Carbon cross bike: anyone ever break/crack one?
#1
Senior Member
Thread Starter
Join Date: Nov 2007
Location: San Diego, CA
Posts: 1,331
Bikes: 19 Look 765 Gravel RS, 18 Cervelo C5, 13 Niner Jet9 RDO, 08 Surly Crosscheck, 05 Serotta Fierte
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Carbon cross bike: anyone ever break/crack one?
So many people claim - carbon road bike, fine. You're not going on any trails, less likely to crash, etc. etc. But for a CROSS BIKE, it has to be steel, ti or aluminum. Carbon - you're gonna crack the thing in two minutes.
Well, I'm somewhat in love with the Ibis Hakkalugi, and yes, it's carbon. So, apart from just a gut feel that "plastic" is more brittle than metals, and not as "strong," has anyone ever actually experienced breaking a carbon cross bike? If so, did you break it in just a normal crash, or a crash that resulted in some broken bones with serious injury? And, if you weren't riding a carbon bike, do you think there would have been some damage - maybe a dent or worse - even if you were riding a metal bike?
Well, I'm somewhat in love with the Ibis Hakkalugi, and yes, it's carbon. So, apart from just a gut feel that "plastic" is more brittle than metals, and not as "strong," has anyone ever actually experienced breaking a carbon cross bike? If so, did you break it in just a normal crash, or a crash that resulted in some broken bones with serious injury? And, if you weren't riding a carbon bike, do you think there would have been some damage - maybe a dent or worse - even if you were riding a metal bike?
#2
Senior Member
Join Date: Jul 2008
Location: Denver
Posts: 619
Bikes: Road and Mountain
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Don't have a carbon cross bike, but a lot of people here in Colorado do. I've never heard of one breaking, at least not yet and I see a lot of X Nights and Scott RCs out there. The Hakkalugi is one sweet frame, definitely on my wish list. You could send an email to Greg from MudandCowbells.com as I know he and others on the Boulder Cycle Sport team have carbon frames.
#3
Senior Member
My only data point is that when I hit a car quite fast last year, it was the aluminium part of my carbon/alu fork that snapped.
CF is, in principle at least, ridiculously strong. Look at F1 cockpits and the testing they're put through for an example. But I guess it depends how it's applied to the specific case. Plenty must have been written about this though.
CF is, in principle at least, ridiculously strong. Look at F1 cockpits and the testing they're put through for an example. But I guess it depends how it's applied to the specific case. Plenty must have been written about this though.
#4
Yes, I have the memo.
Join Date: Jan 2006
Location: South Pasadena, CA
Posts: 85
Bikes: SystemSix
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I got one its as strong and stiff as ant Ti, steel or Alu frame. Also there are a fair amount of carbon fiber mountain bikes out there which take a lot more abuse than a cross bike.
#5
Senior Member
Join Date: Jun 2008
Location: Chicago
Posts: 789
Bikes: 09 Pinarello Prince, 09 Cervelo P3, 10 Stevens Team Carbon
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
They make military aircraft and commercial passenger jets with carbon fiber and they are subjected to greater stress than bicycle frames. Carbon fiber is perfectly fine for cyclocross racing. Look at what the top riders are racing. The goal for all cycling equipment is strong and lightweight. Carbon fiber excels at that.
#6
Junior Member
Join Date: Aug 2007
Posts: 17
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I race a Ridley X-Fire (2nd season on it) and have had no issues but have not really tested it with big crashes though do have a couple smaller ones. I have ridden it pretty hard though and it is still fine. For that matter so are my Reynolds carbon wheels.
A couple of the locals have broken the Stevens carbon frames though. They seem to be built on the thinner/lighter side as compared to the Ridley.
Mike
A couple of the locals have broken the Stevens carbon frames though. They seem to be built on the thinner/lighter side as compared to the Ridley.
Mike
#7
Senior Member
Join Date: Dec 2004
Posts: 108
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
The only failure that I heard about the carbon frames was the early versions of the Specialized Tricross had problems with the derailleur tab. I guess they didn't use the bolt-on type and so a couple of Cal Giant riders broke off the tab and had to get another frame. Other than that, I haven't heard of a frame failure in the Norcal area.
#8
Mitcholo
Join Date: Aug 2006
Location: Oost Vlaanderen in mind, Cleveland in body
Posts: 8,850
Bikes: 2010 Mitcholo w/ Sram Force/Red
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
It's not a 'cross bike, but I crashed my '09 Giant TCR Advanced headfirst into a turning rider at 35 mph. My shifter, bars, seat, both wheels, rear quick release skewer and helmet broke.
My frame came away with a chip in the clearcoat. The fork was perfect, too.
I raced that frame until September when I sold it.
My frame came away with a chip in the clearcoat. The fork was perfect, too.
I raced that frame until September when I sold it.
#9
Senior Member
Join Date: Jul 2008
Location: Denver
Posts: 619
Bikes: Road and Mountain
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
The rear brake mount on the Hakkalugi is pretty cool, and the Flanders symbol is a nice touch. The price isn't bad either for what you get.
#10
Senior Member
Join Date: Jun 2008
Posts: 4,033
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
No. That's not how materials work! There is no such thing as a single strength metric. Plus when a material is "strong" in a relevant way then less of it is used - that's how lightness is achieved.
The concern with CF bikes is crash damage writing off an expensive frame after a comparatively low speed spill. This is almost irrelevant to F1.
That's correct. CF is a great material in many ways - or rather it can be, because there is a lot of variation in the qualities of the CF tubing used - but it really is more susceptible to crash, and the failure mode really is a problem. I.e. CF can look fine and then CRACK! it's gone while in the same circumstances chromolly would be visibly dented but still perfectly safe to ride.
Otoh - cross races take place (mostly) on soft ground. Even if crossers are crashed more frequently than road bikes, this has to count for something. Plus I'd argue that a catastrophic failure of a crosser frame is less serious than that of a road bike or MTB frame. I'd rather have a fork fail on me riding moderately sloping grass or gravel than on a car filled road or during a severe descent.
Look at F1 cockpits and the testing they're put through for an example.
But I guess it depends how it's applied to the specific case. Plenty must have been written about this though.
Otoh - cross races take place (mostly) on soft ground. Even if crossers are crashed more frequently than road bikes, this has to count for something. Plus I'd argue that a catastrophic failure of a crosser frame is less serious than that of a road bike or MTB frame. I'd rather have a fork fail on me riding moderately sloping grass or gravel than on a car filled road or during a severe descent.
Last edited by meanwhile; 11-03-09 at 01:22 PM.
#11
Senior Member
Join Date: Jun 2008
Posts: 4,033
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
If you want to understand what cf is and isn't good for, then use the Internet the way it was meant to be used and do some actual research. Try reading this article - which I'll excerpt - in full:
https://spokesmanbicycles.com/page.cfm?PageID=332
Since carbon-fiber structures are not very fault tolerant (unlike metal structures), the design and execution plays an even more important role. And sometimes the fault is not in the design or execution of the structure - the fault may be a big rock coming in contact with the downtube. While the tube might not fail from such a large impact, the repercussions are usually hidden on the inside of the laminate, or within the laminate. Microcracks can then spread through the matrix, decreasing the ability of the fiber to transfer load. Metal tends to do a bit better in these situations - but you can make metal frames that break without warning, too...
Now for the bad news: carbon's weak link is elongation. Elongation is your safety net, but with carbon it's low, low, low. Depending on lay-up, it's possible to get some elongation out of carbon. For example, there is a scissoring of layers in the 45-degree plies, but in general we're dealing with a material that doesn't have an overabundance of ductility. Composite designs are not meant to permanently bend. And when they fail, they fail all at once, so designers build in a big safety net. This is similar to what the aluminum designers do, in order to overcome the low elongation of that material.Most manufacturers are very secretive about their lay-ups, so getting good info isn't always easy. Reading through the Trek technical manual yields numbers for the specific modulus of that company's lay-up, which measures the modulus divided by the density. Backing these numbers out yields an 8 MSI modulus for the Trek OCLV lay-up.
Since carbon-fiber structures are not very fault tolerant (unlike metal structures), the design and execution plays an even more important role. And sometimes the fault is not in the design or execution of the structure - the fault may be a big rock coming in contact with the downtube. While the tube might not fail from such a large impact, the repercussions are usually hidden on the inside of the laminate, or within the laminate. Microcracks can then spread through the matrix, decreasing the ability of the fiber to transfer load. Metal tends to do a bit better in these situations - but you can make metal frames that break without warning, too...
Now for the bad news: carbon's weak link is elongation. Elongation is your safety net, but with carbon it's low, low, low. Depending on lay-up, it's possible to get some elongation out of carbon. For example, there is a scissoring of layers in the 45-degree plies, but in general we're dealing with a material that doesn't have an overabundance of ductility. Composite designs are not meant to permanently bend. And when they fail, they fail all at once, so designers build in a big safety net. This is similar to what the aluminum designers do, in order to overcome the low elongation of that material.Most manufacturers are very secretive about their lay-ups, so getting good info isn't always easy. Reading through the Trek technical manual yields numbers for the specific modulus of that company's lay-up, which measures the modulus divided by the density. Backing these numbers out yields an 8 MSI modulus for the Trek OCLV lay-up.
#12
Carpe Diem
Join Date: Sep 2006
Location: MABRA
Posts: 13,149
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
They make shopping carts out of steel and they are subjected to greater stress, and more frequent impacts with immovable objects, than bicycle frames.
__________________
"When you are chewing the bars at the business end of a 90 mile road race you really dont care what gear you have hanging from your bike so long as it works."
ΛΧΑ ΔΞ179 - 15% off your first Hammer Nutrition order!
"When you are chewing the bars at the business end of a 90 mile road race you really dont care what gear you have hanging from your bike so long as it works."
ΛΧΑ ΔΞ179 - 15% off your first Hammer Nutrition order!
#13
Senior Member
Join Date: Jun 2008
Posts: 4,033
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Or look at:
https://answers.yahoo.com/question/in...9213430AAK6xzA
Carbon's weakness is damage.....you can scratch them up, but if you get any strong impacts or deep gouges, the frame is basically toast. (You can have some cracks/damage repaired, but it's very expensive and not usually worth doing it.)
Several years ago, Trek did a warranty replacement for me on an aluminum Fuel 95 frame that cracked. Since they didn't have that frame anymore and refused to downgrade me to a cheaper frame, or upgrade me to the newer Fuel EX.....and this is odd.....they gave me a beautiful Top Fuel carbon fiber frame with a special finish. They didn't ask me or run it through the shop first....they just sent it.
It was a beauty, and nimble and lightweight.....but on the third ride I laid the bike over in a rocky turn and put a big gouge with running cracks in the top tube. Trash. And, of course, with carbon fiber there basically is no warranty for damage.
It actually takes quite a bit to fatally damage a carbon frame, but when you do, you'll find yourself shopping for a new frame. I think aluminum is the way to go for most mountain bikes.
Carbon's weakness is damage.....you can scratch them up, but if you get any strong impacts or deep gouges, the frame is basically toast. (You can have some cracks/damage repaired, but it's very expensive and not usually worth doing it.)
Several years ago, Trek did a warranty replacement for me on an aluminum Fuel 95 frame that cracked. Since they didn't have that frame anymore and refused to downgrade me to a cheaper frame, or upgrade me to the newer Fuel EX.....and this is odd.....they gave me a beautiful Top Fuel carbon fiber frame with a special finish. They didn't ask me or run it through the shop first....they just sent it.
It was a beauty, and nimble and lightweight.....but on the third ride I laid the bike over in a rocky turn and put a big gouge with running cracks in the top tube. Trash. And, of course, with carbon fiber there basically is no warranty for damage.
It actually takes quite a bit to fatally damage a carbon frame, but when you do, you'll find yourself shopping for a new frame. I think aluminum is the way to go for most mountain bikes.
Last edited by meanwhile; 11-03-09 at 01:57 PM.
#15
Senior Member
Join Date: Jul 2008
Location: Denver
Posts: 619
Bikes: Road and Mountain
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Actually, Calfee and others have had a lot of success fixing carbon frames, and some will argue that fixing a carbon frame is sometimes easier than steel/alu/ti because you don't have to replace a whole tube. There may be cases where you have to "write off" a carbon frame, but this isn't the rule.
#16
Senior Member
Join Date: Jun 2008
Posts: 4,033
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
https://www.calfeedesign.com/howtosendrepair.htm
And in the UK
https://www.fibre-lyte.co.uk/
And I found a repair service and a home repair kit at:
https://www.carbonology.com/repair-mo...8dc50fc4bf410f
But that still leaves the problems of carbon damage being hard to spot by visual inspection, and of the dreaded catastrophic - ie sudden and total - failure mode. A set of guidelines and ideally tools to make inspecting would be really nice to have. Any suggestions?
#17
Senior Member
Join Date: Jun 2008
Posts: 4,033
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
..And here's a thread reporting on the use of the repair kit:
https://www.roadcyclinguk.com/forum/f...last=1&V=5&SP=
https://www.roadcyclinguk.com/forum/f...last=1&V=5&SP=