cirrus wrote:
> Just got my Trek 7200 back from the bike shop after a service. They
> mentioned that is had "50% chain wear". I didn't have the forthought to
> ask how long before I'd need to replace the chain.
>
> Is it a straight linear relationship between km cycled & chain wear
> (I've done 5000 km or so to get to 50% chain wear ... so another 5000km
> to 100%??). Do you wait to 100% before you replace the chain? Or some
> other number?
Depending on the performance you want from your drivetrain, expecting
10,000km out of a chain is possibly a little over-ambitious
As the chain wears (it doesn't stretch, the rollers wear away) it
elongates, and thus doesn't mesh properly with the gears on the bike.
This leads to wear on the gears you use the most, and poor performance
on the other gears and until such time as things start to jump and skip
this is probably bearable - you're riding a hybrid, it's odds-on you're
not sprinting or anything likely to cause chain skip etc until it's
*very* worn.
The decision re chain replacement comes down to a compromise between
regular (say every 2 or so thou) chain replacement, which preserves
your gears for longer, or let the chain wear to the point of death, and
then replacing all the rest of the gears at the same time.
So it's up to you, regular chain replacement (which you can easily do
yourself) or less regular but much more expensive replacement of most
of the drive train. It sounds simple except that by replacing the
chain you don't get infinate life out of the gears (alas!), so you'll
still have to replace them every now and then, but less often than if
you let the chain go all the way. The decision is swayed by the sort
of riding you do and your preference.
