Grant Petersen / Rivendell on carbon forks

In article
,
landotter wrote:

On Jun 19, 10:41*am, Tim McNamara wrote:
In article
,

*landotter wrote:

Every con-man's story needs a grain of truth. But if crabon forks
were raging liabilities--they would get banned like Jarts were.

Peterson's replacement forks are handsome and well priced--his
tactics of marketing through FUD are loathsome.

Loathsome also is your tarring of Petersen- who has been known as
one of the bike industry's stand-up guys throughout his career and
whose company does a lot of philanthropy- as a "con man."


I called his FUD loathsome. The guy is a character, mostly
admirable-- but I won't stand for more unnecessary fear injected into
cycling dialog.

When you lie about danger in order to promote your own product, you
are indeed a con man.

Well. Let's look at the text. This will give landotter a clear and
straightforward way to point out specifically how Petersen is lying.
From the page cited by the OP:



"When carbon forks fail, they do so suddenly, and you crash. It happens
more frequently than anybody would like, especially riders and carbon
fork makers."

The failure mode of CFRP is well-known to be catastrophic, so that's not
a lie. Any catastrophic failures of bike forks are more than anyone
would like, so also not a lie. If your fork breaks while you're riding,
you crash- not a lie either


"If you haven't seen a snapped carbon fork, you've been looking in the
wrong dumpsters."

Aha! A lie? Hyperbole? Whaddya think? Tar and feathers?


"There used to be two sites devoted to carbon failures; now there's one:"

"Bustedcarbon.com

"We feel no happiness or smugness when we hear of or see a broken carbon
frame or fork. Behind every one that breaks is a crackerjack designer, a
quality manufacturer, a skilled engineer, and an enthusiastic retailer.
Nobody is dishonest, nobody is out to get you, but there is a learning
curve with carbon forks, and the zenith has not been reached.

"Sometimes an accident causes the break---if a truck hits you, the
snapping of your bike or fork is nobody's fault but the truckdriver's.
The accident is no worse than it would be if you'd had a solid steel
bike."


Any lies in there, landotter? Maybe they close the doors, pull the
blinds and do Numfar's Dance of Joy when they hear about broken CFRP
frames or forks. Or maybe the people designing CFRP forks really are
incompetent, fraudulent hacks- maybe undercover agents from AAA- with
suicidal intent and Petersen is colluding with them to cover it up.
Maybe the zenith of CFRP *has* been reached and Petersen doesn't want to
admit it.



"But in many of cases, you're riding along, hit a pothole or some other
relatively mild obstruction/fact of life on the road, and the fork
snaps. Maybe it was a manufacturing flaw that went undetected, or a
weakness that developed through use. With carbon fiber, the failures
happen suddenly. Carbon forks don't creak for a week, and they don't
soldier on injured; like one of those super cheap steel bikes you see
with bent-backwards forks and oblivious owners. Carbon forks snap in an
instant. And in many of those cases, a steel fork would have suffered
the blow and sloughed it off.

"Ironically, in lab tests, carbon forks beat the pants off all others.
When all things are good with them and they're fresh, they cream all
contenders. But they're like super-buff well-armored and gunned street
thugs who just happen to be supremely scared of blood. In the case of
forks, "blood," can be a defect hidden in the laminations that's
impossible to detect; or it can be a gouge that turns into a crack; or
age and sun damage that compromise the resin holding the laminations
together."

How about there, landotter?


"It doesn't really matter what it is. The bottom line is this: Carbon
forks have a shameful record of failure, and they give no warning. Is
this fear-mongering at its worst? Some will take it that way. But we're
not going to make a lot of money on these steel replacement forks.
I/Grant doubt we'll sell a dozen, because it's easier to keep going than
to change what you're doing, and you'll get no support for it among your
peer group. It'll be easier to write me off as a nut, or write Rivendell
off as having the steel-fork axe to grind. We do."

Well, clearly he is biased against CFRP. Must be sumkinda commie to be
critical of the latest and greatest salvation of bike manufacturers. An
honest person *couldn't* have reservations about CFRP, the greatest
material in the history of bicycles.


"Because steel is inherently safer. It's tougher. It soldiers on hurt
and unless the damage is severe, it remains rideable, not risky---at
least until you get home. Carpenters don't replace their hammers every
year, and they don't toss a miss-hit nail----they hammer it straight and
pound it in again. Steel is an incredible material, and it's main virtue
is toughness----just what you want in a bicycle fork.

That's the point behind these steel (Chrome-moly) forks."

Maybe Petersen is lying about the virtues of steel?

There's a lot more text describing their forks which I didn't cut and
paste. If landotter thinks the lies are in there, then he can certainly
cut and paste them.

--
That'll put marzipan in your pie plate, Bingo.

In article ,
Nate Nagel wrote:

On 06/19/2010 11:41 AM, Tim McNamara wrote:
In article
,
wrote:

On Jun 18, 5:13 pm, Jay wrote:
On Jun 18, 1:38 pm, wrote:

Any comment here on this strong anti-carbon position? He's
making up steel forks, not expecting to sell many, and even
buying back your old carbon fork, such great risk does he think
the carbon fork poses to your health.

http://www.rivbike.com/products/show...ms-fork/50-718

Not a troll's question. I ride a glued aluminum fork, myself. I
do wonder how much fragility can be built into carbon forks
while paring more and more weight off of them, and at what place
riders, even pros, say, "No, that's just too risky."

Carbon forks rarely fall apart, and when they do, it is because
of inadequate bonding, e.g., someone forgot to glue a leg to a
crown. That has been my experience. I have seen steel forks
break for the same reason -- someone tack brazed the leg to the
crown but did not finish off the fork.

Aluminum forks can fall apart for the same reasons, and
historically, some were dangerous due to the joining of
dissimilar materials (Viscount/Lambert). Modern bonded aluminum
forks are everywhere and seem to have a good service record.

The deal is that with CF, it can be damaged in a way that does
not show and then can fail later. I ride CF forks and have since
they hit the market (starting with first generation Kestrel
forks) and have never had a set fail. But then again, the one
time I had a bad frontal crash while riding a CF fork, I replaced
the fork just to be safe (it was a cheapie fork). Absent damage,
though, they aren't just falling apart.

Grant is right that CF is not as safe as steel under some
circumstances (where there is latent damage). His forks look
like a nice product at a not too outrageous price. I like that
crown (with no internal plug stress risers) and the drop outs,
too. If I had a steel bike that needed a fork, I'd consider that
one. -- Jay Beattie.

Every con-man's story needs a grain of truth. But if crabon forks
were raging liabilities--they would get banned like Jarts were.

Peterson's replacement forks are handsome and well priced--his
tactics of marketing through FUD are loathsome.

Loathsome also is your tarring of Petersen- who has been known as
one of the bike industry's stand-up guys throughout his career and
whose company does a lot of philanthropy- as a "con man."


I'd characterize Mr. Petersen as more of a "retro-grouch" - I suspect
that he honestly believes that "steel is real" even if I don't always
agree with the dangers of crabon fribe. (I wouldn't ride my
Cannondale if I felt that doing so was putting me in imminent danger
of faceplanting...) At worst, he's guilty of hyperbole...

He is conservative about bike design- in materials, in fit, in
appearance, etc. He could have his products built in any material-
steel, aluminum, titanium, CFRP, bamboo. He chooses steel so clearly
"steel is real" is a part of his thinking.

The term "retro-grouch" was coined about Petersen, BTW.

I have zero CFRP on my bikes, although I do have a pair of Campy CFRP
brake levers I've never gotten around to installing. Neat looking
stuff, the visual sense of depth when looking at the weave is
intriguing. For frames and especially forks I just don't trust the
stuff, having seen too many reports of catastrophic failures and knowing
of people who were severely injured as a result. I wouldn't use it for
seat posts, stems or handlebars either. Hmm. CFR water bottle cages-
I'd be willing to use those.

--
That'll put marzipan in your pie plate, Bingo.

Tim McNamara wrote:
In article ,
Nate Nagel wrote:

On 06/19/2010 11:41 AM, Tim McNamara wrote:
In article
,
wrote:

On Jun 18, 5:13 pm, Jay wrote:
On Jun 18, 1:38 pm, wrote:

Any comment here on this strong anti-carbon position? He's
making up steel forks, not expecting to sell many, and even
buying back your old carbon fork, such great risk does he think
the carbon fork poses to your health.
http://www.rivbike.com/products/show...ms-fork/50-718
Not a troll's question. I ride a glued aluminum fork, myself. I
do wonder how much fragility can be built into carbon forks
while paring more and more weight off of them, and at what place
riders, even pros, say, "No, that's just too risky."
Carbon forks rarely fall apart, and when they do, it is because
of inadequate bonding, e.g., someone forgot to glue a leg to a
crown. That has been my experience. I have seen steel forks
break for the same reason -- someone tack brazed the leg to the
crown but did not finish off the fork.

Aluminum forks can fall apart for the same reasons, and
historically, some were dangerous due to the joining of
dissimilar materials (Viscount/Lambert). Modern bonded aluminum
forks are everywhere and seem to have a good service record.

The deal is that with CF, it can be damaged in a way that does
not show and then can fail later. I ride CF forks and have since
they hit the market (starting with first generation Kestrel
forks) and have never had a set fail. But then again, the one
time I had a bad frontal crash while riding a CF fork, I replaced
the fork just to be safe (it was a cheapie fork). Absent damage,
though, they aren't just falling apart.

Grant is right that CF is not as safe as steel under some
circumstances (where there is latent damage). His forks look
like a nice product at a not too outrageous price. I like that
crown (with no internal plug stress risers) and the drop outs,
too. If I had a steel bike that needed a fork, I'd consider that
one. -- Jay Beattie.
Every con-man's story needs a grain of truth. But if crabon forks
were raging liabilities--they would get banned like Jarts were.

Peterson's replacement forks are handsome and well priced--his
tactics of marketing through FUD are loathsome.
Loathsome also is your tarring of Petersen- who has been known as
one of the bike industry's stand-up guys throughout his career and
whose company does a lot of philanthropy- as a "con man."

I'd characterize Mr. Petersen as more of a "retro-grouch" - I suspect
that he honestly believes that "steel is real" even if I don't always
agree with the dangers of crabon fribe. (I wouldn't ride my
Cannondale if I felt that doing so was putting me in imminent danger
of faceplanting...) At worst, he's guilty of hyperbole...

He is conservative about bike design- in materials, in fit, in
appearance, etc. He could have his products built in any material-
steel, aluminum, titanium, CFRP, bamboo. He chooses steel so clearly
"steel is real" is a part of his thinking.

The term "retro-grouch" was coined about Petersen, BTW.

I have zero CFRP on my bikes, although I do have a pair of Campy CFRP
brake levers I've never gotten around to installing. Neat looking
stuff, the visual sense of depth when looking at the weave is
intriguing. For frames and especially forks I just don't trust the
stuff, having seen too many reports of catastrophic failures and knowing
of people who were severely injured as a result. I wouldn't use it for
seat posts, stems or handlebars either. Hmm. CFR water bottle cages-
I'd be willing to use those.


Tim,

I read this reply as well as your other one to Landotter. If carbon is
such a fragile, inadequate material, why would companies such as Trek,
Giant, and others bank on it for theit flagship products? I don't see
either company as self destructive.

On Jun 19, 3:38*am, SMS wrote:
incredulous wrote:
Any comment here on this strong anti-carbon position? He's making up
steel forks, not expecting to sell many, and even buying back your old
carbon fork, such great risk does he think the carbon fork poses to
your health.

Consider a carbon fork a wear item and replace it periodically, every
few thousand miles.

His statement "Maybe it was a manufacturing flaw that went undetected,
or a weakness that developed through use" is true, but the latter is
much more likely than the former, and the former can occur no matter
what the material (though it's less likely with steel or aluminum than
with CF).

I would have to do a lot of research to convince myself that carbon
steerers are safe and durable. I have gotten good service out of my CF
forks with aluminum and steel steerers. In any event, someone should
do a real survey to find out what percentage of CF forks are failing
and by what mode. There are so many on the market now that if there
were a serious problem, I would expect to see an epidemic of failures.
-- Jay Beattie.

"David Scheidt" wrote in message
...
landotter wrote:
:On Jun 19, 10:41 am, Tim McNamara wrote:
: In article
: ,
:
:
:
:
:
: landotter wrote:
: On Jun 18, 5:13 pm, Jay Beattie wrote:
: On Jun 18, 1:38 pm, incredulous wrote:
:
: Any comment here on this strong anti-carbon position? He's
making
: up steel forks, not expecting to sell many, and even buying
back
: your old carbon fork, such great risk does he think the
carbon
: fork poses to your health.
:
: http://www.rivbike.com/products/show...ms-fork/50-718
:
: Not a troll's question. I ride a glued aluminum fork, myself.
I
: do wonder how much fragility can be built into carbon forks
while
: paring more and more weight off of them, and at what place
: riders, even pros, say, "No, that's just too risky."
:
: Carbon forks rarely fall apart, and when they do, it is because
of
: inadequate bonding, e.g., someone forgot to glue a leg to a
crown.
: That has been my experience. I have seen steel forks break for
the
: same reason -- someone tack brazed the leg to the crown but did
not
: finish off the fork.
:
: Aluminum forks can fall apart for the same reasons, and
: historically, some were dangerous due to the joining of
dissimilar
: materials (Viscount/Lambert). Modern bonded aluminum forks are
: everywhere and seem to have a good service record.
:
: The deal is that with CF, it can be damaged in a way that does
not
: show and then can fail later. I ride CF forks and have since
they
: hit the market (starting with first generation Kestrel forks)
and
: have never had a set fail. But then again, the one time I had a
: bad frontal crash while riding a CF fork, I replaced the fork
just
: to be safe (it was a cheapie fork). Absent damage, though, they
: aren't just falling apart.
:
: Grant is right that CF is not as safe as steel under some
: circumstances (where there is latent damage). His forks look
like
: a nice product at a not too outrageous price. I like that crown
: (with no internal plug stress risers) and the drop outs, too.
If I
: had a steel bike that needed a fork, I'd consider that one. --
Jay
: Beattie.
:
: Every con-man's story needs a grain of truth. But if crabon forks
: were raging liabilities--they would get banned like Jarts were.
:
: Peterson's replacement forks are handsome and well priced--his
: tactics of marketing through FUD are loathsome.
:
: Loathsome also is your tarring of Petersen- who has been known as
one of
: the bike industry's stand-up guys throughout his career and whose
: company does a lot of philanthropy- as a "con man."


:I called his FUD loathsome. The guy is a character, mostly
admirable--
:but I won't stand for more unnecessary fear injected into cycling
:dialog.

Have you paid attention to the problem trek is having with their
carbon forks? If you torque the stem bolts to enough preload that
they don't fall out (and cause your bars to fall off), they break.
Trek is specifically instructing people to install their stems so that
the bolts fall out. Now that's a safe product!




--
sig 89

4mm Bolts do not fall out, nor do they loosen, at 5nm of torque. Nor can
you twist the stem on the fork at the recommended torque.
Improperly-designed stems that point-load a carbon steer tube are an
issue, as is installing a stem without using a 5mm spacer on top of it
(to prevent compression and cracking of the steer tube when the top cap
is tightened down). There is an issue that the industry has no testing
standards for steer tube/stem interfaces on advanced materials, and in
the absence of that, it is wise to stick only to what the manufacturer
recommends, because that combination *has* been tested.

Carbon fiber is not an adjective. It's a material, which can be used to
make ultra-light equipment that needs more care & attention than
something built using more of it. I have owned four carbon bikes since
1992, and have ridden, and will continue to ride, without fear that
they're about to fall apart underneath me. On the other hand, I have had
three stem failures (two quill one threadless).

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

In article ,
"z, fred" wrote:

Tim McNamara wrote:
In article ,
Nate Nagel wrote:

On 06/19/2010 11:41 AM, Tim McNamara wrote:
In article

,
wrote:

On Jun 18, 5:13 pm, Jay
wrote:
On Jun 18, 1:38 pm, wrote:

Any comment here on this strong anti-carbon position? He's
making up steel forks, not expecting to sell many, and even
buying back your old carbon fork, such great risk does he
think the carbon fork poses to your health.
http://www.rivbike.com/products/show...ms-fork/50-718 Not
a troll's question. I ride a glued aluminum fork, myself. I do
wonder how much fragility can be built into carbon forks while
paring more and more weight off of them, and at what place
riders, even pros, say, "No, that's just too risky."
Carbon forks rarely fall apart, and when they do, it is because
of inadequate bonding, e.g., someone forgot to glue a leg to a
crown. That has been my experience. I have seen steel forks
break for the same reason -- someone tack brazed the leg to the
crown but did not finish off the fork.

Aluminum forks can fall apart for the same reasons, and
historically, some were dangerous due to the joining of
dissimilar materials (Viscount/Lambert). Modern bonded
aluminum forks are everywhere and seem to have a good service
record.

The deal is that with CF, it can be damaged in a way that does
not show and then can fail later. I ride CF forks and have
since they hit the market (starting with first generation
Kestrel forks) and have never had a set fail. But then again,
the one time I had a bad frontal crash while riding a CF fork,
I replaced the fork just to be safe (it was a cheapie fork).
Absent damage, though, they aren't just falling apart.

Grant is right that CF is not as safe as steel under some
circumstances (where there is latent damage). His forks look
like a nice product at a not too outrageous price. I like that
crown (with no internal plug stress risers) and the drop outs,
too. If I had a steel bike that needed a fork, I'd consider
that one. -- Jay Beattie.
Every con-man's story needs a grain of truth. But if crabon
forks were raging liabilities--they would get banned like Jarts
were.

Peterson's replacement forks are handsome and well priced--his
tactics of marketing through FUD are loathsome.
Loathsome also is your tarring of Petersen- who has been known as
one of the bike industry's stand-up guys throughout his career
and whose company does a lot of philanthropy- as a "con man."

I'd characterize Mr. Petersen as more of a "retro-grouch" - I
suspect that he honestly believes that "steel is real" even if I
don't always agree with the dangers of crabon fribe. (I wouldn't
ride my Cannondale if I felt that doing so was putting me in
imminent danger of faceplanting...) At worst, he's guilty of
hyperbole...

He is conservative about bike design- in materials, in fit, in
appearance, etc. He could have his products built in any material-
steel, aluminum, titanium, CFRP, bamboo. He chooses steel so
clearly "steel is real" is a part of his thinking.

The term "retro-grouch" was coined about Petersen, BTW.

I have zero CFRP on my bikes, although I do have a pair of Campy
CFRP brake levers I've never gotten around to installing. Neat
looking stuff, the visual sense of depth when looking at the weave
is intriguing. For frames and especially forks I just don't trust
the stuff, having seen too many reports of catastrophic failures
and knowing of people who were severely injured as a result. I
wouldn't use it for seat posts, stems or handlebars either. Hmm.
CFR water bottle cages- I'd be willing to use those.


Tim,

I read this reply as well as your other one to Landotter. If carbon
is such a fragile, inadequate material, why would companies such as
Trek, Giant, and others bank on it for theit flagship products? I
don't see either company as self destructive.

Interesting question. I think there are a few aspects to that. First,
following the approach of Sturmey-Archer for decades, it's easy to blame
the user. Second, it's stiffer/lighter/stronger/faster which really
matters to the fat old guys and the pro-racer wannabes I usually see on
these things. Third, it looks cool. Fourth, I hear lots of carbon
owners no longer thinking of their bikes as a durable good but as a
consumable good... so they'll be buying a new $5000 bike every few
years. Score! And if it breaks, blame the user who "tightened the
bolts too tight" or otherwise didn't do the mumbo-jumbo voodoo
maintenance that needs to be done.

There's a lot of busted carbon out there, but most people never hear of
it. If you can cause a catastrophic failure by tightening two bolts to
10 Nm instead of 5 Nm, this is a material that has NO business on a
bicycle in that application, IMHO. You, OTOH, can ride whatever bike
you want. It's not my problem.

--
That'll put marzipan in your pie plate, Bingo.

"Tim McNamara" wrote in message
There's a lot of busted carbon out there, but most people never hear
of
it. If you can cause a catastrophic failure by tightening two bolts
to
10 Nm instead of 5 Nm, this is a material that has NO business on a
bicycle in that application, IMHO. You, OTOH, can ride whatever bike
you want. It's not my problem.

I set up my bike without using a torque wrench a while back (built it at
home, not at the shop, and didn't have a torque wrench available). So I
checked it a few months later (my goodness, I didn't crash & die in the
meantime???) and found that all six bolts on my stem (the two that clamp
the steer tube, and the four clamping the bars) were under-spec for
torque, as much as 20%. But never any slippage, and they felt pretty
tight. I think you'd need to be pretty ham-fisted to exceed the max
torque spec, and taking it to 10nm (double) would be darn near
impossible.

Another experiment I've done, several times to make sure it repeats, is
to have a bolt that's at proper torque, use a standard allen wrench to
loosen it a turn (more than enough to re-straighten a handlebar), then
retighten the same amount, again with the allen wrench. After doing so,
torque was measured and found to be the same as before. In other words,
there's no need to be so paranoid that someone thinks they have to bring
a torque wrench with them on a ride.

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


"Tim McNamara" wrote in message
...
In article ,
"z, fred" wrote:

Tim McNamara wrote:
In article ,
Nate Nagel wrote:

On 06/19/2010 11:41 AM, Tim McNamara wrote:
In article

,
wrote:

On Jun 18, 5:13 pm, Jay
wrote:
On Jun 18, 1:38 pm, wrote:

Any comment here on this strong anti-carbon position? He's
making up steel forks, not expecting to sell many, and even
buying back your old carbon fork, such great risk does he
think the carbon fork poses to your health.
http://www.rivbike.com/products/show...ms-fork/50-718 Not
a troll's question. I ride a glued aluminum fork, myself. I do
wonder how much fragility can be built into carbon forks while
paring more and more weight off of them, and at what place
riders, even pros, say, "No, that's just too risky."
Carbon forks rarely fall apart, and when they do, it is because
of inadequate bonding, e.g., someone forgot to glue a leg to a
crown. That has been my experience. I have seen steel forks
break for the same reason -- someone tack brazed the leg to the
crown but did not finish off the fork.

Aluminum forks can fall apart for the same reasons, and
historically, some were dangerous due to the joining of
dissimilar materials (Viscount/Lambert). Modern bonded
aluminum forks are everywhere and seem to have a good service
record.

The deal is that with CF, it can be damaged in a way that does
not show and then can fail later. I ride CF forks and have
since they hit the market (starting with first generation
Kestrel forks) and have never had a set fail. But then again,
the one time I had a bad frontal crash while riding a CF fork,
I replaced the fork just to be safe (it was a cheapie fork).
Absent damage, though, they aren't just falling apart.

Grant is right that CF is not as safe as steel under some
circumstances (where there is latent damage). His forks look
like a nice product at a not too outrageous price. I like that
crown (with no internal plug stress risers) and the drop outs,
too. If I had a steel bike that needed a fork, I'd consider
that one. -- Jay Beattie.
Every con-man's story needs a grain of truth. But if crabon
forks were raging liabilities--they would get banned like Jarts
were.

Peterson's replacement forks are handsome and well priced--his
tactics of marketing through FUD are loathsome.
Loathsome also is your tarring of Petersen- who has been known as
one of the bike industry's stand-up guys throughout his career
and whose company does a lot of philanthropy- as a "con man."

I'd characterize Mr. Petersen as more of a "retro-grouch" - I
suspect that he honestly believes that "steel is real" even if I
don't always agree with the dangers of crabon fribe. (I wouldn't
ride my Cannondale if I felt that doing so was putting me in
imminent danger of faceplanting...) At worst, he's guilty of
hyperbole...

He is conservative about bike design- in materials, in fit, in
appearance, etc. He could have his products built in any material-
steel, aluminum, titanium, CFRP, bamboo. He chooses steel so
clearly "steel is real" is a part of his thinking.

The term "retro-grouch" was coined about Petersen, BTW.

I have zero CFRP on my bikes, although I do have a pair of Campy
CFRP brake levers I've never gotten around to installing. Neat
looking stuff, the visual sense of depth when looking at the weave
is intriguing. For frames and especially forks I just don't trust
the stuff, having seen too many reports of catastrophic failures
and knowing of people who were severely injured as a result. I
wouldn't use it for seat posts, stems or handlebars either. Hmm.
CFR water bottle cages- I'd be willing to use those.


Tim,

I read this reply as well as your other one to Landotter. If carbon
is such a fragile, inadequate material, why would companies such as
Trek, Giant, and others bank on it for theit flagship products? I
don't see either company as self destructive.

Interesting question. I think there are a few aspects to that.
First,
following the approach of Sturmey-Archer for decades, it's easy to
blame
the user. Second, it's stiffer/lighter/stronger/faster which really
matters to the fat old guys and the pro-racer wannabes I usually see
on
these things. Third, it looks cool. Fourth, I hear lots of carbon
owners no longer thinking of their bikes as a durable good but as a
consumable good... so they'll be buying a new $5000 bike every few
years. Score! And if it breaks, blame the user who "tightened the
bolts too tight" or otherwise didn't do the mumbo-jumbo voodoo
maintenance that needs to be done.

There's a lot of busted carbon out there, but most people never hear
of
it. If you can cause a catastrophic failure by tightening two bolts
to
10 Nm instead of 5 Nm, this is a material that has NO business on a
bicycle in that application, IMHO. You, OTOH, can ride whatever bike
you want. It's not my problem.

--
That'll put marzipan in your pie plate, Bingo.

Op 20-6-2010 5:40, Tim McNamara schreef:

There's a lot of busted carbon out there, but most people never hear of
it. If you can cause a catastrophic failure by tightening two bolts to
10 Nm instead of 5 Nm, this is a material that has NO business on a
bicycle in that application, IMHO.


If you torque a M5/M4 bolt to 10 Nm you better stay away from any wrench
and bike(part).

Lou

Op 20-6-2010 5:56, Mike Jacoubowsky schreef:
"Tim wrote in message
There's a lot of busted carbon out there, but most people never hear
of
it. If you can cause a catastrophic failure by tightening two bolts
to
10 Nm instead of 5 Nm, this is a material that has NO business on a
bicycle in that application, IMHO. You, OTOH, can ride whatever bike
you want. It's not my problem.

I set up my bike without using a torque wrench a while back (built it at
home, not at the shop, and didn't have a torque wrench available). So I
checked it a few months later (my goodness, I didn't crash& die in the
meantime???) and found that all six bolts on my stem (the two that clamp
the steer tube, and the four clamping the bars) were under-spec for
torque, as much as 20%. But never any slippage, and they felt pretty
tight. I think you'd need to be pretty ham-fisted to exceed the max
torque spec, and taking it to 10nm (double) would be darn near
impossible.

Exactly. Gorilla's will break everything.

Lou

Tim McNamara wrote:
CFR water bottle cages-
I'd be willing to use those.

Bloody things, many are so thin/sharp you can easily cut your hands when
washing a bike



--
/Marten

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