Sprocket wear: How much is OK?

In article <ZS8qc.106727$Ik.8700558@attbi_s53>,
[email hidden] says...

Quoted message said:

I went a bit too long with my chain (3000 miles or so) and
I wore down some of my Ultegra sprockets a bit. The new
chain rides up a little bit as I apply pressure to the
pedals on some of the sprockets. For chains I was able to
find out rules for when they should be replaced (once every
1500 miles or when there is 1/8in of "stretch" for every
foot), but I couldn't find anything on when sprockets
should be replaced. Any pointers would be appreciated.

Going by mileage is really not a good idea since you can
never tell what kind of conditions were present during those
miles. How long was your chain when you tossed it? That can
usually give you an idea if you will need to change your
cogs, or if really bad your chain wheels too.
-------------
Alex

Quoted post said:

Originally posted by Shayne Wissler
I went a bit too long with my chain (3000 miles or so) and I
wore down some of my Ultegra sprockets a bit. The new chain
rides up a little bit as I apply pressure to the pedals on
some of the sprockets. For chains I was able to find out
rules for when they should be replaced (once every 1500
miles or when there is 1/8in of "stretch" for every foot),
but I couldn't find anything on when sprockets should be
replaced. Any pointers would be appreciated.

Shayne Wissler

If the chain jumps when under full pedal pressure, that cog needs immediate replacement.
It is visually indicated by pulling on a new chain engaged with suspect worn cogs. You can see a good explanation and visual on Sheldon Brown's site:

<http://sheldonbrown.com/chains.html>

If you have a mismatch of new chain and worn cogs you will waste some of your energy just rolling the chain on the teeth and warming the chain, cogs, lube, and surrounding air... please don't contribute to global warming.

Shayne Wissler said:

I went a bit too long with my chain (3000 miles or so) and
I wore down some of my Ultegra sprockets a bit. The new
chain rides up a little bit as I apply pressure to the
pedals on some of the sprockets. For chains I was able to
find out rules for when they should be replaced (once
every 1500 miles or when there is 1/8in of "stretch" for
every foot)

12 1/16 is a better measurement. At 12 1/8 the damage is
done.

"Alex Rodriguez" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

In article <ZS8qc.106727$Ik.8700558@attbi_s53>,
[email hidden] says...

Quoted message said:

I went a bit too long with my chain (3000 miles or so)
and I wore down

some

Quoted message said:

Quoted message said:

of my Ultegra sprockets a bit. The new chain rides up a
little bit as I apply pressure to the pedals on some of
the sprockets. For chains I was

able

Quoted message said:

Quoted message said:

to find out rules for when they should be replaced (once
every 1500 miles

or

Quoted message said:

Quoted message said:

when there is 1/8in of "stretch" for every foot), but I
couldn't find anything on when sprockets should be
replaced. Any pointers would be appreciated.

Going by mileage is really not a good idea since you can
never tell what kind of conditions were present during
those miles. How long was your

chain

Quoted message said:

when you tossed it? That can usually give you an idea if
you will need to change your cogs, or if really bad your
chain wheels too.

I don't like a method that doesn't incorporate inspection of
the actual cogs or their actual behavior.

Shayne Wissler

"daveornee" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Shayne Wissler said:

I went a bit too long with my chain (3000 miles or so)
and I wore down some of my Ultegra sprockets a bit.
The new chain rides up a little

bit

Quoted message said:

Quoted message said:

as I apply pressure to the pedals on some of the
sprockets. For chains

I

Quoted message said:

Quoted message said:

was able to find out rules for when they should be
replaced (once

every

Quoted message said:

Quoted message said:

1500 miles or when there is 1/8in of "stretch" for
every foot), but I couldn't find anything on when
sprockets should be replaced. Any pointers would be
appreciated. Shayne Wissler

If the chain jumps when under full pedal pressure, that
cog needs immediate replacement. It is visually indicated
by pulling on a new chain engaged with suspect worn cogs.

This is the method my LBS suggested--a cog is fine until it
starts to slip. One concern with this is that a worn cog
might not slip but will still eat into the chain, which will
in turn eat into other cogs. Perhaps this doesn't happen.
Another issue is that slippage is subjective, dependent on
how much force a given rider exerts. Another concern is lost
efficiency, as you point out:

Quoted message said:

If you have a mismatch of new chain and worn cogs you will
waste some of your energy just rolling the chain on the
teeth and warming the chain, cogs, lube, and surrounding
air... please don't contribute to global warming.

Every used cog is going to have some wear, and therefore
some amount of increased friction. So this seems like an
unusable standard for replacement (as opposed to 1/16"
stretch, which is a clear line).

Shayne Wissler

Shayne Wissler said:

This is the method my LBS suggested--a cog is fine until
it starts to slip. One concern with this is that a worn
cog might not slip but will still eat into the chain,
which will in turn eat into other cogs. Perhaps this
doesn't happen.

Jobst says this is not an issue.
groups.google.comgroupsOpen ↗
--
Rick Onanian

"Rick Onanian" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Shayne Wissler said:

This is the method my LBS suggested--a cog is fine until
it starts to

slip.

Quoted message said:

Quoted message said:

One concern with this is that a worn cog might not slip
but will still

eat

Quoted message said:

Quoted message said:

into the chain, which will in turn eat into other cogs.
Perhaps this

doesn't

Quoted message said:

Quoted message said:

happen.

Jobst says this is not an issue. groups.google.com-groups.google.com-Open ↗
/groups?&th=aefc0ab88472cdd8#link3

Thanks for posting that!!

Shayne Wissler