How can you tell when a chainring is worn?

I'm looking at this one I just bought (used) and it looks great. The chain and the
cassette are new and 10 speed so I'm concerned and don't want to wear them out
quickly. Is there something I could measure?

Charles

--
Catamaran racing is like being a kid: Wide Eyes, Big Smile, Wet Bottom

Charles Smith writes:

I'm looking at this one I just bought (used) and it looks great. The
chain and the cassette are new and 10 speed so I'm concerned and
don't want to wear them out quickly. Is there something I could
measure?

Yes, measure the chain, not the sprockets. Sprockets take care of
themselves. They either mesh effectively or skip under load.
Chainwheels just keeps on working until teeth break off. I have never
seen a chainwheel that won't drive a new or worn chain but I have seen
plenty of rear sprockets over which the chain skips under load. A
worn (elongated) chain is what wears out sprockets.

http://www.sheldonbrown.com/brandt/chain-care.html

Jobst Brandt

On Mon, 10 Jan 2005 05:20:44 GMT,
wrote:

Charles Smith writes:

I'm looking at this one I just bought (used) and it looks great. The
chain and the cassette are new and 10 speed so I'm concerned and
don't want to wear them out quickly. Is there something I could
measure?

Yes, measure the chain, not the sprockets. Sprockets take care of
themselves. They either mesh effectively or skip under load.
Chainwheels just keeps on working until teeth break off. I have never
seen a chainwheel that won't drive a new or worn chain but I have seen
plenty of rear sprockets over which the chain skips under load. A
worn (elongated) chain is what wears out sprockets.

http://www.sheldonbrown.com/brandt/chain-care.html

Jobst Brandt


Dear Jobst,

About a year ago, I replaced my chain and rear cluster.

The new chain came off my worn front 53-tooth chain ring the
moment that I pushed down on the pedal to roll out the
driveway.

The new chain came off the worn chain ring twice more,
despite the derailleur being apparently sitting in the right
place.

The new chain worked fine on the 39-tooth chain ring, which
is used on onlyl about 15% of my daily ride, so I replaced
the big chain ring.

The new front chain ring worked fine.

No broken teeth on the old chain ring, just badly worn teeth
when compared in profile to a new chain ring. I rotated them
to match the irregular factory tooth shaping.

Maybe this was a fluke? If rear cogs can wear out enough to
skip, shouldn't front cogs be able to do the same?

Carl Fogel

On Sun, 09 Jan 2005 23:37:52 -0500, Charles Smith
wrote:

I'm looking at this one I just bought (used) and it looks great. The chain and the
cassette are new and 10 speed so I'm concerned and don't want to wear them out
quickly. Is there something I could measure?

Two steps. First measure the chain wear;

http://www.sheldonbrown.com/chains.html

(The details are near the bottom of that page.)

If the chain's not worn, then you can check for sprocket wear as
detailed elsewhere on that page. A worn chain won't tell the truth
about whether the sprockets are worn or not. A 10-speed-cassette
setup is unlikely to have enough wear in the front sprockets to pose a
problem at this point, unless the rider put an incredible number of
miles on the bike.


--
Typoes are a feature, not a bug.
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Words processed in a facility that contains nuts.

wrote:

The new chain came off my worn front 53-tooth chain ring the
moment that I pushed down on the pedal to roll out the
driveway.

The new chain came off the worn chain ring twice more,
despite the derailleur being apparently sitting in the right
place.

The new chain worked fine on the 39-tooth chain ring, which
is used on onlyl about 15% of my daily ride, so I replaced
the big chain ring.

The new front chain ring worked fine.

No broken teeth on the old chain ring, just badly worn teeth
when compared in profile to a new chain ring. I rotated them
to match the irregular factory tooth shaping.

Maybe this was a fluke? If rear cogs can wear out enough to
skip, shouldn't front cogs be able to do the same?

I've also had a chainring worn down to this state. It was skipping very
badly on the large ring: occasionally badly enough to unship the chain.
It was actually getting dangerous as it would be most likely to skip
when the greatest load was being placed on it - either starting off or
getting out of the saddle to climb. There were no broken teeth; they
were just exremely worn.

The middle ring and granny did not skip at all. The worn chainring was
also prone to chain suck when changing down forn the large ring to the
middle. The large ring was a 46 tooth Shimano LX.

--
Dave...

On Mon, 10 Jan 2005 05:20:44 GMT,
wrote:

I have never
seen a chainwheel that won't drive a new or worn chain but I have seen
plenty of rear sprockets over which the chain skips under load.

I have to agree that in most cases, it is a worn rear sprocket/chain
that causes skipping... but...
On my mountain bike... i've had the 32T ring skip. Took a while to
figure out what was happening... started after putting on a new chain
and cassette. From a standstill, I could stand on the cranks and the
chain would slip on the chainring.

Our riding is mostly in wet/muddy conditions.. and I get maybe 400
miles on a chain and have to replace the cassettes after 2-3 chains
have been replaced and have to replace the chainrings at least once
per year.

charlieb in ct

On Mon, 10 Jan 2005 14:11:30 GMT, Charles Beristain
wrote:



Our riding is mostly in wet/muddy conditions.. and I get maybe 400
miles on a chain and have to replace the cassettes after 2-3 chains
have been replaced and have to replace the chainrings at least once
per year.

charlieb in ct

Hi, I hope you meant 4000[four thousand], not 400[four hundred] miles
If you put on a reasonable amount of miles per year, at 400, it would
get costly.

So, is the above correct?, If so, how many chains did you go through
last year?

Life is Good!
Jeff

"Jeff Starr" wrote in message
...
On Mon, 10 Jan 2005 14:11:30 GMT, Charles Beristain
wrote:



Our riding is mostly in wet/muddy conditions.. and I get maybe 400
miles on a chain and have to replace the cassettes after 2-3 chains
have been replaced and have to replace the chainrings at least once
per year.

charlieb in ct

Hi, I hope you meant 4000[four thousand], not 400[four hundred] miles
If you put on a reasonable amount of miles per year, at 400, it would
get costly.

So, is the above correct?, If so, how many chains did you go through
last year?

When you ride mostly in wet and muddy conditions as I do here during
wintertime in the Netherlands I get about 2500 km out of a chain and I take
good care of my bike. So 400 miles is not much, but 4000 miles is way to
high.

Lou

Lou Holtman wrote:


When you ride mostly in wet and muddy conditions as I do here during
wintertime in the Netherlands I get about 2500 km out of a chain and I take
good care of my bike. So 400 miles is not much, but 4000 miles is way to
high.

Please don't mention the X-word Lou, you know Jan couldn't cope
--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

On Mon, 10 Jan 2005 14:11:30 GMT, Charles Beristain
wrote:

On my mountain bike... i've had the 32T ring skip. Took a while to
figure out what was happening... started after putting on a new chain
and cassette. From a standstill, I could stand on the cranks and the
chain would slip on the chainring.

I had and maybe still have in the garage:

A 42t Campy middle ring that skipped with new chain and sprockets.
Teeth are worn in one area and it would probably work ok if rotated on
crankarm.

A 43t DA ring that Gerry Tatrai used for RAAM that skipped. The teeth
are wave shaped and needle sharp.