Dropped bike. Damage to carbon or just lacquer?

paulmon
paulmon Posts: 315
edited July 2019 in Workshop
My bike fell onto my bike stand yesterday. The main impact was the top tube onto the stand. Looking at the damage I cant make my mind up if its just paint and lacquer or the carbon itself? If its just the paint then I'll get some lacquer from Halfords and go over it.

32313008427_b437df2e7e_k.jpgTop tube. Middle by Paul Monaghan, on Flickr
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Comments

  • Alejandrosdog
    Alejandrosdog Posts: 1,975
    Ouch, spend £50 couriering too and from a carbon repair specialist and see what they say. It looks like quite a bash
  • cougie
    cougie Posts: 22,512
    Doesn't look that superficial from the photo I'm afraid. But can at least be repaired very easily.
  • shiznit76
    shiznit76 Posts: 640
    Looks fair bash to just have fallen on to the stand. Is it indented? Certainly looks more than just paint work damage
  • paulmon
    paulmon Posts: 315
    shiznit76 wrote:
    Looks fair bash to just have fallen on to the stand. Is it indented? Certainly looks more than just paint work damage

    Nope no indentation. There is someone local to me http://www.targetcomposites.co.uk/ so I'll get in touch and see what they say.
  • Matthewfalle
    Matthewfalle Posts: 17,380
    thats just paint and lacquer. its fine.
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • imposter2.0
    imposter2.0 Posts: 12,028
    Difficult to tell from that pic. It certainly isn't yer average 'ding', that's for sure. Worth taking a closer look...
  • bonzo_banana
    bonzo_banana Posts: 256
    Carbon frames in theory don't suffer from fatigue but many carbon frames suffer from manufacturing imperfections which effectively cause fatigue as a small crack or void gradually worsens. These sort of dings/impacts can also be the start of such fatigue too if there is a small crack. On metal frames the top tube is often the thinnest weakest tube as its not as critical to the integrity of the frame. It's more about preventing the seat tube and downtube/headtube collapsing together and the higher the toptube is the weaker it can be. It's mainly under a compression force I believe due to the weight of the rider pushing down towards the bottom bracket area. Unfortunately this is one of the big issues with carbon it is a very brittle material so despite its great strength is very vulnerable to such impacts. I would take it seriously and if you look in your manual you should find text stating any accident involving a carbon frame should be inspected by your dealer or a qualified expert in carbon frames. I've read the text in a Giant manual and while you can inspect other materials for damage yourself and asses it but that isn't allowed for carbon at all. Some structural damage can be caused without any visible sign on the surface I believe. Ideally the bike should be completely dissembled to a bare frame and then scanned. Remember when a carbon frame or forks fail they can fail without any prior warning, it is by far the least safe material to ride.
  • imposter2.0
    imposter2.0 Posts: 12,028
    Bonzo Banana wrote:
    it is by far the least safe material to ride.

    If this sentence was at the start of your post, I'd have stopped reading. Unfortunately, it was at the end...
  • rafletcher
    rafletcher Posts: 1,235
    Imposter wrote:
    Bonzo Banana wrote:
    it is by far the least safe material to ride.

    If this sentence was at the start of your post, I'd have stopped reading. Unfortunately, it was at the end...

    Ditto. Tho' TLDR...

    Carbon lay-ups are multi-directional in several layers. The damage is, at worst, superficial damage to an outer layer, and it's in a position where the stresses will not work to worsen it. I'd clean it up and lacquer it and keep on riding.
  • thegreatdivide
    thegreatdivide Posts: 5,807
    Imposter wrote:
    Bonzo Banana wrote:
    it is by far the least safe material to ride.

    If this sentence was at the start of your post, I'd have stopped reading. Unfortunately, it was at the end...

    Bongomunchbanana strikes again!

    OP - I'm in the superficial camp too, but if it's concerning you go and get it checked out.
  • imposter2.0
    imposter2.0 Posts: 12,028
    thegreatdivide wrote:
    Bongomunchbanana strikes again!

    Bongobananamuncher?
  • Alejandrosdog
    Alejandrosdog Posts: 1,975
    Bonzo Banana wrote:
    Carbon frames in theory don't suffer from fatigue but many carbon frames suffer from manufacturing imperfections which effectively cause fatigue as a small crack or void gradually worsens. These sort of dings/impacts can also be the start of such fatigue too

    So, is there fatigue or is there not?
  • Alejandrosdog
    Alejandrosdog Posts: 1,975
    Imposter wrote:
    thegreatdivide wrote:
    Bongomunchbanana strikes again!

    Bongobananamuncher?

    Bongobutmuncher
  • pippi_langsamer-2
    pippi_langsamer-2 Posts: 1,470
    If Target are local to you, no harm in trundling down there for their appraisal.

    Looks fairly superficial to me too. Maybe it just needs sanding back lightly a bit and re-coating.
  • thegreatdivide
    thegreatdivide Posts: 5,807
    Imposter wrote:
    thegreatdivide wrote:
    Bongomunchbanana strikes again!

    Bongobananamuncher?

    Him, not you.
  • thistle_
    thistle_ Posts: 7,217
    PaulMon wrote:
    Nope no indentation. There is someone local to me http://www.targetcomposites.co.uk/ so I'll get in touch and see what they say.
    Never used them but Target have a good reputation. Even if there's no structural damage they can probably make it nice again.
  • imposter2.0
    imposter2.0 Posts: 12,028
    thegreatdivide wrote:
    Imposter wrote:
    thegreatdivide wrote:
    Bongomunchbanana strikes again!

    Bongobananamuncher?

    Him, not you.

    I was just suggesting a modified name - I know you didn't mean me.. ;)
  • paulmon
    paulmon Posts: 315
    Here is another photo which give some idea of how small the impact area is. I've sent an email to target and await their reply.
    32336947927_67c8692144_k.jpg20190304_085226 by Paul Monaghan, on Flickr
  • imposter2.0
    imposter2.0 Posts: 12,028
    The second pic looks a lot less serious than the first - if that's an accurate representation, then it looks like just superficial paint damage..
  • bonzo_banana
    bonzo_banana Posts: 256
    Alejandrosdog wrote:
    Bonzo Banana wrote:
    Carbon frames in theory don't suffer from fatigue but many carbon frames suffer from manufacturing imperfections which effectively cause fatigue as a small crack or void gradually worsens. These sort of dings/impacts can also be the start of such fatigue too

    So, is there fatigue or is there not?

    That was my point if there is some minor imperfection in the carbon due to manufacturing that can act as a fatigue fault because as you use the frame that imperfection might increase in size. However without an imperfection it doesn't fatigue. Carbon frames are handmade layer by layer so there is ample opportunity for imperfections. The best source of info is Luescher Technik on youtube who explains it very well despite being a huge fan of carbon.

    I really don't get the debate with stating carbon fibre is the most dangerous material, it's clearly a low weight performance material often with shorter warranties and lower weight limits. The material may fail without warning which is why it is the most dangerous frame material and may not necessarily have visible faults on the outside. It's difficult for someone to scan their own frame to check frame integrity. Why is this even debatable it's a well established fact that surely apart from moronic internet warriors needs no further explanation. Also to see childish name calling in a thread of presumably adult people not five year olds is in my opinion pathetic but there you go.

    From the British cycling organisation;
    Resistance to accidental knocks and the effect of apparently minor scratches and dings on structural integrity can be a concern.

    Can break suddenly (if weakened) without warning. Particularly prone to those of us who can be over zealous with an allen key.

    https://www.britishcycling.org.uk/knowl ... aterials-0
  • imposter2.0
    imposter2.0 Posts: 12,028
    Bonzo Banana wrote:
    I really don't get the debate with stating carbon fibre is the most dangerous material, it's clearly a low weight performance material often with shorter warranties and lower weight limits. The material may fail without warning which is why it is the most dangerous frame material and may not necessarily have visible faults on the outside.

    Sorry, but this is just ignorant nonsense. As with any other material, it depends on how it is built. As a case in point, F1 racecar chassis and Boeing 787 airframes rely almost entirely on CF for their strength and integrity. I can't be bothered to go on - it's such an utterly stupid comment, it's simply not worth debating..
  • webboo
    webboo Posts: 6,087
    They’ll be burning weaving machines next.
  • timothyw
    timothyw Posts: 2,482
    Straw poll then - how many people ride bikes with carbon or carbon bladed forks?

    And how many people have had those forks fail?

    Not a dangerous material.
  • cougie
    cougie Posts: 22,512
    Is Bonzo MileMuncher ?
  • mr_mojo
    mr_mojo Posts: 200
    PaulMon wrote:
    shiznit76 wrote:
    Looks fair bash to just have fallen on to the stand. Is it indented? Certainly looks more than just paint work damage

    Nope no indentation. There is someone local to me http://www.targetcomposites.co.uk/ so I'll get in touch and see what they say.

    I’ve used Target Composites for a repair to a Colnago C40. Excellent repair and excellent company to deal with.
  • lesfirth
    lesfirth Posts: 1,382
    cougie wrote:
    Is Bonzo MileMuncher ?
    If he isn't ,he is another that should be ignored.
  • thegreatdivide
    thegreatdivide Posts: 5,807
    lesfirth wrote:
    cougie wrote:
    Is Bonzo MileMuncher ?
    If he isn't ,he is another that should be ignored.

    He’s one and the same. I think he’s running four, possibly five live accounts at the moment and the Mods (if there’s such a thing anymore) have done nothing much about it.
  • Alejandrosdog
    Alejandrosdog Posts: 1,975
    thegreatdivide wrote:
    lesfirth wrote:
    cougie wrote:
    Is Bonzo MileMuncher ?
    If he isn't ,he is another that should be ignored.

    He’s one and the same. I think he’s running four, possibly five live accounts at the moment and the Mods (if there’s such a thing anymore) have done nothing much about it.
    Sometimes he argues with himself :lol:
  • shirley_basso
    shirley_basso Posts: 6,195
    Dunno. BB has posted some quite sensible stuff elsewhere. It's hard to keep track of who the lunatics are around here.
  • Wayne Plunger
    Wayne Plunger Posts: 444
    Target did a repair on my Orbea last year, not cheap by any means but did a good job on accident damage by the BB.

    Always appears to be busy and an average lead time was 4-6 weeks when mine was fixed.

    Forgot to add, if a repair is required he will only want the frame, you will have to strip everything off it.

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