what's a hairline crack? and do I have one!?
- Thread starter jim m
- Start date
Ellsworth crack?
pic of the crack available here - it's across the bottom edge of the inside weld, opposite the hole
http://jim713.fotopic.net/c1592139.html
pic of the crack available here - it's across the bottom edge of the inside weld, opposite the hole
http://jim713.fotopic.net/c1592139.html
cows_in_cars
Old School Hero
- Feedback
- View
Sadly I would say, yes thats a crack.
I would ecco the comments above, Ellsworth do have a reptation for cracking swing arms.
I knew someone who cracked the chain stay on his Ellsworth Truth at least 3 times.
Bad luck
I would ecco the comments above, Ellsworth do have a reptation for cracking swing arms.
I knew someone who cracked the chain stay on his Ellsworth Truth at least 3 times.
Bad luck
It may be my eyes are going but that's nothing like I've ever seen.
A (fatigue) crack should have a starting point, or initiation point. Usually there's a clear anomaly or at least a stress concentration factor: a weld flaw, an inclusion, a hole, a machined surface, a gouge or other damage to the surface, an abrupt change of wall thickness etc.
This little crack seems to have two end points and no beginning, doesn't make sense. So what's on the backside of this surface in the picture and can we see that please?
I would not retire the swingarm on the evidence I see in this picture alone, but would persist until I understand what it is.
Or does it start at the hole and is the light so that we can't see it?
Just my 0.02$
A (fatigue) crack should have a starting point, or initiation point. Usually there's a clear anomaly or at least a stress concentration factor: a weld flaw, an inclusion, a hole, a machined surface, a gouge or other damage to the surface, an abrupt change of wall thickness etc.
This little crack seems to have two end points and no beginning, doesn't make sense. So what's on the backside of this surface in the picture and can we see that please?
I would not retire the swingarm on the evidence I see in this picture alone, but would persist until I understand what it is.
Or does it start at the hole and is the light so that we can't see it?
Just my 0.02$
utahdog2003
Senior Retro Guru
- Feedback
- View
IbocProSX":3ekb5cgb said:
I agree. Its not conclusive enough to toss it. I'd take it to a local framebuilder or even a machine shop, somebody wih materials smarts you can hand the part over to and let them paw it before giving you an opinion. I would consider sending it in to Ellsworth.
Good luck!
Thanks for that - yes it is a bit odd - it's a tinny wiggly line like a thread. it doesn't start anywhere near the hole, and there's nothing behind it - it's like a flaw rather than a crack.
There is a kit to test cracks (as an earlier poster helpfully told me), but it's about £50, so I was holding off on that since I only need it for this frame.
I guess riding it and seeing if it gets any bigger might be the only cost-effective way to tell.
Jim
There is a kit to test cracks (as an earlier poster helpfully told me), but it's about £50, so I was holding off on that since I only need it for this frame.
I guess riding it and seeing if it gets any bigger might be the only cost-effective way to tell.
Jim
Hey Jim, if it's the dye penetrant kit you're referring to then it can be inconclusive for suspect cracks where weld is present. I'm not saying it won't show it up, just that it might be vague. An X-ray would tell you straight away, any X-ray kits around?
As already said it's probably best to get in touch with Elsworth and see what they have to say about it. I think that'd be my first action. I've heard that they are quite approachable.
As already said it's probably best to get in touch with Elsworth and see what they have to say about it. I think that'd be my first action. I've heard that they are quite approachable.
jim m":3hisap3t said:
Jim,
Thought so, it's a surface flaw at the most and a small one at that. No need for 50 squids test kits. Ride it and watch it for growth works, but I guess you shouldn't paint it at first, once you've observed no growth you can paint it.
In normal engineering practise we'd grind a shallow flaw out smooth before paint, i.e. Dremel time. But that would defo void any warranty and destroy the "evidence".
