Originally Posted by
crhilton
I believe I read in velonews a few months ago that campy claims you can run 10 new chains on one cassette for about 2,000 miles apiece. That's 20,000 miles on $520. Interestingly enough, that's more cost than your scenario. I'm more curious if you think it's actually plausible to run 10 chains on a cassette before it's replacement time.
Also, how many cassettes do you get to a set a chain rings on average? 1, 2, 3?
How many new chains you can go through before encountering chain skip with one of the cogs will vary greatly depending on the rider's power output, the riding conditions (dirty, gritty, wet) and how much time the rider uses only one or two of the cogs. It's those most-used cogs that matter. Using those cogs with the little ring increases chain tension and can't help but increase wear.
Tossing Campy chains after 2,000 miles is really stupid and obviously not cost effective when the chains cost as much as 3-4 cassettes.
FWIW, when I used a triple crank in the Colorado mountains, I wore out a 19T steel cog in only 6,000 miles and both the 19 and 21T titanium cogs on a Record cassette in only 4,000 miles. Ti cogs linked to a 28T chainring won't last long, even with a 135 lb rider.
What most people don't know is that a cog that is not severely worn, but skips with a new chain will not skip with a chain having only a few hundred miles of use. That cassette of mine that skipped with a new chain on the 19T cog did not get tossed, since it only had 6,000 miles on it. It went onto my winter bike and worked fine with any chain that wasn't brand new. Those worn Ti cogs were trash though. I've never bought a Ti cog since then.
Chainrings should last a very long time. I've never kept a bike long enough to wear out a chainring. I expected the 28T rings on my triples to wear quickly, but they didn't. Some users report 20-50,000 miles for the big ring.