Carbon fork crack?

Mike Reed said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the
circumference, and just on the outside, not the front where I'd
expect braking stress to expose any weakness.

I have done a reasonable amount of rain riding in recent weeks, and
I'm wondering if a scratch let some water in, and that's now messing
up the paint.

I can't detect any play with forceful tests using my hands -- the
dropout feels completely normal.

They're 3-year-old Weyless forks.

Am I in trouble here?

Pic, please.

--
Phil, Squid-in-Training

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

Has the fork ever been involved in a crash? Carried on a roof rack that
clamps the dropout? If the answer to either question is yes, then you
definitely need to look into things some more.

Back in the day, we used to sell a ton of steel and aluminum road bike forks
(to people who had crashed and damaged them). There are more people out
riding now than there were then, and in all likelihood, they crash just as
often. And yet, we replace virtually no forks anymore. Why? Because carbon
forks don't fail in the same manner... they don't bend backward, for
example, because carbon can't bend. But that doesn't mean they haven't been
damaged, but unfortunately, people don't know what to look for (cracks,
perhaps like what you've noticed, or a buzzing tone when you tap the fork),
and, when they've crashed and it still *looks* OK, rationalization sets in
because people don't want to think about replacing something expensive.

There are a *lot* of dangerously-weakened carbon forks out on the road.
Please, anyone reading this, use some common sense. If your bike had a
serious crash, *assume* that the fork may have been damaged. We've got a
frame in our shop... one of our employees... he ran into a curb, and the
steel frame buckled on the top tube and actually tore on the downtube. The
carbon fiber fork appears perfect. And I'll bet a lot of people would take
that fork and put it onto a new bike. But geez, that fork was NOT made to
take that kind of force without damage. Nothing is. Common sense says to
assume the worst, but again, I'll bet many are riding on forks that have
been through something like that, and think it's fine.

Sorry, a bit of a crusade here, and it may have nothing to do with your
fork whatsoever.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

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

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I can't detect any play with forceful tests using my hands -- the
dropout feels completely normal.

They're 3-year-old Weyless forks.

Am I in trouble here?

-Mike

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

Quoted message said:

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

Has the fork ever been involved in a crash? Carried on a roof rack that
clamps the dropout? If the answer to either question is yes, then you
definitely need to look into things some more.

Back in the day, we used to sell a ton of steel and aluminum road bike
forks (to people who had crashed and damaged them). There are more people
out riding now than there were then, and in all likelihood, they crash
just as often. And yet, we replace virtually no forks anymore. Why?
Because carbon forks don't fail in the same manner... they don't bend
backward, for example, because carbon can't bend. But that doesn't mean
they haven't been damaged, but unfortunately, people don't know what to
look for (cracks, perhaps like what you've noticed, or a buzzing tone when
you tap the fork), and, when they've crashed and it still *looks* OK,
rationalization sets in because people don't want to think about replacing
something expensive.

There are a *lot* of dangerously-weakened carbon forks out on the road.
Please, anyone reading this, use some common sense. If your bike had a
serious crash, *assume* that the fork may have been damaged. We've got a
frame in our shop... one of our employees... he ran into a curb, and the
steel frame buckled on the top tube and actually tore on the downtube. The
carbon fiber fork appears perfect. And I'll bet a lot of people would take
that fork and put it onto a new bike. But geez, that fork was NOT made to
take that kind of force without damage. Nothing is. Common sense says to
assume the worst, but again, I'll bet many are riding on forks that have
been through something like that, and think it's fine.

Sorry, a bit of a crusade here, and it may have nothing to do with your
fork whatsoever.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

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

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I can't detect any play with forceful tests using my hands -- the
dropout feels completely normal.

They're 3-year-old Weyless forks.

Am I in trouble here?

-Mike

Given the number of bikes I see riding round town with 'extra steep' head
angle, ripply down tubes and rake-less forks, this may well be true for
composite forks. I'd like to think that while composite parts are still
quite expensive, the buyers might care a bit more. Clearly this won't apply
to the second-hand market, which will likely remain ignorant. I don't
think you are on a crusade if it results in fewer unnecessary accidents.

I admit that I rode a demo bike from an LBS today without giving it the once
over. They're good guys, so I'm assuming they had. I think I will chack in
future though!

Skippy
E&OE

Mike Jacoubowsky said:

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

Quoted message said:

Has the fork ever been involved in a crash? Carried on a roof rack that
clamps the dropout? If the answer to either question is yes, then you
definitely need to look into things some more.

Back in the day, we used to sell a ton of steel and aluminum road bike
forks (to people who had crashed and damaged them). There are more
people out riding now than there were then, and in all likelihood, they
crash just as often. And yet, we replace virtually no forks anymore.
Why? Because carbon forks don't fail in the same manner... they don't
bend backward, for example, because carbon can't bend. But that doesn't
mean they haven't been damaged, but unfortunately, people don't know
what to look for (cracks, perhaps like what you've noticed, or a buzzing
tone when you tap the fork), and, when they've crashed and it still
*looks* OK, rationalization sets in because people don't want to think
about replacing something expensive.

There are a *lot* of dangerously-weakened carbon forks out on the road.
Please, anyone reading this, use some common sense. If your bike had a
serious crash, *assume* that the fork may have been damaged. We've got a
frame in our shop... one of our employees... he ran into a curb, and the
steel frame buckled on the top tube and actually tore on the downtube.
The carbon fiber fork appears perfect. And I'll bet a lot of people
would take that fork and put it onto a new bike. But geez, that fork was
NOT made to take that kind of force without damage. Nothing is. Common
sense says to assume the worst, but again, I'll bet many are riding on
forks that have been through something like that, and think it's fine.

Sorry, a bit of a crusade here, and it may have nothing to do with your
fork whatsoever.

I'll join you in your crusade. Carbon forks are probably the strongest
ones out there. I'm not surprised a steel frame buckled before the carbon
fork did. But you're right, there's no way to tell such a fork is not
damaged. It could very well be cracked internally without any external
signs. The "tuning fork" test isn't reliable either. The only reliable
tests I know of are X-ray, etc., which race car teams and other high tech
operations may have access to, but the rest of us do not.

When in doubt, throw it out!

It would be interesting to crash-test some carbon forks, and publish the
results. They may in fact be a lot stronger than we think. I'm sure the
BigBikeCo's do this, but keep the data to themselves.

Matt O.

Photos are here:
http://img20.imageshack.us/img20/5223/cimg20019oi.jpg
http://img137.imageshack.us/img137/3641/cimg20020yj.jpg
http://img137.imageshack.us/img137/8244/cimg20038xe.jpg
http://img137.imageshack.us/img137/7539/cimg20045lt.jpg

Thanks,
Mike

Mike Reed said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I can't detect any play with forceful tests using my hands -- the
dropout feels completely normal.

They're 3-year-old Weyless forks.

Am I in trouble here?

-Mike

Mike Jacoubowsky said:

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

Has the fork ever been involved in a crash? Carried on a roof rack that
clamps the dropout? If the answer to either question is yes, then you
definitely need to look into things some more.

No crashes. I use a roof rack twice a week. I did some research on this
and found Zinn's tests on it. It looks like the racks themselves do no
damage to carbon forks in normal use. If you tip the bike before
getting it out of the rack, that can crack them.

I don't hear anything strange. I just noticed the crack and I actually
look the forks over once a week, so this is a new development. That's
why I mentioned the rain. I had a friend with a carbon Trek frame that
started shedding paint because of rain (according to LBS and Trek rep).

I'm certainly cautious with the fork though, examining it often. It's
my first and only carbon part, and I'm still not so trusting of it --
mostly from lack of experience.

-Mike

Quoted message said:

Back in the day, we used to sell a ton of steel and aluminum road bike forks
(to people who had crashed and damaged them). There are more people out
riding now than there were then, and in all likelihood, they crash just as
often. And yet, we replace virtually no forks anymore. Why? Because carbon
forks don't fail in the same manner... they don't bend backward, for
example, because carbon can't bend. But that doesn't mean they haven't been
damaged, but unfortunately, people don't know what to look for (cracks,
perhaps like what you've noticed, or a buzzing tone when you tap the fork),
and, when they've crashed and it still *looks* OK, rationalization sets in
because people don't want to think about replacing something expensive.

There are a *lot* of dangerously-weakened carbon forks out on the road.
Please, anyone reading this, use some common sense. If your bike had a
serious crash, *assume* that the fork may have been damaged. We've got a
frame in our shop... one of our employees... he ran into a curb, and the
steel frame buckled on the top tube and actually tore on the downtube. The
carbon fiber fork appears perfect. And I'll bet a lot of people would take
that fork and put it onto a new bike. But geez, that fork was NOT made to
take that kind of force without damage. Nothing is. Common sense says to
assume the worst, but again, I'll bet many are riding on forks that have
been through something like that, and think it's fine.

Sorry, a bit of a crusade here, and it may have nothing to do with your
fork whatsoever.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

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

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I can't detect any play with forceful tests using my hands -- the
dropout feels completely normal.

They're 3-year-old Weyless forks.

Am I in trouble here?

-Mike

Mike Reed said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked,

It sure looks cracked to me, and it looks like the dropout is no longer
secure in the fork. These things are glued on, and the glue can fail. I
had a dropout come loose once. I glued it back on with super glue, but my
wife made me replace the fork anyway. Probably a good idea. While it's
hard to imagine a catastrophic failure mode given the separation you have,
if it were to spread a crack up the fork itself it could fail suddenly.

Quoted message said:

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I doubt that. It looks like it had some side force that was a bit too
much for it. No crashes?

--

David L. Johnson

__o | You will say Christ saith this and the apostles say this; but
_`\(,_ | what canst thou say? -- George Fox.
(_)/ (_) |

Matt O'Toole said:

It would be interesting to crash-test some carbon forks, and publish the
results. They may in fact be a lot stronger than we think. I'm sure the
BigBikeCo's do this, but keep the data to themselves.

It would be interesting. But I would not be so sure that the big
companies crash-test forks.

--

David L. Johnson

__o | Deserves death! I daresay he does. Many that live deserve
_`\(,_ | death. And some that die deserve life. Can you give it to
(_)/ (_) | them? Then do not be too eager to deal out death in judgement.
-- J. R. R. Tolkein

Quoted message said:

Quoted message said:

It would be interesting to crash-test some carbon forks, and publish the
results. They may in fact be a lot stronger than we think. I'm sure the
BigBikeCo's do this, but keep the data to themselves.

It would be interesting. But I would not be so sure that the big
companies crash-test forks.

At least one big company is crash-testing forks. A *lot* of forks. Their own
forks, and everybody else's. The holy grail is to create a new failure mode
that occurs before the carbon fails, but isn't catastrophic. Whoever first
accomplishes that has done a great service. Of course, there are going to be
a whole lot of people saying "Well gee, if that hadn't happend, the fork
would have been fine! They're just doing this so I have to replace things I
don't really have to."

Sigh.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

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

Quoted message said:

Matt O'Toole said:

It would be interesting to crash-test some carbon forks, and publish the
results. They may in fact be a lot stronger than we think. I'm sure the
BigBikeCo's do this, but keep the data to themselves.

It would be interesting. But I would not be so sure that the big
companies crash-test forks.

--

David L. Johnson

__o | Deserves death! I daresay he does. Many that live deserve
_`\(,_ | death. And some that die deserve life. Can you give it to
(_)/ (_) | them? Then do not be too eager to deal out death in judgement.
-- J. R. R. Tolkein

Quoted message said:

Quoted message said:

Has the fork ever been involved in a crash? Carried on a roof rack that
clamps the dropout? If the answer to either question is yes, then you
definitely need to look into things some more.

No crashes. I use a roof rack twice a week. I did some research on this
and found Zinn's tests on it. It looks like the racks themselves do no
damage to carbon forks in normal use. If you tip the bike before
getting it out of the rack, that can crack them.

Yes, that's how people crack them. Glad you're aware of it.

I'd bring the bike back into the shop you got it from and have someone take
a look at it there. Hopefully they have a digital camera so, if they have
any questions about what's going on, they can forward photos to the
manufacturer. Even with all our experience, we still find ourselves doing
that from time-to-time, although we consider ourselves fortunate; we've got
a long-term relationship with the techs, engineers and warranty people such
that, if they tell us "That's the first we've ever seen that", we can
actually believe them. (This doesn't happen very often)

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

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

Quoted message said:

Mike Jacoubowsky said:

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

Has the fork ever been involved in a crash? Carried on a roof rack that
clamps the dropout? If the answer to either question is yes, then you
definitely need to look into things some more.

No crashes. I use a roof rack twice a week. I did some research on this
and found Zinn's tests on it. It looks like the racks themselves do no
damage to carbon forks in normal use. If you tip the bike before
getting it out of the rack, that can crack them.

I don't hear anything strange. I just noticed the crack and I actually
look the forks over once a week, so this is a new development. That's
why I mentioned the rain. I had a friend with a carbon Trek frame that
started shedding paint because of rain (according to LBS and Trek rep).

I'm certainly cautious with the fork though, examining it often. It's
my first and only carbon part, and I'm still not so trusting of it --
mostly from lack of experience.

-Mike

Quoted message said:

Back in the day, we used to sell a ton of steel and aluminum road bike
forks
(to people who had crashed and damaged them). There are more people out
riding now than there were then, and in all likelihood, they crash just
as
often. And yet, we replace virtually no forks anymore. Why? Because
carbon
forks don't fail in the same manner... they don't bend backward, for
example, because carbon can't bend. But that doesn't mean they haven't
been
damaged, but unfortunately, people don't know what to look for (cracks,
perhaps like what you've noticed, or a buzzing tone when you tap the
fork),
and, when they've crashed and it still *looks* OK, rationalization sets
in
because people don't want to think about replacing something expensive.

There are a *lot* of dangerously-weakened carbon forks out on the road.
Please, anyone reading this, use some common sense. If your bike had a
serious crash, *assume* that the fork may have been damaged. We've got a
frame in our shop... one of our employees... he ran into a curb, and the
steel frame buckled on the top tube and actually tore on the downtube.
The
carbon fiber fork appears perfect. And I'll bet a lot of people would
take
that fork and put it onto a new bike. But geez, that fork was NOT made to
take that kind of force without damage. Nothing is. Common sense says to
assume the worst, but again, I'll bet many are riding on forks that have
been through something like that, and think it's fine.

Sorry, a bit of a crusade here, and it may have nothing to do with your
fork whatsoever.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

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

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I can't detect any play with forceful tests using my hands -- the
dropout feels completely normal.

They're 3-year-old Weyless forks.

Am I in trouble here?

-Mike

Quoted message said:

Photos are here:
http://img20.imageshack.us/img20/5223/cimg20019oi.jpg
http://img137.imageshack.us/img137/3641/cimg20020yj.jpg
http://img137.imageshack.us/img137/8244/cimg20038xe.jpg
http://img137.imageshack.us/img137/7539/cimg20045lt.jpg

Thanks,
Mike

Not liking what I'm seeing here. Looks like an adhesive failure; if it was
actual carbon cracking, you'd typically see a more-jagged edge. BUT... this
is a bit jaggy, not the usual straight line I'm used to.

Get it to the shop, and have them forward the photos.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA
"Mike Reed" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Photos are here:
http://img20.imageshack.us/img20/5223/cimg20019oi.jpg
http://img137.imageshack.us/img137/3641/cimg20020yj.jpg
http://img137.imageshack.us/img137/8244/cimg20038xe.jpg
http://img137.imageshack.us/img137/7539/cimg20045lt.jpg

Thanks,
Mike

Mike Reed said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I can't detect any play with forceful tests using my hands -- the
dropout feels completely normal.

They're 3-year-old Weyless forks.

Am I in trouble here?

-Mike

In article <[email hidden]>,

Mike Jacoubowsky said:

Quoted message said:

Quoted message said:

It would be interesting to crash-test some carbon forks, and
publish the results. They may in fact be a lot stronger than we
think. I'm sure the BigBikeCo's do this, but keep the data to
themselves.

It would be interesting. But I would not be so sure that the big
companies crash-test forks.

At least one big company is crash-testing forks. A *lot* of forks.
Their own forks, and everybody else's. The holy grail is to create a
new failure mode that occurs before the carbon fails, but isn't
catastrophic. Whoever first accomplishes that has done a great
service. Of course, there are going to be a whole lot of people
saying "Well gee, if that hadn't happend, the fork would have been
fine! They're just doing this so I have to replace things I don't
really have to."

Sigh.

Yup, it's a lot easier to replace a face than a fork, I guess.

Mike Jacoubowsky said:

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right.
It's not really cracked, but looks like it might be getting ready to
flake off a little. The effected region is on about 1/3 of the
circumference, and just on the outside, not the front where I'd
expect braking stress to expose any weakness.

Has the fork ever been involved in a crash? Carried on a roof rack
that clamps the dropout? If the answer to either question is yes,
then you definitely need to look into things some more.

Back in the day, we used to sell a ton of steel and aluminum road
bike forks (to people who had crashed and damaged them). There are
more people out riding now than there were then, and in all
likelihood, they crash just as often. And yet, we replace virtually
no forks anymore. Why?

I'm all about being safe here, but I think you answered your own question.

What I'm saying is that the vast majority of forks are plenty strong enough
to take a crash and keep on truckin. What everyone's worried about is the
next crash that causes the fork to break catastrophically instead of simply
becoming internally damaged.

But with the number of forks out there, isn't the lack of carbon fork
replacement itself a data point? It is almost as if that fact is ignored
completely.

--
Phil, Squid-in-Training

Mike Reed said:

Photos are here:
http://img20.imageshack.us/img20/5223/cimg20019oi.jpg
http://img137.imageshack.us/img137/3641/cimg20020yj.jpg
http://img137.imageshack.us/img137/8244/cimg20038xe.jpg
http://img137.imageshack.us/img137/7539/cimg20045lt.jpg

What's that long vertical crack (doesn't appear to be a reflection) that
goes up the front of the fork leg?

It looks pretty fargin dangerous to me.

--
Phil, Squid-in-Training

Phil said:

Mike Reed said:

Photos are here:
http://img20.imageshack.us/img20/5223/cimg20019oi.jpg
http://img137.imageshack.us/img137/3641/cimg20020yj.jpg
http://img137.imageshack.us/img137/8244/cimg20038xe.jpg
http://img137.imageshack.us/img137/7539/cimg20045lt.jpg

What's that long vertical crack (doesn't appear to be a reflection)
that goes up the front of the fork leg?

It looks pretty fargin dangerous to me.

Nevermind, I realized it's a spoke reflection. Still looks scary.
--
Phil, Squid-in-Training

David L. Johnson said:

Mike Reed said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked,

It sure looks cracked to me, and it looks like the dropout is no longer
secure in the fork. These things are glued on, and the glue can fail. I
had a dropout come loose once. I glued it back on with super glue, but my
wife made me replace the fork anyway. Probably a good idea. While it's
hard to imagine a catastrophic failure mode given the separation you have,
if it were to spread a crack up the fork itself it could fail suddenly.

Quoted message said:

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I doubt that. It looks like it had some side force that was a bit too
much for it. No crashes?

Nope no crashes ever on this fork.

I do have a theory now that I've had a day to think on it. I have
partially filed the lawyer's lips so the QR clears them without backing
off the nut. I didn't go all the way flush because I figured there was
an off chance that the little nubs my help one day, but they weren't in
the way of normal use -- so I left them.

So, it's possible that at some point I tightened the QR with the nut
over the lawyer-lips. This would be possible for the wheel or the roof
rack attachment, but I don't recall ever doing that. It would cause the
dropout to bend inward, which could cause a separation like what we
(maybe?) see developing here.

I'm very tedious when putting my bike on the rack or the front wheel
on, and my car is level in the places I usually put the bike on. It
will balance on the fork dropouts while I jiggle the QR to make sure
it's seated. I do this every time the bike goes in the rack.

Anyway, I think this is a possibility because of the leftover nubs.

FWIW, I can knock on the dropout from all directions, and the blade
from all directions, push, pull, and twist -- but both blades feel,
sound, and react identically to each other. The fork still fits my hub
perfectly. So other than this visible evidence, there's no indication
that something is wrong. I also know the visible evidence carries a lot
of weight in this court 🙂

Thanks everyone for the replies so far. I'll try to get it in to a shop
soon, but I imagine they'll refuse to give it the thumbs-up just for
liability reasons.

-Mike

Quoted message said:

Quoted message said:

Back in the day, we used to sell a ton of steel and aluminum road
bike forks (to people who had crashed and damaged them). There are
more people out riding now than there were then, and in all
likelihood, they crash just as often. And yet, we replace virtually
no forks anymore. Why?

I'm all about being safe here, but I think you answered your own question.

What I'm saying is that the vast majority of forks are plenty strong
enough to take a crash and keep on truckin. What everyone's worried about
is the next crash that causes the fork to break catastrophically instead
of simply becoming internally damaged.

But with the number of forks out there, isn't the lack of carbon fork
replacement itself a data point? It is almost as if that fact is ignored
completely.

--
Phil, Squid-in-Training

Phil: Unfortunately, there are an increasing number of "JRA" (Just Riding
Along) fork failures... failures of a very serious, and sometimes deadly
nature... where it has been credibly determined the damage had been caused
by an earlier crash, which the owner didn't think required attention.

The "next crash" may not be related to any impact whatsoever. It may truly
be a "JRA"-type failure, or at least seem so at the time. People *have*
crashed, severely. People *have* died. For doing nothing more than riding on
a fork that they thought was fine, but wasn't. If this sounds like I'm
trying to scare some sense into you, it's because I am.

Yes, present generation carbon forks are much stronger than the steel and
aluminum forks that came before. That can be verified through testing. They
work. The problem is that people don't understand that they're not bomb
proof, they do get damaged, and that damage may not always be easy to find.

Common sense may save your life. If you've had a nasty crash, one in which
it's possible your fork, handlebar or stem took an impact, replace those
parts. Please. A failure of any of those items will lead to far more
excitement than you want.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

"Phil, Squid-in-Training" <[email hidden]> wrote in
message news:jtkZf.4783$fS6.4374@dukeread11...

Quoted message said:

Mike Jacoubowsky said:

Quoted message said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right.
It's not really cracked, but looks like it might be getting ready to
flake off a little. The effected region is on about 1/3 of the
circumference, and just on the outside, not the front where I'd
expect braking stress to expose any weakness.

Has the fork ever been involved in a crash? Carried on a roof rack
that clamps the dropout? If the answer to either question is yes,
then you definitely need to look into things some more.

Back in the day, we used to sell a ton of steel and aluminum road
bike forks (to people who had crashed and damaged them). There are
more people out riding now than there were then, and in all
likelihood, they crash just as often. And yet, we replace virtually
no forks anymore. Why?

I'm all about being safe here, but I think you answered your own question.

What I'm saying is that the vast majority of forks are plenty strong
enough to take a crash and keep on truckin. What everyone's worried about
is the next crash that causes the fork to break catastrophically instead
of simply becoming internally damaged.

But with the number of forks out there, isn't the lack of carbon fork
replacement itself a data point? It is almost as if that fact is ignored
completely.

--
Phil, Squid-in-Training

Phil said:

Mike Jacoubowsky wrote:

Quoted message said:

Quoted message said:

Has the fork ever been involved in a cr ash?

Apart from the line in question, above it there are clearly abrasion
marks, like might be made with a light brush of a scouring pad. It
clearly was rubbed against something rough.

Quoted message said:

Quoted message said:

Back in the day, we used to sell a ton of steel and aluminum road
bike forks (to peop le who had crashed and damaged them). There are
more people out riding now than there were then, and in all
likelihood, they crash just as often. And yet, we replace virtually
no forks anymore. Why?

I'm all about being safe here, but I th ink you answered your own question.

What I'm saying is that the vast majority of forks are plenty strong enough
to take a crash and keep on truckin. What everyone's worried about is the
next crash that causes the fork to break catastrophically instead of simply
becoming internally damaged.

But with the number of forks out there, isn't the lack of carbon fork
replacement itself a data point? It is almost as if that fact is ignored
completely.

Technically no, it is not a data point. Data are reports of facts, and
a non-fact is, as the name suggests, not a fact. No fact, no data.

Apart from the technical philosophical issue, not, it is still not a
data point. It's not just bicycling and bicycles that have changed so
much since those days; it is behaviour and the bicycling environment.
Consider these factors:

-Most people who buy such things are poseurs buying expensive toys.
Most of them are probably hardly ever ridden.
-In the old days, the classic fork bender was collision with some twerp
opening a car door in traffic. Nowadays more and more riding is being
herded off the roads and on to bike paths (non-existent back in those
days), and even for riders on the roads, accidents of that type are no
longer as common as they used to be. Most bicycle riding today is done
in bicycle friendly environments, or at least, infinitely more friendly
than say 20 years ago. Sure most places are still not bicycle friendly,
but most riding is no longer done there. In the old days, there was
nowhere else to go.
-Society today is far more mobile and on top of that we live in a
throw-away era. People move from place to place, getting away from the
store they bought the equipment in, and on top of that, once they
crash, they are looking to "upgrade" anyway.
-Perhaps MJ can clarify, but don't forget, he didn't say "we replace
almost no carbon forks these days", he said they replace almost no
forks, period.

d

The little row of chevron cracks looks like shear in the axis
perpendicular to the fork blade. My guess is that it is a torsion or
twisting of the fork blade. Like if you tried to unscrew the dropout.

Mike Jacoubowsky said:

Quoted message said:

Photos are here:
http://img20.imageshack.us/img20/5223/cimg20019oi.jpg
http://img137.imageshack.us/img137/3641/cimg20020yj.jpg
http://img137.imageshack.us/img137/8244/cimg20038xe.jpg
http://img137.imageshack.us/img137/7539/cimg20045lt.jpg

Thanks,
Mike

Not liking what I'm seeing here. Looks like an adhesive failure; if it was
actual carbon cracking, you'd typically see a more-jagged edge. BUT... this
is a bit jaggy, not the usual straight line I'm used to.

Get it to the shop, and have them forward the photos.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA
"Mike Reed" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Photos are here:
http://img20.imageshack.us/img20/5223/cimg20019oi.jpg
http://img137.imageshack.us/img137/3641/cimg20020yj.jpg
http://img137.imageshack.us/img137/8244/cimg20038xe.jpg
http://img137.imageshack.us/img137/7539/cimg20045lt.jpg

Thanks,
Mike

Mike Reed said:

I've got a carbon fork with aluminum dropouts. The paint looks
"stressed," at the dropout seam on just the outside on the right. It's
not really cracked, but looks like it might be getting ready to flake
off a little. The effected region is on about 1/3 of the circumference,
and just on the outside, not the front where I'd expect braking stress
to expose any weakness.

I have done a reasonable amount of rain riding in recent weeks, and I'm
wondering if a scratch let some water in, and that's now messing up the
paint.

I can't detect any play with forceful tests using my hands -- the
dropout feels completely normal.

They're 3-year-old Weyless forks.

Am I in trouble here?

-Mike