Good sources of information on carbon fiber

[mstateglfr]

I can't imagine being the builder for the OP'S upcoming frame, regardless of material used.

[martl]

Originally Posted by StressStrain

Yeah, good point about PL expertise.

I guess I'm just a bit weirded out by the OP's question. Sounds like he's a layman trying to outthink subject matter experts.

didnt think so. It can't hurt being informed about a subject because in some (rare of course) cases, marketing departments may try to sell you progress or benefit where there is none, or where its only presnt in theory without any real life benefit
And being one myself, it doesnt take an engineer to understand the principles of material characteristics and basic design, only some understanding of high school physics, a good common sense and being intersted to learn that

Only problem is, knowing about the basics of material and design still doesnt give you the skillset to understand whether a given part of equipment is well made, good resp. better than another part. You may be able to sieve through the stuff thats so obviously in the "will never work" category (* and even there one may be wrong; ask any engineer *not* savy about bikes what to think about aluminum spokes yet Ksyriums worked);

--but for the nuances? not even another engineer versed in the subject at hand can always do that if not given all the vital data, which one usually doesnt have available.

resp. wanting to learn about proper care/maintenance, that claim also is a valid one. But all the user needs to know about how to treat a CF partabove some super basic stuff is not found by learning about the first principles of CF design. Here, listening to the practical advice given by experienced users and mechanics is the way to go.

[reuben]

Originally Posted by martl

in some (rare of course) cases, marketing departments may try to sell you progress or benefit where there is none, or where its only presnt in theory without any real life benefit

https://m.youtube.com/watch?v=yPW5JDZolu4

[FastCanon]

Any material can fail. Look at Shimano latest recall. You can have bonded al fork and that could be a point of failure.

[Mark Davison]

Originally Posted by mstateglfr

I can't imagine being the builder for the OP'S upcoming frame, regardless of material used.

I'm currently working with hampco. We decided to put the titanium frame project on hold and just make a steel disk brake fork for my current S&S coupled steel Davidson touring bike.

Both hampco and Bill Davidson unreservedly recommend titanium frames with carbon fiber forks for travel bikes.

I've worked with Davidson on two custom steel bikes with no problems.

What I like about working with local builders is that you can meet the people who do the fabrication. The artisan who is going to build my disc brake fork is the same one who made my current rim brake fork.

This forms a bond of trust that I don't get when I buy a product from a large manufacturer.

I'm sorry if my tone puts people off. In regards to materials science I am a layperson, but in regards to logic I am actually an expert, since I have a Ph.D. in mathematics, and have worked in analyzing defense systems and writing and debugging commercial software. I am one of the authors of the diagramming program Visio. Towards the end of my career I transitioned into technical marketing. It was quite an education to be introduced to the techniques of modern marketing, which is more about emotional appeals than reason.

What I like about PL is that industry experts do participate, and if you ask the right question you can get some real insights you can't get anywhere else.

I am not biased against CFRP in bicycles in general, but I am appalled at the lack of high quality consumer information on the robustness of components.

My personal bias is for purchasing or building up bicycles that are "lightish" but retain a reasonable safety margin, and are resilient to the kind of impacts that you can expect from parking, transporting, and field repair by amateurs.

I wonder if the connection between racing practice and producing and marketing useful, resilient bicycles would be improved by introducing higher minimum weight limits on the bicycles.

Here's an unrealistic thought experiment: imagine that the UCI changed the minimum weight to 20 lbs, and changed the rules on outside support to prohibit swapping bicycles.

This would open up the choice of frame materials, remove the incentives to reducing the safety margins in the design of components, and create a real incentive to insure the bicycles can go the distance. You could even require that the riders use the same bicycle throughout a tour, with the possible exception of allowing a different bicycle for the time trial stages.

You could even revert to the early days of the Tour de France and forbid outside support altogether--racers would have to race with tools and fix their own mechanicals.

I don't for a minute imagine that the UCI is ever going to do this. It is certainly not in the best interests of the bicycle companies that market endless innovation masquerading as real progress.

I find it interesting to compare the role that racing plays in bicycle marketing to the role racing plays in auto marketing.

In cycling, you can actually sell the public bicycles identical to the ones used in professional racing, but with automobiles you can't sell the public F1 cars to use on the open road.

In both cases you can market performance features that are fun and interesting but not demonstrably connected to practical advantages. For example, in cycling you can sell the public on very light weight; with automobiles you can sell very rapid acceleration.

The analogy breaks down if you start looking at overall performance: with bikes the human is the engine, so the system performance depends heavily on athletic ability. For most of the bicycling public the available power is so limited that really light weight is not justified if robustness is sacrificed. It's as if you sold someone an F1 car without an engine, and they had to install the one engine they were given when they were born. (In my case I think (metaphorically) it's the 36hp air cooled flat 4 from my father's first VW bug.)

If I bought a top of the line road racing bike with an under 1 kg frame I would be buying the dream of being young, fit and competitive without any hope of actually getting there. I'm sure it would be exactly like driving an F1 car with a 36hp engine.

Maybe we could all come down to reality if bicycle power meters read out in decimal horsepower rather than watts.

1000 watts (a lot!) = 1.34102 hp.

Or maybe they could read out in equivalent incandescent light bulbs (the old 60 watt kind).

1000 watts = 16 2/3 light bulbs.

When I'm really fit (for me) I can do sustained climbs at 200 watts, which is 3 1/3 light bulbs.

(At the science museum in San Francisco there used to be a display where you could ride a stationary bike hooked up to a generator and actually light up incandescent bulbs as you made more and more power. Back in my youth I could light up 6 bulbs briefly.)

[Mark Davison]

Originally Posted by martl

resp. wanting to learn about proper care/maintenance, that claim also is a valid one. But all the user needs to know about how to treat a CF partabove some super basic stuff is not found by learning about the first principles of CF design. Here, listening to the practical advice given by experienced users and mechanics is the way to go.

I have been talking to mechanics and they uniformly will steer you away from CFRP components of any sort (for non-racing applications) because they can't evaluate crash damage. Evidently it's a real turn-off to have to tell a customer that
a) the mechanic can't evaluate the damage,
b) the bike has to be stripped of all parts and shipped off to the nearest qualified inspection facility,
c) oh yes, it's going to take weeks and at least $500.00, and
d) yes you have to pay to have the bike re-assembled.

The other complaint I hear is that ham-fisted amateur repairs can easily destroy CFRP components. But ham-fisted sometimes just means not using a calibrated torque wrench.

These objections just don't apply to steel or aluminum components. They can fail, but they are easier to inspect. You can damage them with too much torque, but we somehow managed to maintain them without torque wrenches without widespread failure.

[rallizes]

Well, I don't have much to offer beyond that I worry much, much more about getting run over by a car than experiencing any kind of failure of carbon components on my bikes.

[Likes2ridefar]

Originally Posted by rallizes

Well, I don't have much to offer beyond that I worry much, much more about getting run over by a car than experiencing any kind of failure of carbon components on my bikes.

Statistics don’t lie.

[Mark Davison]

My other motivation for learning more about CFRP and materials science in general is that I'm a retired nerd, irretrievably warped by my MIT education.

I have a general interest in how technological innovations are disseminated into the wider society and whether they contribute to progress or make things worse.

There is a generic problem with innovation that is not generally noticed: every disruptive innovation that is widely adopted creates massive ignorance, and an associated outbreak of failures.

This is because technology doesn't live in isolation--once a product leaves the factory it has to be installed, configured, used and maintained. Every person involved in this chain may need to acquire new knowledge for the innovation to be successful.

If you are a fan of new technologies and love learning about new things, you may not appreciate the difficulties new technologies represent to the broader public.

When I worked for Aldus, the makers of desktop publishing software, management decided that all software engineers should spend a couple of days fielding tech support calls, to get a view of the difficulties that end users have with the software.

My favorite call was from a user who claimed they couldn't see their display when they used their mouse (and mouse interaction is critical for an interactive page layout program.) After a long back and forth it turned out the user was placing their mouse on their screen! Clearly the user was ahead to the times--they wanted a touch screen interface (This was back in the late 1980s.) The mouse was getting in the way. The user was encouraged to place the mouse on their desk and just watch the cursor. User complied, and all was well.

Who would have suspected that a user would try to put their mouse directly on the screen? But somehow the user hadn't learned that the mouse was made to roll around on a desktop, even though in this instance the marketing phrase "desktop publishing" conveyed a correct expectation.

For bicycles if you teach home/field maintenance, you will get a view into what cyclists actually know about maintenance, as opposed to what they ought to know. So you get to stop them from clamping their CFRP bikes into the wrong repair stand, installing rim brake pad holders backwards so the brake pads would shoot out, riding with disc brake pads that are worn down to the metal, not replacing brake cables that are so frayed they look like they will sever at any moment, not replacing cassettes and worn chains that have suffered from the dreadful combination of high torque from an electric drive and no cleaning or lubrication for months.

The point is that the success of technological innovation depends on what people actually do with it, not what they ideally should do with it. If a technology is at all complicated you can hasten successful adoption by disseminating accurate, practical, factual educational materials and programs, free of pollution from false marketing claims or overly cautious warnings from liability lawyers.

Perhaps there is a generic problem with bicycles. The broad public assumes that bicycles are cheap compared to cars, should require no more maintenance than a car--once a year should do, can be maintained by the user, and should last for 10 to 20 years.

So I think there is a mis-match between common consumer expectations and current innovations in bicycle technology. And the mis-match is not cured by market forces, because I would guess that the majority of the profit in high quality bicycles (the ones sold by specialty retailers, not by discount big box stores) comes from a minority of the customers--the ones who might purchase a new bicycle every 2 or 3 years, as opposed to every 20 years.

I don't expect this situation to get better. Truly durable consumer goods are bad for business. I'm still riding, and enjoying, the same custom light touring bike Bill Davidson made for me 32 years ago.

If I were really rich I would start an independent consumer test organization that would test bicycle components for robustness and relentlessly expose components that have small safety margins. Perhaps we could develop a meaningful seal of approval and offer our testing services to small builders.

[mstateglfr]

Originally Posted by Mark Davison

What I like about working with local builders is that you can meet the people who do the fabrication. The artisan who is going to build my disc brake fork is the same one who made my current rim brake fork.

This forms a bond of trust that I don't get when I buy a product from a large manufacturer.

What I like about PL is that industry experts do participate, and if you ask the right question you can get some real insights you can't get anywhere else.

I am not biased against CFRP in bicycles in general, but I am appalled at the lack of high quality consumer information on the robustness of components.

Edited that post to these 3 things because they stood out.

- agreed, it's nice to have a connection to the bike and who is creating the frame. That can lead to trust for sure, and that trust may or may not be deserved. Many builders aren't materials specialists, structural engineers, etc. They should have an expert knowledge on the products they use, but even that will likely come from marketing litrrature and industry formed relationships(that hold biases).

- totally agree about PL having industry experts. This thread alone had valuable insight from a carbon fork designer.

- you may be appalled by the lack of high quality consumer info about the robustness of components, but is that really unique to CF products? It it even unique to this industry?
The answer to both of those questions is - no.
You expect something that is atypical.

• CF forks, seatpost, and handlebars are constantly videoed undergoing fatigue testing. YouTube is flooded with these videos and has been for the last 15+ years. Is that not enough for you?
  If that isn't enough for you, then look into the testing certification standards the forks and components must pass. If that testing is meaningful to you, then there ya go- data you expect.

• If it isn't meaningful to you because you don't think the testing is realistic or applicable to riding, then maybe look into consumer reviews, long term tests, and industry insight. That is what you are doing when you talk with hampco, so clearly it's good enough.

• I can't get consumer info on the robustness of all sorts of things I own, even things I trust for safety. Or what safety info does exist, it's manufacturer generated or it is certified as passing established testing. So same as a carbon fork or components.
  Do you do this much 'investigation' for everything you buy that is associated to your safety? How often is data both readily available and meets your arbitrary standard of applicability and thoroughness?

• My main road bike is a Columbus Zona steel frame and fork I built 6 years ago in a local class. I trusted the builder to spec it with tubing that is light, easy to work with, reliable, and long lasting once built into a frameset.
  My main gravel bike is a small batch production Reynolds 853 and cromo frame with carbon fork. The designer had to spec overbuilt tubes and an extremely robust fork in order to pass fatigue/impact testing.
  One of those frame and fork combos was actually designed to pass testing, but your posts seem to say you would trust the one that isn't built to pass testing standards.

Maybe take the first step and just call it 'CF' like everyone else? See how that feels, and go from there.

[FastCanon]

Mark, how much do you weigh? I can see your concern if you're above 200 lb because a lot of the products out there have a weight limit.

Like others have mentioned, you're most likely going to be in a bicycle accident than having your failed carbon frame. You'll more likely going to have a blown tire going downhill than a failed carbon frame. You'll more likely going to crash into another person than a failed carbon frame. You'll more likely going to get into a car accident than a failed carbon frame. You'll more likely going to get robbed than a failed carbon frame. I think you get the gist. But can a carbon frame fail? Yes. We all know someone who have been killed while biking, but it wasn't because of a failed carbon frame.

[NHAero]

Originally Posted by Mike Lopez

40+ year industry veteran in composites here. Currently building tomorrow's
space junk but spent decades designing, testing, and manufacturing composite bicycle components. Reynolds Composites founder, Serotta, Action Composites, etc.

With all respect Mark, it sounds as if you've already drawn your own conclusions so I'm not sure what further internet propaganda may be able to tell you. Most of what you'll find is techie stuff not applicable to the fashion show of the bicycle industry.

What I can say is that the quest for extreme lightweight components at low cost has not helped the durability issue. In the process of designing and testing forks for example I found that roughly an ounce of material in the right spots made the difference between a "adequate" design and a robust design. This was verified through mechanical testing of hundreds of samples in static, dynamic, and impact testing.

I always defaulted to the safety of robust designs but the product managers often said something like "if you can't make it pass at < 300g then don't bother". I generally told them to pack sand and that's why you still see 20+ year old Ouzo Pros & Serotta F3s still performing well and not sending folks to the dentist as the alarmists like to say.

The exception to this was the Reynolds UL which was my final project there before I moved on. I let the product manager have it his way and the rest was history. Adequate v robust. It passed the tests under ideal conditions but in the real world had some issues.

If there are any specific, objective, questions you may have I can try to help answer.

Mike, I always so appreciate your input in these discussions, thank you very much! And same for Steve Hampsten.

Given what folks have written about Enve here, I am curious how you think about other manufacturers of carbon forks.

I have a Whisky No. 9 Road+ disc fork, it weighs 440g according to Whisky (and 464g according to me) and is rated ASTM Condition 2, and rated for max rider plus gear of 250 pounds. I weigh 142 pounds, and I haven't thought twice about this fork on my Bingham all road bike. No recalls I can find on Whisky forks (one on some of their carbon bars).

I have a Columbus Futura Cross Disc fork on my travel/winter all road Habanero. Columbus doesn't show the ASTM rating or a weight limit, but they clearly market this fork to "off-road enthusiasts" and it is a heavier fork than the Whisky, claimed at 515g. I weighed it and it was more but I can't recall the number.

Both forks have tapered 1-1/2 inch steerer tubes and feel robust to the layperson who handles them.

My latest acquisition is a Cannondale Supersix Evo Hi-Mod from 2016. This frameset is rim brake and the fork has a 1-1/8" steerer and is listed as being 280g uncut according to articles on the bike at the time it was released. I wonder where this fork is on the range you note of adequate to robust. I don't plan any off road excursions but potholes exist.

Thanks for any input.

[mcteague]

Originally Posted by Mike Lopez

The exception to this was the Reynolds UL which was my final project there before I moved on. I let the product manager have it his way and the rest was history. Adequate v robust. It passed the tests under ideal conditions but in the real world had some issues.

If there are any specific, objective, questions you may have I can try to help answer.

I had an Ouzo Pro on a Ti bike that I had to replace after an "incident" . A car turned in front of me, and realizing what he did... just stopped. I had to do an extreme right turn to avoid him and ran directly into a curb. Had I more reaction time maybe I could have hopped it. The impact flipped me over the bars and onto my back. Miraculously, I suffered no severe damage. The front wheel was bent but the fork was still looking fine! Turns out the headset ring was driven into the carbon and could not be removed. This was revealed when the fork was inspected by a shop. I replaced the fork anyway even though it looked nearly perfect.

The replacement was the Reynolds UL as Tom Kellogg told me what a great fork it was. Of course he is a pretty little guy but rides hard. About 5 years later I sold the bike but the UL fork was still going strong.

My newer Pursuit has an Enve road fork so I hope they have a robust design.

Tim

[dustyrider]

I know I don’t have a PHd from MiT, and truth be told I’m way more apt to believe a guy like Sam Pilgrim when it comes to what a carbon bike can withstand. Ultimately it’s really up to you to decide what information you need to trust if your carbon fork can withstand crosswinds in a roof rack or not, if you have 12 minutes you can check out his recent bike sponsorship test: YouTube. Have fun with your new build!

[Mike Lopez]

Mark D. Thanks for your question! I believe Mark M and others have already made the same suggestions I would regarding information on industry standard testing.

NHAero. Since changing industries I haven't been keeping up with the current fork offerings but I remember the Whiskey products as pretty beefy looking designs and not pushing the envelope on low weight. Combined with the stout tapered steerer I'd expect them to fall into the robust category.

mcteague. Tom was involved in the UL project as a test rider to provide feedback on feel, stiffness, etc. He also did his own rudimentary bench testing of the flexural & torsional properties to add to his ride test info. I also did these tests with better fixturing in my lab and his results were generally similar to my own. I believe I provided him with about 5-6 different lay-ups to try before we settled on the ride characteristics. I enjoyed working with him on this project and many folks thought it was a great riding fork. The real challenge on that one was trying to make it pass the new impact testing criteria and not blow the marketing depts weight budget. Keep in mind this was a straight 1-1/8 steerer and needed to pass the new test standards that were being driven by the early adopters of tapered steerers and the EU. We managed to pass the test but I'd place that one in the adequate category, not robust.

Over the past 25+ years the test standards for composite bike parts has gone from very very basic, (and scary), to much more sophisticated. When we started on the OP project in '98 we were underwhelmed with the published standards based on metals and created our own composite specific tests. And...we tested several hundred forks before releasing the product to the public. Chris Horner was an exception and got to ride and provide rider feedback on these early forks. He was a local bro and had faith in our effort.

Those were the early days of composite forks and the designs, testing, and manufacturing methods have gone from infancy to mature. We had to make decisions based on relatively small samples in the field and now there's a population of forks out there to study analytically/anecdotally etc.

At this point, the tests are so hard that if the products are properly tested with a reasonable sample size they should mostly fall into the robust category.

There have always been doubters and I long ago gave up trying to convince them otherwise. If you feel the need to worry about your composite parts while riding then don't use them. You're supposed to be enjoying the ride! Not worrying about what may break underneath you. As others have said, you're much more likely to get in another manner.

If you're afraid of the water, stay out of the pool.