NYMXer

At yesterday's club after ride chat, the subject of frame failures came up. Probably from a few members riding strange bikes (other than their normal bike) and I learned that at least 4 frames (within our club) have failed and how the manufacturers are handling the matters.

Three are Trek's but none of the failures are related and one was from an accident. One is particular seems due to a weak design of the rear frame triangle. One is the top tube (maybe from using a bike rack?) and the other from a rock (Mtb) hitting the BB part of the frame. Trek is "looking" into these frames for over a month and slow to respond.

The fourth one was on a Cannondale (Old Mtb) and they replaced it within 30 days and upgraded a few dated parts. IDK why, but they did it.

Has carbon fiber frame failure been an issue with other fellow cyclists? I don't think this is a "Trek" issue, as we have a large number of Trek owners in the club due to good team support from a local dealer. That dealer has his hands tied with the frame issues though.

What I've learned is that CF isn't all what the hype (marketing?) makes it out to be. A top tube failure from using a bike rack seems like a design problem. A rear triangle break (yes, apart) is another design flaw. I don't think anyone can build a BB frame strong enough to stand up to hitting a rock (but maybe a protector plate?).

I'm glad I still have my old alum bike. I'm sure that alum frames have issues too, so what's the answer titanium?

FBinNY 

IMO - this isn't a question of the material, ie. CF vs. steel, but how it's used.

CF allowed for a tremendous weight savings vs other materials, but it seems that once on the weight savings track, bike makers aren't satisfied and the CF frames we see are the result of an effort to build the lightest possible bikes.

CF structures are serving well in other applications, and I strongly suspect that with a small penalty in added weight, plus some greater care in choosing manufacturing partners, CF bike frames can match steel (the standard) for durability, while still being lighter.

The question is whether bike makers can be comfortable marketing stronger more reliable frames that aren't as light as the sketchiest ones out there.

GravelMN

I'm with FB. The quest to save weight often pushes the envelope of material strength, eliminating any overkill in the design. This works fine until you subject the bike to something beyond what it was intended for. I've got a 1990s butted chrome-moly hybrid frame for the early 1990s that is overbuilt by today's standards but has held up to a couple of significant crashes and numerous lesser insults as a mixed use bike (winter, gravel grinder, etc) over several years. It's been bunny hopped, taken through rock gardens and off small drops by a 230# rider and I have absolutely no concern over this frame failing catastrophically. That said, it weighs significantly more than many higher-end modern butted cro-mo frames and way more than CF.

Lightness and durability have an inverse relationship. For any given material, the less material you use, the less force it takes to cause failure. Design can compensate to some degree and maximize the material's potential but the reality is that you give up durability to save weight.

FBinNY 

Let me add that CF may be getting a bad rap because of a significant different on how it fails, rather than the fact that it does.

The metals used in frames have varying degrees of ductility, while CF has near zero. This means that when over stressed, say by a crash or road hazard metal frames will protest and announce the problem by bending or buckling rather than snapping.

So when a crashed steel or aluminum frame bends we don't blame the material, and if it should later snap, we know why and chalk it up to our own stupidity in riding a compromised frame.

However, CF being the strong silent type, there's usually no evidence of crash damage, short of a total failure. That means we're given no visible warning of issues, and continue riding a frame that may be compromised. When it ultimately fails, it's hard to trace it back to the earlier event, and we blame the material instead.

Combine that with the underbuilding I mentioned earlier, and you have a recipe for the sudden catastrophic failures that we're seeing.

NYMXer

I tend to agree with your statements FBinNY and wonder if there is a system to forewarn failure, like a change in paint color or similar type or warning system. I read about something along those lines somewhere but couldn't find it today. Basically, the finish changes hue at the area of high stress, "pre failure".

I would think that the properties of CF would make this very difficult. Maybe since it is so light weight, build up the layers as we find the common areas of failure.

One of my questions was why would one manufacturer repair/replace a frame and upgrade the owner for his troubles when another seems to want to take it's time? This is the peak of bike riding season, and people want their bikes back, safe and repaired.

I was looking at titanium bikes and thought, what can go wrong with this material. I think I will be asking myself that question for a long time.

FBinNY 

There's a long list of possible reasons for differences in maker warranty policy, but one is simply a numbers game. Assuming all things equal, the gross numbers of failures will mirror success in the market place. So a company with fewer CF frames out there won't see many failures and can more easily rationalize the cost of those few replacements as a marketing expense.

With more bikes and more failures, replacement cost is significant, so a larger company may (only a possibility) feel that they need to look closer and separate true defects from those failing from outside causes. This would be especially true if their sales are skewed to an audience that rides more, so the rate of failure is higher. After all bikes don't fail while sitting in garages collecting dust.

Personally, I have a bias toward metal frames, reflecting the fact that I work in metals and understand them better. But in fairness, I'm not sure that CF frames are more dangerous. They only seem to be, because they're under a microscope, and have a larger share among riders that ride more.

dim

get a good carbon fibre frame such as a Giant TCR .... weighs a bit more than some others, but it's more robust

Todd Richards

i have an older cervelo R2.5, (2003?) the seat tube had a crack near the bottom bracket, so i got the frame for $300, but Calfee repaired it for $200, and since then i've put approx 40,000 miles on it without issue, it is 14.3 pounds with my race tubular wheelset.

overall i think the fact that carbon frames are here, and have stayed at the very top of the long list of quality bikes speaks for itself, you will of course hear of failures here and there, and i have no doubt a CF will not survive a dramatic crash or mistake with a garage door as good as alum or steel, but aside from the weight the CF ride just SO MUCH BETTER than anything, with the drive train responsiveness, lightweight, precise steering AND comfortable flex where it counts due to the variations of lay up.

I have a steel Basso ss/fix, titanium litespeed MB, titanium Dean gravel RB, and alluminum fatbike.

I am an older guy and been called a retro grouch by friends as i'm not very interested in pursuing the latest craze, but carbon fiber just isn't in that club anymore. Wasn't it 1990 when Greg Lemond first competed on CF in the TdF? that's 25 plus years ago.

fietsbob

Carbon is Trendy these days .. People came into the shop. Invariably weight is 2nd question, Price the 1st.

They usually buy a Metal frame , aluminum popular , Price is the final decider.



./.

gsa103

The welds fail. It's actually relatively common. Titanium is an extremely difficult material to work with, making welding very tricky.

3alarmer 

.
...****.

turkey9186

Is it because a higher percentage are failing, or are you hearing of more failures because there are more CF bikes on the road?
I have a friend that broke the drive side chain stay on three Trek Madone's. The fact he is 6'3" and 240#s may have had something to do with it?
I have a 2012 Supersix frame with a cracked seat tube. After a sudden stop the bike went airborne and landed on a corner of the seat. A metal frame would have probably survived.

davidad

The only difference between it and Al. or Chrome moly is that the weld and heat affected zone needs to be under an inert shield until the temp drops below about 700 degrees or so. Other than that it's no big deal to weld.

NYMXer

I have a SuperSix too, in Team colors. This whole CF issue might be due to the number of bikes with carbon frames out there, I really don't know...hence why I raise the question.

My problem is failure while at speed and what happens to the rider, combined with why some manufacturers are hedging replacement/repairs?

I mean, maybe we are just getting too spoiled and need to just focus on the ride and our strengths, not risk personal health and more money to be a few minutes faster on a club ride.

Oh, and ****, I mean really....... what are we doing to cause this thread to get locked down? Drama Mama!

turkey9186

I have seen several pictures of Ti frames with the failures in the middle of tubes, especially the down and seat tubes. Possible inclusions in the metal?

FBinNY 

There's a hint of truth to that. Imagine what would happen if everybody bought Formula V for street use instead of regular cars.

OTOH the internet creates a distorted view of reality. We see posted pictures and hear of a large percentage of failures, mainly because they are an oddity. But we have no base line in terms if the numbers of high end CF, Ti, Al or super light steel frames out there, and so have no idea of the actual failure rates involved.

There's also a certain irony to all the CF concern. Many of those commenting about the risks and posting photos of broken CF frames are riding steel or Ti frames with carbon forks, and don't seem concerned about that. Is CF somehow too risky for frames, and yet perfectly reliable and safe for forks? Or is the perception that a fork failure doesn't entail as much risk of personal injury?

NYMXer

FBinNY, my cheap Mercier Galaxy AL has a carbon fork and I always thought forks were under a lot of stress and pressure, given steering, head on bumps and other laws of physics. I know the front doesn't carry weight as much as the rear, but it does take on other forces.

To be fair, the Mercier is only a $400 BD bike and the entire fork isn't CF, but most of it is. For the price, it's a decent bike that took me from beginner to A rider.

FBinNY 

You're making my point.

You started a thread expressing concern about CF frames, and wondering if metal made more sense. But you seem comfortable with CF fork despite the fact that a fork failure is more likely to have serious consequences than one anywhere else on a bike.

So you're in the ironic position of using the material you trust the least in the most critical application. IMO this position is only tenable after a few beers.

Todd Richards

like

NYMXer

Maybe I am helping you make a point, but the whole purpose of me starting this thread was to see if the carbon fiber frame failures was chronic (hence worrysome) or sporadic and to just ride on and enjoy the scenery.

My other concern was the differences between how some manufacturers handle failures. Trek frames supposedly have a lifetime warranty, but apparently there are huge holes in that warranty. Maybe (my theory), is that by honoring some claims, they admit there are issues from a legal point of view.

I don't know, it just concerns me so I thought I would discuss it here. I've read enough of your post FBinNY that I think we would agree on many points of interest brought up here on BF. Maybe it's the New Yorker in us, or is it, lol

TGT1

They don't call it the "bleeding edge" of technology vainly. You couldn't buy the equivalent of a street legal formula 1 car, but if you have enough money to burn you can buy the cycling equivalent and the marketing types will do all they can to convince you that's what you have to have. Even though you don't have a stable of identical steeds, a sponsor to gift you a new set every year, and a team mechanic to keep them all in running order.

drlogik 

I'm an avid fly fisherman. What's that got to do with this thread? Well, it is well known in the fly fishing community that if a split shot hits a graphite, boron or carbon rod during the cast it will weaken it and it will snap unexpectedly...almost guaranteed, you just don't know when.

My guess is the same with carbon bike frames. Even a little nick from leaning against a brick wall, or falling over can compromise the integrity of the frame in that spot. Like an earlier poster noted, it won't bend, crumple or protest or give a warning, it will just snap all at once.

Fly rods are no different. I've had two snap unexpectedly over the years. Both were expensive and high performance rods. For this reason I shy away from anything carbon. It just doesn't take much abuse. For me, longevity and durability are paramount in my equipment. I will sacrifice more weight for dependability in adverse conditions. For me, carbon just isn't my material of choice.

markjenn

Your "guess" would be wrong.

- Mark

Ball Bearing

I've never seen a carbon frame bend like a fishing pole. I think there is a huge difference.

Rowan

No, it isn't. He's one of the best.