chain roller pitting/wear

vinograd said:

I was cleaning up my bike the other day and noticed some unusual (to me
at least) wear on the rollers of the chain. There's a picture here:

http://flickr.com/photos/vinograd/40539321/

Basically the surface of the rollers is getting chewed up. This is an
SRAM PC-68 chain, on a road bike. The chain probably has less than 500
miles on it, and was replaced at the same time as the cassette (also an
SRAM). I'm just wondering if there's anything in particular that's
causing this - I hadn't noticed it on previous chains. This wear
hasn't really caused any performance degradation that I can detect.

Since production moved to Portugal all Sram chains will show these
marks: the rollers are made by punching the rings out of sheet, and the
shearmarks are pretty rough nowadays

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

Patrick Vinograd said:

I was cleaning up my bike the other day and noticed some unusual (to
me at least) wear on the rollers of the chain. There's a picture
here:

http://flickr.com/photos/vinograd/40539321/

That looks like a faulty chain to me. The rollers have shiny wear
grooves and an unused edge that is pitting.

Quoted message said:

Basically the surface of the rollers is getting chewed up. This is
an SRAM PC-68 chain, on a road bike. The chain probably has less
than 500 miles on it, and was replaced at the same time as the
cassette (also an SRAM). I'm just wondering if there's anything in
particular that's causing this - I hadn't noticed it on previous
chains. This wear hasn't really caused any performance degradation
that I can detect.

Quoted message said:

The wear definitely tends to be on the outside edges of the roller
rather than the middle. I could see that being due to how the chain
meshes with the cog at something of an angle when in the lowest
gears (such as when climbing, when there would also be more force
being applied to the drivetrain).

Quoted message said:

Anyway, just wanted to see if anybody had seen this wear pattern
before and if it indicative of an adjustment I should make.

I've never seen one like that. However, I wonder whether the
sprockets are for a different width chain. All my chains wear
uniformly (or are at least shiny) full width and there isn't much
clearance between sprocket and side plates of the chain. Besides,
rollers usually do not show much wear other than being clean, they are
all about 0.302" in diameter new and on an old worn out chain.

Take it back and get another chain... and check whether its the right
kind.

Jobst Brandt

Quoted message said:

Patrick Vinograd said:

I was cleaning up my bike the other day and noticed some unusual (to
me at least) wear on the rollers of the chain. There's a picture
here:

http://flickr.com/photos/vinograd/40539321/

That looks like a faulty chain to me. The rollers have shiny wear
grooves and an unused edge that is pitting.

Quoted message said:

Basically the surface of the rollers is getting chewed up. This is
an SRAM PC-68 chain, on a road bike. The chain probably has less
than 500 miles on it, and was replaced at the same time as the
cassette (also an SRAM). I'm just wondering if there's anything in
particular that's causing this - I hadn't noticed it on previous
chains. This wear hasn't really caused any performance degradation
that I can detect.

Quoted message said:

The wear definitely tends to be on the outside edges of the roller
rather than the middle. I could see that being due to how the chain
meshes with the cog at something of an angle when in the lowest
gears (such as when climbing, when there would also be more force
being applied to the drivetrain).

Quoted message said:

Anyway, just wanted to see if anybody had seen this wear pattern
before and if it indicative of an adjustment I should make.

I've never seen one like that. However, I wonder whether the
sprockets are for a different width chain. All my chains wear
uniformly (or are at least shiny) full width and there isn't much
clearance between sprocket and side plates of the chain. Besides,
rollers usually do not show much wear other than being clean, they are
all about 0.302" in diameter new and on an old worn out chain.

Take it back and get another chain... and check whether its the right
kind.

Jobst Brandt

As m-gineering said, the rollers are punched. I've seen plenty of chains
this way.

--
Phil, Squid-in-Training

"Phil, Squid-in-Training" <[email hidden]>

Quoted message said:

As m-gineering said, the rollers are punched. I've seen plenty of chains
this way.

From new, then? You'd see this on a brand new SRAM? If so, is it all
of their line, or just particular styles/speeds?

Phil Lee said:

Quoted message said:

Quoted message said:

Anyway, just wanted to see if anybody had seen this wear pattern
before and if it indicative of an adjustment I should make.

Quoted message said:

Quoted message said:

I've never seen one like that. However, I wonder whether the
sprockets are for a different width chain. All my chains wear
uniformly (or are at least shiny) full width and there isn't much
clearance between sprocket and side plates of the chain. Besides,
rollers usually do not show much wear other than being clean, they
are all about 0.302" in diameter new and on an old worn out chain.

Quoted message said:

Quoted message said:

Take it back and get another chain... and check whether its the
right kind.

Quoted message said:

As m-gineering said, the rollers are punched. I've seen plenty of
chains this way.

As far as I know they have always been punched but the finish was
smooth. I was looking at the picture offered and noticed that the
shiny part of the roller seemed to have a wear groove so that the
roller surface was no longer a true cylinder. The most worn chains I
have don't show the slightest deviation from a right circular cylinder
to the eye or to measurement within a few 0.0001" of 0.302" diameter.

Are you defending this low quality chain or what am I sensing? I may
not appreciate the status quo, not having bought a chain in a long
time. I have a large box full of them for replacements. Somewhat
like my MA-2 rims that don't crack even though I am told my wheels are
spoked much too tight and that this causes cracking, rather than
anodizing and lack of sockets in current rims. Now it's chains that
are OK with spalled and worn roller surfaces.

Jobst Brandt

Quoted message said:

The most worn chains I
have don't show the slightest deviation from a right circular cylinder
to the eye or to measurement within a few 0.0001" of 0.302" diameter.

Yeah, but (and I mean absolutely no offense here) you replace your chains
before they get much wear. I just threw away a chain which had a fair
amount of rollers missing, cracked and most severely bowed in profile (ie,
deeper valleys in the middle). Since you ride your chainwheels until the
teeth are razor-thin, wouldn't that tend to cause central wear more than
side wear?

Jasper

m-gineering said:

Since production moved to Portugal all Sram chains will show these
marks: the rollers are made by punching the rings out of sheet, and the
shearmarks are pretty rough nowadays

Ditto here. My PC-98 came out of the package (let's not debate the
wisdom of using jewel cases) looking like this.

Neil Brooks said:

"Phil, Squid-in-Training" <[email hidden]>

Quoted message said:

As m-gineering said, the rollers are punched. I've seen plenty of
chains this way.

From new, then? You'd see this on a brand new SRAM? If so, is it all
of their line, or just particular styles/speeds?

I can't recall which brands I saw this on, but I forgot that the chain in
question was a SRAM. I would have assumed higher quality on a SRAM chain,
but it wouldn't bother me to use it.

--
Phil, Squid-in-Training

Jasper Janssen said:

Quoted message said:

The most worn chains I have don't show the slightest deviation from
a right circular cylinder to the eye or to measurement within a few
0.0001" of 0.302" diameter.

Quoted message said:

Yeah, but (and I mean absolutely no offense here) you replace your
chains before they get much wear. I just threw away a chain which
had a fair amount of rollers missing, cracked and most severely
bowed in profile (ie, deeper valleys in the middle). Since you ride
your chainwheels until the teeth are razor-thin, wouldn't that tend
to cause central wear more than side wear?

I don't kn0ow how far you ride youre chains but I get the impression
that I am lucky to have a stash of ancient chains that don't do that.

However, in this case the OP stated what mileage he had:

# The chain probably has less than 500 miles on it, and was replaced
# at the same time as the cassette (also an SRAM).

You wouldn't be trying to drag this one of into a side track over
which we can argue endlessly? That seems to be the new paradigm.

Jobst Brandt

vinograd said:

I was cleaning up my bike the other day and noticed some unusual (to me
at least) wear on the rollers of the chain. There's a picture here:

http://flickr.com/photos/vinograd/40539321/

Basically the surface of the rollers is getting chewed up. This is an
SRAM PC-68 chain, on a road bike. The chain probably has less than 500
miles on it, and was replaced at the same time as the cassette (also an
SRAM). I'm just wondering if there's anything in particular that's
causing this - I hadn't noticed it on previous chains. This wear
hasn't really caused any performance degradation that I can detect.

The wear definitely tends to be on the outside edges of the roller
rather than the middle. I could see that being due to how the chain
meshes with the cog at something of an angle when in the lowest gears
(such as when climbing, when there would also be more force being
applied to the drivetrain).

Anyway, just wanted to see if anybody had seen this wear pattern before
and if it indicative of an adjustment I should make.

Quoted message said:

It was probably like that when new. SRAM quality seems to have taken a
nosedive recently; I couldn't get a new PC48 running properly on a new
8-speed cassette for love nor money. The more expensive PC58 was fine.

Quoted message said:

You wouldn't be trying to drag this one of into a side track over
which we can argue endlessly? That seems to be the new paradigm.

How dare you accuse me of such a thing? I, sir, am shocked and wounded
that you would even consider the idea!

Jasper (or, in other words, nice catch, and this is where I'll drop it)

vinograd said:

I was cleaning up my bike the other day and noticed some unusual (to me
at least) wear on the rollers of the chain. There's a picture here:

http://flickr.com/photos/vinograd/40539321/

Basically the surface of the rollers is getting chewed up. This is an
SRAM PC-68 chain, on a road bike. The chain probably has less than 500
miles on it, and was replaced at the same time as the cassette (also an
SRAM). I'm just wondering if there's anything in particular that's
causing this - I hadn't noticed it on previous chains. This wear
hasn't really caused any performance degradation that I can detect.

The wear definitely tends to be on the outside edges of the roller
rather than the middle. I could see that being due to how the chain
meshes with the cog at something of an angle when in the lowest gears
(such as when climbing, when there would also be more force being
applied to the drivetrain).

Anyway, just wanted to see if anybody had seen this wear pattern before
and if it indicative of an adjustment I should make.

Thanks,
Patrick

I received one out of the box in the same condition. Maybe SRAM wants
to sell more replacement cogs?

/s

Jasper Janssen said:

Quoted message said:

You wouldn't be trying to drag this one of into a side track over
which we can argue endlessly? That seems to be the new paradigm.

Quoted message said:

How dare you accuse me of such a thing? I, sir, am shocked and
wounded that you would even consider the idea!

I'm sorry for jumping to conclusions on such a fine sidestep.

Quoted message said:

Jasper (or, in other words, nice catch, and this is where I'll drop it)

Thanks, I thought you would be a gentleman about it, although I can
never be sure on this forum. As you see, I was disappointed by Carl
Fogel in the comment about lung volume and bicycling.

Jobst Brandt

Quoted message said:

Jasper Janssen said:

Quoted message said:

You wouldn't be trying to drag this one of into a side track over
which we can argue endlessly? That seems to be the new paradigm.

Quoted message said:

How dare you accuse me of such a thing? I, sir, am shocked and
wounded that you would even consider the idea!

I'm sorry for jumping to conclusions on such a fine sidestep.

Quoted message said:

Jasper (or, in other words, nice catch, and this is where I'll drop it)

Thanks, I thought you would be a gentleman about it, although I can
never be sure on this forum. As you see, I was disappointed by Carl
Fogel in the comment about lung volume and bicycling.

Jobst Brandt

Dear Jobst,

I was disappointed in your claim of 10 liters exhalation for
bicyclists.

Your sidestepping was impressive, but becoming all too
familiar.

First you changed your high school memory to university.

Then you announced (as usual) that the rather detailed
explanation of lung capacity was too hard for you to follow
and that it was all too complicated anyway and why do they
make such a fuss.

Then you amazingly changed to an explicit claim of exhaling
10 liters.

Then you started the duck-and-weave about how you don't care
how it's measured after your 10 liter nonsense became
patently indefensible.

(For crying out loud, the Tour de France publishes the
average for about 180 entrants, and it's around 5-6 liters,
with 8.1 as the max exhale for Eddy's son, who was never any
threat to Armstrong--whose lung capacity is reduced by
surgery and seven years of aging.)

So you started out chattering about how lung volume is 10
liters, waffled and evaded and dismissed several web sites
(as you dismiss every article or book except the one that
you promote tirelessly here) changed your memory, and
then--after starting out with measurements--announced that
measurements didn't matter anyway.

All of this, of course, without offering the slightest signs
of understanding anything at all about how lungs work.

If we're lucky, you'll treat us to the usual whine that
you're being hounded--after you dragged me into this
completely unrelated thread!

Tell us about how titanium doesn't spark again.

Carl Fogel

Quoted message said:

Dear Jobst,

Quoted message said:

Your sidestepping was impressive, but becoming all too
familiar.

First you changed your high school memory to university.

I challenge you to provide the citation where he said the test was done
in high school. The only person to mention high school in that thread
was you. Are you still in it? Or yet to graduate elementary school?

Before you accuse someone of being incompetent and a cheat, better
check first that you yourself are not delusional.

Quoted message said:

Then you announced (as usual) that the rather detailed
explanation of lung capacity was too hard for you to follow
and that it was all too complicated anyway and why do they
make such a fuss.

This is completely asinine. It was in fact you who was incapable of
realizing that vital capacity was a perfectly good underestimate of
total capacity, which can be corrected reasonably well to estimate the
latter, if necessary. And in context it was not necessary, as I already
explained to you at the time.

Quoted message said:

(For crying out loud, the Tour de France publishes the
average for about 180 en trants, and it's around 5-6 liters,
with 8.1 as the max exhale for Eddy's son

So who is dodging and weaving and changing his tune? You began by
stating that normal sized men have total capacities of 4-6 litres, and
cyclists are smaller than average and so should have lower totals. Then
you upped the bidding to 5-7, and now you conveniently ignore the fact
that if the max exhale for the TdF averages to 5.67 litres (5.75 in
2001), with Axel Merckx at 8.17, then these must be increased to
estimate the total capacity. I was quite conservative in adding 1.5l to
these figures, since actually 25% of total is usually figured to be
residual. This would give an average of 7.6l and Merckx at 10.9l..