Well if you're talking solely about welding then of course the middle portion of the tube is going to be in trouble, maybe. I mean a touring rig would likely have the thinnest tube portion at 0.6mm which isn't really that thin. And rather than weld it, brazing would probably be a better solution anyway since it has no real chance of burning through. Of course it would be a good idea to learn how to do it yourself, but you only really need a butane torch (of course an acetylene torch would be optimal) for brazing. The flux and bronze is going to be the biggest issues, but I'd imagine any decent city has at least one metal shop which does some kind of brazing.

You mentioned earlier that carbon can be repaired without vacuum pump. This of course depends where the frame has broken, but it really is not that simple. Without a vac pump the repaired point will require a huge chunk of carbon because uncompressed it's really not very durable. And getting the right kind of carbon fiber would be a massive problem as well. You can't just slap some mat you found in an auto store on there. And getting the right kind of epoxy. It is certainly something I would not dream of trying by myself.

Oh, that reminds me actually. IF one wants to get a weld repair, one could find a sheet steel shop. My mom works in one and they certainly weld some seriously thin steel/other metals there.

The point you seem to be missing is for every person that is worried about having a bike that weighs 27 lb instead of ~35 lbs (what my L.H.T. weighs) their are three people that don't care . I do agree finding some one to fix a steel bike in a third world country is not great . Though I would just need to find tools and material as I can braze steel enough to get by
Roy

You are clearly passionate about CF. I agree that it has great properties for bikes and other equipment where high strength to weight ratio is needed. The fact of the matter is that CF is never stronger than the day it leaves production. From that point on plastisizers are gassing off the resin holding the fibers together, making it more brittle every day. In addition to that, when it fails, it usually is in a sudden and dramatic fashion. You only need to look at the many youtube videos showing failed frames, handlebars, steering tubes, etc. I would love to trust this material under demanding conditions, but knowing what I know, It just cannot provide the security that steel can provide.

In my line of work, this is known as a negative sale. A negative sale is one that relies on the portrayal of a rival product as poor so that it makes an alternative seem strong. The "sale" doesn't require that the individual state anything positive about their own product or preference. The hope is that the listener will be so turned off by this portrayal that the alternative suggestion, empty of any claims, is elevated to a higher standing. Sound familiar?

I have no axe to grind here cale. It is an awesome material, just stating that steel is preferable (TO ME) due to its durability and longevity. CF is fragile. It is the property of the material. Not trying to put a spin on it. For those that have not seen some of the catastrophic failures of CF, here is one of the many videos on the net. www.youtube.com/watch?v=Zn29u7GoqPk

You realize, I hope, that neither aluminum nor steel become stronger after they leave production either. And BTW, Steel and Aluminum frames often fail as well - usually at the joints. I get that you don't trust Carbpn frames robustness. That doesn't mean that there is any objective rationale behind that belief of yours.

You know, I've got memories of failed steel frames. Saying CF is fragile is the sort of uninformed comment that just goes to show you're more interested in grinding axes. Did you or someone you know have a bad CF experience? Are trying to save me from a bad CF experience? Because if that's the case you're too late. I already did my own test, ran my bike into a telephone pole head tube first, and it came out with flying colors. But I wouldn't expect you to believe me because in your world, what happened in my world, can't happen.

Even people who don't tour ultralight worry about weight. Every bicycle tourist I've had discussions with worries about carrying less load. They will go to great lengths to carry 2 lb less gear but then put it on a bike that weighs 8 lbs more than the bike I currently use. But ask them to use a material other than steel and they go all wiggy.

Why wouldn't it be appropriate? It's used in aircraft and cars without problems. Those are places with much greater stresses than bicycles every put on the material. Composites can be tuned to the stressed needed for the application.

I doubt that a modern touring bike from someone like Surly, for example, uses tubing with thicker walls than a 1984 Miyata Ridge Runner. That was the frame that I had repaired long ago and the one where I became aware of how easy the metal is to burn through. On the touring forums, a rider had an accident in China and had a repair done so that he could finish his trip and the welder burned through his tubes as well. It's easier than you think.

And, again, the "myth" is that a bicycle can be repaired in any small village in a Third World country. Not a "decent city" but by the village smithy. It's still a myth.

We are talking short term repair here. Welding or even brazing a frame is the same short term repair.

Yes, they would be about the only welders who could do the job correctly but they need to be informed about how thin the metal is so that they know what they are getting into. And I'm not sure how many sheet metal shops you are going to find in a small village in the Third World.

So you carry a 6 lb tent, 6 lb sleeping bag, cast iron skillet, full size Coleman campstove, camp chair, cot, etc.? Maybe 150 lbs of gear? "Weight doesn't matter" after all:rolleyes:

Of course weight "matters". Talk to any of those 3 people who tour and they will go on a litany of things they use to reduce the weight they have to carry. Some are more willing to carry more so that they can have some comforts but most will forgo a lot of comforts so that they don't have to huck it up every hill they run across.

You clearly don't understand the material. Carbon fiber composites are made with thermoset resins. The "plastisizers" don't off gas and make the material more brittle. Many thermosets continue to cross link even after the initial curing. Thermoplastics can embrittle as they age but thermosets are different.

Many of the same arguments like "it will shatter on impact" have been aimed at aluminum when it was introduced. Along with the same videos. Videos weren't ubiquitous when steel bikes were in vogue but I suspect you could find similar failures of welds with those as well.

But remember Aircraft have Time in service Logs and are taken Out of service and scrapped after a limit is reached ..

Buying a Used Carbon Fiber Bicycle will not have such FAA required log books attached .

& race cars, Like F1, are New, every year.

I see benefits and drawbacks of all materials. For me, safety is one of the most important concerns. A broken fork will ruin anyone's day/year/life.

Yes, failure may be rare, and CF is pretty safe if you look at the overall numbers.

But I don't believe it is possible for anyone to form a logical argument against this statement:

Carbon fiber is more likely to fail in catastrophic fashion than steel or aluminum.

I don't have a dog in this fight, but advocates on both sides are comparing apples to oranges. I don't mean the material, but the application. Most CF/steel comparisons don't hold, because the vast majority of CF bikes were built with weight at a premium, whereas steel bikes run a full spectrum.

Nothing but market considerations prevent building heavier, more durable CF bikes, which would compare more favorably with steel. I'd venture that if built to the same weight the CF bike would be staggeringly stronger.

IMO the biggest difference between CF and steel is where we are on the learning curve. Steel bikes reflect over a century of evolution and experience. CF is newer, and we're still learning about it, and developing strategies to use it better or smarter.

When I think about this generally, it strikes me that we ask the wrong question. It seems to me that the difference in an aluminum frame and a steel frame, for example, isn't directly due to the frame material but more reasonably due to design constraints imposed by material properties in the context of marketing.

For one example, an aluminum is stiffer than a steel only because it has to be designed that way. Because aluminum will break if you flex it too often. Aluminum is not stiffer than steel (it's much less stiff) but the frame is. So it never really quite makes sense to me to ask which material is better. Which design is better?

I am not! I did not say that I imagined anything. I alluded to an racing accident many years ago when I went down and was subsequently run over by the pack. My steel frame pride and joy was irrepairbly daamaged. I'd owned that frame since high school and it had just been repainted and was wearing 600 SIS throughout.

I also said I'd hit a telephone pole and I kid you not, it hurt like hell and my stem still bears the marks from the headon impact. I still can't use my thumbs as well as I once could but hell, I was riding, wasn't I?! Oh yeah, the frame and fork were undamaged. The rescue squad consisted of a bunch of firemen from a station down the road who gave me coffee and a seat on the sofa where we watched the game while I waited for my wife to show up with the car. I was out of it. I could go on...

There are a lot of generalizations about the stuff. I could have gotten one of those lightweight CF frames but declined and bought one that weighs almost 1,400G. That's pretty porky where CF is concerned but I'm no dainty road racer. Now, I decline your offer to drop my bike on a rock because THAT WOULD BE INSANE but will say this, I am no more concerned about the fragility of this bike than any others, steel, aluminum, bamboo (JK), that I've owned. :-)

So you see, you'd have had to have caught me speculating about the properties of another frame material in order to "catch me" but I admire the effort. Haha.

If by "catastrophic", you mean sudden and unexpected, I would say that steel fails in exactly that way based on my experiences with steel frames and parts failing vs aluminum frames and parts failing. Probably the most common steel part to fail on me has been spokes. They definitely fail suddenly and without warning. They make a loud "ping" noise when they go and they don't make any kind of noise before them break. I've broken pedal axles, hub axles and frames. All of them gave no warning and didn't bend before they broke. They seemed just fine and were broken an instant later. One axle break even broke the dropout on a frame.

Aluminum, on the other hand, has always creaked and groaned for a very long time before it broke. Broken frames, rims, and cranks have all creaked loudly for a long time before they broke. I may not have recognized the signs but when I found a broken part...only the crank arm sheared off...I instantly recognized where the creaking was coming from. That's because aluminum is a soft metal that, as wphamilton states, isn't stiff nor brittle. Steel is stiff. And steel is brittle.

I would suspect that carbon fiber is going to fail much more like aluminum than like steel when it fails. Carbon fiber is more like green wood than a metal so to shear it off requires shearing different layers running in different directions which isn't likely to happen. It's going to bend and crack and release energy more slowly.

First, I doubt that you would need to build a carbon frame with the same weight as steel to have a staggeringly strong frame. You could build it with much less weight and still have a staggeringly strong frame. If it were the same weight at a steel frame, the tubes would make aluminum tubes look puny and thin;)

That said, you are absolutely correct that it is marketing. Partly because carbon fiber isn't a material that is that readily available. It currently runs $10 to $12 per pound and is limited in supply. Even auto manufacturers want to use it but it is currently too expensive for widespread use. And, for some bicycle application, the market just won't accept it. Not because it's a bad material but because it is "new". Mountain bike riders didn't have any problem accepting aluminum and now carbon for applications that put more stress on bicycles than other parts of the market *COUtouringGH* put on bicycles but that part of the market *COUtouringGH* won't accept anything but steel based on the myths I've illustrated above.

There's a reason that touring bikes are a niche market. A large part of that is resistance to something new. The other part is buying and keeping the same bike for 40 years and wondering why no one makes touring bikes anymore.

Exactly. The way you use the material is as (or more) important as the material. Mountain bikes have shown that for a good 25 years now.

If carbon is so strong, why does it fail at only 2,050 pounds of bending?

I'm sorry but I have to laugh at this. Aluminum metal fatigue induced breakage will hit as catastrophically as anything else, and without prior warning. I know, I have the scars to prove it.

By "consumerism" I'm assuming you mean when people discard something that's perfectly serviceable for something new just because they want something new. A concept that might be hard for you to grasp is that not every purchase of current technology is "consumerism". Sometimes you're just buying something you want or need, and choose something with current rather than older technology.

How can any mass-produced product have "soul"? I'm a lover of old steel bikes (have one each 20 and 30 years old, and am very nostalgic for my old Raleigh SuperCourse which I don't have), but also absolutely love my new-ish (~5 yo) CF and aluminum bikes, they're lively, comfortable and the mechanics are fantastic and nearly flawless. Old or new, regardless of the material, they're all great, fun to ride and have equal measures of "soul" which is none. Maybe they do have soul, but it's not based on the materials, but based on the great attachments I have to all of them because they're fun to ride and look nice.

I get this feeling that those who disparage current technology think that somehow things haven't been improved or innovated since [insert date of their favorite technology here]. Reminds me of the religions think that for some reason culture, values and tradition (and even technology) should be locked into what they were at some very arbitrary point decades or centuries ago.

I'm not an experienced tourer, and I have no doubt that the design, including material specifications need to be made to work well with that use, and steel might actually have a preponderance of factors in it's favor for that use.

But as for the weight: If touring is anything like backpacking, yes indeed you do everything practical to reduce weight, even an ounce. The difference between a 41 pound pack and a 40 pound pack might be insignificant statistically, but every backpacker in the world would absolutely make a good effort and pay money to upgrade gear to lose that pound. I would think that for loaded touring, all other things being equal (i.e. durability of the bike, design/balance/handling, etc.) I would invest time, effort and money to lose a pound.

First Full disclosure With a wife that does not drive other obligations One or 2 nights is the most I have an opportunity to go. I am not one to worry about weight to the point of sacrificing comfort . And yes if there is a good chance of frying fish I will carry a small cast iron skillet . I don't like aluminum bikes I had a Ross mtn bike that I liked the looks of, it had decent components bikeapedia listed msrp of a 93 model at around a grand . I think the one I had was a 92 as it had no shocks on the front forks I road it around for a year trying to like it just could not . I am not argueing your point on the strengths of a carbon fiber bike. Cost which are coming down on carbon bikes is one thing stopping some. 2 Having the lightest fast newest material is not as important to some as it is to others.
Carbon arrows feel like plastic that does not instill confidence to me . Lets try this as an example I hunt I have a stainless steel /synthetic ***** if it isn't windy I can routinely shoot through the mouth of a pop bottle not touch the neck and out the bottom at 200 yards. the *** is just metal and plastic to me a tool to take out animals destroying crops in the summer to get me access to ground to hunt in the fall. On the other hand I hunt with a muzzle loader made in the 70's walnut and blued to me it is art and my ability to harvest food with older tech 1850's touches something inside that the latest greatest doesn't.

Less than a minute of angle isn't bad for a bow, and that sounds like a 1/2 minute. Congratulations, because most *****s can't touch that kind of accuracy.

When I hunt, my goal is to kill (and therefore eat) the animal with as little effort and as much efficiency as possible, and, most importantly, to maximize the chance that it will die quickly and minimize the chance that the bullet will be mis-aimed or inadequate for the task. I don't believe in "style points" in hunting and therefore don't believe in bow hunting or hunting with technology that is inferior in killing the animal, such as muzzle loaders. That stuff is all for style and not for the intent of the hunt..... in my opinion.

I'm all about the end in hunting (within the regulations and my ethics as stated above), not the means. I like hunting, but it's the meat I'm after, not the lifestyle. In my experience bow hunters and muzzle loaders are more of lifestyle people. We both love the hunt and the meat, but they like to spend way more time on it than I do. To me, it would be like a golfer who wanted to golf with old hickory shafted clubs instead of more modern ones. Kudos, but it's style not effectiveness.

However, I do not criticize any other hunter's ethics or "style" as long as #1 is killing as quickly and humanely as possible. They have every right to hunt the way they choose. I'm seriously glad they hunt, do respect their efforts, knowledge and skill, and do enjoy talking to them and learning about their hobby.

But back to the point of the discussion - I love old bikes and I love modern technology. I don't believe for a minute that carbon fiber is in any way inadequate for the application of bicycling. But I also don't feel that steel or aluminum are inadequate either.

We could all be reduced to one of the four major choices (steel, alu, ti, CF) for frame material, and not a one of us would suffer in any meaningful way and none of us would be unhappy or quit cycling.

Sudden and unexpected, yes. And quickly followed up with a serious crash. Spokes breaking don't usually cause a serious (or any) crash, so I'm not so concerned about that. (besides, there's no reliable alternative to steel spokes anyway... I wonder why that is?)

Not according to most CF failure stories. Which is why we see so many threads on BF asking... "Has this scratch/scrape/crack compromised the integrity of my CF frame/fork/component?"

The owners understandably don't want to have to pay to replace their high dollar parts, but more importantly, they don't want to suffer grave injury due to catastrophic failure!

I rather like the idea of a bike lasting 40 years or more. It seems to me that one material clearly has an edge in this area. If you disagree, please explain why.

Sounds good, but pause to think a little more deeply. How much money does it cost to buy and maintain a car? A lot, but where does that money go? Part goes to the designers of the car, the engineers who work with the designers, the workers who build the car, the miners who mine the metal, the factories which make the glass, wires, rubber, and later seats. Then there is the dealer, who pay his staff, for his car lot, and other overhead. Then there are the gas stations, car repair garages, accessory store, car washes, and parking garages. Reducing the number of cars reduces the money these people make, and the taxes they pay. How much does the auto industry and car culture contribute to the national economy?

Next, when people want to buy a large home or a second car, they have to plan their lives and careers accordingly. They have to work smarter and harder to provide enough income for these things. The money they spend on education pays teachers and professors, and the increased knowledge and skills they acquire in their education provides benefits to their employers. Also, many people who want to earn greater incomes often start their own businesses, many of which grow, and employ other people, which benefits the economy, and every member of the economy.

For myself, I don't own a car, I do all of my commuting on a bicycle. I don't do so because I think doing so "helps" the world in any way. I do it because here in Tokyo, a bicycle is the fastest way to get around. On the other hand, I do have a nice home, and what I save by not owning a car, I spend on a larger mortgage.

My bicycle is steel, I have ridden it since I raced in Europe in the 1990's. It was given to me by my team's sponsor, and after 18 years of very hard use, and countless kilometres, it still rides perfectly well. I have replaced chains, chain rings, shifter mechanisms, and such as these have worn out, but the frame is as wonderful as it ever was.

Yours is an old (and tired) argument that has been used against just about every material that isn't "steel". It's no more true when applied to carbon fiber than it was when it was (and still is) applied to aluminum. Yes, welds and joints can fail but any weld or joint can fail. Steel frames break as well and it is just a sudden and unexpected...I've had it happen. The steel frames (notice the plurality) I've broken were sudden and unexpected. They didn't "bend" or "yield". They fractured with a loud release of energy. Luckily, they didn't break anywhere that would cause a crash but they did break.

Let's say you bought a pair of shoes when you were 20 and they lasted you until you were buried in them. They are the only pair of shoes you ever bought and everyone around you did the same thing. How long do you think that someone who makes shoes could stay in business if they made one pair of shoes for each person that lasted a lifetime? How many people are going to go into the business of making shoes if everyone buys only one pair of shoes in their lives? How long is it going to take before no one remembers how to make shoes?

Touring bikes fit into this category very well. People buy a touring bike and the thing lasts for 20 years to 40 years. People keep them for that long and never buy anything else. Even worse, people buy up the old ones that were produced during the boom years and keep them running for another 20 to 40 years. New ones don't get sold and the makers starve and go out of business.

As to the materials, Cannondale has made aluminum bikes in classic touring geometry since 1983. You can still find old Cannondales that are capable of touring. A carbon bike engineered for touring instead of for weight would last quite a while as well.

Meh - carbon doesn't just explode unexpectedly. I rode about 500 miles on a fork that had a visible crack in it. When the crack started widening, I took it off the road and I'm currently fixing it. (Long story short: it's too custom to just go out and by a new one.) Like Aluminum, a crack in carbon starts small and grows, until the final break surprises you.