Isotropic basically means the material has the same properties in all directions. Carbon fibre is anisotropic because the fibres have very different properties in different directions. Also, the gradual failure property you say carbon has is also exists in aluminum and other metals. Small cracks can exist in aluminum and grow each time a high enough load acts on the area of the crack. Its always worthwhile inspecting a frame for cracks, whether it's carbon, aluminum or any other material.
+Andrew Bedford No need for a channel ban! Simon has the best engineering / mechanical knowledge of the GCN presenters! Having said that, I do charge for sharing my knowledge... a GCN casquette should cover it ;)
+Simon Rendell Yep. In fact that (fatigue) is usually the critical failure mode of aluminium in a vibration loaded part like a bike frame. It's also the reason why aluminium frames are so uncomfortably stiff: once you have dimensioned aluminium so sthe part is more or less fatigue-safe, you arrive at very stiff cross sections.
+Simon Rendell I wouldn't say carbon composite has a gradual failure mode unless you're comparing it to some sort of ceramic. Once you load a carbon composite much beyond it's yeild point it will experience sudden failure, compared to aluminium which have up to a 11% elongation before total failure. That said I'm pretty sure the high strength 7xxx series alloys have a much lower elongation percentage before failure. The fatigue strength of aluminium alloys may not be great compared to steel alloys but It seems unlikely to me a carbon composite would be able to sustain as many load cycles as an aluminium alloy. That said I never enjoyed material science at university so I could be wrong on that part.
FYI for anyone who is interested, an isotropic material is a material that has the same material properties in all directions, i.e., it's modulus of elasticity (stiffness), tensile strength, modulus of toughness, modulus of resilience, fatigue failure mechanisms, etc. (all of which are quantifiable properties) are all the same no matter which direction a load is applied. Carbon fiber, since it is a fiber, is inherently not isotropic. If you take a fiber and stretch it along the length of the fiber, it will behave differently than if you (just imagine it) try to stretch it along the short way of the fiber. Since the fibers are laid up in bundles, obviously the "non-isotropic-ness" is exacerbated. The truth of the matter is, no material on earth is perfectly isotropic. Steel, aluminum, titanium, and all metals have a crystal structure that have slip planes along different axes, and have grains made up of those crystals that face in different directions, and the size of those grains have a significant impact on the material properties. However, that's pretty much just theoretical shizz that most people don't care about. For the most part, standard steel and aluminum can be modeled as isotropic. Just your materials science lesson for the day.
Bringing me back to my first year materials subject at university - the alteration of crystal structure through heat treating, alloying (the substitution/addition of elements of different sizes), and applying mechanical stresses during cooling (amongst other things). It's interesting how you can enhance or diminish almost any properties through minor alterations.
one of the best bikes I ever owned was a Principia Rex ellipse with isaac CF forks.absolute rocket ship, put your foot down and it just took off. I sold a well used RS6 pro to an experienced cat rider who was going to use it for crits...this was only 3 years ago.
Don't choose an aluminium frame for mountain biking though: on 2 bikes I had 4 breakages and on my last bike as the frame was still under warranty the manufacturer offered me a free carbon frame in replacement, that tells volume about what they think of aluminium !
Scandium and Titanium are highly specialised frame materials requiring a really high skill ceiling to manufacture properly. The properties would be similar to what you could imagine as a steel/al hybrid. Comfy and tough yet still tough and light. Unfortunately that makes them really, really expensive. Wood and bamboo frames you could imagine as nature's carbon fibre (fibrous layers of anisotropic sheets) but really really soft.
+Windoges I know guys riding the bamboo fixies. They say they do bunny hopps and often ride downstairs. So I wonder for how long their bikes will last.
Great video, thanks! Lads, how about you do a survey among GCN viewers to make a top 10 bike makes that we all ride? I think that might make for interesting viewing. Well, I'd like that, anyway...
+Mickey Pius My family has three Fuji bikes and one Specialized bike. I ride a Team Fuji with a composite frame. In the future, I think my next bike will come from Canyon. But Canyon still needs a way for U.S. residents to order from them (I hear they are working on it).
My carbon Felt F1 Sprint came off the bike rack of my trunk at 45 mph and I watched it do about 5 toppling crashes down the highway before it came to rest. I picked it up and bent the Dura-Ace shifter back into place with my hand, rode it in that day’s century ride, and proceeded to add another 30,000 miles to the bike over the last 6 years. Try that with a metal bike.
Would love to see GCN talk about bikes other than super bling carbon bikes that cost more than my car. The new CAAD 12 is a fantastic bike, and still a contender for crits. The new Allez Sprint is also very cool. I'd be willing to bet most of your viewers don't have or can't afford only the top pro level builds. Bring it back down for the regular folks once in a while.
If you are still skeptical about sunlight weakening your bike you can always use factor 50. Remember to put more sunscreen on regularly throughout the day while riding and especially after rain.
Hi Guys, i wrote my master thesis over the fatigue of fibre reinforced plastics and i have to tell you that the fatigue behavior of carbon fibre reinforced plastics is in fact much better then that of alluminum. That is one reason why airplane builders are so enthusiastic about changing to that new material. The Big Problem with it is of course that when you design a part according to the load cases you assume making full advantage of the unisotropic material properties (depending on the orientation) the part is very good and lightweight for this load case. But of corse not for a load case that was not considered and applies loads to the part in other directions. So you can say that aluminum or other isotropic materials are less vulnerable to unexpected load cases (crashes) but a carbon bike used of its designated purpose (riding it) is less vulnerable to fatigue and can thus last a lot of years being used hard.
Good video, I'm still a steel guy. love the ride characteristics and the long term reliability. Plus I don't want to be worried about over torquing bolts on components out on a ride if anything happens.
+Chasing Cornfields i love steel alot, but i would like to say i have done thousands of raggo miles in the shite back lanes of dorset on my canyon and i have never taken a tool with me, just tubes co2 and tyre lever!!
Carefully lightly-sand the "chip", & then apply 2-part epoxy. Buy the epoxy from a marine supplier, NOT from a hardware store! Add some additive to thicken the epoxy, or it's too-runny. Tape off the adjacent area. Make it slightly "proud", so you can finish the repair with a final sanding, using a HARD-backed fine sandpaper (so you'll not depress the repair using finger-pressure). Epoxy should set in a few minutes, & it's easier to final sand when still-soft (slightly). Prime, & paint to match. Easy :-) I build catamarans with CF & epoxy. My epoxy supplier is: US Composites in FLORIDA, USA. Buona fortuna!!
There are actually some things YOU didn't know about carbon fiber :PPP There are more than 5 CF manufacturers. Toray (+Zoltek), SGL Carbon, Toho, Mitsubishi, Formosa, Hexcel, Cytec and some more ;) Ultra High Modulus fibers are heavier, because of the denser arrangement of the carbon atoms. If you take PAN fibers for example. High Strength PAN CF has a density of arounf 1,78-1,80g/cm^3 while UHM PAN CF is about 2,0g/cm^3.
Hey GCN, could you do please, or have you done a video on carbon fibre vs aluminium frames please? Something like the pros and cons of each. I vote for a Lloyd vs Stephens duo!
Isotropic means that a material has strength in all directions. metal, for instance. Carbon isn't isotropic. That can mean it is weak in some directions. Drop something heavy on the frame? it may crack. It is also why carbon frames break more easily in a pile up. It's strength is not in all directions.
Drop something heavy on a ti, steel or aliminium and it may crack, just the failure mechanism may be different depending on load orientation and properties of the material. Metals are not perfectly isotropic either, especially when alloying, heat treatment, welding and forming are involved. Carbon frames do not 'brake more easily in a pile up', that is simply incorrect. They are strong in all directions if layed up correctly, with the correct lamination and resin match. The weave of the fibres orientated within the laminate must matched for the loads and the directiona predicted....exactly what good bike manufacturers intend to achieve in the design process.
Carbon fiber is strong on "simple geometry" notably on boats. Carbon fiber is weak on "very sophisticated geometry" like on bikes. Carbon fiber is strong on 1 direction because they are simply overlapping fibers but with bikes of having multiple stress points, it doesnt really play well on long term durability. The sheer number of stress points on bikes are what makes carbon fiber frames weak in the long term also the glue that bonds them which disintegrates overtime. In the molecular level, alloys or aluminum frames are better since they are single construction (homogenous), but carbon fiber is built from many raw materials to form. So more parts, more prone to failures.
@@arvincabugnason6728 I still have a 40 year old steel frame road bike. With simple anti corrosion maintenence the frame is rock solid and i do use fatter rims and tires to go off road as well. Steel can really take a beating, its heavy though. Obsolete in racing terms.
Nice Video! I work a lot with carbon, just one thing to mention.. carbon, as fabric out of strings, the dangers by braking are getting carbon pieces in your skin, which could cause blood poisoning if the pieces are not removed.
I have to disagree with the claim that "you [can] lean your carbon bike against a radiator". Most of you didn't come to read essays so, in short, leaning a carbon fiber bike on a radiator (I'm assuming an operating automotive rad) will most likely ruin it. DON'T DO IT I would like to speak to the point about the temperature resistance of carbon fiber reinforced plastics (carbon fiber for short). As an engineer with experience in designing and manufacturing with carbon fiber composites for automotive racing applications, I feel the need to point out that high temperatures can be a significant hazard for carbon fiber. First it is worth pointing out that the operating coolant temperature is 90 degree Celsius for most road cars (110 degrees C for some motors eg. Audis' TSFI motors) so radiators will feasibly reach 90 degrees in certain areas. Although 90 degrees C will have very little effect on the properties of elemental carbon (as compared to 20 degrees C), resins used in carbon fiber MAY be affected. As opposed to elemental carbon which have little variation between different manufacturers, different resins will exhibit vastly different reactions to temperature. The important metric to note pertaining to the operating temperature of a resin is its glass transition temperature (Tg) and not the melting temperature. The Tg is effectively the temperature at which a (amorphous) material turns from a brittle solid to a rubbery substance. Beyond the Tg, the composite loses it's structural properties and is easily deformed. The resin used in many of our components on our race car (ties rods, steering column, intake, body panels, etc...) has an operating temperature of up to 70 degrees C (160 degrees F) and heat exposure is a large concern of ours when designing and implementing these items. The specific resin we use is valued for it's strength and chemical resistance despite the heat concerns we have. It is worth noting that the resin we use is in fact marketed as a "high temperature resin" (just not quite up to all our requirements). There are, of course, resins that have much higher Tg's of up to 300 degrees C (2000 degrees C, even, for carbon-carbon though that's completely different), this often comes at the cost of strength, chemical resistance, ease of manufacturing, and most importantly, money , and therefore, are not preferred. I applaud the creators of this video for recognizing that bicycles are designed with their intended uses in mind, and this leads me to my point. Although I don't know the properties of every single different resin used in bicycles, considering that the typical use of a bicycle is not to be leaned against a radiator but rather to be ridden in mild climate, resins are not required to withstand the temperatures of the radiator and probably will not. Composites used on bicycles will be required to have excellent specific strength primarily with operating temperature being of very minor concern of its designer. I've focused on the resin for carbon fiber bikes in this comment but the glue used to bond sections of carbon fiber together, the clear coat used to make bikes look pretty, the vinyl liveries on bikes bike are whole other cans of worms... I'm not certain why this video had to go out of its way to offer people potentially hazardous information, but for anyone who didn't feel my first two lines of this comment were of common sense and felt the need to read the justification, hopefully this clears things up for you.
CF is good, my friends have exotic cars with lots of CF parts. Here are some of their complaints. The resin chips easily(expensive to fix), in really cold weather it cracks(expensive), Any hidden chips turn fatal if you drive on wet salty roads. Extremely strong in some direction but surprisingly weak in others(if you move it in an unusual way it can break easily). To me its not worth the price right now vs aluminium. In the future CF bikes will probably cost the same as a current aluminium bike, when the price comes down ill get one.
+Robert Flagg Car parts are subjected to vastly different stresses than bicycle parts and many aftermarket carbon fibre parts are poorly engineered compared to OEM.Both my road and CX bikes have seen multiple winters of -15C and hit with salt, sand, gravel, and flexed through sprints or bunny hops (CX) without any issues. I even have a few bare carbon spots on my road bike (before I started using 3M clearbra material to protect vulnerable areas) and only the very thin paint chipped away. Unlike carbon fibre, aluminum fatigues over time when repeatedly flexed. That's not to say there aren't great metal bikes out there but, honestly, most carbon fibre bikes built in the past five years or so are just as durable, if not more so, than aluminum.
+Robert Flagg agree with you... been using steel and aluminum frames for many years, then i upgraded to a carbon frame road bike yes its stiff and light but durability not really. frame and other components made from CF you have to treat them with tender and loving care.. for sponsored pro teams its not really a big concern for them because they can easily replace their bikes..
mneedes2 nope, seems tough as nails. Mind you, I ride a pronghorn, which is the only CF frame that comes with a lifetime guarantee. If I do manage to break it, they'll give me a new one. Used by the Peruvian olympic MTB team, so if they can't break it... doubt I can.
About frame repairs: after an accident, steel tubes can often be bent back to shape, no welding necessary. Forks can be bent for more offset (rake) as well. Neither aluminum nor carbon can do this, since they overwhelmingly crack during crashes. It follows that frames made of these materials require much more involved and costly repairs outside the scope of most home or local bike mechanics. This myth is pretty accurate
charlesissleepy Steel can be bent no problems, but aluminum is very prone to metal fatigue if its bent without being heat treated. You have to heat treat aluminum when bending it to avoid metal fatigue.
Building bike frames was such a artform before carbon came a long. Wonder what ever happened to all the Italian master frame builders from De Rosa, Colnago etc. from back in the day? My all time favorite bike is still a classic red De Rosa with campy.
+Alan Lamb It's still an art. Just a different one. The non-isotropic properties allow stiffness in certain directions and compliance in others while saving weight. That's why I love riding my carbon bike over my heat-treated steel bike.
I have yet made the switch from AL to CF primarily because there is always that stigma amongst CF bikes that you have to treat it with more TLC because its more delicate and refine, but I do want to try one to see how much more compliant and stiff a CF bike is compared to an AL.
On my 125 miles ride yesterday I got a massive stick stuck between my back wheel and the downstay and chainstay. Pretty sure that would have messed up a carbon bike pretty good. My aluminum bike just had some paint scuffs.
I got goosebumps when this video uploaded because several hours before I wondering and try to find answer , is that affected if I put my carbon frame bike on the outside getting directly hit by sun day and night. Thanks for the video GCN!
For those who ride Carbon, if you store your bike indoors you ought to seal it in a bag of some type. This will prevent wear or damage from temperature and other things of that nature. Might want to put a blanket over it to as your bike could get cold.
Nice video- I am using a carbon XC full suspension bike last 4 years and I am tired of people (even in the bike shop) that are telling me that I should leave it layed down on the ground because if I leave it leaned to something it may fall ang crack far more easily than the aluminium bikes :)
.....always informative, thank you. Motorist struck me at the rear end pushing me some 3m out of my lane, managed to stay on the saddle. Seems it would be prudent to have the frame replaced to maintain the manufacturers warrantee at the expense of the drivers insurance.
What about the grease question. When I picked up my first carbon framed bicycle the last thing the guy at the shop told me was that I should never use any kind of grease on the frame or any components that come into contact with it. Since then I have heard many differences of opinion on this topic and I have personally thrown caution to the wind.
5:50 isotropic means that the material properties are the same no matter how the material is orientated. Carbon fiber is anisotropic, which means that it has different properties for different orientations, i.e. it only has high strength in the longitudinal direction of the fibers.
Excellent video guys, there's just one myth that didn't got unveiled, (at least here in South America and Mexico), people tend to believe that carbon fiber has an expiration date, is that true?? o.O and if it is, how can I know when my bike is no longer suitable for riding?? or any other carbon fiber component, Rims, Handlebars, Stem, etc!
+Rob Granville (CBR) I've been riding my Reynolds Strike SLG carbon clinchers for 2 years now, all year long, rain or shine, flat roads, alpine descents, everything. No sign of wear on my Reynolds brakepads or the rims either, while before that my alu clinchers would not even last me 1 winter...
As a composites engineer, I think I know where this misunderstanding is coming from - carbon fibre does in fact have an expiry date - but this relates to the uncured prepreg. i.e. before the components are put in the oven. Once they are cured in the oven there is no longer any relevant expiration. Also note, any carbon prepreg material will cure itself in room temperature if given enough time to do so, this is why we store the material in freezers.
I have 12-year-old carbon bike, 3 alu bikes of more than 15 yeras old, 1 20+ year oldTange steel vintage bike Panasonic, 15 year-old 1 titanium MTB. None has ever broken down, but I am more confident that my Ti bike will be very safe and last well over my dead body than any other bike.
What about the grease question? When I picked up my first carbon framed bicycle the last thing the guy at the shop told me was that I should never use any kind of grease on the frame or any components that come into contact with it. Since then I have heard many differences of opinion on this topic and I have personally thrown caution to the wind.
outandaboutDave technically grease should not ever be needed on a carbon frame. Seat post should be coated in fiber grip instead. The headset is the only place where opinion differs, some say fiber grip messes up your headset bearings and others say grease makes your stem slip (CF Stem and CF steerer o course)
I buckled a seat stay in a prang. My local bike shop said it couldn't be repaired so I took it to the local yacht club instead. Their engineer inserted a carbon rod, filled the gap with resin and then wrapped it with kevlar. Finished with a lick of paint it looks almost perfect and it's stronger than it was before.
Alimunium is isotropic because the physical properties are the same in all directions. Composite layers are engineered to be anisotropic, desiring those physical properties to vary depending on the directions. For instance, you need more resistance for vertical loads then for lateral forces on a frame. On aluminium bikes you can compensate that by designing different thickness depending on the section. On a composite, you will increase direction on one direction. Plus, using 45degree alternated directions, it distributes tension within a plane instead of in space. I am not an expert in bike design and construction, but am a polymer and composites graduated engineer with some R&D working experience for automotive. Not my field of work lately.
Future will develop intelligent anisotropic materials that can vary their properties depending on solicitation to prevent failure or catastrophic (collapsing) failure. R&D was still a challenge when I was involved in it.
Hi, I got myself a Canyon Aeroad (2XL) 2 years ago, transitioning from an older Alu bike. What I have never seen mentioned anywhere is the fact how wobbely the damn thing is up front. The carbon bike industry is talking about comfort all the time, whereas I break out in hives when the talk comes to comfort. If you want comfort then buy 25's and let some air out. You do get a lighter bike when you buy carbon but you might not always get a stiffer bike. I have tested a few of my friends carbon bikes and none of them were as stiff and responsive as my old Aluminium bike. I weigh 94Kg and would love a light frame which is stiff enough for a 197cm tall rider. I would love to see a bike test from you guys looking into bikes for the taller and heavier segment rider.
Hahaha. Love the comment about uv rays and carbon. “If you have your doubts just look at your airplane next time you board”. Some of those airplanes did use the wrong resins and needed to be painted before being exposed to outside. Made the manufacturing hangers really warm not being able to open the big bay doors.
Thanks for the vid. Just bought my first ever carbon bike last week, a 2009 Scattante Comp. I know that's entry level for carbon frames. It rides awesome but I still have this nagging fear of the carbon fork snapping on a large bump at 30 mph. Anyone ever experience that? Would it be stupid to try to find a steel fork?
As for repairability: 1. If you know what exactly is damaged, it’s easy to glue a new sheet of carbon fiber onto that spot, heat it, and the part will be even stronger than before. 2. But you can’t really know whether structural integrity of some part could be compromised. If an aluminium frame is intact on the outside, it’s intact on the inside, not necessarily so with carbon, which could have invisible cracks. 3. And actually, you can’t really re-weld most aluminium tubes because they’re butted, making them too thin in the middle. But guess what, you can glue them together using a sheet of carbon fiber!
Thank you Si! Nice video and definitely information that needs to be seen more often. Modern jet aircraft have massive amounts of carbon fiber in them yet people think it isn't safe to make a bike from. It is all about recognizing the different properties of different materials.
+Guillermo Bright The carbon fiber itself (specifically what modulus the fibers used are) is only one part of what makes it strong, and as stated by Simon, with ultra-high modulus carbon fiber you're trading strength for brittleness. The LAYUP is the much larger determining factor.
+TypeVertigo well I would hope that the makers of an aircraft that has to lift thousands of tons would use a little different layup that a bike company that only needs to hold one person.
+Brian Moore That's the real beauty of carbon fiber. With proper layup and use of different modulus sheets you can make it as strong or as light as it needs to be. Wings such as those used in aeroplanes and race cars have to contend with lots of kilos of lift or downforce, as the case may be, so as load-bearing structures they need to be strong. A car hood by comparison is just a cover so making it out of strong carbon isn't as critical - most people just make them as light as possible.
+Mike Pop If someone offers to repair a carbon fork for you they may not like you very much. If a repair on a frame fails more than likely you can just pull to the side of the road.....if the fork or steerer tube goes: 4.bp.blogspot.com/-mtnPUqUgsYw/VCnImmTRswI/AAAAAAAAD5c/0NJezheAVcM/s1600/moses%2B2014.jpg
+clearly not me It's more involved than that. You have to chamfer out the broken part at the crack at a very shallow angle. (1:50..1:100 are needed to arrive at the same strength as the original part.) Then additional layers of ideally the same prepreg materials are laid on and heat cured (not melted, those are thermosetting materials, no melting once they are finally cured.) Alternatively non prepreg carbon fiber can be used and laid up with low temperature curing two component epoxy. Don't know if this is done on bike frames; It's common in other applications of such composites. Finally you have to chamfer out the freshly laid up material, so the transition to the original part is as gradual as possible. Simply adding material over the crack is possible, but it is heavy and you never arrive at the original strength because of abrupt stiffness changes in the part.
+clearly not me : Yes it can be done at home but in my view a bike is not the place to learn the techniques on. Before thinking about doing a bike repair you'd want to be comfortable with vacuum bagging techniques and have the equipment to do it. Also if it's the fork that's damaged then I wouldn't even consider a repair, just not worth the risk. I learnt how to work with carbon fibre through my hobby of flying radio control model gliders - at the top level the composite technology is actually very similar but the advantage is if you get it wrong you can pick up the pieces without being part of the wreck...
I believe you only actually have to go back 10 years to find a non carbon Tour de France winning bicycle. I think Oscar Pereiro used a magnesium Pinarello Dogma in 2006.
I have worked with carbon fiber sheets and tube and reference a NASA article which details issues related to radial, axial, lateral, planar, perpendicular and hoop strength. The strength of a CF vessel to withstand high internal pressure is extreme but the eternal crush strength is at the opposite end of the scale, i.e., easy to crush. Very little Perpendicular force is required to penetrate a sheet whereas kevlar is the opposite making it useful for bullet-proof vests. Only graphene can further improve perpendicular strength and not by a lot.
The material your bike is made from, or the manufacturer, doesn’t matter as much as how much you enjoy riding it. If you find yourself daydreaming about your bike, you’ve chosen the right one.
+Sander Bærøy Johansen The rear triangle takes a beating, usually when we lay the bike down. also most breaks happen here from contact with rocks etc. that is why the switch to alum.
+Guillermo Bright Good point. In a perfect environment where the perfectly engineered carbon fiber bike/components have no force acted on them from the imperfect, unpredictable outside world, Carbon Fiber is the king of all, on paper. Truth is, it's hard to tell what's going to happen when you go for a ride. Aluminum is more forgiving in my opinion, a dent on the chain stays doesn't mean your frame is scrapped (legal disclaimer, replace all damaged parts blah blah)
Great theory, but my experience is that aluminium bends before it snaps, were as the first sign with carbon fibre was catastrophic failure! But now I'm thinking that maybe not all carbon fibre is made equally ;)
when you eat high carb vegan, you begin to defy the laws of physics, and can no longer put on weight, and will lose weight. no matter how much you eat. so, by being lighter your carbon will last longer.
Myth 1: Definitely. I bought my Domane 5.2 last year when I weighed about 335 lbs (was down about 25 from a high point and 35 more since then). My LBS had 1 concern: the wheels. So the shop let me trade in the stock wheels and gave me a pair of custom Mavic Open Pro Shimano Ultegra hub 32/32 wheels. The owner reinforced the rear wheel with washers along the hub. I've broken 1 spoke in 5000 miles (21mph during intervals I hit a pot hole really hard because it was night and I didn't see it). And I've taken it in for minor truing 2 times. Other than that, the bike works great. I've replaced the chain once and will again soon. And I'll probably replace some of the bearings soon too. But my petite wife has had the same done other than the wheels. She's using the stock wheels and never needed truing.
+MRGRUMPY53 You are right. Looking back I should have gone 36 at least in back. Shop has maintained my wheels for free so I'm not complaining. In fact I crashed my first week and he rebuilt the wheel for free for me (minor crash but it bent the rim). I've considered getting a truing stand for myself so I can do my own work. I even asked him about the price of the Park stand and he said he'd be happy to sell me one but I get free minor truing for life. I may still get a stand one day so I can learn how to true my own wheels since I may try and get a pair of Flo carbon clinchers one day and would like to have a good idea how to do it before I had some carbon wheels on the stand. I tell all heavier cyclists these days to err on the side of caution with spoke counts. I probably could've got away with 24/28 but 32/32 or even 36/36 would simply mean less maintenance. Nothing worse than not being able trust your wheels. But the myth was carbon frames don't work when heavier and the video is right. My frame is in great shape. Now one reason why people may say carbon is for lighter riders is carbon frames are expensive. If we care about weight, we are better off losing it from our bodies. My reason for the 5.2 rather than say a 2.3 is because I wanted a bike that would last me 5-10 years. It was my 3rd bike in about a year (got a Trek Shift 4 because of the high weight limit but then switched to a used Sirrus when that Shift wasn't doing what I wanted. I didn't want to buy a temporary bike like a Domane 2.3 or a Giant Defy 3 or 4 and then upgrade in another year or 2). Looking back I probably should've got a Defy and a power meter last year and then planned to get a carbon bike after getting down to about 250 lbs or less. But hindsight is 20/20 and my power meter will be here next week. So I guess I got to save the ~$1000 from a temporary bike but just had to go without the meter for a year. And until about 3 months ago I probably didn't care enough to justify one. It's only the past 3 or 4 months that I've been training harder. Been using the power meter on my smart trainer but now I want one on the road too. That and I'm not sure how trustworthy the numbers are from the Wahoo. I swear in Zwift on the mountain 180 watts going uphill makes my heart rate HIGHER than 250 watts on a flat section. There's something weird about the meter and resistance when climbing at higher weight. And next week I can hopefully confirm my suspicion with a different meter to see if I am either putting out fewer watts on the flat sections or more on the climbs.
The reason for the catastrophic failure is that carbon can develop micro cracks not seen, however i must add you'll generally see a large indication in the area as well. After a while these micro cracks can join up if not repaired and when they join that creates the failure. Carbon is very strong in the intended direction it was designed for but something like being driven into sideways by a car for example can put pressures on the frame in a direction it wasn't engineered for. In that scenario you may have unseen damage but frame can be ultra sounded to see any voids that may develop from that kind of impact.
That's hilarious. Quite a few of the "wrong" ones were then justified using "well actually, it's could certainly be true." Great way to avoid answering the actual questions. Politician answers if I've ever heard them.
The thing with aluminum and steel bike frames is that if the frame does get cracked somehow it can take a very long time to fail completely. When I was a kid I used to dirt jump steel framed BMX bikes that had cracks in the frame and it never failed catastrophically, the crack would just grow over time until I got it welded or concluded that it had gotten too big to be safe anymore. Aluminum will fail quicker but it seems that they don't crack as much as steel does, more flexible material I guess. Carbon on the hand, because it's built in layers, if it starts to fail it can fail completely very quickly due to the delamination of layers or just sheer force completely breaking it by shear forces (like an impact from a car, hitting a curb or something like that).
Kiln cured carbon fiber structures aren't UV sensitive, but if the carbon composite is wet laid up, i.e. using a process whereby the glues set without being baked in an oven, then they do degrade over time due to sunlight. Like fiberglass boats for example. Doubt that any producers make wet laid up bike frames, but maybe a cheaper or no name brand coming out of China...?
I have a carbon fork. I have added rubber strap on bottle cage mounts (from Decathlon). put 4 cable ties over these to make solid. And when I tour I attach a couple of Blackburn outpost cargo cages ,hammock on one side inflatable mat on the other. Should be cool eh? one test ride so far.
Please take a look at the cannondale-caad12-105, this is alloy and is lighter than carbon in its price range. How is this possible? is the game changing?
I've got a friend, who's carbon front wheel melted - to the point of front tyre popping and a visible melted patch on the rim was evident - when he took his bike for a 4 hour drive on a tow ball mounted bike carrier. Aparently, the heat of the exhaust did the damage. Point to note is, the vehicle is a brand new Holden diesel SUV.
Metal bends before it breaks, carbon breaks catastrophically. I would completely argue that last point about carbon bikes being just as safe. That said I do race a carbon bike and love the way it feels when riding, but that doesn't mean I don't get a little scared when I hit a pot hole.
+Niklas Barreto Carbon bends considerably without breaking. Frame deflection is one of the selling points of a good carbon frame. The carbon can be made to flex in one direction predictably, like a spring, to absorb shock, and be rigid in other directions for efficiency and ride control. That's why they feel so great to ride on. Look Bicycles even uses carbon as the material of choice in the cleat binding springs for their pedals. Cannondale made a few full-suspension MTBs with no pivots between the BB and rear wheel, because the carbon chainstays had the flexibility they needed. Have a look at the testing shots they have from Canyon. Dropping a huge weight on the end of the blue fork??? (1:03) If it can bend like that without it breaking, it's probably not going to break with only you riding on it.
+Niklas Barreto I hit a rock at 45mph down a mountain road on my Canyon Endurace CF. The aluminium handlebar bent a little (2mm approx). The CF frame didn't even scratch, I'm still riding it like a maniac down hills.
+Niklas Barreto Metal can crack as well, for instance if the failure is caused by fatigue. And CF composites can fail progressively, like what GCN said about the layers giving one by one.
I watched the entire video! The only thing I could think about is how they don't sell Canyon in the US. Can I have one shipped to GCN and then shipped to me? You seem like great fellas. Thanks in advance 😄
I just returned a full carbon fiber frame from cannondale. I ride strictly mountain bike. I can tell you without a dought that the carbon fiber frame was the most uncomfortable ride I have ever had. I would wake up sore all over my body and I could feel the stiffness of the frame through my bones! I went right back to my incredible 7005 triple gauge aluminum bike and almost all the pain is gone! To me the aluminum frame absorbs more of the vibration and hits and I can actually feel the frame flex and gives me a better feel of the dirt, concrete etc...The aluminum frame is more responsive and just as light and strong is not more than the carbon fiber. I dont care what anyone says but aluminum is way better than any carbon fiber frame ive ever ridden! Carbon fiber is way overrated!!
great video, 1 thing no one ever mentions though is how carbon does in extremes(for some softies) Cold, I am talking about freezing temps? I live in international falls, Mn. 1 colder area. I ride when its zero outside. I keep warmth, but how will my new carbon frame set keep up? I would like to see a video on this.
I have a question for you. I'm planning to purchase a gravel bike and am liking the Ridley XTrail Alloy. Would then the aluminum be a better bike for gravel riding than carbon?
Isotropic materials have constant properties throughout. So cracks propagate through the material very easily. Anisotropic (like carbon) have different properties depending on the direction. So cracks may propagate with ease in one direction, but with difficulty in another. Anisotropy is (partly) what makes bones so strong!
5:47 I havent laughed out loud so hard because of a video in a long time! :D The 5 minute poised build up with the serious science bit made it so unexpected and halirious.
Hello,i search handlebars,and others parts carbon,for my fatbike,which brand take on aliexpress,for quality ? what do you think of Ullicyc ?thank's for your help :)
i have bought a 2006 trek SL 1000 , will the carbon fork and seatpost be still as strong as the day the carbon parts was made? , the bike is in almost brand new looking quality
Hey guys, this video make me think that I would really like a video of you where you explain what things one should check for when buying a second hand bike!
Here's what isotropic means: non-directional. What does that mean about carbon vs aluminum? Well, carbon is ANisotropic. Meaning directional. A key factor in the light weight of carbon fiber is that it has a full range of strengths depending on the direction in which it's stressed. Your first thought might be, does that mean it just gets weaker? In some directions, yes, but compared to a similar isotropic material what that really means is that it gets exceptionally strong in some directions. For framebuilding, this means that you can get huge performance out of carbon by orienting it directionally and using very little material in addition to the high average strength to weight. If you were to create a carbon fiber with the same average strength and properties as carbon fiber, but isotropically, and you compared that frame to an aluminum frame, the difference wouldn't be nearly as marked.
I got 2 bikes. One all al mtb and one al with carbon fork and is gravel. I do find gravel bike to be more comfortable despite drop bar and thinner tires and at same pressure. I also notice I feel jittery on rough roads in turns… may be more to do with less grip of tires. Gravel has 47mm and mtb is 2.2 inch one. Though I suspect the carbon fork is not that stable in turns when the road is patchy. Also, front fork has sus on mtb…. Now I have to be extra careful on turns with carbon fork if the road ain’t good. I suspect the side sway strength is not there. I like the comfort through. Despite no sus it is as good as mtb with air sus and sus has right air pressure as per my weight. And I had to reduce rebound considerably to make sus comfortable.
One important consideration: What is the environmental impact of carbon fiber over its lifecycle (particularly at end of life and waste management). Can GCN address this?
You know it's a complete mess. All the microscopic waste will end up in the ocean. The planet is doomed to become a hell hole but I won't have to see it.
www.bikebiz.com/news/read/snap-crackle-and-pop-do-fake-bikes-and-parts-crumple/019437 At the bottom of this page is a pdf link which will tell you everything you need to know about the Chinese bike composite industry.
I watched this vid while pooping. Definitely made the download more enjoyable. Nope, I will not be exceeding the weight limit on my bike now, if you know what I mean.
Isotropic basically means the material has the same properties in all directions. Carbon fibre is anisotropic because the fibres have very different properties in different directions.
Also, the gradual failure property you say carbon has is also exists in aluminum and other metals. Small cracks can exist in aluminum and grow each time a high enough load acts on the area of the crack. Its always worthwhile inspecting a frame for cracks, whether it's carbon, aluminum or any other material.
+Simon Rendell I feel like Mr Richardson should get a channel ban for not knowing this !
+Andrew Bedford No need for a channel ban! Simon has the best engineering / mechanical knowledge of the GCN presenters! Having said that, I do charge for sharing my knowledge... a GCN casquette should cover it ;)
Simon Rendell haha i like your style sir.
+Simon Rendell Yep. In fact that (fatigue) is usually the critical failure mode of aluminium in a vibration loaded part like a bike frame. It's also the reason why aluminium frames are so uncomfortably stiff: once you have dimensioned aluminium so sthe part is more or less fatigue-safe, you arrive at very stiff cross sections.
+Simon Rendell I wouldn't say carbon composite has a gradual failure mode unless you're comparing it to some sort of ceramic. Once you load a carbon composite much beyond it's yeild point it will experience sudden failure, compared to aluminium which have up to a 11% elongation before total failure. That said I'm pretty sure the high strength 7xxx series alloys have a much lower elongation percentage before failure.
The fatigue strength of aluminium alloys may not be great compared to steel alloys but It seems unlikely to me a carbon composite would be able to sustain as many load cycles as an aluminium alloy. That said I never enjoyed material science at university so I could be wrong on that part.
FYI for anyone who is interested, an isotropic material is a material that has the same material properties in all directions, i.e., it's modulus of elasticity (stiffness), tensile strength, modulus of toughness, modulus of resilience, fatigue failure mechanisms, etc. (all of which are quantifiable properties) are all the same no matter which direction a load is applied. Carbon fiber, since it is a fiber, is inherently not isotropic. If you take a fiber and stretch it along the length of the fiber, it will behave differently than if you (just imagine it) try to stretch it along the short way of the fiber. Since the fibers are laid up in bundles, obviously the "non-isotropic-ness" is exacerbated.
The truth of the matter is, no material on earth is perfectly isotropic. Steel, aluminum, titanium, and all metals have a crystal structure that have slip planes along different axes, and have grains made up of those crystals that face in different directions, and the size of those grains have a significant impact on the material properties. However, that's pretty much just theoretical shizz that most people don't care about. For the most part, standard steel and aluminum can be modeled as isotropic.
Just your materials science lesson for the day.
Bringing me back to my first year materials subject at university - the alteration of crystal structure through heat treating, alloying (the substitution/addition of elements of different sizes), and applying mechanical stresses during cooling (amongst other things). It's interesting how you can enhance or diminish almost any properties through minor alterations.
Now that i have learned all these 7 things about carbon fiber i can take my aluminium bike and go for a ride
+chousiself ikr :D
Likes this.
one of the best bikes I ever owned was a Principia Rex ellipse with isaac CF forks.absolute rocket ship, put your foot down and it just took off. I sold a well used RS6 pro to an experienced cat rider who was going to use it for crits...this was only 3 years ago.
With a carbon fork :^)
Don't choose an aluminium frame for mountain biking though: on 2 bikes I had 4 breakages and on my last bike as the frame was still under warranty the manufacturer offered me a free carbon frame in replacement, that tells volume about what they think of aluminium !
Could you guys do a video on the characteristics of some more uncommon frame materials--Titanium? Scandium? Wood? Bamboo?
I fully support this
Scandium and Titanium are highly specialised frame materials requiring a really high skill ceiling to manufacture properly. The properties would be similar to what you could imagine as a steel/al hybrid. Comfy and tough yet still tough and light. Unfortunately that makes them really, really expensive. Wood and bamboo frames you could imagine as nature's carbon fibre (fibrous layers of anisotropic sheets) but really really soft.
+Windoges I'd be happy with the different steel and tubing types. Wood would be interesting too.
+Windoges I know guys riding the bamboo fixies. They say they do bunny hopps and often ride downstairs. So I wonder for how long their bikes will last.
+ssef15 Both form alloys with Aluminium. Especially Scandium (and Niobium) are used in small amounts ≪5% in Aluminium.
Great video, thanks!
Lads, how about you do a survey among GCN viewers to make a top 10 bike makes that we all ride? I think that might make for interesting viewing. Well, I'd like that, anyway...
+Mickey Pius My family has three Fuji bikes and one Specialized bike. I ride a Team Fuji with a composite frame. In the future, I think my next bike will come from Canyon. But Canyon still needs a way for U.S. residents to order from them (I hear they are working on it).
+Mickey Pius Colnago and Raleigh
+Mickey Pius i ride a scoot foil 40 from 2013 and i alsow have a specialized tarmac expert and my sister has a canondale synapse
+Mickey Pius An old "Race Mountain" from the 90's. I think it's Italian. Has anyone else heard of them or got one?!
My carbon Felt F1 Sprint came off the bike rack of my trunk at 45 mph and I watched it do about 5 toppling crashes down the highway before it came to rest. I picked it up and bent the Dura-Ace shifter back into place with my hand, rode it in that day’s century ride, and proceeded to add another 30,000 miles to the bike over the last 6 years. Try that with a metal bike.
Would love to see GCN talk about bikes other than super bling carbon bikes that cost more than my car. The new CAAD 12 is a fantastic bike, and still a contender for crits. The new Allez Sprint is also very cool. I'd be willing to bet most of your viewers don't have or can't afford only the top pro level builds. Bring it back down for the regular folks once in a while.
Regular folks want bikes from the big box stores . How boring
Amen Sir!
👍👍
If you are still skeptical about sunlight weakening your bike you can always use factor 50. Remember to put more sunscreen on regularly throughout the day while riding and especially after rain.
+ronnyjegan Lmao
Hi Guys, i wrote my master thesis over the fatigue of fibre reinforced plastics and i have to tell you that the fatigue behavior of carbon fibre reinforced plastics is in fact much better then that of alluminum. That is one reason why airplane builders are so enthusiastic about changing to that new material. The Big Problem with it is of course that when you design a part according to the load cases you assume making full advantage of the unisotropic material properties (depending on the orientation) the part is very good and lightweight for this load case. But of corse not for a load case that was not considered and applies loads to the part in other directions. So you can say that aluminum or other isotropic materials are less vulnerable to unexpected load cases (crashes) but a carbon bike used of its designated purpose (riding it) is less vulnerable to fatigue and can thus last a lot of years being used hard.
Haha, Simon, the science bit was almost a throwback to Holoship Arnold Rimmer off Red Dwarf. Bravo!
it so was, ah happy days.
Good video, I'm still a steel guy. love the ride characteristics and the long term reliability. Plus I don't want to be worried about over torquing bolts on components out on a ride if anything happens.
+Chasing Cornfields i love steel alot, but i would like to say i have done thousands of raggo miles in the shite back lanes of dorset on my canyon and i have never taken a tool with me, just tubes co2 and tyre lever!!
Oh sh*t, must go and take my bike out of the oven. What was I thinking!?
+Matt Williams nah warm it up for those cold morning rides
So you could say that Sebastian was a....carbon copy... of John Degenkolb (cue putting on sun glasses in slow motion)
+Will Baker Comment of the week? Maybe.
+Will Baker BADUM TSSSS
I really enjoy your presentations - you speak very clearly and have a great style. Thanks.
Carefully lightly-sand the "chip", & then apply 2-part epoxy. Buy the epoxy from a marine supplier, NOT from a hardware store! Add some additive to thicken the epoxy, or it's too-runny. Tape off the adjacent area.
Make it slightly "proud", so you can finish the repair with a final sanding, using a HARD-backed fine sandpaper (so you'll not depress the repair using finger-pressure).
Epoxy should set in a few minutes, & it's easier to final sand when still-soft (slightly).
Prime, & paint to match. Easy :-)
I build catamarans with CF & epoxy. My epoxy supplier is: US Composites in FLORIDA, USA. Buona fortuna!!
There are actually some things YOU didn't know about carbon fiber :PPP
There are more than 5 CF manufacturers. Toray (+Zoltek), SGL Carbon, Toho, Mitsubishi, Formosa, Hexcel, Cytec and some more ;)
Ultra High Modulus fibers are heavier, because of the denser arrangement of the carbon atoms. If you take PAN fibers for example. High Strength PAN CF has a density of arounf 1,78-1,80g/cm^3 while UHM PAN CF is about 2,0g/cm^3.
Hey GCN, could you do please, or have you done a video on carbon fibre vs aluminium frames please? Something like the pros and cons of each. I vote for a Lloyd vs Stephens duo!
Isotropic means that a material has strength in all directions. metal, for instance.
Carbon isn't isotropic. That can mean it is weak in some directions. Drop something heavy on the frame? it may crack. It is also why carbon frames break more easily in a pile up. It's strength is not in all directions.
+Scooper MG Very good explanation. I didn't know that. Thanks!
+Alexandar Hull-Richter You're welcome, Alex.
Drop something heavy on a ti, steel or aliminium and it may crack, just the failure mechanism may be different depending on load orientation and properties of the material. Metals are not perfectly isotropic either, especially when alloying, heat treatment, welding and forming are involved. Carbon frames do not 'brake more easily in a pile up', that is simply incorrect. They are strong in all directions if layed up correctly, with the correct lamination and resin match. The weave of the fibres orientated within the laminate must matched for the loads and the directiona predicted....exactly what good bike manufacturers intend to achieve in the design process.
@@skippyguy3 You must be a manufacturer, clearly not a scientist.
Carbon fiber is strong on "simple geometry" notably on boats. Carbon fiber is weak on "very sophisticated geometry" like on bikes. Carbon fiber is strong on 1 direction because they are simply overlapping fibers but with bikes of having multiple stress points, it doesnt really play well on long term durability. The sheer number of stress points on bikes are what makes carbon fiber frames weak in the long term also the glue that bonds them which disintegrates overtime. In the molecular level, alloys or aluminum frames are better since they are single construction (homogenous), but carbon fiber is built from many raw materials to form. So more parts, more prone to failures.
Is it ok to use caebon fiber bikes when it's raining and is it ok to wash them with water?
@@bogeyman9979 yes they have coatings anyways. It's physical forces that usually strains carbon.
@@arvincabugnason6728 I still have a 40 year old steel frame road bike. With simple anti corrosion maintenence the frame is rock solid and i do use fatter rims and tires to go off road as well. Steel can really take a beating, its heavy though. Obsolete in racing terms.
@@cycomiles4225 yes simplicity is better than any complex bike system. But go with shimano/sram parts if you can for safety.
Nice Video!
I work a lot with carbon, just one thing to mention.. carbon, as fabric out of strings, the dangers by braking are getting carbon pieces in your skin, which could cause blood poisoning if the pieces are not removed.
Stop talking total bollocks
I have to disagree with the claim that "you [can] lean your carbon bike against a radiator".
Most of you didn't come to read essays so, in short, leaning a carbon fiber bike on a radiator (I'm assuming an operating automotive rad) will most likely ruin it. DON'T DO IT
I would like to speak to the point about the temperature resistance of carbon fiber reinforced plastics (carbon fiber for short). As an engineer with experience in designing and manufacturing with carbon fiber composites for automotive racing applications, I feel the need to point out that high temperatures can be a significant hazard for carbon fiber. First it is worth pointing out that the operating coolant temperature is 90 degree Celsius for most road cars (110 degrees C for some motors eg. Audis' TSFI motors) so radiators will feasibly reach 90 degrees in certain areas. Although 90 degrees C will have very little effect on the properties of elemental carbon (as compared to 20 degrees C), resins used in carbon fiber MAY be affected. As opposed to elemental carbon which have little variation between different manufacturers, different resins will exhibit vastly different reactions to temperature. The important metric to note pertaining to the operating temperature of a resin is its glass transition temperature (Tg) and not the melting temperature. The Tg is effectively the temperature at which a (amorphous) material turns from a brittle solid to a rubbery substance. Beyond the Tg, the composite loses it's structural properties and is easily deformed. The resin used in many of our components on our race car (ties rods, steering column, intake, body panels, etc...) has an operating temperature of up to 70 degrees C (160 degrees F) and heat exposure is a large concern of ours when designing and implementing these items. The specific resin we use is valued for it's strength and chemical resistance despite the heat concerns we have. It is worth noting that the resin we use is in fact marketed as a "high temperature resin" (just not quite up to all our requirements). There are, of course, resins that have much higher Tg's of up to 300 degrees C (2000 degrees C, even, for carbon-carbon though that's completely different), this often comes at the cost of strength, chemical resistance, ease of manufacturing, and most importantly, money , and therefore, are not preferred. I applaud the creators of this video for recognizing that bicycles are designed with their intended uses in mind, and this leads me to my point. Although I don't know the properties of every single different resin used in bicycles, considering that the typical use of a bicycle is not to be leaned against a radiator but rather to be ridden in mild climate, resins are not required to withstand the temperatures of the radiator and probably will not. Composites used on bicycles will be required to have excellent specific strength primarily with operating temperature being of very minor concern of its designer. I've focused on the resin for carbon fiber bikes in this comment but the glue used to bond sections of carbon fiber together, the clear coat used to make bikes look pretty, the vinyl liveries on bikes bike are whole other cans of worms... I'm not certain why this video had to go out of its way to offer people potentially hazardous information, but for anyone who didn't feel my first two lines of this comment were of common sense and felt the need to read the justification, hopefully this clears things up for you.
@Human Bean He's not talking about a car radiator. Instead, he's talking about the radiators used in your home, for heating.
Well this reply made me crack up. Why would they be talking about car radiators???
Interesting but too long and no paragraph = not easy to read.
CF is good, my friends have exotic cars with lots of CF parts. Here are some of their complaints. The resin chips easily(expensive to fix), in really cold weather it cracks(expensive), Any hidden chips turn fatal if you drive on wet salty roads. Extremely strong in some direction but surprisingly weak in others(if you move it in an unusual way it can break easily). To me its not worth the price right now vs aluminium. In the future CF bikes will probably cost the same as a current aluminium bike, when the price comes down ill get one.
+Robert Flagg Car parts are subjected to vastly different stresses than bicycle parts and many aftermarket carbon fibre parts are poorly engineered compared to OEM.Both my road and CX bikes have seen multiple winters of -15C and hit with salt, sand, gravel, and flexed through sprints or bunny hops (CX) without any issues. I even have a few bare carbon spots on my road bike (before I started using 3M clearbra material to protect vulnerable areas) and only the very thin paint chipped away. Unlike carbon fibre, aluminum fatigues over time when repeatedly flexed. That's not to say there aren't great metal bikes out there but, honestly, most carbon fibre bikes built in the past five years or so are just as durable, if not more so, than aluminum.
+Robert Flagg agree with you... been using steel and aluminum frames for many years, then i upgraded to a carbon frame road bike yes its stiff and light but durability not really.
frame and other components made from CF you have to treat them with tender and loving care..
for sponsored pro teams its not really a big concern for them because they can easily replace their bikes..
+Robert Flagg If you want the most durable, buy titanium. If you thought carbon was pricey, you haven't seen Ti.
+Weng Ten You mention durability. Did your bike fail?
mneedes2 nope, seems tough as nails. Mind you, I ride a pronghorn, which is the only CF frame that comes with a lifetime guarantee. If I do manage to break it, they'll give me a new one. Used by the Peruvian olympic MTB team, so if they can't break it... doubt I can.
Thanks Simon and of course GCN for making every monday just that little bit better!
About frame repairs: after an accident, steel tubes can often be bent back to shape, no welding necessary. Forks can be bent for more offset (rake) as well. Neither aluminum nor carbon can do this, since they overwhelmingly crack during crashes. It follows that frames made of these materials require much more involved and costly repairs outside the scope of most home or local bike mechanics. This myth is pretty accurate
charlesissleepy Steel can be bent no problems, but aluminum is very prone to metal fatigue if its bent without being heat treated. You have to heat treat aluminum when bending it to avoid metal fatigue.
106kg rider looking for a new bike here, who can't decide between carbon or high spec aluminium, so this video came at the perfect time. Thanks.
Building bike frames was such a artform before carbon came a long. Wonder what ever happened to all the Italian master frame builders from De Rosa, Colnago etc. from back in the day? My all time favorite bike is still a classic red De Rosa with campy.
+Alan Lamb It's still an art. Just a different one. The non-isotropic properties allow stiffness in certain directions and compliance in others while saving weight. That's why I love riding my carbon bike over my heat-treated steel bike.
I have yet made the switch from AL to CF primarily because there is always that stigma amongst CF bikes that you have to treat it with more TLC because its more delicate and refine, but I do want to try one to see how much more compliant and stiff a CF bike is compared to an AL.
On my 125 miles ride yesterday I got a massive stick stuck between my back wheel and the downstay and chainstay. Pretty sure that would have messed up a carbon bike pretty good. My aluminum bike just had some paint scuffs.
I got goosebumps when this video uploaded because several hours before I wondering and try to find answer , is that affected if I put my carbon frame bike on the outside getting directly hit by sun day and night. Thanks for the video GCN!
Titanium is light, bomb proof and comfortable to ride. I am a big advocate and in its raw form is very cool and timeless.
For those who ride Carbon, if you store your bike indoors you ought to seal it in a bag of some type. This will prevent wear or damage from temperature and other things of that nature. Might want to put a blanket over it to as your bike could get cold.
carbon fiber is not affected by cold. The materials are stored frozen before use. They are cured at temps of 350 F. Whats with the blanket comment?
I see you have yet to learn the art of sarcasm...
Nice video- I am using a carbon XC full suspension bike last 4 years and I am tired of people (even in the bike shop) that are telling me that I should leave it layed down on the ground because if I leave it leaned to something it may fall ang crack far more easily than the aluminium bikes :)
.....always informative, thank you. Motorist struck me at the rear end pushing me some 3m out of my lane, managed to stay on the saddle. Seems it would be prudent to have the frame replaced to maintain the manufacturers warrantee at the expense of the drivers insurance.
What about the grease question. When I picked up my first carbon framed bicycle the last thing the guy at the shop told me was that I should never use any kind of grease on the frame or any components that come into contact with it. Since then I have heard many differences of opinion on this topic and I have personally thrown caution to the wind.
5:50 isotropic means that the material properties are the same no matter how the material is orientated. Carbon fiber is anisotropic, which means that it has different properties for different orientations, i.e. it only has high strength in the longitudinal direction of the fibers.
Excellent video guys, there's just one myth that didn't got unveiled, (at least here in South America and Mexico), people tend to believe that carbon fiber has an expiration date, is that true?? o.O and if it is, how can I know when my bike is no longer suitable for riding?? or any other carbon fiber component, Rims, Handlebars, Stem, etc!
+Paula Outon Hi Paula, your carbon frame is likely to last indefinitely. The question you might want to ask is how best to recycle it!
Global Cycling Network
Thanks Guys, now I'm going to start researching ways to recycle used up carbon fiber
+Rob Granville (CBR) I've been riding my Reynolds Strike SLG carbon clinchers for 2 years now, all year long, rain or shine, flat roads, alpine descents, everything. No sign of wear on my Reynolds brakepads or the rims either, while before that my alu clinchers would not even last me 1 winter...
+Rob Granville (CBR) true, but not a problem anymore once disc brakes catch up
As a composites engineer, I think I know where this misunderstanding is coming from - carbon fibre does in fact have an expiry date - but this relates to the uncured prepreg. i.e. before the components are put in the oven. Once they are cured in the oven there is no longer any relevant expiration.
Also note, any carbon prepreg material will cure itself in room temperature if given enough time to do so, this is why we store the material in freezers.
So, what distinguishes high end carbon frames from low end ones?
I have 12-year-old carbon bike, 3 alu bikes of more than 15 yeras old, 1 20+ year oldTange steel vintage bike Panasonic, 15 year-old 1 titanium MTB. None has ever broken down, but I am more confident that my Ti bike will be very safe and last well over my dead body than any other bike.
Kamol Hengkiatisak A 12 year old carbon bike is nothing like the high end bikes of today. Lots of advances in performance and comfort.
What about the grease question? When I picked up my first carbon framed bicycle the last thing the guy at the shop told me was that I should never use any kind of grease on the frame or any components that come into contact with it. Since then I have heard many differences of opinion on this topic and I have personally thrown caution to the wind.
outandaboutDave technically grease should not ever be needed on a carbon frame. Seat post should be coated in fiber grip instead. The headset is the only place where opinion differs, some say fiber grip messes up your headset bearings and others say grease makes your stem slip (CF Stem and CF steerer o course)
I buckled a seat stay in a prang. My local bike shop said it couldn't be repaired so I took it to the local yacht club instead. Their engineer inserted a carbon rod, filled the gap with resin and then wrapped it with kevlar. Finished with a lick of paint it looks almost perfect and it's stronger than it was before.
Alimunium is isotropic because the physical properties are the same in all directions. Composite layers are engineered to be anisotropic, desiring those physical properties to vary depending on the directions. For instance, you need more resistance for vertical loads then for lateral forces on a frame. On aluminium bikes you can compensate that by designing different thickness depending on the section. On a composite, you will increase direction on one direction. Plus, using 45degree alternated directions, it distributes tension within a plane instead of in space. I am not an expert in bike design and construction, but am a polymer and composites graduated engineer with some R&D working experience for automotive. Not my field of work lately.
Future will develop intelligent anisotropic materials that can vary their properties depending on solicitation to prevent failure or catastrophic (collapsing) failure. R&D was still a challenge when I was involved in it.
Hi, I got myself a Canyon Aeroad (2XL) 2 years ago, transitioning from
an older Alu bike. What I have never seen mentioned anywhere is the fact
how wobbely the damn thing is up front. The carbon bike industry is
talking about comfort all the time, whereas I break out in hives when
the talk comes to comfort. If you want comfort then buy 25's and let
some air out. You do get a lighter bike when you buy carbon but you might
not always get a stiffer bike. I have tested a few of my friends carbon
bikes and none of them were as stiff and responsive as my old Aluminium
bike. I weigh 94Kg and would love a light frame which is stiff enough for a 197cm tall rider.
I would love to see a bike test from you guys looking into bikes for the taller and heavier segment rider.
loving that as soon as simon puts on the science glasses he turns into michael cain lol brilliant
My Orbea Orca was repaired by Calfee many years ago. Still going strong!
Hahaha. Love the comment about uv rays and carbon. “If you have your doubts just look at your airplane next time you board”. Some of those airplanes did use the wrong resins and needed to be painted before being exposed to outside. Made the manufacturing hangers really warm not being able to open the big bay doors.
The thing that worries me most about my carbon bike is abrasion. At least on a metal frame, if you knacker a wheel you can still get home.
Thanks for the vid. Just bought my first ever carbon bike last week, a 2009 Scattante Comp. I know that's entry level for carbon frames. It rides awesome but I still have this nagging fear of the carbon fork snapping on a large bump at 30 mph. Anyone ever experience that? Would it be stupid to try to find a steel fork?
All frames materials have their fans. Friend of mine has only lightweight steel frames for last 20 years. Each to his own
As for repairability:
1. If you know what exactly is damaged, it’s easy to glue a new sheet of carbon fiber onto that spot, heat it, and the part will be even stronger than before.
2. But you can’t really know whether structural integrity of some part could be compromised. If an aluminium frame is intact on the outside, it’s intact on the inside, not necessarily so with carbon, which could have invisible cracks.
3. And actually, you can’t really re-weld most aluminium tubes because they’re butted, making them too thin in the middle. But guess what, you can glue them together using a sheet of carbon fiber!
What about ware on the carbon frame do I need to maintain it more or are the maintenance cycles the same?
I find carbon bikes have a strange hollow plastic pipe like sound as you ride along. Not surprising really, but I have never heard anyone mention it.
Thank you Si! Nice video and definitely information that needs to be seen more often. Modern jet aircraft have massive amounts of carbon fiber in them yet people think it isn't safe to make a bike from. It is all about recognizing the different properties of different materials.
+Brian Moore Planes use carbon fiber 10x stronger than bikes
+Guillermo Bright watch the video again. 5 factories make it all.
+Guillermo Bright The carbon fiber itself (specifically what modulus the fibers used are) is only one part of what makes it strong, and as stated by Simon, with ultra-high modulus carbon fiber you're trading strength for brittleness. The LAYUP is the much larger determining factor.
+TypeVertigo well I would hope that the makers of an aircraft that has to lift thousands of tons would use a little different layup that a bike company that only needs to hold one person.
+Brian Moore That's the real beauty of carbon fiber. With proper layup and use of different modulus sheets you can make it as strong or as light as it needs to be.
Wings such as those used in aeroplanes and race cars have to contend with lots of kilos of lift or downforce, as the case may be, so as load-bearing structures they need to be strong. A car hood by comparison is just a cover so making it out of strong carbon isn't as critical - most people just make them as light as possible.
Make a video on how to repair carbon bikes, for instance a frame or a fork. I haven't moved to carbon yet but am interested.
+Mike Pop If someone offers to repair a carbon fork for you they may not like you very much. If a repair on a frame fails more than likely you can just pull to the side of the road.....if the fork or steerer tube goes:
4.bp.blogspot.com/-mtnPUqUgsYw/VCnImmTRswI/AAAAAAAAD5c/0NJezheAVcM/s1600/moses%2B2014.jpg
+clearly not me my friend did it with a home kit, but heavier now but still a good bike
+clearly not me It's more involved than that. You have to chamfer out the broken part at the crack at a very shallow angle. (1:50..1:100 are needed to arrive at the same strength as the original part.) Then additional layers of ideally the same prepreg materials are laid on and heat cured (not melted, those are thermosetting materials, no melting once they are finally cured.) Alternatively non prepreg carbon fiber can be used and laid up with low temperature curing two component epoxy. Don't know if this is done on bike frames; It's common in other applications of such composites.
Finally you have to chamfer out the freshly laid up material, so the transition to the original part is as gradual as possible.
Simply adding material over the crack is possible, but it is heavy and you never arrive at the original strength because of abrupt stiffness changes in the part.
+clearly not me : Yes it can be done at home but in my view a bike is not the place to learn the techniques on. Before thinking about doing a bike repair you'd want to be comfortable with vacuum bagging techniques and have the equipment to do it. Also if it's the fork that's damaged then I wouldn't even consider a repair, just not worth the risk.
I learnt how to work with carbon fibre through my hobby of flying radio control model gliders - at the top level the composite technology is actually very similar but the advantage is if you get it wrong you can pick up the pieces without being part of the wreck...
Would be great to see a GCN Tech segment on how to properly fix a small cosmetic chip in a carbon fiber frame.
I believe you only actually have to go back 10 years to find a non carbon Tour de France winning bicycle. I think Oscar Pereiro used a magnesium Pinarello Dogma in 2006.
Thanks mate. Very informative. I ride a Merida Scultura 5000 carbon. Love it.
I have worked with carbon fiber sheets and tube and reference a NASA article which details issues related to radial, axial, lateral, planar, perpendicular and hoop strength. The strength of a CF vessel to withstand high internal pressure is extreme but the eternal crush strength is at the opposite end of the scale, i.e., easy to crush. Very little Perpendicular force is required to penetrate a sheet whereas kevlar is the opposite making it useful for bullet-proof vests. Only graphene can further improve perpendicular strength and not by a lot.
The material your bike is made from, or the manufacturer, doesn’t matter as much as how much you enjoy riding it. If you find yourself daydreaming about your bike, you’ve chosen the right one.
Well said!Enjoy your ride!!😂
Still rocking my 2012 nomad c. No problems at all
Im mostly a mountainbiker but god damn that canyon looks demonic..
+Sander Bærøy Johansen Smart MTb bike companies have an aluminium rear triangle , see Santa Cruz for example.
Yeah, my canyon strive cf 8 race has one=)
Not sure if its to cut cost or /and ease production?
+Sander Bærøy Johansen The rear triangle takes a beating, usually when we lay the bike down. also most breaks happen here from contact with rocks etc.
that is why the switch to alum.
+Sander Bærøy Johansen As someone pointed out, aluminium is isotropic so maybe it can withstand those forces acting on it better
+Guillermo Bright Good point. In a perfect environment where the perfectly engineered carbon fiber bike/components have no force acted on them from the imperfect, unpredictable outside world, Carbon Fiber is the king of all, on paper. Truth is, it's hard to tell what's going to happen when you go for a ride. Aluminum is more forgiving in my opinion, a dent on the chain stays doesn't mean your frame is scrapped (legal disclaimer, replace all damaged parts blah blah)
Great theory, but my experience is that aluminium bends before it snaps, were as the first sign with carbon fibre was catastrophic failure! But now I'm thinking that maybe not all carbon fibre is made equally ;)
Still like my custom Reynolds 753! Although I do own a carbon Cannondale that I love...
Will 30 bananas a day make my carbon bike stronger?
+Medium Rick where exactly are you putting those bananas?
RicardoRix I don't know. But some of the vegans make all kinds of wild claims, so I just thought I'd ask.
when you eat high carb vegan, you begin to defy the laws of physics, and can no longer put on weight, and will lose weight. no matter how much you eat. so, by being lighter your carbon will last longer.
+Medium Rick Ask Durianrider
Nobody springs to mind....
thanks, suppose comes down to money. My Puch vent noir was one of last 531c 79-81, good old days.
Myth 1: Definitely. I bought my Domane 5.2 last year when I weighed about 335 lbs (was down about 25 from a high point and 35 more since then). My LBS had 1 concern: the wheels. So the shop let me trade in the stock wheels and gave me a pair of custom Mavic Open Pro Shimano Ultegra hub 32/32 wheels. The owner reinforced the rear wheel with washers along the hub. I've broken 1 spoke in 5000 miles (21mph during intervals I hit a pot hole really hard because it was night and I didn't see it). And I've taken it in for minor truing 2 times. Other than that, the bike works great. I've replaced the chain once and will again soon. And I'll probably replace some of the bearings soon too. But my petite wife has had the same done other than the wheels. She's using the stock wheels and never needed truing.
+MRGRUMPY53 And the pros said a 32-spoke setup would work and it has.
+MRGRUMPY53 You are right. Looking back I should have gone 36 at least in back. Shop has maintained my wheels for free so I'm not complaining. In fact I crashed my first week and he rebuilt the wheel for free for me (minor crash but it bent the rim). I've considered getting a truing stand for myself so I can do my own work. I even asked him about the price of the Park stand and he said he'd be happy to sell me one but I get free minor truing for life. I may still get a stand one day so I can learn how to true my own wheels since I may try and get a pair of Flo carbon clinchers one day and would like to have a good idea how to do it before I had some carbon wheels on the stand.
I tell all heavier cyclists these days to err on the side of caution with spoke counts. I probably could've got away with 24/28 but 32/32 or even 36/36 would simply mean less maintenance. Nothing worse than not being able trust your wheels.
But the myth was carbon frames don't work when heavier and the video is right. My frame is in great shape. Now one reason why people may say carbon is for lighter riders is carbon frames are expensive. If we care about weight, we are better off losing it from our bodies. My reason for the 5.2 rather than say a 2.3 is because I wanted a bike that would last me 5-10 years. It was my 3rd bike in about a year (got a Trek Shift 4 because of the high weight limit but then switched to a used Sirrus when that Shift wasn't doing what I wanted. I didn't want to buy a temporary bike like a Domane 2.3 or a Giant Defy 3 or 4 and then upgrade in another year or 2).
Looking back I probably should've got a Defy and a power meter last year and then planned to get a carbon bike after getting down to about 250 lbs or less. But hindsight is 20/20 and my power meter will be here next week. So I guess I got to save the ~$1000 from a temporary bike but just had to go without the meter for a year. And until about 3 months ago I probably didn't care enough to justify one. It's only the past 3 or 4 months that I've been training harder. Been using the power meter on my smart trainer but now I want one on the road too. That and I'm not sure how trustworthy the numbers are from the Wahoo. I swear in Zwift on the mountain 180 watts going uphill makes my heart rate HIGHER than 250 watts on a flat section. There's something weird about the meter and resistance when climbing at higher weight. And next week I can hopefully confirm my suspicion with a different meter to see if I am either putting out fewer watts on the flat sections or more on the climbs.
The reason for the catastrophic failure is that carbon can develop micro cracks not seen, however i must add you'll generally see a large indication in the area as well. After a while these micro cracks can join up if not repaired and when they join that creates the failure. Carbon is very strong in the intended direction it was designed for but something like being driven into sideways by a car for example can put pressures on the frame in a direction it wasn't engineered for. In that scenario you may have unseen damage but frame can be ultra sounded to see any voids that may develop from that kind of impact.
All the things I considered before I bought a carbon bike....good job. As I understand it.
That's hilarious. Quite a few of the "wrong" ones were then justified using "well actually, it's could certainly be true." Great way to avoid answering the actual questions. Politician answers if I've ever heard them.
The thing with aluminum and steel bike frames is that if the frame does get cracked somehow it can take a very long time to fail completely. When I was a kid I used to dirt jump steel framed BMX bikes that had cracks in the frame and it never failed catastrophically, the crack would just grow over time until I got it welded or concluded that it had gotten too big to be safe anymore. Aluminum will fail quicker but it seems that they don't crack as much as steel does, more flexible material I guess. Carbon on the hand, because it's built in layers, if it starts to fail it can fail completely very quickly due to the delamination of layers or just sheer force completely breaking it by shear forces (like an impact from a car, hitting a curb or something like that).
Kiln cured carbon fiber structures aren't UV sensitive, but if the carbon composite is wet laid up, i.e. using a process whereby the glues set without being baked in an oven, then they do degrade over time due to sunlight. Like fiberglass boats for example. Doubt that any producers make wet laid up bike frames, but maybe a cheaper or no name brand coming out of China...?
I have a carbon fork. I have added rubber strap on bottle cage mounts (from Decathlon). put 4 cable ties over these to make solid. And when I tour I attach a couple of Blackburn outpost cargo cages ,hammock on one side inflatable mat on the other. Should be cool eh? one test ride so far.
Please take a look at the cannondale-caad12-105, this is alloy and is lighter than carbon in its price range. How is this possible? is the game changing?
I've got a friend, who's carbon front wheel melted - to the point of front tyre popping and a visible melted patch on the rim was evident - when he took his bike for a 4 hour drive on a tow ball mounted bike carrier. Aparently, the heat of the exhaust did the damage. Point to note is, the vehicle is a brand new Holden diesel SUV.
Really good video. Any guidelines about the rider weight limits for carbon fiber? Hopefully I'm nowhere close.
Metal bends before it breaks, carbon breaks catastrophically. I would completely argue that last point about carbon bikes being just as safe. That said I do race a carbon bike and love the way it feels when riding, but that doesn't mean I don't get a little scared when I hit a pot hole.
+Niklas Barreto Carbon bends considerably without breaking. Frame deflection is one of the selling points of a good carbon frame. The carbon can be made to flex in one direction predictably, like a spring, to absorb shock, and be rigid in other directions for efficiency and ride control. That's why they feel so great to ride on. Look Bicycles even uses carbon as the material of choice in the cleat binding springs for their pedals. Cannondale made a few full-suspension MTBs with no pivots between the BB and rear wheel, because the carbon chainstays had the flexibility they needed.
Have a look at the testing shots they have from Canyon. Dropping a huge weight on the end of the blue fork??? (1:03) If it can bend like that without it breaking, it's probably not going to break with only you riding on it.
+Niklas Barreto I hit a rock at 45mph down a mountain road on my Canyon Endurace CF. The aluminium handlebar bent a little (2mm approx). The CF frame didn't even scratch, I'm still riding it like a maniac down hills.
+Niklas Barreto Metal can crack as well, for instance if the failure is caused by fatigue. And CF composites can fail progressively, like what GCN said about the layers giving one by one.
so tell me the 5 name of the manufacturers
Thanks
I watched the entire video! The only thing I could think about is how they don't sell Canyon in the US. Can I have one shipped to GCN and then shipped to me? You seem like great fellas. Thanks in advance 😄
I just returned a full carbon fiber frame from cannondale. I ride strictly mountain bike. I can tell you without a dought that the carbon fiber frame was the most uncomfortable ride I have ever had. I would wake up sore all over my body and I could feel the stiffness of the frame through my bones! I went right back to my incredible 7005 triple gauge aluminum bike and almost all the pain is gone! To me the aluminum frame absorbs more of the vibration and hits and I can actually feel the frame flex and gives me a better feel of the dirt, concrete etc...The aluminum frame is more responsive and just as light and strong is not more than the carbon fiber. I dont care what anyone says but aluminum is way better than any carbon fiber frame ive ever ridden! Carbon fiber is way overrated!!
That is so true. My aluminium bike frame also absorbs vibrations better
great video, 1 thing no one ever mentions though is how carbon does in extremes(for some softies) Cold, I am talking about
freezing temps? I live in international falls, Mn. 1 colder area. I ride when its zero outside. I keep warmth, but how will my new carbon frame set keep up? I would like to see a video on this.
Just wondering, how about a video to determine the 5 most aero bag for commuting? backpack, frame bag, saddle bag etc...
I am currently 140kg, down from 173kg. I am. Currently riding a 2005 Giant TCR aero aluminum framed bike. Am I too heavy for a carbon frame bike?
I have a question for you. I'm planning to purchase a gravel bike and am liking the Ridley XTrail Alloy. Would then the aluminum be a better bike for gravel riding than carbon?
Isotropic materials have constant properties throughout. So cracks propagate through the material very easily.
Anisotropic (like carbon) have different properties depending on the direction. So cracks may propagate with ease in one direction, but with difficulty in another.
Anisotropy is (partly) what makes bones so strong!
5:47
I havent laughed out loud so hard because of a video in a long time! :D The 5 minute poised build up with the serious science bit made it so unexpected and halirious.
7 things i already knew about carbon fiber but i just like watching gcn video's
Hello,i search handlebars,and others parts carbon,for my fatbike,which brand take on aliexpress,for quality ? what do you think of Ullicyc ?thank's for your help :)
Good day... What about mixing\using carbon fibre parts with metal?Carbon fibre handle bars with metal stems, triggers and bar ends for example...
i have bought a 2006 trek SL 1000 , will the carbon fork and seatpost be still as strong as the day the carbon parts was made? , the bike is in almost brand new looking quality
I REALLY like your bike!!!, that matte black is awesome!!!
Make a playlist out of these, please
Hey guys, this video make me think that I would really like a video of you where you explain what things one should check for when buying a second hand bike!
excellent video! thanks for sharing!
Look kg191, 1996. As good now as it was at the first ride. 👍
Here's what isotropic means: non-directional. What does that mean about carbon vs aluminum?
Well, carbon is ANisotropic. Meaning directional. A key factor in the light weight of carbon fiber is that it has a full range of strengths depending on the direction in which it's stressed. Your first thought might be, does that mean it just gets weaker? In some directions, yes, but compared to a similar isotropic material what that really means is that it gets exceptionally strong in some directions.
For framebuilding, this means that you can get huge performance out of carbon by orienting it directionally and using very little material in addition to the high average strength to weight. If you were to create a carbon fiber with the same average strength and properties as carbon fiber, but isotropically, and you compared that frame to an aluminum frame, the difference wouldn't be nearly as marked.
I got 2 bikes. One all al mtb and one al with carbon fork and is gravel. I do find gravel bike to be more comfortable despite drop bar and thinner tires and at same pressure. I also notice I feel jittery on rough roads in turns… may be more to do with less grip of tires. Gravel has 47mm and mtb is 2.2 inch one. Though I suspect the carbon fork is not that stable in turns when the road is patchy. Also, front fork has sus on mtb…. Now I have to be extra careful on turns with carbon fork if the road ain’t good. I suspect the side sway strength is not there.
I like the comfort through. Despite no sus it is as good as mtb with air sus and sus has right air pressure as per my weight. And I had to reduce rebound considerably to make sus comfortable.
Hello GCN,
I have a question regarding carbon wheels, could a heavier rider use carbon wheels and not crack or damage them?
i have the same question, im 105kg and i want to buy carbon wheels 24 spokes back and 20 front but idk if its safe... im just amateur rider
One important consideration: What is the environmental impact of carbon fiber over its lifecycle (particularly at end of life and waste management). Can GCN address this?
You know it's a complete mess. All the microscopic waste will end up in the ocean. The planet is doomed to become a hell hole but I won't have to see it.
I have a carbon fibre and it has two small chips on the paint work will it be impossible to repair or cover up
An isotropic solid is a solid material in which physical properties do not depend on its orientation.
Great video, you should do one taking about chinise parts and frames!
www.bikebiz.com/news/read/snap-crackle-and-pop-do-fake-bikes-and-parts-crumple/019437
At the bottom of this page is a pdf link which will tell you everything you need to know about the Chinese bike composite industry.
thank you!
I watched this vid while pooping. Definitely made the download more enjoyable. Nope, I will not be exceeding the weight limit on my bike now, if you know what I mean.