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Unanswered uhm, is this a crack in my frame? I'm hoping it's just the paint...
- Thread starter EnjOy!
- Start date
Benson
Well-known member
Looks pretty wide, can you get a fingernail or tip of a toothpick in there to confirm if it has depth?
Looks like quite a deep hole, hope it’s not a crack in the frame ?
If it is and the bike is not to old you should get it sorted with your warranty
If it is and the bike is not to old you should get it sorted with your warranty
Bryan Wells
Active member
have an experienced aluminum welder/specialist look at it
- Thread starter
- #6
I just tried to stick the thinnest needle I have in there, and seems to go in for 3-4mm
And there also seems to come a little water out of the crack after washing it as you can see on the bottom.
And here's a video of the needle going in, sorry for my shaky hands
Pukmeister
Active member
Hard to tell without inspecting if it is a crack, a surface flaw or a paint finish defect. I would ask at your supplying dealer. If it is a crack the frame needs replacing or repairing (probably cheaper/easier for them just to exchange the whole bike once labour is charged).
An Engineer will tell you that a crack will propagate under stress as the forces at the absolute tip of the crack are infinite (due to having no radius). You can stress relieve by drilling a hole at the absolute tip of a crack(to create a radius), a silly idea on a bike.
If it is a crack it will only get worse, get it checked. Most frames are guaranteed for the life of the bike.
An Engineer will tell you that a crack will propagate under stress as the forces at the absolute tip of the crack are infinite (due to having no radius). You can stress relieve by drilling a hole at the absolute tip of a crack(to create a radius), a silly idea on a bike.
If it is a crack it will only get worse, get it checked. Most frames are guaranteed for the life of the bike.
Based on your video it is for sure a crack and back to the LBS, you will need a new frame if still on warranty. If not ,a good welder can fix it for you but it will hurt the paint.I just tried to stick the thinnest needle I have in there, and seems to go in for 3-4mm
And there also seems to come a little water out of the crack after washing it as you can see on the bottom.
View attachment 17754
And here's a video of the needle going in, sorry for my shaky hands
Karsten
Benson
Well-known member
I just tried to stick the thinnest needle I have in there, and seems to go in for 3-4mm
I’m no expert but that suggests more than a cosmetic paint crack. I’d get it looked at by someone that knows what they’re doing before it gets any worse.
The only way to know for sure is remove the swing arm and strip back a small area of paint in that area, my guess is it's a crack forming that will get progressively worse. Maybe a shoddy weld, too much heat used perhaps causing a weakness on that bearing tube.
The area where the "crack is located is not part of the seat tube. It looks to me to be the weld holding the pivot tube to the seat tube, which has been machined back. The defect is therefore likely to be a defect/foreign matter in that weld. That face also has some defects not machined smooth at 12 oclock. If I was being super critical I also do not like the look of the weld joining the pivot tube to the bottom of the seat tube either. The weld has undercut the ally of the seat tube ( see your second photo).
Pukmeister
Active member
If the weld has inclusions in that area or porosity, what about the rest of the bike especially the bits you can't see? It doesn't say much for the welding processes or quality control checks during manufacture.
I would be concerned about frame strength/integrity.
I would be concerned about frame strength/integrity.
Rusty
E*POWAH BOSS
This is a perfect illustration why one should regularly perform a close inspection of your frame. Nothing worse than not noticing something then having it fail and cause injury.
Swissrob
Well-known member
There is a fairly simple solution and non destructive test for cracks using dye penetrant, especially so given the bike was bought online. I have used this product in the past so maybe try and find a local supplier.
Flawchek (Crack Detection) – Dy-Mark Industries
Flawchek (Crack Detection) – Dy-Mark Industries
- Thread starter
- #17
Bike24 told me I'm going to get a new frame, just finished packing my bike so I can send it back.
Was hard to find a box that fits my bike but found these big boxes at work and was able to modify them.
From this (x2)
To this
Now I have to ride my stupid city bike again
Was hard to find a box that fits my bike but found these big boxes at work and was able to modify them.
From this (x2)
To this
Now I have to ride my stupid city bike again
My misses has got an old box, do you think you could do anything with that ?Bike24 told me I'm going to get a new frame, just finished packing my bike so I can send it back.
Was hard to find a box that fits my bike but found these big boxes at work and was able to modify them.
From this (x2)
View attachment 18311
To this
View attachment 18312
Now I have to ride my stupid city bike again
- Thread starter
- #20
Time for another update
My bike arrived at bike24 and Cube sent them a new frame... which also had these weird openings
They mailed back to Cube and they didn't seem to have any more of these frames.
But they also told me "Cube confirmed that there will be no stability issues ".
I had the option to take this frame or get a refund, I told them i'd rather have a refund if these openings are not supposed to be in the frame.
Didn't think I would have to look for a new bike this fast, too bad I can't find one that I like as much as this one in the same price range :/
My bike arrived at bike24 and Cube sent them a new frame... which also had these weird openings
They mailed back to Cube and they didn't seem to have any more of these frames.
But they also told me "Cube confirmed that there will be no stability issues ".
I had the option to take this frame or get a refund, I told them i'd rather have a refund if these openings are not supposed to be in the frame.
Didn't think I would have to look for a new bike this fast, too bad I can't find one that I like as much as this one in the same price range :/
Rusty
E*POWAH BOSS
That is just real bad quality control.
If the welding is not correct looking at that, then how can one be sure the rest of the weld has the correct penetration. Not much of a chance I would buy a Cube looking at that.
If the welding is not correct looking at that, then how can one be sure the rest of the weld has the correct penetration. Not much of a chance I would buy a Cube looking at that.
HORSPWR
E*POWAH Master
There is no way that will fail, there is heaps of weld underneath and on top, I would even suggest that there never was any weld in that area where the gap is above, there simply isn’t any need for weld in there. To put weld in that area is overkill.
Rusty
E*POWAH BOSS
Moisture in there could cause corrosion issues I would suggest. Perhaps not an immediate issue but long-term could be a problem. Had a Giant NRS fail 15 years or so ago due to internal corrosion under a weld.
Webike
E*POWAH Master
Surprised that the paint crew does not catch that sort of problem and address it with a bit of epoxy filler prior to paint...
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