> On 26/01/2008 19:20, Martin Dann wrote:
>
> > At a complete guess, if you only get three chains to a cassette, and
> > each chain lasts 2/3 of the time than running a chain cassette
> > combination into the ground would, then you would be paying for three
> > chains and one cassette instead of two chains and two cassettes. This
> > is economically viable, and ignores the cost of replacing the extra
> > chain rings as well.
Bear in mind that the rings and sprockets will wear at different
rates- The combinations you use most often (and/or at highest load)
will see more wear than the others. The first stage of failure is
therefore a tendency to skip on those lightly used combos, where there
is a mismatch between chain wear and cog wear.
A new chain will be fine on the lightly used cogs, but will skip on
the worn ones- if you can change out the worn parts (eg middle ring on
a triple or a couple of the cogs on the cassette/freewheel) then you
can probably get a lot more miles out of the remainder.
I wore out the middle (36t) ring on my tourer well before anything
else. Next time it went I changed the smallest ring, too, but the
biggest (48t) was still OK.
Whether Shimano makes this feasible is another question- I strongly
suspect that they would discourage this sort of cavalier disregard of
their marketing...! Better manufacturers will supply spares for their
products long after the original purchase. I'm using Stronglight
chainsets at the moment- I'd probably go for TA out of choice but they
are expensive.
On 26 Jan, 19:38, Danny Colyer <
[email protected]> wrote:
> Doesn't sound viable to me. Of course, I have to buy 3 standard chains
> to make one complete chain, so it's a choice between paying for 9 chains
> and one cassette or 6 chains and 2 cassettes.
The wear is spread over three times as many links, too, so presumably
the chain lasts much longer, rendering the calculations even less
favourable.
Cheers,
W.
