[Closed] Paint or tube crack?

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

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

looks like a crack starting to me!!

what frame is it ??

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.

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

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....

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

Tis an ST4

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.

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

*goes off to carry on riding*

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.

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.

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.

Agree's with Dusty.

That is quite clearly just a crack in the paint.

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

luke - ygm

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

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 😀

'a bit of flex and the paint cracks'

Every one will have done it then?

Leave it, eh...

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

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

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.

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.

I have felt for ripples already - nothing.

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 😀

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.

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

Go and ride somewhere dry and dusty

bruneep, Is it still that bad? 😯

Go and ride somewhere dry and dusty

hmmm I see a flaw in your plan

Aye, its p*ss*ng down today...!

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

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....

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

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'.

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.