Damage to carbon frame

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ChrisS
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Damage to carbon frame

Post by ChrisS »

So there I am, giving my bike it’s final clean and check before the highland trail, take it out of the stand, lean it against the wall, turn round and it falls over :roll:

It hit a concrete edge on a small wall, taking a small chunk out of the top tube and another deep scratch out of one of the seat stays. :cry: :cry:

So how bad is it? No cracking - the stay damage looks like scratching and the top tube damage is rough feeling like a couple of chips of the carbon came out. Worse damage I’ve done to my frame in three years! Flippin annoyed!

Is it likely to have affected the integrity of the carbon or just cosmetic?
redefined_cycles
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Re: Damage to carbon frame

Post by redefined_cycles »

What frameset is it please Chris?? Not all are created equally and alot can depend on he initial weight aswell..

Any pics of the damage??

(Sorry for the situation btw)
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Alpinum
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Re: Damage to carbon frame

Post by Alpinum »

A read through this (if you haven't already) may give you a fee hints on how to inspect the damage.
Of course we're no experts, but some of the advice like checking on the sound when knocking on the damage, checking if the damaged area is soft under pressure etc. is what I learned from folks who are involved in design and manufacture or fixing carbon frames.

viewtopic.php?f=7&t=19650&hilit=M%C3%A4se

Good luck and hopefully loads of fun with your bike on the HT550.
redefined_cycles
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Re: Damage to carbon frame

Post by redefined_cycles »

Just to add to the 'pressing down'... if it feels soft then don't press anymore and it's a surefire indication it needs repairing/expert help.

There's a youtube chap from Australia (luescher I think), called carbon fibre repair. Expert in that field and you'd learn loads from him.

As a general rule, carbon isn't as soft as what we've always been lead yo think and just falling over (unless it's some super special weight weenie bike) shouldn't cause it that much issue. If you look through my history Chris you'll notice that I took a hammer and dremel to mine and a couple of carbon blades... Couldn't actually break it properly (Sonder Transmitter carbon which was at about 1100g for the frame) and ended up giving up. You'd be surprised how strong these things are
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ChrisS
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Re: Damage to carbon frame

Post by ChrisS »

redefined_cycles wrote: Fri May 14, 2021 12:42 pm What frameset is it please Chris?? Not all are created equally and alot can depend on he initial weight aswell..

Any pics of the damage??

(Sorry for the situation btw)
Merida big nine. I have a pic which I’ll try to upload. Certainly doesn’t feel soft when I push on it.
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ChrisS
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Re: Damage to carbon frame

Post by ChrisS »

Alpinum wrote: Fri May 14, 2021 12:48 pm A read through this (if you haven't already) may give you a fee hints on how to inspect the damage.
Of course we're no experts, but some of the advice like checking on the sound when knocking on the damage, checking if the damaged area is soft under pressure etc. is what I learned from folks who are involved in design and manufacture or fixing carbon frames.

viewtopic.php?f=7&t=19650&hilit=M%C3%A4se

Good luck and hopefully loads of fun with your bike on the HT550.
Thanks will have a read right now.
redefined_cycles
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Re: Damage to carbon frame

Post by redefined_cycles »

ChrisS wrote: Fri May 14, 2021 12:59 pm
redefined_cycles wrote: Fri May 14, 2021 12:42 pm What frameset is it please Chris?? Not all are created equally and alot can depend on he initial weight aswell..

Any pics of the damage??

(Sorry for the situation btw)
Merida big nine. I have a pic which I’ll try to upload. Certainly doesn’t feel soft when I push on it.
In that case, FWIW and my experiment with the Sonder (it was unrideable anyway so in the interests of market research) I'd ride that (your Merida). Won't tell you what else i ride in carbon flavour that's scuffed :-bd
Lazarus
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Re: Damage to carbon frame

Post by Lazarus »

Carbon is bloody strong so its all down to whether its structural or top coat - iwouldbe surprised if that damged it personally

Having thumped a broken on one frame* - others have had a few swings as well - thry cn take some serious impacts
Good luck and hope its fine


* seat clamp areaso it creaks I wasswinging it over my head hitting the ground and bricks as hard as i could.I got bored after about 10 goes.
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UnderTheRadars
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Re: Damage to carbon frame

Post by UnderTheRadars »

A few years ago now I had good fun trying to smash up prototype and warrantied carbon frames for the skip. Swinging them against the side of the skip with my full strength did surprisingly little damage at first.

Was as shame that I couldn't have one or two
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ChrisS
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Re: Damage to carbon frame

Post by ChrisS »

Ok I’m feeling a bit better now after reading these comments... the force wasn’t that great as the bike just toppled and hit an edge about half a metre away. The cosmetic damage is annoying but I’ll get over that. Luckily it’s invisiframed so that’s protected it a bit. There’s definitely no softness at all when I push at the damage.
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fatbikephil
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Re: Damage to carbon frame

Post by fatbikephil »

Would it not have just chipped the gel coat over the carbon tube = no damage to fibres so no structural issues?
I'd be tempted to fill the chip in with araldite as much for cosmetics as anything else.
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Re: Damage to carbon frame

Post by redefined_cycles »

htrider wrote: Fri May 14, 2021 2:42 pm Would it not have just chipped the gel coat over the carbon tube = no damage to fibres so no structural issues?
I'd be tempted to fill the chip in with araldite as much for cosmetics as anything else.
According to onw of the carbon repair shops (as read in Rouleur years ago) its nail varnish. Tha way you can keep an eye on the area cos if you start getting any problems in the rigid/stiff carbon it'll show up as a crack/hairline crack in the nail varnish uaed as top coat. I imagine some clear oil based laquer might do a similar job...
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ChrisS
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Re: Damage to carbon frame

Post by ChrisS »

htrider wrote: Fri May 14, 2021 2:42 pm Would it not have just chipped the gel coat over the carbon tube = no damage to fibres so no structural issues?
I'd be tempted to fill the chip in with araldite as much for cosmetics as anything else.
Yeah I think so. I'm going to tape over it anyhow as it's where one of my framebag straps goes. Once I'm back from the HT I'll probably need to peel off the invisiframe wrap and then see if I can improve it cosmetically. Decided not to worry about it right now!
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ChrisS
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Re: Damage to carbon frame

Post by ChrisS »

ChrisS wrote: Fri May 14, 2021 4:08 pm
htrider wrote: Fri May 14, 2021 2:42 pm Would it not have just chipped the gel coat over the carbon tube = no damage to fibres so no structural issues?
I'd be tempted to fill the chip in with araldite as much for cosmetics as anything else.
Yeah I think so. I'm going to tape over it anyhow as it's where one of my framebag straps goes. Once I'm back from the HT I'll probably need to peel off the invisiframe wrap and then see if I can improve it cosmetically. Decided not to worry about it right now!
Noted thanks :-bd
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stevenshand
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Re: Damage to carbon frame

Post by stevenshand »

redefined_cycles wrote: Fri May 14, 2021 12:56 pm If you look through my history Chris you'll notice that I took a hammer and dremel to mine and a couple of carbon blades... Couldn't actually break it properly (Sonder Transmitter carbon which was at about 1100g for the frame) and ended up giving up. You'd be surprised how strong these things are
I've seen this and similar comments before and it's worth mentioning that checking the strength of something by hitting it with a hammer doesn't really tell you much about how strong it is other than the ability to withstand being hit with a hammer. Those kind of forces don't really fall into the category of failure modes in the bicycle world.

Bicycle frame testing is mainly about fatigue testing. You deflect part of the frame (ideally in a way that is similar to pedalling forces) thousands of times or until it fails (breaks/cracks/whatever).

I'd struggle to break a paperclip with a hammer but it wouldn't take long for me to break it by repeatedly bending it.

I'd be willing to place a very large bet that if you take a chip out of your top tube then the frame will fail sooner than one without the chip if both frames are subjected to the same fatigue testing, I'm not saying it will break in normal use anytime soon however. It may be that the damaged frame survives a loading cycle many thousands of times, perhaps equivalent to many tens of years of riding.

I obviously can't speculate if your frame is going to break or not but I do think it's important to differentiate the difference between being able to withstand being hit with a hammer and breaking while riding.
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Re: Damage to carbon frame

Post by redefined_cycles »

Thanks for that insight Steven :smile:
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Cheeky Monkey
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Re: Damage to carbon frame

Post by Cheeky Monkey »

stevenshand wrote: Fri May 14, 2021 4:52 pm
redefined_cycles wrote: Fri May 14, 2021 12:56 pm If you look through my history Chris you'll notice that I took a hammer and dremel to mine and a couple of carbon blades... Couldn't actually break it properly (Sonder Transmitter carbon which was at about 1100g for the frame) and ended up giving up. You'd be surprised how strong these things are
I've seen this and similar comments before and it's worth mentioning that checking the strength of something by hitting it with a hammer doesn't really tell you much about how strong it is other than the ability to withstand being hit with a hammer. Those kind of forces don't really fall into the category of failure modes in the bicycle world.

Bicycle frame testing is mainly about fatigue testing. You deflect part of the frame (ideally in a way that is similar to pedalling forces) thousands of times or until it fails (breaks/cracks/whatever).

I'd struggle to break a paperclip with a hammer but it wouldn't take long for me to break it by repeatedly bending it.

I'd be willing to place a very large bet that if you take a chip out of your top tube then the frame will fail sooner than one without the chip if both frames are subjected to the same fatigue testing, I'm not saying it will break in normal use anytime soon however. It may be that the damaged frame survives a loading cycle many thousands of times, perhaps equivalent to many tens of years of riding.

I obviously can't speculate if your frame is going to break or not but I do think it's important to differentiate the difference between being able to withstand being hit with a hammer and breaking while riding.
You're going to ruin everybody's fun if you keep coming on here with your informed and balanced opinions based on experience and knowledge :wink: :wink:
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Re: Damage to carbon frame

Post by Lazarus »

I'd struggle to break a paperclip with a hammer
Weakling :wink:

Great post though.
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stevenshand
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Re: Damage to carbon frame

Post by stevenshand »

Cheeky Monkey wrote: Fri May 14, 2021 5:13 pm You're going to ruin everybody's fun if you keep coming on here with your informed and balanced opinions based on experience and knowledge :wink: :wink:
I'm sorry, I forgot where I was for a moment. I will stick to inflammatory, ill-informed posts from now on.
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Re: Damage to carbon frame

Post by voodoo_simon »

Reminds me of this, those unbreakable (is that a word?) phone case that are solid without a phone in them

https://youtu.be/VAsa3EZmahE
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Re: Damage to carbon frame

Post by Cheeky Monkey »

stevenshand wrote: Fri May 14, 2021 5:47 pm
Cheeky Monkey wrote: Fri May 14, 2021 5:13 pm You're going to ruin everybody's fun if you keep coming on here with your informed and balanced opinions based on experience and knowledge :wink: :wink:
I'm sorry, I forgot where I was for a moment. I will stick to inflammatory, ill-informed posts from now on.
:lol: :lol:

Always good to hear stuff though, everyday (can be) a school day :-bd
ScotRoutes
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Re: Damage to carbon frame

Post by ScotRoutes »

Always worth a re-post

https://www.youtube.com/watch?v=w5eMMf11uhM


FF to 5:00 to skip the "scientific" bits :-)
redefined_cycles
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Re: Damage to carbon frame

Post by redefined_cycles »

ScotRoutes wrote: Fri May 14, 2021 8:04 pm Always worth a re-post

https://www.youtube.com/watch?v=w5eMMf11uhM


FF to 5:00 to skip the "scientific" bits :-)
Thanks so much Colin. My Highball is coming at some point this month (won't be able to ride it for a good year though as I save and buy parts) hopefully. This vid just bought a smile to my face as did my Superlight of yesteryear (last nice full sus I owned).
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