How can you tell when a chainring is worn?

Charles Smith said:

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
[email hidden]

Quoted message said:

Charles Smith said:

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
[email hidden]

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

Charles Smith said:

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.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Quoted message said:

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, [email hidden]

Quoted message said:

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

Charles Beristain said:

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

Quoted message said:

Charles Beristain said:

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 said:

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

Charles Beristain said:

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.

dkahn400 said:

Quoted message said:

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.

Dear Dave,

What puzzled me was that my worn chain worked fine on my
worn front 53-tooth chain ring, but the new chain/rear
cluster combination stripped the chain off the front
instantly (same stodgy sram pc48, same number of links, same
rear cluster, and then the same front ring). And both the
old and the new chains stayed put on the small 39-tooth
ring.

As far as I can see, the front ring's teeth, no matter how
worn they were, had to stay the same distance apart, so I
can't figure out why an old worn chain would stay in place
while a new chain that should have fit better would come
off.

That's why I'm wondering if Jobst or someone else is going
to explain that it was a fluke or that something else was
involved. But it certainly reminded me of how a worn rear
cog starts to skip and seems to get worse with a new
chain--which may be another misconception that I need
cleared up.

Of course, if I replaced my chains sooner, I might not get
into such situations.

Carl Fogel

On Mon, 10 Jan 2005 09:19:11 -0600, Jeff Starr <[email hidden]>

Quoted message said:

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?

nope-- 400 miles .. I do about 3-4000miles per year... I wipe the
chain off and relube it with "prolink" after each ride.

charlieb in ct.

Carl Fogel said:

Quoted message said:

Quoted message said:

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?

Quoted message said:

Quoted message said:

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.

Quoted message said:

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

Quoted message said:

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.

Quoted message said:

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

Quoted message said:

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

I don't know what sort of chain ring you have or what other effects
were involved, but I have ridden chainrings until there was barely any
width and length of full height teeth left. I'll let the thing run
until it fails. I can always use the other CW to ride home, it not
being tiny.

I think bicycle shops can attest to there being no need to replace a
chainwheel until the teeth are gone. In what manner did your chain
"come off". I can't visualize how the chain did not stay on the
sprocket. Was the chain in a strong cross-over angle, left CW of
three to rightmost rear sprocket of 10? I think this needs some
qualification. Of course since I ride with two CW's and a 6-speed FW,
I may be better off.

Quoted message said:

The new front chain ring worked fine.

Quoted message said:

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.

Quoted message said:

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 would invest in a bit of repeatability before buying a new CW.

Jobst Brandt
[email hidden]

Quoted message said:

Carl Fogel said:

Quoted message said:

> 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?

Quoted message said:

Quoted message said:

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.

Quoted message said:

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

Quoted message said:

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.

Quoted message said:

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

Quoted message said:

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

I don't know what sort of chain ring you have or what other effects
were involved, but I have ridden chainrings until there was barely any
width and length of full height teeth left. I'll let the thing run
until it fails. I can always use the other CW to ride home, it not
being tiny.

I think bicycle shops can attest to there being no need to replace a
chainwheel until the teeth are gone. In what manner did your chain
"come off". I can't visualize how the chain did not stay on the
sprocket. Was the chain in a strong cross-over angle, left CW of
three to rightmost rear sprocket of 10? I think this needs some
qualification. Of course since I ride with two CW's and a 6-speed FW,
I may be better off.

Quoted message said:

The new front chain ring worked fine.

Quoted message said:

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.

Quoted message said:

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 would invest in a bit of repeatability before buying a new CW.

Allow me to recap. Despite the experience of MANY people who've had chains
slip due to worn chain rings (in my case the middle rings on various mtb
cranksets), Jobst says it's not true so we all must be crazy, idiots, or
lying.

Just because it doesn't happen /easily/ on a road bike setup (especially an
old 12-speed), that doesn't mean it's not common on other types of
drivetrains and bikes. (In fact I have an XTR crankset gathering dust in my
garage right now, because I can't justify spending $70 for a new middle
ring. The old one LOOKS FINE, by the way, but will NOT hold a chain under
any significant power.)

I also have a TruVativ mtb triple that recently required a new middle ring
(after a new chain and cassette); fixed the skipping problem immediately.

Bill "we're not imagining this" S.

Charles Smith said:

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?

It develops a hooked appearance. However, chainrings are always the
last thing to wear out and the last to cause any slipping problems. If
a chain lasts 2,000 miles then a cassette will do many chains (provided
you replaced them when 12 links reached 12 1/16" and no later) and a
decent chainring will do more than one cassette.

I make an exception for those tinfoil things Shimano uses in place of
road chainrings these days ;-)

In article <[email hidden]>,

Quoted message said:

I think bicycle shops can attest to there being no need to replace a
chainwheel until the teeth are gone. In what manner did your chain
"come off". I can't visualize how the chain did not stay on the
sprocket. Was the chain in a strong cross-over angle, left CW of
three to rightmost rear sprocket of 10?

With properly adjusted derailleurs and a worn big ring I've had the
chain drop off to the middle ring (Campy Racing-T, 9-speed 13-23) a few
times when in one of the 2-3 bigger cogs. I was blacking out
from the first crash while accelerating, and had a jammed thumb for
a few months from the second while climbing. I then replaced the crankset
with a compact double that had brand new rings.

The next time my chain rings look worn I'm going to replace them.

--
<a href="http://www.poohsticks.org/drew/">Home Page</a>
In 1913 the inflation adjusted (in 2003 dollars) exemption for single people
was $54,567, married couples' exemption $72,756, the next $363,783 was taxed
at 1%, and earnings over $9,094,578 were taxed at the top rate of 7%.

I think the inner ring of a chainwheel can likely wear out. There are
pictures in books like "Sloans book of bicycling" and (i think)
"Effective Cycling" of hook-toothed chainwheels.

On a granny gear you might have a 36T aluminum front ring or smaller.
This ring would probably wear much faster than the rear freewheel
(steel) cog of a similar size because this ring would see more use.

There are some things you can do to extend the life of a worn
chainring, such as (a) Filing away the "hooks" in a hooked chainwheel
tooth, and (b) Reversing the chainring. However, when its gone its
gone.

Which wears faster, anodized or un-anodized rings ?? I have a feeling
that anodization is gone from a chainwheel after the first 100 miles
or so. Who makes 6061 chainrings and who makes 7000-series
chainrings?? Historically I think campagnolo and TA made 7000-series
chainrings. Also, I have heard that on 1970's bikes campagnolo rings
were much more scratch-resistant than Shimano and Sugino chainrings,
indicating that perhaps they used a harder alloy ?? I don't know, I
don't have any 1970's Shimano / Sugino chainrings.

- Don Gillies
San Diego, CA

Drew Eckhardt said:

In article <[email hidden]>,

Quoted message said:

I think bicycle shops can attest to there being no need to replace a
chainwheel until the teeth are gone. In what manner did your chain
"come off". I can't visualize how the chain did not stay on the
sprocket. Was the chain in a strong cross-over angle, left CW of
three to rightmost rear sprocket of 10?

With properly adjusted derailleurs and a worn big ring I've had the
chain drop off to the middle ring (Campy Racing-T, 9-speed 13-23) a
few times when in one of the 2-3 bigger cogs. I was blacking out
from the first crash while accelerating, and had a jammed thumb for
a few months from the second while climbing. I then replaced the
crankset with a compact double that had brand new rings.

The next time my chain rings look worn I'm going to replace them.

But...but...Jobst says it's not necessary! Must be true, right?!?

I've had a couple of chainwheels which were badly worn and the chains
started to come off them, off sideways. They were badly worn so that the
teeth were sharp triangles. Teeth were not missing.

In article <[email hidden]>,

Quoted message said:

I think bicycle shops can attest to there being no need to replace a
chainwheel until the teeth are gone. In what manner did your chain
"come off". I can't visualize how the chain did not stay on the
sprocket. Was the chain in a strong cross-over angle, left CW of
three to rightmost rear sprocket of 10? I think this needs some
qualification. Of course since I ride with two CW's and a 6-speed FW,
I may be better off.

I have had my chain slip over the tops of the teeth--there's no better
way to describe it--on a 50T chainring when starting from a stop. I was
in a mild-crossover gear, using the largest rear sprocket at the time.
I knew the chainring was worn, the teeth being worn to about 2/3 their
normal height, but the chainring had served me well until that moment,
which was the start of a race. The chain continued to slip occasionally
on the middle ring when in smaller rear sprockets for the rest of the
race. I replaced that chainring shortly afterward.

This was a 7-speed triple, SunTour freewheel rear, Sugino chainring
front with SunTour XC-Pro derailers front and rear.