Your Carbon Fibre Bike Won’t Last Forever

[@draggerlane04090]

I own a Trek 5200 from 1998. I raced that frame from 1998 - 2009 I officially retired it only because I I wanted to try out a Madone. I still own that 5200 today and it's just as stiff as it was brand new. I don't race it anymore but I do use it on tours rides, fundraisers, and riding to work. It doesn't just sit. I do keep it inside my house when not using it. It is well cared for as in maitained. The frame doesn't feel dead it's 26 years old I estimate over 200,000 miles on it and it's just as if not faster then most modern bikes

[@r.davies2702]

Probably the best, most informative video GCN has ever produced. Top presenter too, well done Ollie 👌

[@cariboubaby]

Ollie's Ph.D in a hard-science field really adds value to GCN -- it brings an added perspective that I love!

[@richarddennis4600]

Is it divine proclamation that Ollie is wearing a halo during the summary section 34:33, or a bit of cameraman’s fun?

[@guilhermeazevedo1250]

Totally agree.

[@richardsmith6688]

Probably....

[@darrenburbury5505]

Make a GCN+ doc on frame building, testing and design!!

[@pompeymonkey3271]

"It depends" is one of the most common answers given by engineers to engineering questions. For good reason ;)

[@DanTuber]

cos there's a lot of variables

[@12Burton24]

Yeah and thats quite obvious why. You have so many different situations and factors playing a roll for everything in our world. Thats why i dont trust people who say its like this abd nothing else.

[@hondasaurusrex6998]

Depends are adult diapers...

[@pompeymonkey3271]

​@@hondasaurusrex6998 Until someone gets hurt, or dies, as a result of a decision made without taking all the relevant factors into account. I guess that you are not an engineer then? ;)

[@MrJx4000]

Depends on what you're asking?

[@ap6584]

The fatigue on Mark Cavendish's frames is directly related to how many mechanics he's thrown it at.

[@eliteharrington7377]

Real talk 🥴🤔

[@ProWeAreSo]

This is hilarious 🤣

[@jonnythelegs2597]

Ahh the king of hissy fits

[@MrIanD1]

Now that is funny. 😂

[@SeeYouUpTheRoad]

Correct! He’s a man baby!

[@thecrazyhatchemist5051]

Ollie - I love these videos of interviewing cutting edge scientists. I would ask not only about aluminum and steel, but titanium as well when you are able to perform the second interview. I certainly would like to see more videos like this one!

[@jason200912]

You look like yu gi oh

[@markconnelly1806]

Aluminum frames will crack over time as metal is crystal. How long depends on design and heat during construction. I had a road bike fail after 8 years of almost daily use. I also have a mtb frame that's over 10 years old that has not cracked yet and it is used a few days a week on trails without Jumps. I would not worry about steel frames unless it's rusted our crashed hard.

[@austinj8335]

100% want to see a before and after season bike stiffness test for a sprinter.

[@karl_okohan]

I really love listening to gcn tech when I'm working on my bike. I have learned a lot of stuff just by listening to you guys

[@christoingram]

This is the content I want from GCN Tech, love it.

[@simonalexandercritchley439]

The best interviews and subject matter to date on GCN imho.More of these please! I have carbon,steel & Ti bikes from the 90's. Can you do this with titanium? Also further research with polymers and finishes would be great,Thanks !

[@aorta538]

1993 Koga Miyata SkyCarbolite here ;)

[@MegaXtc11]

X2

[@mlee6050]

Glad you are here, I got a carbon frame in 2016-2018 about and was worried it last 5 years only

[@andersbangpoulsen1078]

This is such great content. In a world where the majority of YT videos is an ad for something it's just great to see plain informative content. Thanks!

[@vs1776ny]

Most of the GCN Videos are just elaborate Ads

[@adaycj]

It was refreshing that this GCN content wasn't an ad.

[@haksaw123]

My take out is that Composite Carbon Fibre has as many positives as negatives and that while it is massively strong, the way it is applied to bicycles makes it extremely delicate and in fact less robust than metal frames from a reliability and longevity point of view. My worry is that while it is strong while new, degradation from continuous vibrational amplification is known to weaken the very best polymer substrates that form and bind the Carbon fiber matrix. Basically even the smoothest road surface creates vibration and combined with the intermittent shock forces of striking the occasional pothole obviously will accelerate micro degradation untill catastrophic failure. This may be an unpopular opinion but is based on the sad fact that everything has a lifespan and nothing lasts forever 😕

[@joelkirk1679]

Thank you for creating such high quality content. It's great to hear the opinions of reputable experts on the technical aspects of frame construction and fatigue. For cars there are many independent organizations that test safety, reliability and performance. Cycling just isn't there yet, but it's great to see media like this moving us in that direction.

[@observer1689]

Epoxy resins degrade quickly compared to acrylics, so the paint on a frame performs a vital function: it prevents moisture and and UV degradation (at least until the paint breaks down). How about producing a video on the paint systems used on bikes, carbon, aluminum and steel?

[@arcboy2011]

Also adding the comments below, if there is a part 2, bring in someone from the sailing community as the u/v degradation on sailboats must be more extreme than for bicycles. Perhaps someone from Ben Ainslie's crew. Love the content Ollie!

[@ohhi5237]

ps you dont instantly die if your mast cracks

[@arcboy2011]

@@ohhi5237 This would of course depend on the boat and how rapid the rate of deceleration is.

[@ohhi5237]

@@arcboy2011 a proper boat, like one that floats and u can do baoty things in, they costs as much as a full house, yes thats more than your bike bye

[@charleshiort7153]

I have a LOOK KG 251 which I bought new in 1999.It has carbon forks and carbon frame,however the main joining areas are aluminium. At present I have cycled 307.000km and the only noticeable fatigue is from the aluminium lugs.I have 2 other LOOK bikes that are full carbon,so it will be interesting to see how these cope in the future.I very much liked your video and also the video when you went to the LOOK factory .Thanks!

[@Panagiotis-Skordilis]

wow

[@truthseeker8483]

18.17 "Fatigue is a cycling process" Certainly is for me....😀

[@Jayneflakes]

This kind of deep dive into science and engineering is brilliant. Do please give us more and as a user of metal frames, I too would love to her the analysis of the metals available for frame and component construction.

[@MoxyDave]

Great video. Thank you! I have a 16 year old Giant Carbon NRS-C1 that I bought brand new. Last year I completely rebuilt it with a 1-by GX Eagle drivetrain (something that didn't exist back when I bought it, but it lined right up!) and I still love riding it to this day. I've had some pretty bad crashes but so far, no issues with the frame. I think the lifetime of a hard-use carbon fiber mountain bike frame is mostly down to luck, assuming it was well-made to begin with.

[@paulb9769]

I just bought a 2017 Cirrus Pro carbon and I always have the fear of my frame collapsing on me.

[@richardggeorge]

I highly recommend everyone carefully inspect your bike every 3 months including the fork after a good wash. I have found the following in 17 years of riding carbon bikes: 1. Cracking around the fork crown at junction of carbon fork blades and aluminum fork steerer (bike had been in several crit/bunch crashes) - 2005 Giant OCR1 2. cracks on the underside of chain stay of two bikes frames (one cheap Chinese dengfu FM01 cracked due to being crap, BH G6 which was crashed at 53kmh) 3. Cannondale CAAD10 fork steerer cracked due to stem being so thin (3mm wide at its narrowest point due to stupid attempt at weight savings on stem internals) - poor design! Replaced with carbon stem which has no cut out on the inside of stem (fully supported) and used a 50mm long expander plug. Cannondale one was 15mm!

[@alldayadventures5418]

Agree with checking often.... I use Carbon Forks with Alloy Crowns. (Exotic Brand) Only the tubes are carbon. I have over 8000 miles on one fork (most very rugged CX trail riding) and recently inspected it, no signs of any damage. I do not think I would every trust a fully carbon fork on the trails.

[@MrJx4000]

How do you check for micro cracks in carbon fibre--dye penetrant?

[@richardggeorge]

@@MrJx4000 I found large cracks that were obvious to the eye (a few mm long) but I have watched videos of people using ultrasonic equipment to scan carbon fibre

[@fmstrat2104]

It's a perfect union. While the cyclist ages and loses strength and flexibility the bike ages and loses its stiffness, becoming a more compliant partner as the years wear on.

[@goonzjav]

Until they both break! 😁

[@ohhi5237]

steel ages a lot better, carbon just DIES in sunlight

[@kraatshenk7665]

Getting dropped causes stress to the bike also

[@andreuasencios3620]

lol

[@toddherbst4024]

As we are talking about CF frames seeing potentially a decade or more of use outdoors, regular application of a good polymer-based automobile / marine wax product is probably the best bet for keeping that CF frame in good shape (assuming you don't have the output of Chris Hoy). Since these products seal the surface and protect against UV, moisture, and oxidation damage, I would think this would help, especially for bikes painted in darker shades, like red, blue, and black. These colors should benefit the most from a regular wax treatment, as these pigments are most vulnerable to UV damage. The sealed surface should also help protect the epoxy from oxidation and moisture damage too. Think of paint protection and clear coats treatments on automobiles and how they are used to prevent UV and moisture absorption and oxidation damage as an analogy.

[@KPong1337]

What a fascinating and insightful set of discussions. I bought my steel frames in hopes i can pass them down to my children and children’s children and my carbon frame only for special occasions. I guess nothing is forever - even forever bikes. 🤷‍♂️

[@sandydennylives1392]

Ultra high end steel like 953 might well be termed forever bikes. They say stainless steel cutlery will be the last thing left of humanity.

[@crabtrap]

@@sandydennylives1392 toyotas , kirby vacuums....built forever

[@sandydennylives1392]

@@crabtrap I can attest to toyota. Not so much for Kirby making it to playstation 5, I might be wrong...

[@ericcoxtcu8037]

I am loving these videos from Ollie. What's next? If I can make a recommendation... different power meter technology. Would love to see a discussion of what goes in to pedal based vs crank arm vs spindle, etc.

[@benmodel5745]

Look up the channel "Peak Torque", he's made several very in depth videos about the engineering behind power meters! Great channel, I believe he is an engineer in the bike industry iirc

[@ericcoxtcu8037]

@@benmodel5745 I do like Peak Torque's videos. I saw the one he did on Assioma - I thought it was quite interesting.

[@davepratt9909]

I learned two things today: The next expert Dr. Bridgewood needs to talk to is a polymer chemist and Ollie's hairdo for aerodynamic purposes.

[@marcalvarez4890]

Best GCN video I've ever watched. ACTUAL truth instead of guesses opinions and pretend science. More scientists and engineer interviews please! : )

[@meibing4912]

Have used my carbon Roubaix for 14 years now. Feels like new when riding. However, am getting a new bike just now. Old frame will now be permanently strapped to my trainer. Expect 15-20 more years of use. :-)

[@JitinMisra]

Just curious did the bike ever fall like from standing and also ever hit roughy roads ie pot holes and no problem or any impact and still had no issue ?

[@meibing4912]

@@JitinMisra who does not fall over for 14 years with cleats 😂 - and pot holes are everywhere but tires and wheels take most of the beating. Got run down by a taxi once and repairs included a new fork and 5 ribs. Frame itself amazingly still OK.

[@JitinMisra]

@@meibing4912 I just bought a trek fx bike that is all carbon, to upgrade from my previous bike which was aluminum with carbon fork. Gotta say the difference is amazing, on how smooth it is over bumps. But I sometimes feel paranoid on if I have to baby it. I only ride paved roads though not jumping mountain bikes

[@meibing4912]

@@JitinMisra I had the same feeling/fear in the beginning. 😁Just avoid deep scratches. I recently slammed a (new) Specialized bike with 50mm carbon wheels into a massive pothole going downhill. So surprised the wheel did not even go out of tune. Good luck and enjoy!

[@MyKharli]

I do not know a single cyclist that likes carbon at all . Even less anyone liking a bike over a 1000 quid . I see retro old Raleigh's making a comeback for the last forever fix for sixpence ..a real bicycle . Very informative post . Thankyou .

[@facingup1624]

Love this sort of stuff. Deep dives into bikes science are always appreciated.

[@timsullivan1531]

I have owned and ridden my 35 year old kestral 4000 many many miles. Still no issues or cracks with the frame. Actually i met a few weeks ago the engineer who worked on the structure back in 1986. He was happy to see it was still in good shape.

[@PaulJaquin]

Really great video Olly, really good questions and answers from the experts. It's good to compare the different frame materials, and good to hear about fatigue stress levels and deflection cycles. It would be really good to do a video on tube shapes and sizes and wall thicknesses, which drives the stress and deflections, and then the forming and shape of the joints, such as the bottom bracket area, and how that can stiffen or flex the feel, and is pretty much independent of material. Great to see some engineering principles talked about!

[@jordanrelkey]

Thank you for the time-stamps. So many creators don't make the effort, and it hinders my viewing experience at times. This is my first watch of your content due to youtube recommend, and you get Subscribe from me from first impressions.

[@stevenleffanue]

'With knowledge comes responsibility'....let's hope bike manufacturers get better acquainted with this sort of knowledge and apply it in their production.

[@orsations]

They know it, and there’s probably a reason why they don’t take about it.

[@Riyanable]

Extremely informative content from dr.ollie and GCN ,feeding my hunger about bike as a pandemic newbie cyclist. More content deserve to be waited.

[@ThisIsJoe07]

“It’s nice to get some interesting questions…” - Tom must field some real daft questions frequently. Top marks Ollie - great interviews and great vid 👏

[@fireblade1986]

As a composite glider technician... I can say, yes material softens as described... But engeniered correctly it lasts longer than any metal... I see gliders from the late 60th regularly... In snowboards you can definitely feel that deadening... Unless you buy burton, who prestress their boards and engineer that softening before hand

[@stevezodiac491]

I have a 29 year old Dunlop Hotta Perimeter TT bike with a carbon finish with 1993 carbon specialized carbon finish tri spokes tt wheels, all in perfect condition with no cracks whatsoever. There is your answer ollie, going training on it this afternoon.

[@JasonDBike]

But is the carbon from back then the same as today's?

[@stevezodiac491]

@@JasonDBike I also have a modern trek speed concept i do competition on now. I bought it expecting it to be much faster because it has modern wider wheels and a slightly more aerodynamic profile and obviously lighter. The difference in speed is immeasurable and could easily be the difference between one day and a slightly better weather day,either way. I am in the same position on both bikes and that is what is important. We are being conned, I am sure !

[@FlowJunkie65]

You're on a roll, Ollie. You're broaching so many important questions that CF bike owners have about their bikes. My situation: I own a 2016 Bianchi Specialissima with the matte finish, which was stored in our home, but now that our college graduate/graduate school student has moved back in, my bike has been relegated to our garage which in Southern California can become quite warm. My question would be does long-term exposure not to ultraviolent light, but simply warm temperatures in a garage degrade a CF bike's epoxy resin or laminate?

[@endurancesweat]

16:23 Tom Bahto - Senior Specialist, Materials Engineer: "There must be millions of carbon fiber bike frames out there that are 15 to 20 years old, and they are not falling apart. So by and large, I think the cycling public are pretty safe on aging carbon fiber bikes."

[@arifazhari7598]

Because the load experience by those frame is below the limit of frame fatigue design. And most cyclist dont produce power above 400 watt that's even less than 1 horse power

[@marcalvarez4890]

@@arifazhari7598 Thats about half a horsepower. But real horses put out multiples of 1 horse power.......HP is a measure of long term power output, not short bursts.

[@FoobsTon]

@@marcalvarez4890 But horses don't ride bikes... Not that I've seen anyway.

[@scotthamilton1054]

I experienced UV destruction on my friend’s Orbea Orca 2009 frame about 3 years ago. Clear coat matte finish that showcased the carbon fiber.. 10 years of hot summer riding did it in. The chain stays got real punky like a sheet of plywood that had severe water damage. His bike was leaning against his garage it rolled forward and a corner of a brick pillar and a created a hole. We then poked around with fingers and started to create other holes. I had a similar type of frame at the time that I wound spray UV protective polish on as much as I could. My latest is a painted frame.

[@NiklasEvers]

Would be cool to see a comparison or test of heavily used pro carbon bikes and carbon bikes that are new or used by amateurs. Kept thinking about the sailing industry throughout the vid. In sailing you are starting to see more older carbon components that have been frequently exposed to UV, saltwater and high loads but my understanding is that failures aren't as common as one would expect.

[@ohhi5237]

no boat sank as much as the trispoke broke LOL

[@davidbalentine2110]

I value my steel bike ever more, having been educated further by viewing this video. Thank you!

[@Craweats]

Love GCN, Ollie, tech, carbon fiber, and weekend naps. This video hit the ball out of the park! ⭐⭐⭐⭐⭐

[@kenannable4747]

Great video! Can you make a like video on aluminum, titanium, and steel?

[@pajacobmn]

Great content, real technical information is essential. The thing that shocks me the most is that anybody hadn’t already figured this out! Carbon bikes are throwaway consumer goods. Most quality steel frames that are already 40 or 50 years old will, if not stored outdoors, still be giving their owners a joyful riding experience after every carbon frame ever made is in a landfill.

[@georgebirddrums]

We all know that it's Neo who causes the matrix to fail

[@chrisvanbuggenum871]

I'll pay that!

[@bxbank]

I agree with the 2nd guy. Flex is designed to neutralises the stiffness. Motorcycle swingarms are designed with flex in different ways for each track so there is some kind of suspension when they're horizontal.

[@leighdickinson8299]

Nice Ollie fascinating, the information goes along well with my personal experience of Carbon Fibre failure that I experienced over the 25 to 30 year of using it in cycling, in frames & components. I the aluminium idea but would if you could cover these areas with Titanium frames also?

[@rravimahawal8719]

Excellent work with this video. The panel and presenter both explained and asked things very very precisely and descriptively.

[@fisky2000]

Fascinating, more of this kind of content please 👍

[@bjkactivities]

I like how this conversation is real informative and just on the level that someone who has no real knowledge on this subject can still follow it.

[@richardggeorge]

The basics of composite materials are simple to understand. Stress, strain, Youngs modulus, layup direction fibre/resin composite etc. Modelling them in finite element software in mid 90's for my thesis was a bit more challenging!

[@richardcooley9730]

Best GCN video yet and really interesting to learn from real experts in the field. I would like to add a couple of points, one is that while NDT (non destructive testing) is talked about for testing Carbon frames after a crash, this is rarely available. metals are sonorous so they can be checked by "ringing" them. Secondly Canyon (as an example) recommend changing carbon forks at six years, obviously this is a sensible compromise as they don;t know the usage but it is an expense that requires budgeting and could come to light in the event of a post crash court case.

[@herculesrockefeller8969]

So for 99% of riders, this isn't a real issue, yeah? Thanks for an interesting video!

[@Adam-qw7kc]

I enjoyed watching both of the interviews in this videos much more than I though I would. Good job GCN.

[@Music-pq8cm]

Been riding my Pinarello Dogma 60.1 frameset since 2009 (well over 60,000 miles; closer to 80k miles). Had to repair the front bottle cage nutserts (rivnuts) but no other issues. Frame is still very stiff with pretty much the same handling characteristics. Fingers crossed… I’d like to get another 2 years from it.

[@SonnyDarvishzadeh]

Next week: Muc-Off Ninja UV-Protection Polish

[@Atzan]

Puts a new perspective on buying those secondhand bikes off the pro teams. 1 season of use by someone like Cav or Sagan might be the equivalent fatigue of 10 or 20 years by ordinary mortals.

[@andreemurray7039]

Very informative just look after your frame 👌

[@graemejwsmith]

Didn't get touched on - but to extend on the comments about "ductile" metals. All other things being equal. A steel frame that flexes - but never gets taken to its "yield point" will always recover and not fatigue. An aluminium frame that flexes but never gets taken to its yield point WILL "work harden (fatigue)" and eventually fail. Aluminium has a much lower modulus of elasticity compared to steel.

[@firesurfer]

I love your floor to ceiling cabinet in the background. I wish I had one exactly like it. It's the right size. 19:12

[@acoffeewithsatan]

I think road cyclists stress way too much over these topics, when even the roughest asphalt or even gravel wouldn't compare to the stress applied to a bike frame that of a MTB descend. Full carbon frames are also made and used on mountain bikes yet they aren't noticeably prone to fatigue wear that people complain about it to an abnormal extent. Sure, one might say those frames are more reinforced than road bike ones, but fatigue is an integral problem the entirity of the material suffers as it get exposed to deflection and small impacts, according to these experts. On the bottom line, will YOU keep a bike for long enough that it's something to worry about? While one day the current carbon bikes will become what the collectible, vintage steel bikes of the 70s onwards are today, even if you keep your modern-day bike for decades, or you or someone buys it much down the line, you won't view it as an everyday, dependable piece of sports equipment.

[@keithfurrow5899]

My three takes are 1. buy a well made quality composite frame 2. don't wreck it or drop it and 3. remember fatigue curves (S-N curves) are plotted on log scales which means Ollie's lower fatigue loads result in orders of magnitude more fatigue cycles before failure. Seriously, for mountain bikes, high impact loads and the complex geometry beg the question: Should mountain bikes be made from composite materials?

[@John-ol4eo]

Just like that submarine... carbon fibre... eventually it said no more stress

[@HeyFixThis]

I have some numbers: Glasfiber has a super long shelf life as long as it is covered by a UV and moister barrier such as paint. Composite glider planes can reach up to 12.000 hours+ flying time and the early versions of the 60’s and 70’s are still in service. So it’s safe to say at least 50years shelf life and at least 12.000 hours of normal usage. If you everage at 20km/h you get 240.000km out of your bikeframe under nominal conditions.

[@MJarthur95]

Cool, so buying a pro bikes bike is pretty much going to be a expensive painting on the wall

[@jonnythelegs2597]

Climber's TT bikes would be a safe bet tho especially if they're crap at TT's chances are its had naff all use.

[@cervelo9465]

Fantastic brilliant video, top quality. Average cyclist guy, I believe I will be sticking with : steel, aluminium, titanium. Carbon is only really needed for applications like racing, elite sport. I have several bikes in the garage from 1980's. My first proper road racing bike, which arrived as a Christmas Present in 1985. Reynolds 501 frame. Happy Days. Steel bikes, which generally genuinely can and do last for a lifetime.

[@andrewsallee6044]

So if I go to sell my carbon frame bike, I should include in the ad: "Ridden by a little old man..."

[@tristanhanley8741]

A quick google search on the ISO standards for bicycles led me to see that there are standards for the fatigue testing of bicycle frames laid out by the ISO Standards. This would give minimum values I assume(you have to purchase the standards and while I am interested, I am also a broke engineering student currently, so no purchasing manuals for me). If anyone has a copy of the standards or if GCN Tech wants to do a part two to this video that might reach out to a few frame companies and compare what they do to what the standard says... I am sure that most companies design for an infinite life if possible, but it sounds like composites don't have an endurance limit like a steel would(steel if loaded at a low enough load will never fail due to fatigue, unlike aluminum which will always fail no mater how low the load is). What the actual designed life is would be nice to know and certainly give me peace of mind on my 3 year old race bike(have to wait for real job/adult money to buy a new one).

[@MazzaJ]

You’ll get there kid. I remember picking my lunch out of the trash and walking in the same shoes as you. Keep pushing keep working.

[@drstevenrey]

Hi, I own the third of 86 FFA Diamant gliders. This is noted as the first ever entirely fiber glass glider aircraft. Mine has a year of birth of 1964, yes, that is 58 years ago. When I bought it in 1976 I was told that I need to keep monitoring the material and that the Aviation Authorities will check meticulously regarding ageing. And it was added that I might get some 5 years more out of it. It has been checked regularly ever since and I still fly it every week now, in 2022. So cut the cheese and don't worry about it, since the bike will be around a lot longer than you and I. Please note that my example is a glass fiber, resin compound that is considerably less sophisticated than carbon fiber.

[@frinlucas3924]

I always thought the same about carbon frame bikes. Thanks for the feed back, since no one would be financing me a carbon frame bike, i am happy with my aluminum alloy bike. Its always good to invest in a good quality a alloy bike rather than investing on a carbon fiber bike.

[@xanninc.abrasivewaterjetcu3896]

My aluminum Cannondale is still going after 27 years

[@ZebraLemur]

Aluminum has a lifespan as well. Loaded with the same stress, aluminum would have a massively shorter lifespan because it has substantially less strong. It's only because carbon is used under substantially higher stresses that it might fail sooner

[@simonm1447]

@@ZebraLemur at the end the amount of aluminum used would have to be increased, this lowers stress on the material and increases lifespan. Both materials are also used to build aircraft, 737s for example use very little other material than aluminum for the fuselage, but they still last more than 100k FH until the cell is gonna to be scrapped. F-16s are also built from aluminum. A carbon fiber construction will be more lightweight of course at the same strength, but aluminum still works if something is designed properly

[@ZebraLemur]

@@simonm1447 My main point is that people like to criticize carbon, but if you made an equal weight carbon bike and equal weight aluminum bike, the carbon bike would have a massive lifespan increase over the aluminum. It would be a tank!

[@simonm1447]

@@ZebraLemurThat's right. There had been very light aluminum bikes in the past (Marco Pantani used one), but they are fragile and crack relatively fast. A modern carbon fiber road bike frame is surely superior in strength compared to these bikes. Where metal offers a clear advantage is for offroad bikes (like MTBs), while carbon fiber has a lot of strength in fiber direction it is significantly weaker than metal if it gets a hit from the side (like if the frame hits a rock etc), a metal frame may have a dent afterwards but the carbon is likely to break here. Personally I ride metal frames (aluminum and steel), but I don't do any competition and a way cheaper metal bike is good enough for me, my frames are not that lightweight, but they are stable enough since they use sufficient material.

[@MrKahikahi]

i don't know today, but LOOK were always masters in carbon frames. the kG281 was fantastic and equipped a lot of teams ( kelme, Once , Credit Agricole etc ) the 281 with credit agricole painting is 🥰🥰🥰

[@philipcooper8297]

Aluminium frames tend to come with life time warranty. Tells you a lot about how confident the manufacturers are about aluminium.

[@simongoh9461]

Hmm, my understanding is that unlike steel, aluminium does fatigue. If you put aluminium through enough repetitive cycles that doesn't actually deform the structure, it will eventually fail.

[@kr2082]

I think you are referring to titanium

[@JethroWaldron]

Lifetime warranty is actually defined as 10 years for aluminium frame. “Lifetime” means the typical lifespan of that frame, not your lifetime

[@ultimateoutdoors4659]

@@simongoh9461 maybe but still doesn’t undermine the point about warranties - even at Halfords you get a lifetime frame warranty on their bikes. So even if it did fail, you’d get a new frame as long as it wasn’t due to abuse or a collision.

[@philipcooper8297]

@@kr2082 Titanium tubes are perfect, it's the welding that fails though.

[@Bigoak66]

Bloody brilliant. Helped me get a proper nerd moment in...thanks Ollie! One element to possibly investigate is total weight tolerances and impact on frame soundness over time. (Speaking as a 100+ kg rider).

[@vausemike]

What always gets to me if the amount of investment and justification given by cyclists at the need to own the most elite kit they can (and sometimes can’t) afford. Yet most of the cyclists you see riding these bikes could do with losing 10-15-20kg from their body weight. If you can only ever manage 2 need place in a race and are super lean and ride a steel bike then you might need the upgrade. If not you really should just be asking yourself if you should just invest some time into yourself which is free and pays off far more heavily than throwing money at the issue.

[@richardggeorge]

I agree! I bought a 14kg chromoly steel bike for $160aud with slow durano plus tyres to commute to work. I am 5-10% slower overall as it's rolling hills but on the flat it's not much slower than my fancy carbon bikes. I overtake people with aero bikes and deep carbon wheels all the time whilst keeping my HR below 65% of max (zone 2 training).

[@simonm1447]

Money is usually spent with less effort in equipment than in professional training ;-) The effect however of professional training is likely to be bigger than a more lightweight bike

[@erlkoenig90]

Time is free? If you don't have to pay rent, perhaps...

[@marcalvarez4890]

When i weighed 120 pounds, my super light XC bike was.....gorgeous to ride. I now weigh 145 pounds, and even though they're mostly muscle, i can FEEL those pounds. An entire bikes worth of muscle on my body makes a difference. Being lightweight + light bike = God

[@gen-X-trader]

This explains why so many frames have gotten heavier since 2017. Yeti sb6. 2017 trek fuel 9.9. yeti asr. All just stupid light frames and I have personally seen every one of them break. These new bikes are, like a pound heavier, haven't seen one break yet. Revel rascal. New fuel. Sb150 etc. They aren't as fast but they probably have a fraction of the warranty claims

[@Solarsystem50]

Can’t wait for the follow up show about alloys, specially titanium.

[@albertofernandez3277]

Excellent video and information. Conclussion: if you want your bike to last forever dont move It from home. But if you wanna enjoy It use It as much as you can and dont even think about fatigue 🤠

[@Simbostyle]

I found this video really interesting, and kudos to GCN! I would like to know what effect over time would moisture inside a frame from washing or winter riding have on the composite degradation?

[@LeonidasRex1]

I've got a 2016 Trek Farley 7 with a carbon fork, it gets rode daily in all weather conditions (-20s to 40s c) and it's doing just fine with about 30k miles on it.

[@bicyclist2]

I have a old LOOK carbon bike from 98'. It has been flawless. I tried using a Look carbon seatpost but I kept cracking them because it's fixed in place with a wedge. Then I discovered that it's tapered. It's thicker at the top and very thin at the bottom. After using a aloy seatpost I didn't have any more seatpost problems. After watching many videos by Hambini, I'm very reluctant to buy a new carbon bike or frame. Thank you.

[@johnfilmore7638]

Carbon fiber and fiberglass react to stress very differently from aluminum and titanium alloys. Where the author here mentioned "microfractures" in fibers from repeated deflection, metals tend to "work harden" or become LESS flexible with deflection or impact at the specific metal-grain boundaries the stress forms along. The more brittle or work-hardened metal alloys get, they lose elasticity but don't necessarily lose strength. But where they lose elasticity through increased hardness, if a serious deflection or torsion occurs, the work-hardened alloy will crack catastrophically. Overstressed, work-hardened metal alloys sections can generally both be detected with a $200 Rockwell Hardess guage, and work-hardened damaged sections can be replaced by a halfway competent TIG welder in in their garage with a $600 DC TIG welder. Working with & repairing carbon-fiber requires Xray and significantly more training and expensive equipment, there is no carbon fiber autoclave that I am aware of that a well-resourced hobbyist could setup in a garage, similar to a tintanium or aluminum-alloy bike-frame builder. $40,000 starting price for an autoclave requiring high-temp insulation, wiring, heating coils, fans, and thermocouples, that have relatively short lifecycles and are costly to replace. Nothing autoclave is cheap, or plug-n-play. Carbon fiber is amazing, but the cost of entry both for building and repairing, is very steep. Most people could have a titanium-aluminum alloy frame custom built for comparable to the cost of carbon-fiber, that a hobbyist could easily keep up with the best of carbon-fiber bikes, and that could both survive as bad crashes as carbon-fiber, but also be infinitely more repairable than carbon fiber, for 70+ years through hard abuse. At least until the development of low-heat curing carbon fiber resins, we will never have artisans and hobbyists with carbon fiber autoclaves capable of handling a bicycle frame size piece. A carbon fiber bike will become functionally unrepairable from the nature of carbon fiber.

[@solitaryrefinement6787]

Luescher Teknik is the man to talk to. He speaks out of experience, not speculation.

[@ccousinsr32]

Tom Batho! That’s a face and a name I haven’t seen in a few years, since the heady days of 3T Racing and the BUKC! Glad you’re doing well mate, and proper interesting info - thanks!

[@maxsievers8251]

Steel frames ride fine and safe after 70 years. We know that from old Rene Herse bikes.

[@simonm1447]

lugged and brazed steel frames don't really age as long as they are protected from corrosion.

[@brankododig1585]

Except the ones ridden hard and a lot. Race bikes were also regularly replaced in the steel bike era. Gently nodding along, bikes can last a very long time.

[@mauricetremblay1324]

I have a composite bike, aluminum and carbon fibre. The frame is stiff yet forgiving. I also had a carbon seat post. It failed at some point but it failed gradually. At first I thought I had tire issues as the tige was getting “ spongy. After 2 weird rides I did a full check up to find the seat post was “tearing”. IAM glad it was carbon and not metal failure. Not sure how that would have gone!!!

[@PittApartment]

I literally never comment but had to shout out how impressed I was with this video, nice job!

[@oz6123]

Just can't beat the versatility of a metal frame.

[@stevezodiac491]

I rode 34 miles to work and back for 25 years and I have worn out dozens of bikes mainly through frame cracking and corrosion. I have had titanium, aluminium, reynolds 531c, 653, 753 and in the end, the bikes I rode to work all broke. I currently have a cannondale system 6, a cannondale super six evo, a trek speed concept and still have a 29 year old Dunlop hotta perimeter carbon fibre bike with carbon tri spokes on it. All the carbon bikes are aok and most after many years of use training but not commuting.

[@JR-wj9bh]

@@stevezodiac491 Wow. You must have a really huge garage

[@stevezodiac491]

@@JR-wj9bh i have but all those broken bikes went in the skip over the years. I only have 10 bikes now, the expensive ones( a system 6 being the most expensive ) live in one of my spare bedrooms.

[@richardggeorge]

The welds fail due to fatigue/weld quality. They are not perfect either

[@davidcole6893]

Fasinating . Giant and Specialised offer lifetime guarantees on frame to original owners.

[@stevezodiac491]

I have a pair of 29 year old specialized tri spokes tt wheels on my oldest bike.

[@user-nu5fx6en9h]

My carbon frame been 13 years still going strong 🔥

[@derf9465]

Until sundays ride 😬

[@richardggeorge]

Keep an eye on it, esp fork steerer

[@AG-el6vt]

Great video, thanks! Haha, the Prof. was no-nonsense from the start. I guess when your field of research includes things like 'if this graphite moderator fails, your reactor will turn into another Chernobyl', you are much more keen on how and why materials actually degrade.

[@jestag2]

Which is probably why Specialized is pushing the innovation and development on aluminum with the Allez.

[@acinemanearyoutoday]

Riding a Corima carbon bike for 30 years, road, gravel, even xcountry MTB, presumably 1st generation carbon, works fine!

[@haqitman]

The first interviewee singled out the Specialized Roubaix zertz by name, but i didn't get by what mechanism that's advantageous. But... my 2010 Roubaix, XL carbon frame with zertz fittings has about 8K miles (I think, maybe more). I'm over 100Kg but don't hammer very hard or take it off sweet jumps and it still feels very stiff, no creaks, solid. I'm gonna keep riding it. And maybe lose a few pounds.

[@DrJRMCFC]

Superb. Extremely interesting. More of these in depth and technical editions please

[@SB-mg6xq]

This is a really great and informative video. I think though that obsolescence will claim many more bikes than the material ever will. My aluminum Raleigh mountain bike served me well, through about 2000 miles then the frame cracked due to stress corrosion cracking. That bummed me out. My 2012 Mid Compact Specialized Tarmac is still going strong, and the carbon frame has not had any noticeable degradation in over 34,000 miles. I don't ride it much any more as I've moved on to newer technology, but I suspect my Cervelo 22 Caledonia will probably outlast its technology as well.

[@gerbryf]

Thank for this very interesting video, we would not have access to such knowledge and understanding otherwise, superb! A few things not covered were... how much of a margin do the components have and increasing strength/stiffness and how do these effect things. Can the matrix be repaired? By margin I mean how much more could a frame take compared with a calculated maximum, eg if the calculated max 'strain' is 100 units, how much more is added in for safety and longlivety, none, 1.5x (150units), 2x (200units) or what- guessing, trial and error etc? Increasing stiffness/strength, adding more material (more layers) or different shapes (gussets), introducing further (different) materials (metals, foams etc), am I correct in thinking that a manufacturer added expanding foam around bb area which increased stiffness by a large amount? Can the polymer matrix be re-invigorated? Some polymers will melt, why not heat up a frame for it to melt and fuse again, eliminating the fatigue fractures? Probably not very practical but with the cost of these frames, has anyone looked into this?

[@simaosantos5129]

So, in terms of safety, the supported tensions are calculated to always be 2-5x higher than the real ones. 2 It is commonly used for buildings, 3 for automobiles, and 5 for aerospace applications. Most of the time, after designing a product, it is tested and corrected (in software) trial and error until reaching the intended values. only then is it manufactured and tested again. Adding more layers will improve supported tensions, despite how weight is an important factor, having a bike that supports 10x the actual stresses doesn't make much sense. Adding additional materials won't do much, and may even be detrimental to the intended performance. In this aspect there is still another problem that is the adhesion between materials... Carbon fiber is not known for having many friends! Unfortunately, the polymer matrix is ​​impossible to restore, as a thermosetting resin is used, which will degrade when temperature is applied.

[@monkmchorning]

A friend who raced for Giant in the oughties related that their TCRs were spent towards the end of one season. I got about three from mine before it became unrideable. Now my mid-level OCLV Madone is going strong after 11.

[@henryangus6934]

Best I’ve seen on GCN. Keep it up Ollie👍

[@a1harrogate]

I believe a quality alloy frame has a much longer lifespan than carbon frame, and any failure is likely to be less catastrophic than a carbon frame.

[@RedCommunist]

Aluminum frames wear out within a short enough timespan so as to cause concern, also. It's like how aircraft fuselages (also aluminum) wear out after a few decades even with the best mechanics and strict maintenance. If you are concerned about the lifespan of a frame, steel and titanium are the options that will last a lifetime. Life expectancy would have to go over 200 before we have to start worrying about wearing those frames out.

[@a1harrogate]

@@RedCommunist *LOLZ* that would explain why I still have an alloy mountain bike plus road bike over 20 years old. I'll stick with alloy. It's a well-known fact.

[@stevezodiac491]

@@RedCommunist aluminium frames fail without obvious early warnings.

[@simonm1447]

@@RedCommunist to be fair aluminum fuselages (like the ones of a 737 or an A 320) still last over 100k flying hours before they are gonna to be scrapped. They are made to be fail safe, they are lightweight and cracks in these fuselages can't grow big enough to be a concern until they are discovered in the next regular check.

[@benmeans4700]

Such an in depth informative explanation! I only have an alloy bike and I'd love to learn about their fatigue life as well.

[@andrewbrooke2051]

So interesting. Really great set of questions and answers. Well done Oli.

[@JLneonhug]

Very common thing in carbon rackets (ie most rackets nowadays). In the racket world it will be perhaps 2 years used by a semi pro. The stiffness goes, the joints/stress points will become flexy and weak.

[@bigwave_dave8468]

at 31:05 James says something that is untrue so i'm wondering what the context of his statement is: "the failure [of cf] is less catastrophic". When I was at Boeing in a CF class taught by one of our experts, we were shown stress/strain curves -- for CF composites, you reach the stress limit and the fibers fail in a cascade all at once unlike metals with plastic deformation after the peak of their stress limit util the material ultimately fails -- It's just that the peak of that curve in CF is much higher per unit mass. Interesting discussion about microfractures in epoxy matrix. Good stuff.