Carbon Fork Failure

[saab2000]

I just returned from browsing at the Roadbikereview forum and found a posting on a fairly recent carbon fork failure.

The bike in question was an Aegis and there was a link to a photo of the fork in question.

I mention the brand not to pick on them, but simply to point out that it can happen to "brand name bikes" too.

Now, what is the point? Well, about a month ago I picked up a Merckx titanium frame on e-bay. I am still working on it and waiting for a fork from an LBS in St. Paul. This will be my first ever bike with a carbon fork and I am wondering about them.

I know that carbon has been around for a long time and that failures are very rare. But it is also no secret that a failure is likely to be very bad. The rider of the Aegis was severely injured.

Carbon forks are also getting lighter and lighter. I am likely to go with a Look or Reynolds for the new/used Merckx.

Can anyone comment on the state of carbon and does anyone have any tips to help avoid failure. The Aegis failed right where the crown race was installed and I can imagine that the installation may have damaged the fork somehow.

In my whole career of riding I have only ever had steel forks and I have only ever heard of one failure of a steel fork.

Anyone, anyone....???

Just looking for reassurance here. I know that carbon forks are ubiquitous today and that not having one is a bit unusual, but I have hung on to that last bit of perceived safety a long time. Now I have made the jump to the world of carbon forks with the purchase of the Merckx Majestic (which, btw, I am really looking forward to getting up and running)!

[soulspinner]

Thats why I will only ride Reynolds. Their testing and standards seem to be as good as it gets. I have an Ouzo and an Ouzo lite. Great riding forks. I hear what youre saying about ultralight forks. Some (LOOK) are now going with carbon dropouts. Arent they likely to get a scratch deep enough to compromise the carbon?

[PaulE]

Go with a good quality fork that is appropriate for your size and weight. Don't be a weight weenie and go with something just because the pro's ride it.

Don't do the installation yourself unless you're qualified.

If someone else is doing the installation, it should be someone you have complete faith in.

If you need a fork with a 1 inch steerer, the steerer should not be carbon.

Before each ride, add looking over your fork to your "pre-flight" inspection.

Give your fork a more thorough looking over whenever you clean your bike.

My riding partner had a carbon fork with a 1 inch carbon steerer. He had a nasty creaking sound, and when he finally got it checked out, the steerer was cracked underneath the stem mounting area. The steerer either cracked from 4 years of use or because the stem used an internal wedge to clamp the steerer. Make sure you use a stem that is compatible with the steerer tube.

Good luck.

[Big Dan]

I rather take my chances with a 1 inch full carbon Alpha Q than with a 1 inch
bonded Aluminum thing that Nashbar sells for $59 bucks.... :D

Reynolds
Alpha Q
Kestrel
Easton

Are all good forks, just practice common sense if you see or hear something funky don't take a chance.. :)

[Too Tall]

Fork cutting party at my place. BYOBelgians.

No question we need to really pay attention to installation proceedures with these materials. Gone are the days of going over your bike with a 5mm allen key and giving everything a little tighten-up. no no no. Make friends with your snap-on man.

My experience is with Alpha-Q, Reynolds, WoundUp and Kestrel. Lots of hard miles on all and no worries matey!

[Ken Robb]

I have had several different carbon forks with no failures. My favorites for riding are F1 and Profile Design AC-1. Former has steel steerer, latter is all carbon. I wish the F1 would accept a tire bigger than 700x24.

[djg]

seems just fine after three years. The one inch carbon steerer on my ouzo pro (which adorns the front end of my CSi) seems just fine too. It's your dime and your tuches, and comments about taking care with installation are entirely sensible, but having picked appropriate forks and properly installed them, I don't really worry about it. Given the number of these things floating around, I'll need more than the very occasional, ad hoc, and typically explainable horror story to get me to worry about the technology in any fundamental way.

[Benjamin]

i think about this from time to time and check my carbon bits regularly, but the bottom line is that i'm a not super-light dude (6' 1", 175) and have been hammering on carbon forks, bars, seatpost, and other stuff for a good 6 years plus and many, many thousands of miles now, and nothing has failed on me yet.

i probably wouldn't buy the super light carbon forks with cut-away sections and carbon drops because it costs too much, but if someone handed me one, i'd have zero reservations about riding it.

[OldDog]

Everything fails. Eventually. Old aluminum bars will snap without notice. Eyelets will pop from your rims. Spokes will break. So will chains. All could be ugly. If your going to ride superlight gee-wiz stuff, or even old school alloy bits, you need to keep an eye on it, replacing it when need be. It's too late to think about it when your watching the road surface heading towards your noggin at 35 mph.

[11.4]

I've tried a variety of carbon forks after years of steel and haven't had problems. I'm a track sprinter and use road bikes for lots of intervals and short hill jumps, so I have plenty of opportunity to torque forks. I first had a Serotta F-1, which was just fine -- I'd buy one again in a heartbeat if I could fit a 1" steer on a current bike. I then went to Alpha-Q forks and settled on their X2 tandem fork on a couple bikes and their cross fork on another. Both are hugely overbuilt (1/8" thick steerer walls, extra wraps at the crown, etc.) without being uncomfortable to ride. I don't think it's possible to break either of them -- they're used on a lot of tandems that see much higher loading of all kinds than I could ever apply. Now I also have a bike with an Easton SLX and find it's solid and reliable as well despite the 300 gram weight. I suspect that unprovoked fork failures are extremely extremely rare. The only breakages really come from crashes, rack-related abuse, or damage from mistreatment at the stem. Not that steel won't fail at that point either. With any kind of fork abuse I'd consider replacement anyway.

[Dekonick]

Thats why I wont buy a used carbon fork unless its from someone I trust.

[Kirk Pacenti]

.

[vaxn8r]

Here here Kirk, nice reply.

Seems weird with my being a CF advocate and all that I love steel forks too. Though I guess it would be weird to see any other bike but steel with a steel fork.

[Big Dan]

I agree with you guys on the appeal of the steel fork. I switch forks on my Serotta from time to time. In reality is getting to be a hassle to find affordable steel forks. I hear $350-500 dollars for a steel fork. In that case the carbon fork is very attractive. :confused:

[bubba]

If you need a fork with a 1 inch steerer, the steerer should not be carbon.

...



My riding partner had a carbon fork with a 1 inch carbon steerer. He had a nasty creaking sound, and when he finally got it checked out, the steerer was cracked underneath the stem mounting area. The steerer either cracked from 4 years of use or because the stem used an internal wedge to clamp the steerer. Make sure you use a stem that is compatible with the steerer tube.

And just why should it not be a 1" CF steerer? I have three, and NO issues....Your buddies faillure was due to using the wrong type stem clamp.

[bubba]

My advise is, if you ride carbon, buy new not used. Inspect regularly and replace every 2 years.

Ciao,

Kirk Pacenti
www.bikelugs.comWhy?? Is this something lie the dreaded 3 or 5 year life of aluminum frames one hears so much BS about?

[Kirk Pacenti]

.

[Sandy]

I wish Serotta still had the F1 fork. Although it was relatively heavy, it had a steel steerer and it seemed so firm, solid, and predictable, giving great road feel. I would have gotten it on my Ottrott.


Sandy

[Big Dan]

Kirk, I still agree with the steel fork set up. In a perfect world I would have both a carbon and a steel fork for my 4 bikes!!! :D . Back to reality, let's say I got a nice used steel frame for $500 dollars, do I shell another $500 for a steel fork? I guess the question is where is the $200 -250 dollars steel fork? Taiwan? Mexico??? In the meantime you can get a Kestrel EMS for under $99 dollars and it almost feels like steel... :crap:

[saab2000]

When I bought my Strong I went with a steel fork for a couple reasons.

1. Safety, whether real or imagined

2. Appearance, steel frame with steel fork

3. Something "traditional"

4. Virtually no difference in cost

5. Weight - I don't care about 300 grams on the bike when I am 15 lbs overweight myself

6. Reputation for good performance

I like my steel fork and I am not sorry I got it.

But for my new/used Merckx, it will be a carbon. I guess I will just have to be careful installing it.

BTW, the price for the steel fork for my Strong was within about $50 of the price for a carbon fork. I don't even remember if it was more or less. But the cost difference was really not much.

[Ken Robb]

is there any reason we shouldn't use adapters to put 1" forks like F1s in new bikes with 1 1/8" head tubes?

[bubba]

I guess the question is where is the $200 -250 dollars steel fork? Taiwan? Mexico??? Ebay... I've scored several quality ones for uner $100.One was even an older unused Serotta.

[Kirk Pacenti]

.

[Orin]

I wish Serotta still had the F1 fork. Although it was relatively heavy, it had a steel steerer and it seemed so firm, solid, and predictable, giving great road feel. I would have gotten it on my Ottrott.


Sandy

Yes, FWIW, F1 with approx 200mm steerer and Serotta steel with similar steerer were 700g.

Orin.

[deanster]

I think that you have gotten sage advice from the people who replied to you. I ride a Reynolds Ouzo Pro on my Dean eldiente CTI. I am a heavy rider (230#) and ride my bike fairly hard. I have about 3500 miles on the fork and feel it is very safe when I decend down the cyn roads hear in the CO Rockies. I had the same misgivings about carbon being a steel bike rider myself. I think the testing of Reynolds, Alpha-Q, and Columbus (muscle) are all very good programs. Get a good fork from a reputable seller and then have the LBS setup the fork with all the right Torque values. Note what they are and keep a good record. Good luck. Don Keenan


I just returned from browsing at the Roadbikereview forum and found a posting on a fairly recent carbon fork failure.

The bike in question was an Aegis and there was a link to a photo of the fork in question.

I mention the brand not to pick on them, but simply to point out that it can happen to "brand name bikes" too.

Now, what is the point? Well, about a month ago I picked up a Merckx titanium frame on e-bay. I am still working on it and waiting for a fork from an LBS in St. Paul. This will be my first ever bike with a carbon fork and I am wondering about them.

I know that carbon has been around for a long time and that failures are very rare. But it is also no secret that a failure is likely to be very bad. The rider of the Aegis was severely injured.

Carbon forks are also getting lighter and lighter. I am likely to go with a Look or Reynolds for the new/used Merckx.

Can anyone comment on the state of carbon and does anyone have any tips to help avoid failure. The Aegis failed right where the crown race was installed and I can imagine that the installation may have damaged the fork somehow.

In my whole career of riding I have only ever had steel forks and I have only ever heard of one failure of a steel fork.

Anyone, anyone....???

Just looking for reassurance here. I know that carbon forks are ubiquitous today and that not having one is a bit unusual, but I have hung on to that last bit of perceived safety a long time. Now I have made the jump to the world of carbon forks with the purchase of the Merckx Majestic (which, btw, I am really looking forward to getting up and running)![/QUOTE]

[RichMc]

As an aside here, Specialized recommends replacing carbon components, especially carbon forks, after three years of use. I know that is too open ended because what if you rode once a month for 20 miles? Contrast that with every day for 50 miles. You'd have a huge difference in wear and exposure. I guess they mean these things don't last forever and just to be safe you should consider periodic replacement.

[zap]

Lawyers made them do it.

[bfd]

OK, what about weight limits. Alpha Q is coming out with a 270g, 1" carbon fork with carbon steerer. There is a 200lb weight limit on this fork. If I'm 190-195lbs, is it safe? I know the sub3 version, which weighs in at about 295g has a 225lb limit.

Note - I currently have a 1" kestrel carbonfork with steel steerer. Its a great fork and is about 10 years old. The only reason I would want to replace it is because in my old, fat age, I would like to raise the bar. I currently have a salsa cro-moly threadless with like 115degree rise. A new fork would let me get the bars higher, especially if I can add a headsup thingie (and when is Serotta going to get some more of those!).

[vandeda]

Why?? Is this something lie the dreaded 3 or 5 year life of aluminum frames one hears so much BS about?

Does anyone else see the "replace this part after X yrs of use" a useless measure? What's that based on ... average use of course. What's average use? Due to circumstances, my carbon fork saw <1000 miles of use last summer ... whereas recently, we had a person (forgot his username) post that he just put on 22,000 miles on his Ottrott in 2 yrs, or 11,000 miles a year. So, after 2 yrs, I'd have less than 2k miles, and he'd have 22k miles. Hmmmm ....

Why not give that number in miles? Assume worst case conditions ... 225 lb rider, rough roads, sitting out in the sun all day everyday, and then say "after x miles, the fork should be replaced for safety reasons" as opposed the the worthless measure of years.

Dan

[Darrell]

My thoughts.
Fork failure rate increased since the introduction of carbon forks in the market place.
Carbon forks do require care in fit up and use.
Some manufactures recommend removal and inspection every 1,000 kms.
Who does that?
That is to cover their backsides.
Who is going to produce a signed log book of certified inspections?
Good steel forks will take more riding abuse, and component fit issues.
Why would some one weighing 200 lbs be worried about 300 grams of fork weight?, how embarrasing! Harsh yes, but lets think about it.
Manufactuers put limits on things to think for the unthinking consumer.
Carbon forks, cranks, handle bars and seat posts are of no concern to the owner till they break and thump, Owwwwwwwwwwwhhhhhhhh. How much is this going to hurt? Many people get testy when their you beaut CF extra light part breaks and they have to shell out more hard earned dollars to get back on the road again.
A big problem with 1" CF steerers is that they behave like a fishing pole. This creates head stem creep as it prises itself up the steerer off the spacers and head fittings as it flexs banana like, hence head set rattles.
1" handle real bad when stomping hard and cornering in pot holed corners.
Carbon forks are light. Are you light?
Having said that, if I was racing I would want a CF fork in my race bike.{1 1/18" only}
My training bike would be made so I had complete faith in it.
Don't value a part's worth just on it's weight.
Cheers from a once 59.5 kg rider and now is a 81kg joke who can not get out of his own way, but I am on the sub 60kg mission again.
Add a few grams and let the rest get on with the madness.
Bring it on, rocks, flames, hurling rotton fruit.

[Too Tall]

Keep talking Dazza, you are becoming one of my favorite sages :) You remind me of a guy I rode across the USA with who was from your neck of the woods. Skinny guy with some artificial bit installed in his anatomy. He really really like to ride ALOT ;)

[zap]

Darrel, 1" carbon steerers are like fishing poles? Boy, I have a surprise for you. You gotta try better parts mate.

And who cares, many ride these Ritchey and Deda noodles called stems so who's to know what flexes. Well, at least the longer stems flex. Maybe shorty stems are better.

But your right about the rest.

[Darrell]

Darrel, 1" carbon steerers are like fishing poles? Boy, I have a surprise for you. You gotta try better parts mate.

And who cares, many ride these Ritchey and Deda noodles called stems so who's to know what flexes. Well, at least the longer stems flex. Maybe shorty stems are better.

But your right about the rest.

What forks are better than Reynolds, Columbus, Alpha Q and what ever Colnago are using?
I have not seen good results from 1" Carbon steerers as mentioned before.
I liked Alpha Q 1" titanium steerer forks but they stoped making them.

And I have seen failures in all the you beaut brands at the steerer to crown area.
Not pleasant results in two cases.
For 1" steerers I am all for metalic steerers. Steel, tit, alloy in that order
Boy, I got a surprise for you, Go ask the fork manufacturers what they prefer. 1 1/8 for the extra carbon material. Which is one of the reasons the head tubes got bigger.
My take and perspective and collective wisdom on it.

[zap]

Have Alpha 1" with carbon steerer. With there bonded "nut" assembly, it does appear to make for a stiffer steerer. I think I have the medium stiff version of Alpha's original carbon rooting system. I do know that it is stiffer than the original al fork with steel steerer.

It's on my beater bike and was never really given tender loving care. Never needed to adjust the headset either.

I know of others that are quite pleased with the Alpha Q 1" carbon as well.

As for the rest, at the time, I didn't think their 1" designs where comparable.

Yes 1 1/8" designs or larger can be stiffer and lighter, are easier to manufacture and of course would be my choice for any future frames

or..

.. the design that doesn't use an internal steerer tube which seems to work quite well and is quite stiff. But no one else but Look seems to use it.

[Needs Help]

Bring it on, rocks, flames, hurling rotton fruit.
lol.

[Brons2]

As for aluminum frames, they too have a finite life span. It's the nature of the material. I have hefted many 4+ lb. aluminum road frames, they will probably last forever. But at this level, we are most likely talking about sub 3 pounders. In my experience, anything less than 1300 grams (in aluminum) is simply not reliable in frequent/hard use conditions for more than a few years.



Hmm.

My Cannondale mountain bike is a 3.0 lb aluminum frame, and I've owned it since 1992. At the time I bought it, I was playing offensive tackle for a large state university based here in town and weighing about a twinkie away from 300 lbs. I have put that bike through HELL. It was a daily commuter to class, and curb jumping was almost a hourly occurance. If there were stairs in the way, no stopping, just ride down the damn things! Usually did a weekly offroad trip down various greenbelts sometimes catching as much as 6-8 feet of air. There is barely any paint left on the bottom of the bike and fork due to rack rash and other various damage. I broke off some pedals and bent my seat post a couple of times. Getting rode hard and put away wet by a 300 lb guy is the most torturous environment imaginable for a fairly light aluminum frame, and it's still intact.

In fact, before I got my road bike, I picked up 1.25" slicks for it and starting doing distance rides. It's still doing great, I ride it to work quite a bit and I can assure you I still jump curbs and rocks with the same aplomb that I always did. I had to replace a crank bearing and a derailer hanger recently, but still no frame worries...I'll let you know if that ever happens.

As for the concern about carbon fiber in your forks, consider this: Boeing is building an all-new, all composite airplane that will fly in 2008, the 787. It will be the first commerical jet with a composite fuselage and composite wings. How do you feel about flying in that airplane?

Bottom line for me, check your carbon fiber parts for evidence of delamination, that is your enemy.

[shinomaster]

I love my Cannondale.

[Brons2]

I love my Cannondale.

more than your ex-gf?

[shinomaster]

No!

[Darrell]

Hmm.

As for the concern about carbon fiber in your forks, consider this: Boeing is building an all-new, all composite airplane that will fly in 2008, the 787. It will be the first commerical jet with a composite fuselage and composite wings. How do you feel about flying in that airplane?
.

I would be surprised if the main wing spars and attachment points are in Carbon???/ and are epoxied in place????
Are the undercarrige legs in carbon???
Carbon sheeting has been used in aircraft for decades now. Think sail planes.
I have flown as a passenger in a few composite aircraft, wooden and fabric ones!Tiger Moths and wooden vintage two seat gliders. I am happy with that as they are looked after and used correctly.
Space limitations in bicycle design is the problem. One can make a carbon fork bloody strong, but it may be twice as big as it is now. Higher density materials need less volume to achieve the desired objective. In some cases there is room, in some there will not be room.
Have fun.

[97CSI]

Agree with the above statements concerning the 1" Alpha Q. Used a Sub3 with 1" steerer on a Dean Ti frame last season and was very pleased with its performance. While the Dean wasn't up to the standards of my Coeur d'Acier, the Alpha Q was fine. And I weigh ~200 lbs.

[OldDog]

with fancy crowns :banana:

'nuff said

[CNote]

with fancy crowns :banana:

'nuff said

Like this one?

[Brons2]

I would be surprised if the main wing spars and attachment points are in Carbon???/ and are epoxied in place????
Are the undercarrige legs in carbon???
Carbon sheeting has been used in aircraft for decades now. Think sail planes.
I have flown as a passenger in a few composite aircraft, wooden and fabric ones!Tiger Moths and wooden vintage two seat gliders. I am happy with that as they are looked after and used correctly.
Space limitations in bicycle design is the problem. One can make a carbon fork bloody strong, but it may be twice as big as it is now. Higher density materials need less volume to achieve the desired objective. In some cases there is room, in some there will not be room.
Have fun.

I don't know about the spars or the hardpoints, but I do know the center wingbox will be CFRP. As is the wingbox on the A380 which should take it's first flight any day now.

[hypnospin]

some random observations and thoughts,

the only carbon fork i know of to break was a kestrel on a steel serotta. it broke at the steer tube above the lower race. it was a steel steerer.
you would think this would occur at the attached and bonded piece areas but no.
it was attributed to a lack of chamfer on the race causing an identation over time. the guy never knew what hit, it was while descending "The Wall" on Calaveras Rd above Fremont, Ca. when it snapped off all at once.

it should be noted this guy rode this kind of climbs and descents, very bumpy, near daily, and could climb in the big ring while conversing normally.
he was not a heavy person, but this is more stess than most will incurr.



he got a new bike with new build kit, the works, on warranty and was riding in the group again.

a good installation of this lower race is a safety factor. the thing should go on straight, reasonably tight and bottom out flush.

the area should be prepped with a sharp tool and steady hand as needed.

always listen for clicks and weird noises, do not ignore these sounds, and inspect. look for chipping and peeling paint and clearcoat.

couldn't hurt to remove fork and look up close and personal from time to time as well.

as for me i have been riding a profile bsc, this is a truly great fork. beefy, near flex free and comfortable. this is the steel steerer, threaded version.

The profile carbon forks are offerred on waterford and gunnar and they report no prob. plus warranty is "lifetime".

i did replace my steel fork (Wilier) for this one after noting a hairling curly shaped crack on the outside of one of the blades. i cannot say if this was caused by me as i bought this frameset used. an odd place for a crack as not a big stress area.
could have been caused by previous crash or flaw from tube shape forming.


colnago star in 1" has had no breakage i have seen reported, and the guys at trialtir say it has only happened from a roof rack incident.

they are rated for a 190 lb. rider.

it is, some say, questionable if 1 1/8 is a big diff from 1" , esp. if the wall thickness is there.

saw a pic of a colnago from from a tour crash, the headtube was snapped off but the fork intact. and this on a C50.

the use of an expander rather than star nut is a good precaution according to some who think it strengthens the area.

some also think you should have excess carbon steer tube above the stem with an extra spacer,so the area near the end is not compressed by clamping force, but you do not see this on lots of pro bikes.

if anyone does snap a fork these forums will let the multitude know.

just look at all the publicity the broken colnago crankset has on the web.




Go with a good quality fork that is appropriate for your size and weight. Don't be a weight weenie and go with something just because the pro's ride it.

Don't do the installation yourself unless you're qualified.

If someone else is doing the installation, it should be someone you have complete faith in.

If you need a fork with a 1 inch steerer, the steerer should not be carbon.

Before each ride, add looking over your fork to your "pre-flight" inspection.

Give your fork a more thorough looking over whenever you clean your bike.

My riding partner had a carbon fork with a 1 inch carbon steerer. He had a nasty creaking sound, and when he finally got it checked out, the steerer was cracked underneath the stem mounting area. The steerer either cracked from 4 years of use or because the stem used an internal wedge to clamp the steerer. Make sure you use a stem that is compatible with the steerer tube.

Good luck.

[Brons2]

I've had my road bike leaning against a wall in my living room since sunday, well today I bring it in to work and I see it's gotten some rack rash on the effing front carbon fork.

I'm gonna kill my dad, and here's why:

On the way home from the MS150 on Sunday, we rode home in my sister's vehicle. She has a two bicycle rack. In an attempt to be nice, he offered two other friends rides. Using zip ties and towels, we put 4 bikes on that 2 bike racks. I was hesitant, but I shrugged it off.

I should have ridden home. Even though I just finished 82 miles, it wasn't that far home and I wasn't feeling nearly as bad as the day before.

I tried to take some pictures with my webcam, but they are kinda small. Maybe you can get the idea.

Should I be worried?

(edit: I also included a pic of the whole thing :D)

[Air Jer]

CNOTE: I am not Old Dog but I like to read his posts and I too am old so if I could jump in I would say YES like that. However, I would not presume to answer for OLD DOG but that is a great looking fork. May I ask who built it? :banana:

[97CSI]

Unless it is deep enough to get to the fibers it is probably fine and not a structural concern. If it were me, I would simply polish a bit till smooth and hit it with some more clearcoat.

[CNote]

May I ask who built it? :banana:

Nic Schmidt
Capital Bicycles

[musgravecycles]

I don't know about the spars or the hardpoints, but I do know the center wingbox will be CFRP. As is the wingbox on the A380 which should take it's first flight any day now.


Brons2
As an FAA certified aircraft mechanic I can tell you that the difference between using carbon in aircraft construction versus your average carbon road frame is the rigorous inspection process aircraft go through. Aircraft parts are thoroughly inspected very often. To make an analogy, how many people pull the fork off their bike after every 50-100 miles for an inspection? I’ve got a 1” Alpha Q Pro on my personal bike and I can feel the steerer flex on hard cornering, my next bike will have a steel fork.

[Climb01742]

poorly constructed carbon bits can fail. the key it seems is rigorous testing, improved design and serious quality control. which i bet is how the F3 fork came about.

[Too Tall]

Looks OK.

[saab2000]

Musgravescycles has it right. I put my life in a mechanic's hands every time I fly. The inspection process is rigorous. Also, the carbon used in aviation might be similar to bike carbon, but it also is used differently. The new Boeing 787 will not, contrary to popular belief, be all carbon.

[Big Dan]

wrong thread.....sorry.. :D

[hypnospin]

some gross generalizations are presented as facts here, let's not jump to conclusions without some analysis.

1. steel forks sre prone to failure and CF may have vastly superior fatigue resistance in every measureable way, look at road bike review.com colnago c40 reviews, there are lots, none mention the star fork snappin'. In fact, where can you lead us to factual evidence of this big increase in failure?
maybe just more folklore.

2. as for the "behaving like a fishing pole" analogy, this is not a valid comparison in terms of defining performance for a steer tube. fishing poles were made of steel, as well, but this is an apples to er, bannanas comparison, the manner in which force applied, the characteristics of the material design,
the predjudicial fingering of 1" steerers, none of these things make for a valid conclusion.

3. steel steerers flex and ruin headsets, too, esp. if long and light. this is one reason why columbus spec'd slx steer tubes for lightweight thinwall tubesets such as genius and nemo in the pre carbon fork bandwagon days of the 90's.

"nothing leads so sure so sure a path to ignorance as condemnation without investigation"


My thoughts.
Fork failure rate increased since the introduction of carbon forks in the market place.
Carbon forks do require care in fit up and use.
Some manufactures recommend removal and inspection every 1,000 kms.
Who does that?
That is to cover their backsides.
Who is going to produce a signed log book of certified inspections?
Good steel forks will take more riding abuse, and component fit issues.
Why would some one weighing 200 lbs be worried about 300 grams of fork weight?, how embarrasing! Harsh yes, but lets think about it.
Manufactuers put limits on things to think for the unthinking consumer.
Carbon forks, cranks, handle bars and seat posts are of no concern to the owner till they break and thump, Owwwwwwwwwwwhhhhhhhh. How much is this going to hurt? Many people get testy when their you beaut CF extra light part breaks and they have to shell out more hard earned dollars to get back on the road again.
A big problem with 1" CF steerers is that they behave like a fishing pole. This creates head stem creep as it prises itself up the steerer off the spacers and head fittings as it flexs banana like, hence head set rattles.
1" handle real bad when stomping hard and cornering in pot holed corners.
Carbon forks are light. Are you light?
Having said that, if I was racing I would want a CF fork in my race bike.{1 1/18" only}
My training bike would be made so I had complete faith in it.
Don't value a part's worth just on it's weight.
Cheers from a once 59.5 kg rider and now is a 81kg joke who can not get out of his own way, but I am on the sub 60kg mission again.
Add a few grams and let the rest get on with the madness.
Bring it on, rocks, flames, hurling rotton fruit.

[hypnospin]

funny thing is, these nashbar forks are built in , perhaps, the same factories as the hallowed big buck brands, and rarely will they fail at the bonded regions because the adhesion can be stronger than the surrounding area esp if on the overbuilt side.

as for alpha Q, guy i know, shop manager built a mondonico foco record bike
with 1" alpha Q. I asked if he had concern about safety, he related how they(shop employees) took turns trying to "snap the thing off"
(induce spontaneous catastrophic failure) by grabbing a handfull of record front brake and lifting the back wheel from speed. they lived to ride again, as it was still in one piece, at least for now.

granted, most failures will occur when the component reaches a high number of stress cycles, but this show some strength to start with.

it should be noted this was a smaller frame size with no spacers used, and this guy was not too heavy for a cyclist, and does not ride too awful much, so perhaps he will live long after all.




I rather take my chances with a 1 inch full carbon Alpha Q than with a 1 inch
bonded Aluminum thing that Nashbar sells for $59 bucks.... :D

Reynolds
Alpha Q
Kestrel
Easton

Are all good forks, just practice common sense if you see or hear something funky don't take a chance.. :)

[Darrell]

some gross generalizations are presented as facts here, let's not jump to conclusions without some analysis.

1. steel forks sre prone to failure and CF may have vastly superior fatigue resistance in every measureable way, look at road bike review.com colnago c40 reviews, there are lots, none mention the star fork snappin'. In fact, where can you lead us to factual evidence of this big increase in failure?
maybe just more folklore.

2. as for the "behaving like a fishing pole" analogy, this is not a valid comparison in terms of defining performance for a steer tube. fishing poles were made of steel, as well, but this is an apples to er, bannanas comparison, the manner in which force applied, the characteristics of the material design,
the predjudicial fingering of 1" steerers, none of these things make for a valid conclusion.

3. steel steerers flex and ruin headsets, too, esp. if long and light. this is one reason why columbus spec'd slx steer tubes for lightweight thinwall tubesets such as genius and nemo in the pre carbon fork bandwagon days of the 90's.

"nothing leads so sure so sure a path to ignorance as condemnation without investigation"

Point 1. Palmares. 26 years in the bike industry and working with suppliers of carbon products with the National Australian cycling team } and thus contact with these suppliers and manufacturers backs this up. A lot of info that is researched down under {Australia}is Hush Hush info {remember that when you look at the results on the track at Athens!} Ask the fork manufacturers why they like 1 1/8" more than 1", and why they want 1" banished from their life. They say rigidity and more room to work the material, to reduce the breakage rate. {The sales reps are not going to tell you this}
In 20 years I saw three steel forks fail.
Steel forks being "Prone to failure" is way way off the mark. maybe some supermarket ones. This cannot be applied to higher quality steel forks. In five years I have seen 16 carbon forks fail. Including two last year from a famous Italian brand that I fitted to frames I built. They were one inch and the top model fork. These failed at the crown to steerer. Failures I ahve seen include crown area failures, split steerers, one leg failure and a few drop outs pop out.These were not direct crash failures.
Carbon can be used correctly and safely. My beef is the market demand for ever increasing weight reduction is becoming irrational and dangerous if not done wisely and rushed and carbon is used on places where it has no real benefit other than sales attraction.
Point 2. One example was the Bianchi factory testing I witnessed. They supplied bikes for our national women's and men's team for a while. {I was mechanico}I was there when the showed me a few 1" forks going through the testing. I saw the box of failures, and the flex figures. Granted, that did not include every brand of fork.
Also have you ridden the same bike with different forks and seen and felt the steerer flex? This is very percievable. I can bolt various forks to my v blocks on my surface plate and run the dial guages on it if you like. It may surprise you!
The constant headset rattles that occur with 1" carbon steerers is the stem prising it self up the steerer as it flexs against the spacers. Why Colnago introduced a headset with the compression O ring to let this happen but keep rattle at bay in the head set. {Milan show discussion a few year ago at the Colnago stand}This is one reason some steerers are damaged as they over tighten the stem to stop the prising.
SO you see I have done some investigation into this!!
Granted I have not written a PHD on the subject. {I never will}
Point 3. After 26 years of frames, I have to disagree with this!
To quote you again "In fact, where can you lead us to factual evidence maybe just more folklore."
So do you have evidence of this? Refer to your point #3
Columbus actually speced GN0I1& steerers with Genuis. 2.3/1.55 elliptical butt. Same for Nemo, Altec and Neuron and EL OS. I have used a couple hundred of these.
SLX steerers were speced for Max and also EL OS for a while.
Reynolds did make 753/653 steerers which were buttless 1.60mm. {I have the 753 Cert for what it is worth}
I actually broke one of these on my own 653 race bike that I used for a season of racing in France and some racing in Belguim {Circa 1993} I hit the ground.
Premature headset death is caused by ingression of water. Poor alignment due to machining. Mal adjustment, too loose or too tight. Or the rattle which hammers the bearing.
Lastly. My concern is the failure rate of critical componants such as seat posts, handle bars and cranks and forks has increased due to the wrong use of carbon. Just because it is carbon does not mean it is high tech. High tech does not mean reliable or useful.
Stength, reliablity, rigidity are three seperate values!
I think Shimano has been wise in not introducing carbon into their parts.
They even express this in their brouchures.
How long will they hold out till the market demands it and they relent to sales figures, who knows.
Carbon sells units. They have to make money. Lots of mums and dads work for them.
As Dave said, not all Carbon is the same.
I have got to go, my sweet heart has cooked me dinner so I am out in a rush.
I am all for "No Hype and Spin".
Till next time hypnospin.

[Climb01742]

careful, hypospin. don't dare question the steel folklore. the natives bite when angered. :D

had an interesting conversation with a bike builder honored at the houston show. years of experience building with steel. years of experience building with carbon. which does he now favor? naw...i don't wanna get bitten. :p apparently not as black+white as the folklore has it.

[Big Dan]

Climb, we know the answer. The guy likes to smell of glue. Go to the Steelman site and look what crap he is doing now. He buys the Deda carbon kit and builds you a "custom bike"......swell.........
I'll give it a try myself but don't like the smell of glue......... :D

Now let's get this thread going........ :fight:


Hypno...I still take my chances with the Alpha Q instead of the 59 dollar bonded Nashbar thing........ :p

[hypnospin]

great engagement here, i have heard a diplomat can tell you to go to h@@l in such a manner as you will look forward to the experience. now i have an look in at what that means.
Mr. D, you obviously have vastly more experience than i, but this does not mean there is no room for obsevation of variables within cycling and equipment.
1" has and can work damn good, any technical advantage of 1 1/8 is probably overshadowed by marketing driven hopping on of the trend bandwagon.
like you mention all along here, the primary concern of safety over weight reduction is the most important design factor. a lot of the oversize stuff coming out, forks, headsets, bars, 'n stems below a certain price point will never be as good as as the high end 1" stuff.

I still do not hear of the carbon failures so it really must be hush hush.
and i can not help but wonder if said failures were crash induced.
as for headsets clicking around down there, this has always happened even with quill stems too.

as for different forks on the same bike, yes, i have tried this and felt some differences, i had a beefy steel thron fork that flexed enough to scape tire against fork unicrown lower region (granted the thing had tight clearance)
swapped this out for a look lds pro that was alarmingly flexible. verdict, steel back on.

since then tried GT oversize fork and now profile BSC both of which are absolutely great, so from this small sample i can say things are looking up.

the only carbon fork i have known to break in this area (dist 5 uscf calif.)
was a steel steerer, cracked in the steel.

i have seen most everything else bend and or break.

i personally replaced a steel fork replete with crack in favor of carbon.

the '96 columbus tube spec booklet i got that year at interbike did appear to spec slx steerer on genius and nemo, but this is obviously limited experience on my part.

i certainly agree with your key point of sane design, but where are we headed, 1 1/4 headsets like the Kuota? will this then trickle down to the masses as perceived need at a low price point where the design and material quality is @rap?

BTW, as for cookin'? I did polenta with fresh mozzarella and proscuitto & fire roasted peppers tonight to bolster for the next ride.
Cheers,
"not immune to hype" spin




Point 1. Palmares. 26 years in the bike industry and working with suppliers of carbon products with the National Australian cycling team } and thus contact with these suppliers and manufacturers backs this up. A lot of info that is researched down under {Australia}is Hush Hush info {remember that when you look at the results on the track at Athens!} Ask the fork manufacturers why they like 1 1/8" more than 1", and why they want 1" banished from their life. They say rigidity and more room to work the material, to reduce the breakage rate. {The sales reps are not going to tell you this}
In 20 years I saw three steel forks fail.
Steel forks being "Prone to failure" is way way off the mark. maybe some supermarket ones. This cannot be applied to higher quality steel forks. In five years I have seen 16 carbon forks fail. Including two last year from a famous Italian brand that I fitted to frames I built. They were one inch and the top model fork. These failed at the crown to steerer. Failures I ahve seen include crown area failures, split steerers, one leg failure and a few drop outs pop out.These were not direct crash failures.
Carbon can be used correctly and safely. My beef is the market demand for ever increasing weight reduction is becoming irrational and dangerous if not done wisely and rushed and carbon is used on places where it has no real benefit other than sales attraction.
Point 2. One example was the Bianchi factory testing I witnessed. They supplied bikes for our national women's and men's team for a while. {I was mechanico}I was there when the showed me a few 1" forks going through the testing. I saw the box of failures, and the flex figures. Granted, that did not include every brand of fork.
Also have you ridden the same bike with different forks and seen and felt the steerer flex? This is very percievable. I can bolt various forks to my v blocks on my surface plate and run the dial guages on it if you like. It may surprise you!
The constant headset rattles that occur with 1" carbon steerers is the stem prising it self up the steerer as it flexs against the spacers. Why Colnago introduced a headset with the compression O ring to let this happen but keep rattle at bay in the head set. {Milan show discussion a few year ago at the Colnago stand}This is one reason some steerers are damaged as they over tighten the stem to stop the prising.
SO you see I have done some investigation into this!!
Granted I have not written a PHD on the subject. {I never will}
Point 3. After 26 years of frames, I have to disagree with this!
To quote you again "In fact, where can you lead us to factual evidence maybe just more folklore."
So do you have evidence of this? Refer to your point #3
Columbus actually speced GN0I1& steerers with Genuis. 2.3/1.55 elliptical butt. Same for Nemo, Altec and Neuron and EL OS. I have used a couple hundred of these.
SLX steerers were speced for Max and also EL OS for a while.
Reynolds did make 753/653 steerers which were buttless 1.60mm. {I have the 753 Cert for what it is worth}
I actually broke one of these on my own 653 race bike that I used for a season of racing in France and some racing in Belguim {Circa 1993} I hit the ground.
Premature headset death is caused by ingression of water. Poor alignment due to machining. Mal adjustment, too loose or too tight. Or the rattle which hammers the bearing.
Lastly. My concern is the failure rate of critical componants such as seat posts, handle bars and cranks and forks has increased due to the wrong use of carbon. Just because it is carbon does not mean it is high tech. High tech does not mean reliable or useful.
Stength, reliablity, rigidity are three seperate values!
I think Shimano has been wise in not introducing carbon into their parts.
They even express this in their brouchures.
How long will they hold out till the market demands it and they relent to sales figures, who knows.
Carbon sells units. They have to make money. Lots of mums and dads work for them.
As Dave said, not all Carbon is the same.
I have got to go, my sweet heart has cooked me dinner so I am out in a rush.
I am all for "No Hype and Spin".
Till next time hypnospin.