chain related?

the 3500 mile-old chain on my commuter bike has been slipping off every time
i put much torque on the pedals, like when standing on a start or hill. i
thought this would happen because of wear on the chainring and not the chain
but the chainrings look ok to the eye. i tried cleaning the chain and
adjusting the FD and RD very carefully also the hight and low screws but
this did not help. any ideas? thanks.
-alan

Sun, 12 Sep 2004 16:11:04 -0700,
, "dreaded"
wrote:

any ideas? thanks.

Read the other current thread detailing this exact subject.
Measure the chain.
http://sheldonbrown.com/chains.html
--
zk

"dreaded" wrote in message
...
the 3500 mile-old chain on my commuter bike has been slipping off every
time
i put much torque on the pedals, like when standing on a start or hill. i
thought this would happen because of wear on the chainring and not the
chain
but the chainrings look ok to the eye. i tried cleaning the chain and
adjusting the FD and RD very carefully also the hight and low screws but
this did not help. any ideas? thanks.

Had that problem a couple of months back. Had to replace both the chain and
the cassette to fix the problem.
--
Jon
JPinOH

poke the "i" out to reply

Alan who? writes:

The 3500 mile-old chain on my commuter bike has been slipping off
every time I put much torque on the pedals, like when standing on a
start or hill.

Slipping is an analog effect as in sliding down a hill on a sled.
Skipping is a digital effect as a chain skipping over one or more
sprocket teeth. So if we are to analyze what needs fixing, I would
like to know what is occurring and on the chainwheel of the crank or
the sprockets on the rear wheel.

I thought this would happen because of wear on the chainring and not
the chain but the chainrings look OK to the eye. I tried cleaning
the chain and adjusting the FD and RD very carefully also the high
and low screws but this did not help. Any ideas?

When you turn the crank backwards manually, are there any chain links
that do not straighten when exiting the rear derailleur, especially
when you use the left hand to reduce tension of the derailleur enough
to make the chain sag a bit on the bottom run?

The point I am pursuing is that if the chain worked before sitting
around, it should work now, nothing having worn in the meantime from
what you reveal. External rust on the chain should not affect its
performance but if the chain was idle after riding on wet roads, all
bets are off because the innards were bereft of lubricant and full of
water. This will generate binding rust. That's why I propose the
rotating flex test.

The problem is that if you use a new chain, it will most likely skip
on the cluster sprockets because new, in-pitch chains do not engage
well on sprockets that previously ran with an elongated (out-of-pitch)
chain.

http://draco.acs.uci.edu/rbfaq/FAQ/8d.2.html

Jobst Brandt