Viewing 37 posts - 1 through 37 (of 37 total)
  • Paint or tube crack?
  • matt_outandabout
    Full Member

    The bike is an insurance replacement, so no LBS to fall back on 🙁 I have sent two emails to the supplying company but got no response.

    Should I be worried, or is this just paint cracking? Clicky for huge.

    DustyLilac
    Free Member

    Looks to me like there's no weld there to crack?

    druidh
    Free Member

    That's not actually a weld, is it? I'd have said that's just paint

    renton
    Free Member

    looks like a crack starting to me!!

    what frame is it ??

    Dimmadan
    Free Member

    May be a bit of a pain in the arse but looks like you may be able to see from the other way up if you remove that part of the linkage.

    I wouldn't like to say on that without a better look, but the welds are in the direction of the applied force so there is no weld where the crack is.

    Rockhopper
    Free Member

    There is no weld there so i think its just the paint thats cracking.

    clubber
    Free Member

    Looks lik a crack I'm afraid. Try painting some paint or tippex across the "crack", let it dry and then ride it. If the new paint crack then….

    mushrooms
    Free Member

    Looks like paint to me.
    There could be movement in that area as it's not welded or stuck on in any way??

    Guybrush
    Free Member

    Tis an ST4

    singlespeedstu
    Full Member

    I'd say it's just the paint as there's clearley no weld there to crack.

    Scrape the paint off a bit for a closer look if you're not sure.

    matt_outandabout
    Full Member

    I thought it looked like paint – made little sense as it wasn't welded etc there….

    *goes off to carry on riding*

    kempfab
    Free Member

    I would say frame crack too. Paint would only crack if two parts were moving apart, ie the tube has cracked between the two weld ends.

    Good luck with the supplier.

    DustyLilac
    Free Member

    I would say frame crack too. Paint would only crack if two parts were moving apart, ie the tube has cracked between the two weld ends

    The shock bracket is only welded down the sides and is merely touching the tube where the 'crack' is, a bit of flex and the paint cracks. If the bracket were to be welded all the way around it would create a weak point. Gussets are often only partly welded for the same reason.

    bent_udder
    Free Member

    Have you talked to Orange?

    Mind you, your contract is with the original supplier you mention earlier. If they're unwilling to help out, it might be worth calling Trading Standards and asking their advice.

    singlespeedstu
    Full Member

    Agree's with Dusty.

    Smee
    Free Member

    That is quite clearly just a crack in the paint.

    rolfharris
    Free Member

    Matt- please can you e-mail me? I'm keen to have a go at riding your local trails some time soon.

    matt_outandabout
    Full Member

    luke – ygm

    knott4me
    Free Member

    paint crack .a dremmel & some white touch up should give you piece of mind though.

    nuke
    Full Member

    I'd say paint.

    Right, no engineer (clearly) but bear with me: this shock mount is on the top of the downtube and, as the shock compresses, the force is going to be transferred downwards on to the top of the tube and 'bend' the downtube downwards. Therefore if the force was sufficient to crack wouldn't the crack be on the underside?

    Awaits flaming 😀

    kempfab
    Free Member

    'a bit of flex and the paint cracks'

    Every one will have done it then?

    Leave it, eh…

    djglover
    Free Member

    surely paint doesn't crack unless something beneath has cracked, as I recently found out on my commencal (a similar design..)

    TheSwede
    Free Member

    Metal flex's, hard coat gloss paint does'nt. Unless its that new fangled elastomer polymer witchcraft.

    DustyLilac
    Free Member

    kempfab, read the other bits I wrote too…

    I'm not surprised the OP is concerned, any kind of crack needs to be thought about and investigated, but from what I can understand from his photo the shock bracket is not physically joined in any way to the downtube where the crack is, the welds are down the sides only. The paint will have filled a small gap and then cracked as the frame has flexed (quite normally).

    For peace of mind then careful paint removal as already suggested.

    hora
    Free Member

    djglover, a commencal cracking? Noooo? 🙄 😛

    I say paint although agree something else has moved to cause that 'vibration'. What is wierd though is the side welds are bloody strong looking. Remove the linkages and bolts and feel the walls of the tubes for slighy ripples etc.

    matt_outandabout
    Full Member

    I have felt for ripples already – nothing.

    kempfab
    Free Member

    Dusty Lilac, I am fully appreciate what you are saying, but IMO I doubt that the bracket and tube would have enough room to 'move' in normal frame flex, to crack the paint, so close to the welds. I believe that bracket is on the downtube(?), so a thorough investigation is clearly advised.

    I do hope it is just paint tho 😀

    WTF
    Free Member

    I would say paint ,maybe the "crack" is the paint not adhering at the joint due to contamination prior to painting.
    Paint needs removed for proper inspection/crack testing.

    stratobiker
    Free Member

    Try this……….

    Spray it with some GT85.
    Wipe it off completely. Make sure you wipe it all off.
    Go and ride somewhere dry and dusty.
    If it's a crack the frame will be venting through it. You'll find dust sticking/building up along the crack edge (stuck to the GT85 that entered the crack).
    That's how I proved my old Ti frame was cracked.

    Hope yours isn't BTW.
    SB

    bruneep
    Full Member

    Go and ride somewhere dry and dusty

    hmmm I see a flaw in your plan 😉

    stratobiker
    Free Member

    bruneep, Is it still that bad? 😯

    matt_outandabout
    Full Member

    Go and ride somewhere dry and dusty

    hmmm I see a flaw in your plan

    Aye, its p*ss*ng down today…!

    stratobiker
    Free Member

    matt,
    Sorry to hear that. It's baking hot and sunny here. I just assumed it was everywhere. 😉

    matt_outandabout
    Full Member

    bugger – Loch Tay has risen by 1m in a night, second week on the trot. So that's 10km3 of water in a week….not accounting for how much goes out the River Tay….

    Onzadog
    Free Member

    How old is it? if it's not that old, I'd be annoyed at the paint cracking if that's all it is.

    stuey
    Free Member

    Along Stratobiker line of thinking – but pour some 'oil' in the seat tube, hang/stand the bike up – and see if the oil gets out through the 'crack'.

    Inbred456
    Free Member

    We use this method at work, but you can easily do this at home.
    http://en.wikipedia.org/wiki/Dye_penetrant_inspection

    FWIW from experience I would say the paint has cracked due to the Material underneath flexing. If it was my bike I'd leave it alone. The weakest part of that structure is where the weld joins the frame and there are no cracks around that area.

    Obviously you would need to put the dye penetrant on the inside of the tube, if its cracked it will creep through.

Viewing 37 posts - 1 through 37 (of 37 total)

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