Conor bought a crash-damaged, top-spec carbon frame for only £20 to see if he could create a dream bike on a tiny budget. With absolutely no experience, he uses a simple DIY repair kit to fix a huge crack in the down tube. To find out if the bike is a rideable success or a dangerous failure, he enlists Dr. Peter Giddings, a composite materials expert, to give his professional and final verdict.
Chapters: ⏱️
0:00 – The £20 Dream Frame
2:06 – Preparing For Surgery
5:35 – The Stressful Bit: Applying The Carbon
8:06 – The Big Reveal
11:10 – Calling In The Expert
14:20 – Analysing The Repair
19:35 – The Coin Tap Test
22:53 – The Ultimate Test: Max Sprints
25:40 – The Final Verdict
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It was a rollercoaster of stress and sticky epoxy, but we got there in the end! After seeing the whole process and the expert’s final verdict, would you be tempted to use the frame on an indoor trainer? Let us know your thoughts in the comment 👉
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I just bought this dream frame set for only £20. Brand new, this would cost thousands, but I’ve managed to get it for less than 1% of the price. This is topsp spec and built up. It could be someone’s dream bike. So, how did I get it so cheap? And what’s the catch? The truth is, it’s crash damaged with one huge crack on the down tube here. In this video, I’m going to try and repair this beautiful frame and do it on a budget using a DIY carbon repair kit that I bought online. I’ve got no experience of fixing carbon fiber, but I’m going to give it a go. Is it possible? Can I do it? There’s only one way to find out. So, I actually spotted this frame set on Facebook Marketplace. It was listed for £20 in English money. That’s pretty similar. in terms of euros and dollars, €20, $20, which is even with the crash damage is a bit of a bargain. Um, I paid £10 on top of that to have it cured here to GTN HQ. Bring my total spend to £30 all in for this frame set. But as you can see, the damage is actually it’s pretty it’s pretty solid. Let’s admit it. It’s a bit worse than what I was hoping for. So, it looks like there’s been a proper strike here on the down tube. There’s a really big gash which is taking a lot of paint off. It’s almost like if you press that if you gave that a really good shove you I think you could push something through it. And the crack actually extends all the way up here just to the O of the look. And it’s the same on the other side as you can almost see where the impact has moved through the frame onto the left hand side as well. There’s a solid gash there which kind of spreads out very very obviously broken. And I mean, if you really got in there, you could start peeling bits off, you’d be absolutely gutted if that happened to your bike. Okay, so this is what what I bought with my my DIY repair kit. So, I’ve got my my carbon fiber cloth here. It’s a good roll of it as well, actually. It’s a solid solid amount, so I can kind of cut and shape that as needed. And then I’ve got the epoxy that I’ll need to mix up and apply to the frame. Paint brush. Got the cloth I’ll need when I wrap it. Um getting into all those steps. Got some sanding paper um as well. So it’s all there. I’m a little nervous. I really genuinely don’t know how this is going to go. I’m going to give it my best. But first off, it’s time to get into it. First step for me, going to give this frame a bit of a clean down. And I need to sand off all the paint around this crack, get to the bottom of it, and see exactly kind of how bad the damage really is. All right, then. So, first step, as I said, I’m going to sand off all this paint. There is dissent amongst the ranks here because Ollie said not to use a mechanical sander. Alex reckoned to use one. I’m going to use one because the amount of paint I’ve got to sand off here, I need every bit of help I can get. And I’m just going to be careful. Basically, I need to be really careful not to go too far through the paint and into the carbon and cause like more damage than I need because I’ve got enough on here already. Um, but this is the job for outside. So, I’m heading out and yeah, time to get sanding. You know, it’s not actually that deep. So, I was actually kind of thinking it wasn’t as bad as it looked, but if you do go into this this right, it’s the left hand side crack, you can see it quite clearly there. Give it a little bobble. You can really push it in. I think that’s the key spot just there. Okay. So, giving it a proper sand down. It’s been quite a large error actually um to do. I’ve done a bit of a rough job on it. I’m not going to lie, but it’s done the job. I’ve made the mistake I should have taped this off earlier and just kind of restricted myself, but it was really hard doing this for the first time to know exactly where the crack would go to and how far I’d need to sand. But got there. It’s actually not as bad as I thought it would be. So there’s one really solid whack here. It looked like this would just be one long crack, but when you get down to this layer, it really is just this bit, which you can you can push your thumb in there. Also, that bit there. I could give that a solid push. And then there’s a hit here. That’s really flimsy. You can almost see that move. So they’re kind of like proper impacts. Boom. Boom. Boom. Boom. All on that area. Everything else is pretty solid around here. So now I’m just I’ve given it a bit of a wipe down outside. I’m just getting it ready to to put the epoxy on now. So it a little wipe down with an alcohol wipe. So, basically, this is the epoxy, mixed it together with an epoxy hardener. So, this is the resin that I’m going to kind of brush onto the frame according to the the steps. Then, I’ve cut my kind of bits of carbon that I’m going to patch where the frame’s broken. And in effect, it’s kind of like paper mâe. And then, we’ll see how we get on. The bait brush is broken. There’s something going wrong. Oh, what’s that steaming stuff? Look at it steaming. For sake. Oh, it’s all going wrong. Oh my god, it’s baking hot. That was more stressful than I thought it would be. So, I finished. I’ve got to be honest, I massively panicked in the middle of that. It was a lot harder than I thought it would be. The hardest part was the um the carbon fiber cloth. They just as I was trying to get the epoxy onto it, it was really tough to kind of keep the fibers together, they kept kind of falling apart. So, I think that my first little patches were quite neat, but then by the end, it just got really messy. Um, and the epoxy also started hardening quicker than I thought it would be. So, I was kind of like in a bit of a race against time to get it finished off. And at the end it was really tough because it was just barely barely able to to apply. But I’ve managed to get some heat wrap tape on. So I’ve basically wrapped the whole lot, heated that up, and that should kind of constrict and keep everything nice and tight and force the epoxy into everywhere where it needs to be. It looks like such a rough job for a first attempt. Very rough. But the job is done now. It could all be for nothing cuz I could have done an absolutely terrible job. We’re about to find out. But I need to leave this overnight. I need to leave it set. Then I’m going to take all the tape back off and then in the morning we’ll be able to see what it looks like. Right, time for a cup of tea. Okay, it’s the following day. I’ve left the carbon overnight to set with the epoxy. Got to say, yesterday was a bit harder than I thought it would be. um few moments where I thought this was going to go horribly, horribly wrong. It still might have gone wrong. I’m really not sure. But actually, after I’ve heat wrapped it and looking at it now, it’s set really well. Maybe it’s worked. I don’t know. Basically though, now I’m going to take off all the heat wrapping and the electrical tape, and then we’re going to see what’s uh what’s left, what’s under the hood. Moment of truth. It’s coming off. It is actually coming off. It’s not that bad, you know. It actually isn’t that bad. It’s not looking that bad. Solid as a rock. You know, I I would ride this. The only problem is the heat wrap tape’s kind of got stuck on the There was one bit I really did mess up on with this. Um, and I found it really difficult applying the epoxy over the carbon fiber cloth because basically as I was applying it and I didn’t foresee this, it started pulling the fibers out and they started fraying and going down onto the electrical tape. And actually, this has been my biggest mistake of the whole thing cuz now the fibers are over the electrical tape. So, I don’t really know what I’m going to do about that. Okay, I’ll tell you what. After getting everything off and looking at it now in the morning, it’s actually not that bad. I’m quite proud of myself for a first attempt. Look, it’s it’s pretty rough. It’s a rough job, but it’s not as rough as I thought it would be. I’ve made some mistakes for sure. I definitely do things differently the second time around, but this was like total first time getting into this. I think what I would have done is sanded more of the paint off to expose the carbon here and here. I’m not really sure why I put the electrical tape on. That scuppered me and it’s made it really hard to get a nice finish between the carbon and what exists already. This is kind of flaking a bit here cuz it hasn’t quite bonded right. That’s been a major mistake. I don’t know if it quite matters cuz what I was repairing was more in here. So, there’s a solid bit of margin either side. And when you feel it, that is like absolutely solid as a rock. Like solid as a rock. It’s It’s harder than the rest of the frame. I remember I had two patches in. I wrapped it once, wrapped it twice, and that epoxy has just set on it incredibly well. frame fixed. According to my own judgment, it was time to get a true professional to assess my work before I actually felt confident enough to take it for a spin. Dr. Peter Giddings is chief engineer at NCC, the UK’s national R&D center for composite materials and is also a keen lifelong cyclist. So, when it comes to learning more about the material used in our carbon fiber bikes, he’s the perfect person to talk to. Peter, thanks so much for joining us today. I am fascinated to get your opinion on my my my repair job. I when I did it in the moment, I really thought it was going downhill rapidly, but then now I’ve managed to build it up a little bit just to show you today. I’m actually not that disappointed in it. You know what? I think it’s going to be super interesting. Like, thanks for asking. Even just from a distance, I think you done a pretty good job. Obviously devil’s in the detail, but from a first cut actually you look all right. Yeah. Can I have a closer look? Yeah, have a close have a have a look. Have a just have a little moment. I mean there’s two there’s one big point which I think I did mess up on. Um and I’m pretty confident I can own it and it’s maybe been my undoing and that is so go from the start. So there’s there was big impacts on the down tube at the bottom here like top here big one here. So, I sanded it all down and then I got to use a really budget kit, repair kit to fix it. Um, I’ll show you a bit later what happened. It was a little bit of a disaster, but I got to this point. Every every success looks like a failure in the middle, Connor. It felt like we weren’t going to get to this point. Put it that way. But what I I think my mistake is I put electrical tape here to kind of protect the frame top and bottom. But then as I was fixing it, the carbon just spled way more than I thought. The epoxy went further and I got the electrical tape trapped. And when did you take the tape off? After the next day when it was cured. When it was cured. Oh, Connor, it’s that bad. Well, we’ll get into it, but it’s not that’s not the way you’d want it to be. I think the the the coin tap might undo you on that. Really? Yeah. We’ll talk about But I mean, it’s a good thing protecting the rest of the frame. Really sensible. I can see you sanded it out nicely to give yourself places to bond. Yeah, super good. Um, it’d be interesting to see what kit it was and talk through how you did it. But like I said, there’s there are some wrinkles I can see. And wrinkles aren’t great. They make the fibers wavy. They’re less strong, less stiff. There’s no obvious dry bits. There’s no obvious bits where it’s not um stuck together. So, from the eyeball test, it’s not terrible, which is I’m more positive than I thought I was going to be. I’ll tell you what, let’s get back to GCN HQ then. Let’s get back into our set where it’s quieter and we can like properly delve into this and see see if it it might surprise you. You never know. Yeah, let’s do it. I I kind of want to see the video of you. have trying your hand. Yeah, I think that’s important as well. You need to see that. Thanks, Peter. Let’s go. Right, we’ve come inside. We’re going to kind of really have a deep dive now into whether this was successful or not. First though, I thought I’d just show Peter how I actually repaired this, just so you’ve got an idea of what happened and and what happened in the process. I mean, I’m excited just from the the description. Seems like it’s going to be fun. I’m just going to count the red flags as we go through. Yeah. Before I show you this, just remember I was in at the deep end here. Well, I wasn’t just in at the deep end. I was going over Niagara Falls without a paddle. Absolutely panic. Don’t worry, we’re in a safe space. Conor, no one’s watching. Okay, here we go. Everyone’s watching. It’s all right. I’ll play it. Yeah, it’s good to see the glasses, the mask, and the gloves. That’s a That’s a brownie point. Yeah. Once I got into it, the hole got bigger. And like that was thin. Like if I pushed my thumb in there, I’d have pushed my thumb through. Yeah. Yeah. There there’s there’s not going to be much more than a millimeter and a half on that area of the down tube. Power sander was a bold move. The power sander was me being a bit of a bodgege and trying to save time, but once I started I was like, “This is way too powerful.” But I’m I’m in it now. Was it the same gloves from before? Right. Different gloves. Different gloves. Okay. Yeah, different gloves. That was my alcohol wiping. The one you’ve been holding in your hand for like 3 minutes with all the alcohol flashing off. That was the one. That’s the one. That is a lot of resin. Yeah. So then, so this is the resin mixing. Um I basically just wanted to keep the ratios the same. So I knew that would be important. Yeah. And that’s right. That is really important. So I just did them all at once cuz I don’t want to make an error. Um I realized after that it happens quick and it also gets very hot. Yeah. Big amounts of epoxy mixed together aren’t super safe. The small pots, no problem. They don’t get too hot. The bigger the pot, the more that they’re in one tight bucket, that heat can get out of control really quickly. And the look on your face tells me that you learned that. I learned that. You learned that. I had the doors open. I had ventilation going through, but still like when I saw it smoking, I was like, that’s not good. Smoking epoxy isn’t nice stuff. Like you need to get that outside. Um they they tell you to mix it in small batches for that reason. Yeah, it’s not super safe to mix a big batch, so please don’t do that. Yeah, that was a big lesson learned. Sorry, everyone. That’s And then this is me putting the the carbon the twill on. How did you cut the carbon? I just use scissors. H. How’d that go? It was hard. I mean, it was easy, but it was like once you started cutting it, just it’s Yeah, it started fraying pretty easy. But already like the it frayed quite easy anyway on the edges. Yeah, I noticed earlier in the video you kind of unrolled it and sort of waggled it about a bit to kind of look at it, which is good. It looks cool. It’s really difficult to not have the fibers come apart. Um, and you you want to have that fabric as pristine as you can get it. The more you touch, the more you move it around, it’s it’s going to fray up on you. It’s tough. Um, to be honest, like it looks like you did an all right job at that. That was the hardest bit was the the frame. Then um I had a bit of drama with the paintbrush. The music’s not a very supportive choice by the edit team. Oh, they’ve absolutely rinsed me. They’ve not done you well there. Deservedly rinsed me. This is when the epoxy starts steaming. Smoking is the technical term. Then this is where it just went downhill from here. What were like the key red flags for you there looking at that process? um power sander in the hands of a non-composite expert. No offense. Um because it’s such a thin structure and you want to keep as much of that material in as you can, it’s really easy to sand through. Yeah. And end up taking off more than you want. Like you’ll see in some of the shots, you can see this like rippley look to it where Connor sanded through multiple layers of composite. Um hand sanding is far safer. It does take time, but if you’ve never done it before, it’s the only way that’s going to end. Okay. Okay. Like some of that sponginess you found was cuz you’d taken it back to the last couple of layers. Yeah. Um and I think unless you’re cutting out the whole tube, which you weren’t going to do, just use hand sanding to one. Um nowhere near enough cleaning. Okay. Um like one one alcohol wipe for an area of that size just isn’t enough. But you want to be wiping once, wiping again, and then let it all flash off. You want to do an alcohol wipe, and it comes off, and it is pristine clean. Like really, and that’s really different from loads of other stuff we do. Actually, handling the composite side of things, I think you’ve done all right. Like I to be really clear, I’m not going to ever ride that bike on the road. You’re not. No, for sure. For sure not. So, it’s a hard no. It’s a hard no. Okay. The down tube is one of the things that keeps my face off the floor. And with the best will in the world, you’ve done a decent beginner’s job. It’s my first job. It’s first job. And it it’s it’s a solid beginner’s job. Yeah. Can you just talk me through the coin like the you call it like a lowfi check, the the coin test. Just go through that cuz I am interested just to see just to take this to the limit and see if we can actually break this like how much it can withstand. Um, so I mean you were doing it in the video like you were tapping it with your nail and it sort of sounded different. Yeah. So the coin tap um which is a lowfi version of a test that is used in industry for really high um fidelity structures is you’re literally tapping it down and getting and listening to the sound. So up here it has a solid almost glassy sound. Yeah. Um, now let’s see. I reckon as you go across, still all right here. Decent there. Nice and hard. Softer, softer, softer. So, I think we need to get the the actual 50p out cuz the fingernail is not quite there. Okay. But anywhere where it sounds quieter or duller, it’s likely the layers are separated. Right. Let’s get the coin out then and have a look. So if we find a bit which we are pretty sure is good. Got a high pitch hard like almost ringing sound. And as you work your way down starts to change a little bit. And you’d expect that cuz that’s going to be super sick cuz it’s heavy stress. As you get down here it will thin out a little bit more. Then you get down into the damage bit and it changes and then hardens up again. You can hear that the pitch goes up and it rings a bit more, lower, quieter, and a bit more dead. So there’s a bit here I can get my fingernail behind where the uh super flat. Oh yeah, I hear that. Yeah, it it it doesn’t sound like a glassy super stiff material. It sounds soft. I think it’s still pretty soft up there. Really? Yeah. Yeah, for sure. No one rides outside. Not Not in like a jokey eyes. It’ be quite fun. Like, don’t put a human being on that. Really? It’s that it’s that bad. It’s It’s fine, right? ride it on the turbo. You’re not in any danger. Do not put them on the road. I think it’s one of those things like you’ve done a really good job for a first off. You really have like fair play. But it’s a good example. Just because you can do the repair, it doesn’t mean you should do the repair. Like a professional could repair this and it’d be safe and it’d probably be stronger than it was before, but they would have cut out a big section of that tube. And I think that’s that’s it. Like if you’re going to get a bike to repair, give it to someone who can repair it properly cuz composites can be repaired. If you want a turbo bike and an afternoon of fun, send it to Connor. Fill your boots. Yeah, we might not even have that at this stage. Let’s find out. All that area is bad composite. Okay. So, you would want that area repaired. Next up, Peter suggested we put the bike on a Wahoo Kicker. It sadly may not have been fit for the road in his eyes, but could it survive a series of max sprints indoors? I don’t reckon you’ll pop it in the sprint. No, you might get some a little bit of tinging, but I don’t think it’s going to throw you off, but that it’s because you have bits where it’s not bonded. So, the the the sleeve will gradually debond as you load the bike. That’s why I’m saying it’s a definite no for outside. Um, I might be wrong. Maybe you do have the megawatts and you can pop it. But I mean I kind of feel positive in a way like that was my takeaway as well that I felt I didn’t do that right. So I’m glad you’ve kind of backs that up. I should have gone further. Um but just seeing that big circle you made there and you telling me that is a bad composite does not fill me with much confidence before I do a max sprint trainer. Well I said earlier right you’ve done a pretty solid beginner’s job. You made a bunch of sensible decisions, but just without knowing a couple of important things. Yeah. But there’s no reason to feel bad about it. Most times you do something for the first time, you screw it up. Yeah. Well, I can kind of like No, you can’t. You You can imagine you can, but you can’t. You can’t. No, you can’t. Also, I’m not sure if I mentioned this before. This isn’t actually my size bike. It’s uh Alex or Ollie’s size. I was hoping they’d be the ones to test it on the road, not me. Um, but I can still get bit of beans on the turbo. So basic just go I’ll just go max sprint and like should I give it some here? Yeah. Yeah. Yeah. Okay. Yeah. Yeah. That is the kind of testing you can’t get in a laboratory. Should we go for a few more or should we have a look or just just give it give it a couple I reckon? Give it a couple. Yeah. Then give yourself a rest as well obviously. Right. You stand on the end. Stand on the trainer. Give it a bit of give it a real Come on, Connor. All right, that’s training done for the day. Yeah, definitely get a recovery shake. As you can tell, I’ve given it a series of max sprints. I’ve really gone for it. Never like actively tried to break my own bike like this before, so this is something new to me. But sprint’s complete. Let’s just take a look. Yeah. and see see if we can spot anything. It’s probably hasn’t moved. So, like we said, I don’t think you’re going to break it on the turbo. And to be honest, I mean, you gave it your best shot. I I think it would be fine as a turbo bike, right? That’s something. It’s It’s a And it’s a cracking turbo bike for not loads of money. And you’ve got a good story. that that is not great, but for what it’s for, for riding indoors, you could carry on riding that, I think, and you just every now and again bust out a 50p and check you’re not going to die. That’s and in terms of the road, it’s an absolute definite no. Yeah. If you think of it in this way, like anything in front of the bottom bracket is actively holding your face off the tarmac. Why would you do that to yourself? If it if you have a sudden failure this half of the bike, you are going down. If you have a failure on this half of the bike, you might be going down, but it’s probably going to be backside first. And that’s on you. If you need that in your life, fill your boots. I can’t say anything other than please don’t self-rep the front of a bike. If a professional repairs it, it’s almost certainly going to be ridable, stronger than it was before. That’s a good idea. You can do a repair yourself. You shouldn’t do a repair yourself on the front half of a bike. Okay, take it to a professional. There we go then. So, unfortunately, it’s a no. But I have made a nice turbo bike, which so at least I’ve salvaged something out of this. not in my size, but but anyway, um but Peter, it’s been absolutely fascinating to speak to you. Thank you so much for coming in and taking a look at this. Um it’s been also I found it really interesting delving into carbon fiber and how it works in our bikes and how easy is it to repair, I feel like I’ve learned so much and despite not actually making or getting this bike a new lease of life, it’s been really interesting to to delve into. Um, so yeah, I hope you found this video useful. If you have, please give it a big thumbs up. Let us know in the comments what you think as well. And also let us know, have you ever tried to repair a carbon fiber frame yourself? And if you have, love to hear from you. Um, but for now, if anyone wants a turbo bike, drop us a message. There you go. Thanks, Colin. I don’t reckon you should ride it on the road. I definitely wouldn’t. But hey, good video content is your job. It would be cracking video. Sorry guys, I’m not I’m not riding this on the road. Not after talking to Peter.
48 Comments
It was a rollercoaster of stress and sticky epoxy, but we got there in the end! After seeing the whole process and the expert's final verdict, would you be tempted to use the frame on an indoor trainer? Let us know your thoughts in the comments
Upload it to hack or bodge for the gcn show
I would want the bike 🙏
You could have asked easy composites how to do it. Or even just looked at some of their videos. Then you would have succeeded. You were 80% there, just missed some simple methods.
How much would a professional repair cost?
Is the "Look" lettering stickers or painted on, if its stickers just peal them off before you start sanding the black paint of the frame.
I would absolutely want that checked out.
Should have had the professional opinion first to guide the process first before making the repair.
15:24 I work with engineers. "The power sander is a bold move" means "That was a huge mistake" 😅
This is the most relatable DIY video I’ve ever watched 😂
I repaired my cube with a kit off eBay it cost me about £40 for all the bits and saved me a fortune. It's sound and after a full respray you can't tell it's been done.
Interesting Topic. I was curious
I expect that the flexing is not just due to a crack but the delamination of the layers of the carbon fibre sheet.
This is the most interesting I've watched.
I think a good next step would be to take it to a professional repair shop and have them diagnose Connor’s repair. Then find out what it would be to fix the amateur repair and make it a safe bicycle.
The direction of the carbon weave is the essential in the strength of the final product. Layered carbon perpendicular or bidirectional is the way to go in higher loaded areas.
Can you do a follow up where you go to Peter’s workshop and do it properly
Sorry… but I’m not interested in doing 40kph on that thing. 😮 Even on a turbo. Call me a coward.
9:03 I wasn't using my ears anymore anyway.
Have done a lot of epoxy (glass & carbon) repairs for my boat. While this is entertaining and interesting, there is a super simple method of DIY repair that you can do which will be safe: just use more carbon over a longer stretch of the frame. It will be stronger than new that way. If you want to be a bit more precise, I would use unilateral fibre on the downside of the tube, as most of the forces will be pulling the downtube apart. There is unilateral carbon tape that’s even a lot easier to handle. You could even combine that with winding the length of the tube with unilaterial carbon tape going round the tube afterward, even clockwise and anticlockwise.
FIrst put resin on the tube, put the length piece in, wind the next piece(s) around and then put very stretchy plastic tape around to squeeze the carbon together. Stronger than new, that way. The frame will end up a few grams heavier, but who cares for that price…
Tarrifs are going to make this go viral……everyone is buying used/new from in country as the 1,000 tarrifs aren't worth it anymore…
Love it, REPAIR CARBON
Bike frame turned into an _ _ OK frame. Solid attempt and a good lesson for all of us. Its possible, its not without potential hitches.
I bet connor could still repair it with a second go. Same process with a bit more experience.
Great video Connor as always but if there is one resounding message from all this…..I love my Steel bikes even more than I did before!
As someone who works with composites for a living that was hard to watch, lol. Should drill a hole at the end of the cracks to stop them tracing as well.
If you want a propper stress test get it in the hands of Sam Pilgrim
hack/bodge?
Repaired my chain stay on a Caonnondale Super Six Evo. No problem 2 layers of uni 3 layers of twill. Hand sanding is the only way to go. Transitions are the killer and they are the bits the pros do really well. Broken frames should be repaired by the pros. Dr Peter Giddings delivered some sound advice.
So maybe buy 3 frames… 2 for practice and one to repair
suggestion: get a professional to repair it for the next episode
Lol the exotherm
For a performance bike you really need to replicate the original layup with UD and woven to get it back to proper stiffness and strength
GCN always top notch and helpful content. This one scares me! Frame could have been a warranty replacement and may have legal implications selling it. Would make a perfect high-end Zwift or other dedicated trainer. No 30mph decents for me on this. Be safe out there! And keep on mind, for every Crack you see there could be 10 more you don't.
“It doesn’t look that bad”- and gives his hysterical laugh. We all knew where it went from there 😂😂😂
I have an aluminium mtb with a section of the top tube replaced with 3D printed PLA plastic and epoxyed into the frame 😅. I expected it to break on the first ride but I kept checking it and giving it more abuse. After pulling a bunch of endos, and riding down stairs I've gained enough confidence that it's perfectly safe to ride as a normal mtb! I will of course keep checking it multiple times each ride. I wouldn't recommend anyone else to do this, but it was a fun project.
Great video. Gives us carbon owners and bike mechanics some cool options to bring a frame back from certain death!
Holy exothermic reaction, Batman! Time to call Ollie in to consult!!!
Anyone doing this work would behoove themselves to wear more robust and appropriate respiratory protection. That mask is not adequate. There are better mask/filter combinations that will prevent air blow-by in the fit interface. Not only a better seal, but will allow the user to CONFIRM it's air-tight. You don't want to be inhaling any of these particles.
Additionally, I'd use a HEPA filtration "Shop Vac" to suck up the vast majority of the sanding dust you're creating while doing the work. Letting it blow away to your neighbor's house isn't very nice. And filing your shop with this fine dust isn't good either.
The moment you fixed on a power sander I feared for your outcome. While yours was was not positive, I think I learned a lot from your failure. In some ways, wasn’t that the point? Hand sanding, cleaning extra—above and below, multiple small batches, extra sanding to facilitate adherence of new layers…. Saving a good frame to keep it from being thrown out as junk is worth the extra time. I’ll be sure to take the extra time.
Please, please, please do not attempt this unsupervised! There were so many mistakes and only a few were mentioned. I have spent the past 15 years repairing frames like this professionally and there is no safe way to do this on a hobby level. To start, the coin test will only give an indication of structural integrity but isn’t 100 %. When this downtube fails the toptube will go as well. In all likelihood, this will happen when the frame is under higher stress than on that trainer (i.e. during a fast decent). I can’t stress enough how unsafe trying something like this is.
'Good job' in British English means you've failed miserably
I would love that as a turbo bike! If you're actually looking to part with it, reach out!
I want to hear the story of the wreck/damage that cracked the frame.
This was a crackin’ video. Super informative
$20 is a bargain, I regularly see cracked frames for 300-800 dollars on marketplace. Always think it's crazy …
Bike looks so cool. Might purposely crack my frame and do a dodgy fix on it to replicate the aesthetic. 😆
Could the repair be repaired? By wrapping more carbon fiber further up and down the frame and covering the whole repaired area?
Could be a subsequent video where the process is repeated with the lessons learned and the supervision of a professional?
Would be interesting to see but GCN might not want to go in that direction to avoid people trying it at home which would be understandable!
Very interesting video though, thank you Conor!
Conner – you have a composites professional to quiz – and you do it after you ruined the bike.
If you had consulted him before – instead of Alex and Ollie you might have actually fixed it properly and been able to show us how.
Connor, great putting yourself out there. Good form.
For your first time repairing the frame it looks good. From which site you bought the frame?