Trust Carbon Fork After Wreck?



"Donald Gillies" <[email protected]> wrote in message
news:[email protected]...
> to be quite honest,
>
> I've never been able to straighten an aluminum derailleur after it
> threw the chain into the spokes. In my case, the parallelogram (most
> likely, the front plate) is split after such an accident.
>
> I do agree that with a steel fork, you get a "free" straighten after
> one crash. In other words, it's o.k. to ride a steel fork that's been
> re-raked back to normal after a single crash. After the second crash,
> however, the fork is toast. Same thing goes for a steel frameset.
>
> I do not like the fact that carbon components can get easily scratched
> and marred, and cannot be polished clean. This is a definite step
> backwards in my opinion. Moreover, campy's tendency to etch logos
> into every part - rather than stamp them - is also a step backwards.
>
> I am already living in the retro world due to other perceived
> disadvantages of modern components. I already lost a hi-tech bike
> after only about 2000 mi of usage.
>
> My current bike is 19-20 lbs and it's all steel and aluminum. Only
> the bottom bracket was made after 1980. Not a single part was made in
> Italy.
>
> - Don Gillies
> San Diego, CA

The only Campy stuff on my early 80's Colnago Super are the NR hubs and
a braze-on FD (because it came with the frame); Stronglight 105bis
cranks, Shimano Crane RD, Suntour Superbe downtube shift levers,
DiaCompe Pro brakes and so on.

I've had a number of all Campy bikes and I just don't care for most of
their components. I still DO like old Campy hubs but that's about it. A
friend keeps offering me an old NR grupo for free, thanks but no thanks.

Chas.
Certified Retro Grouch
 
Mike Jacoubowsky wrote:
>> we debated this a while back. care is indeed needed, and quality varies
>> substantially with manufacturer [VERY bad experience with chinese-made
>> kestrel forks]. but to remind you, this ratio is not just weight for
>> weight. reynolds forks had graphs showing their forks /three/ times
>> stronger than steel for less than half the weight. this is entirely in
>> accordance with my attempts at destruction. i have bent several steel
>> forks over the years and relatively low stresses. the two carbon forks
>> i've "tested" have been much stronger. and frankly, if i was on the bike
>> at impact levels sufficient to break them, i'd be in the e.r. regardless.
>
> The problem is that you don't know how much impact the fork actually took,
> but common sense says that, at 15mph, it was a fair amount. Yes, carbon
> fiber is dramatically stronger (for its weight) than steel, but there are
> limits, and you just don't know where those limits are until it fails. Not
> with present fork technology anyway; that will change in the future as
> manufacturers work on the holy grail of the carbon component industry...
> designs that indicate that limits have been exceeded prior to actual
> failure. But we're not there yet.
>
> Here's the really scary thing. Back in the day, we sold a *lot* of
> replacement forks, when forks were made of steel. People ran into cars or
> crashed into things, whatever, and bent the forks, so they had to get new
> ones. Now? Virtually zero replacement forks. In my estimation, as many, or
> more people, are riding road bikes now as back then. And they're still
> crashing into things. Crashes which, since they would have bent a steel
> fork, are reasonably expected to be beyond the design criteria for a carbon
> fork. But instead of replacing them, people think whew, fork looks OK, got
> away with that one, don't need to spend all that $$$. And then a subsequent
> minor event finishes off the damaged (but not visibly so) fork and you have
> the makings of a JRA story (I was just riding along and my fork broke in
> two).
>
> If your fork took a heavy hit, assume the worst. There are very few things
> your life depends upon more than your fork staying intact.

if i were the lbs, i'd be looking after my liability insurance premiums.
however, while i'm not that much of an expert on composites, i do know
a little about them and i'm satisfied that i can inspect both visually
and physically, and more importantly, maintain ongoing observation, such
that i can identify likely failure. that's how i identified issues with
my chinese kestrel forks - i certainly didn't wait until they broke.
admittedly, others may not be so careful, but otoh, a bike shop
condemning a composite frame or fork or whatever because of a scratch on
the clearcoat is somewhat over-zealous.

bottom line, failures can and do happen, but observed failure rates are
/well/ below that which we're used to for conventional materials, and
that alone speaks to this subject way more than you or i arguing the
ends of the spectrum.

>
> --Mike Jacoubowsky
> Chain Reaction Bicycles
> www.ChainReaction.com
> Redwood City & Los Altos, CA USA
>
> "jim beam" <[email protected]> wrote in message
> news:[email protected]...
>> Qui si parla Campagnolo wrote:
>>> jim beam wrote:
>>>> bg wrote:
>>>>> I got hit from the side the other day. Car was going maybe 15mph.
>>>>> Bumper hit my knee and front wheel. Knocked me off the bike. Bent the
>>>>> wheel. No obvious damage to the fork or carbon rear stay and I left it
>>>>> with the LBS to check out. But absent any visible wrinkles how much can
>>>>> one trust carbon stuff esp the fork bars and stem after a shot like
>>>>> that? It's got a carbon steerer. I had a StupidLight seat post break
>>>>> last year unexpectedly
>>>> collar probably over-tightened and cracked the tube.
>>>>
>>>>> (I weigh 140lbs) so I'm kinda leery of trusting
>>>>> the fork.
>>>>> thanks,
>>>>> bill g
>>>> do the squeeze test. [google for details] if it passes, keep on riding
>>>> it. carbon is stronger than steel. scratches in the clearcoat mean
>>>> nothing. i have carbon forks that have been in impacts severe enough to
>>>> give haematomas in the palms on both hands and to smash rims - and both
>>>> forks are fine. i'm #205.
>>> You gamble with this gents teeth pretty readily. Carbon is stronger
>>> than steel for a given weight. Carbon use is lots lighter than steel,
>>> so not necessariluy 'stronger'. Steel bends, carbon breaks.
>>> We have had customers that have broken carbon handlebars, seatposts,
>>> rims, frames and forks.Many JRA..so MY suggestion is you be careful.
>>>
>> we debated this a while back. care is indeed needed, and quality varies
>> substantially with manufacturer [VERY bad experience with chinese-made
>> kestrel forks]. but to remind you, this ratio is not just weight for
>> weight. reynolds forks had graphs showing their forks /three/ times
>> stronger than steel for less than half the weight. this is entirely in
>> accordance with my attempts at destruction. i have bent several steel
>> forks over the years and relatively low stresses. the two carbon forks
>> i've "tested" have been much stronger. and frankly, if i was on the bike
>> at impact levels sufficient to break them, i'd be in the e.r. regardless.
>
>
 
"jim beam" <[email protected]> wrote in message
news:D[email protected]...
<snip>

Your defense of the material properties of the carbon fiber composite
material in used CF forks sounds like they are all constructed in a
manner that would meet aerospace standards of quality.

I've seen some photos of cut away cross sections of CF forks and frames
that showed major design flaws in their construction.

The question then is how does Joe biker know how well their new CF fork
or bike is constructed?

Chas.
 
My current bike is 19-20 lbs and it's all steel and aluminum. Only
>> the bottom bracket was made after 1980. Not a single part was made in
>> Italy.
>>

>That's interesting, Don. Somehow, I had gotten the (apparently wrong)
>impression that you were a big retro Campy fan.

Ok, maybe I should say : the saddle and hubs are post-1980, too :

Carlton PRO 531 race frameset, 1977 (not a raleigh - straight from the UK).
SR Royal Bars
SR Royal Stem
SR Four Sir fluted seatpost
SR Royal Campy-copy crank
SR Royal SP-100BL superleggara-copy pedals
SR Alloy Toe Clips
Tange Levin Alloy (Super Record) Headset
Simplex front derailleur (SLJ)
Simplex rear derailleur (SLJ6600 - soon to be SX410)
Simplex downtube shifters (pre retrofriction SLJ)
Dia Compe Royal Brakes
Dia Compe Super Record-type levers, engraved & drilled
Suntour Superbe NOS Gum hoods
Velo JET Titanium saddle (200gm)
Shimano UN-71 bottom bracket
MAVIC 501 wheels
MAVIC 330 GEL rims
Panaracer 270gm Tubulars
Red Cateye Bartape
Red Japanese bar plugs
Red Suede Saddle
Red Brake Cables
Red Toe Straps
Silver frameset

Looks like a chrome paramount, IMHO.

- Don Gillies
San Diego, CA
 
[email protected] (Donald Gillies) writes:

http://www.ece.ubc.ca/~gillies/raleigh/Carlton PRO with Kids.JPG

>Carlton PRO 531 race frameset, 1977 (not a raleigh - straight from the UK).
>SR Royal Bars
>SR Royal Stem
>SR Four Sir fluted seatpost
>SR Royal Campy SR-copy crank (Stronglight / Specialized Chainrings)
>SR Royal SP-100BL superleggara-copy pedals
>SR Alloy Toe Clips
>Tange Levin Alloy (Super Record) Headset
>Simplex front derailleur (SLJ)
>Simplex rear derailleur (SLJ6600 - soon to be SX410)
>Simplex downtube shifters (pre retrofriction SLJ)
>Dia Compe Royal Brakes
>Dia Compe Super Record-type levers, engraved & drilled
>Suntour Superbe NOS Gum hoods
>Velo JET Titanium saddle (200gm)
>Shimano UN-71 bottom bracket
>MAVIC 501 wheels
>MAVIC 330 GEL rims
>Panaracer 270gm Tubulars
>Red Cateye Bartape
>Red Japanese bar plugs
>Red Suede Saddle
>Red Brake Cables
>Red Toe Straps
>Silver frameset

>Looks like a chrome paramount, IMHO.

>- Don Gillies
>San Diego, CA
 
On 3 Nov 2006 02:24:58 -0800, [email protected] (Donald Gillies)
wrote:

> My current bike is 19-20 lbs and it's all steel and aluminum. Only
>>> the bottom bracket was made after 1980. Not a single part was made in
>>> Italy.
>>>
>
>>That's interesting, Don. Somehow, I had gotten the (apparently wrong)
>>impression that you were a big retro Campy fan.
>
>Ok, maybe I should say : the saddle and hubs are post-1980, too :
[other parts snipped]
>SR Alloy Toe Clips

I'm amazed these have lasted so long.
--
JT
****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************
 
[email protected] wrote:
> bg wrote:
> > I got hit from the side the other day. Car was going maybe 15mph.
> > Bumper hit my knee and front wheel. Knocked me off the bike. Bent the
> > wheel. No obvious damage to the fork or carbon rear stay and I left it
> > with the LBS to check out. But absent any visible wrinkles how much can
> > one trust carbon stuff esp the fork bars and stem after a shot like
> > that? It's got a carbon steerer. I had a StupidLight seat post break
> > last year unexpectedly (I weigh 140lbs) so I'm kinda leery of trusting
> > the fork.
> > thanks,
> > bill g
> > --
>
> It depends on how much excitement do you want in your life. If you want
> certainty and safety, replace it. However, if you want to live your
> life on the edge, then don't. Do you enjoy the adrenaline rush? Does it
> turn you on to think that your fork may give up halfway through the
> ride? will it make you go faster just to finish the ride sooner?
> This are important questions that you need to ask yourself.
> As you can see, there is a split between Peter ana Jim. Maybe, you are
> completely safe, but not knowing will make you feel alive. At least
> until you get the bill from the orthodontist.
>
> Andres

The split also comes from being in retail. I err on the side of
caution, even if he buys the new stuff elsewhere.
 
On Thu, 02 Nov 2006 22:03:30 -0800, jim beam
<[email protected]> wrote:

> however, while i'm not that much of an expert on composites, i do know
>a little about them and i'm satisfied that i can inspect both visually
>and physically, and more importantly, maintain ongoing observation, such
>that i can identify likely failure.

Wow - jim has X-ray eyes.

Tell us, do you still claim that crank cotters are properly tightened
with the nut?
 
* * Chas wrote:
> "jim beam" <[email protected]> wrote in message
> news:D[email protected]...
> <snip>
>
> Your defense of the material properties of the carbon fiber composite
> material in used CF forks sounds like they are all constructed in a
> manner that would meet aerospace standards of quality.

of course not - and i said so.

>
> I've seen some photos of cut away cross sections of CF forks and frames
> that showed major design flaws in their construction.

indeed - but we see the same for many materials, not just composites. i
wonder how many engineers ever graduate frankly.

>
> The question then is how does Joe biker know how well their new CF fork
> or bike is constructed?
>
that's a good question, and you're absolutely right, quality is the
absolute most important issue. personally, i stick with manufacturers
that know what they're doing, like french or even [shock] usa-made, and
avoid the cheap asian stuff, regardless of whose "reputable" label is on it.
 
Qui si parla Campagnolo wrote:
> [email protected] wrote:
> > bg wrote:
> > > I got hit from the side the other day. Car was going maybe 15mph.
> > > Bumper hit my knee and front wheel. Knocked me off the bike. Bent the
> > > wheel. No obvious damage to the fork or carbon rear stay and I left it
> > > with the LBS to check out. But absent any visible wrinkles how much can
> > > one trust carbon stuff esp the fork bars and stem after a shot like
> > > that? It's got a carbon steerer. I had a StupidLight seat post break
> > > last year unexpectedly (I weigh 140lbs) so I'm kinda leery of trusting
> > > the fork.
> > > thanks,
> > > bill g
> > > --
> >
> > It depends on how much excitement do you want in your life. If you want
> > certainty and safety, replace it. However, if you want to live your
> > life on the edge, then don't. Do you enjoy the adrenaline rush? Does it
> > turn you on to think that your fork may give up halfway through the
> > ride? will it make you go faster just to finish the ride sooner?
> > This are important questions that you need to ask yourself.
> > As you can see, there is a split between Peter ana Jim. Maybe, you are
> > completely safe, but not knowing will make you feel alive. At least
> > until you get the bill from the orthodontist.
> >
> > Andres
>
> The split also comes from being in retail. I err on the side of
> caution, even if he buys the new stuff elsewhere.

I err on the side of caution and I'm in wholesale :)
 
bg wrote:
> I got hit from the side the other day. Car was going maybe 15mph.
> Bumper hit my knee and front wheel. Knocked me off the bike. Bent the
> wheel. No obvious damage to the fork or carbon rear stay and I left it
> with the LBS to check out. But absent any visible wrinkles how much can
> one trust carbon stuff esp the fork bars and stem after a shot like
> that? It's got a carbon steerer. I had a StupidLight seat post break
> last year unexpectedly (I weigh 140lbs) so I'm kinda leery of trusting
> the fork.
> thanks,
> bill g
> --

http://www.signonsandiego.com/uniontrib/20051129/news_1m29hart.html

Read this link. This happened Thanksgiving morning last year. This
man was a friend of mine. A few months earlier he had an minor
accident, similar to yours, with the same bike. But he really liked
that Trek bike. Thanksgiving morning his carbon fork let go while
going downhill. If you want to read a lot of opinions about it Google
"East County" in rec.bicycles.racing.

BTW, his fork also passed the "squeeze test" prior to the accident.

Craig Calfee will inspect (I'm not sure how, maybe by xray) and fix any
carbon frame and fork. If you really love your bike then the cost is
worth it. Otherwise, please follow your wife's advice and get a new
bike.

Tom
 
"Donald Gillies" <[email protected]> wrote in message
news:[email protected]...
> [email protected] (Donald Gillies) writes:
>
> http://www.ece.ubc.ca/~gillies/raleigh/Carlton PRO with Kids.JPG
>
> >Carlton PRO 531 race frameset, 1977 (not a raleigh - straight from
the UK).
> >SR Royal Bars
> >SR Royal Stem
> >SR Four Sir fluted seatpost
> >SR Royal Campy SR-copy crank (Stronglight / Specialized Chainrings)
> >SR Royal SP-100BL superleggara-copy pedals
> >SR Alloy Toe Clips
> >Tange Levin Alloy (Super Record) Headset
> >Simplex front derailleur (SLJ)
> >Simplex rear derailleur (SLJ6600 - soon to be SX410)
> >Simplex downtube shifters (pre retrofriction SLJ)
> >Dia Compe Royal Brakes
> >Dia Compe Super Record-type levers, engraved & drilled
> >Suntour Superbe NOS Gum hoods
> >Velo JET Titanium saddle (200gm)
> >Shimano UN-71 bottom bracket
> >MAVIC 501 wheels
> >MAVIC 330 GEL rims
> >Panaracer 270gm Tubulars
> >Red Cateye Bartape
> >Red Japanese bar plugs
> >Red Suede Saddle
> >Red Brake Cables
> >Red Toe Straps
> >Silver frameset
>
> >Looks like a chrome paramount, IMHO.
>
> >- Don Gillies
> >San Diego, CA

Don,

Looks nice. I have some Simplex retro-friction shift levers with the
holes in them to top off your classic. They are still my favorite
shifters.

Chas.
 
"Bill Sornson" <[email protected]> wrote in message
news:[email protected]...
> Donald Gillies wrote:
> > [email protected] (Donald Gillies) writes:
> >
> >> My current bike is 19-20 lbs and it's all steel and aluminum. Only
> >>>> the bottom bracket was made after 1980. Not a single part was
> >>>> made in Italy.
> >
> >
> >
http://www.ece.ubc.ca/~gillies/raleigh/Carlton PRO with Kids.JPG
>
> Loopy cable housings much? :)
>
> (Kid on left missed the color-of-the-day dress code, I think.)
>
>

Looks like a typical Brit bike, there's oil on the floor under the
crank! ;-)

Chas.
 
"Bill Sornson" <[email protected]> writes:

>Donald Gillies wrote:
>> [email protected] (Donald Gillies) writes:
>>
>>> My current bike is 19-20 lbs and it's all steel and aluminum. Only
>>>>> the bottom bracket was made after 1980. Not a single part was
>>>>> made in Italy.
>>
>>
>> http://www.ece.ubc.ca/~gillies/raleigh/Carlton PRO with Kids.JPG

>Loopy cable housings much? :)

Yeah, I was noticing that with the rear brake cable as well. I
recycled the brake cables from another bike and they _should_ be
perfect, since the frame sizes were identical, but I think i'll have
to revisit the positioning of the rear brake cable, and perhaps the
rear derailleur cable.

- Don Gillies
San Diego, CA
 
"* * Chas" <[email protected]> writes:
> ... I have some retrofriction levers that would look great ...

Chas,

Thanx for the offer - I ave some uninstalled retrofriction levers,
too. The point, though, is to get something that looks "campy" from a
fairly close distance, even after picking up the bike.

The bike is kind of a mental exercise, and an inside joke, on my part.
I bought a blurry orange Carlton (same decals) from the UK for $20
that looked like it was "full campy" but nothing was campy and the
frame wasn't even 100% 531-throughout.

The goal here is to give people a double-take on whether it's a full
super record bicycle or not. Drilled retrofriction levers would bring
me no closer to that goal (although the original retrofriction
undrilled embossed levers would be a step closer ... anyone got some
for sale?) An SX-410 derailleur (A special one with the delrin lower
pivot, and i may paint the upper pivot black, and add a black badge)
will bring me much closer to that goal.

- Don Gillies
San Diego, CA
 
John Forrest Tomlinson <[email protected]> writes:

>On 3 Nov 2006 02:24:58 -0800, [email protected] (Donald Gillies)
>wrote:
>>Ok, maybe I should say : the saddle and hubs are post-1980, too :
>[other parts snipped]
>>SR Alloy Toe Clips

>I'm amazed these have lasted so long.

No surprise; this bicycle was newly built-up 2 weeks ago and i'm still
debugging it; roughly half of the bike is NOS or nearly-NOS, including
: toe clips, outer chainring, levers/hoods/tape, saddle, seatpost,
bottom bracket, toe straps, several brake caliper parts (brakes were
modified to be "very close" to super record appearance), tires, and
the wheels ($20) had lost no anodization so they haven't had much
usage yet. The rest of the parts were in "hardly used" condition.

The worst part on this bike was the rusty framset, which i masked,
oversprayed in silver (front half) and re-lined the lugs (a *****,
don't try this at home, folks ...)

- Don Gillies
San Diego, CA
 
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