockets. If you use a thicker 1/8 chain, that will be extra life too,
Also, for fixed and hub gear sprockets, when the chain is worn out you can turn the sprocket round and wear the other side of the teeth from fresh with the new chain.

 

[davidg]

There's two schools of thought on chain life.

One is to just use the chain for as long as possible. In this case you will always have to replace the cassette, and sometimes a chainring or two as well.
The other is to replace the chain before it's worn enough to start damaging the cassette.

In the first case, you've the occasional cost of a chain plus a cassette plus (possibly) a chainring or two.
In the second case, you've the cost of lots of chains.
What works out cheapest depends on what particular chains, cassettes etc you buy. For example, if you buy a chain like this one, I doubt that you'd discard it at 0.75%, or even 1%.

this sums up what I thought....

ie lots of chains or do the cassette etc when you the chain is kaput...

seems to make sense to me to change the chain more frequently as you are going to get better running, but I dont think there is a definite answer

 

[johnr]

I let my lbs man decide when the does maintenance twice a year. Works out to about 3 chains per cassette (plus the chain ring I use my hilly commute most days, once). That's over 4 years.