Paint crack? hopefully not

[marciero]

Originally Posted by cachagua

Put a drop of oil at one end and see if it soaks in.

With nothing to go on but your pictures, I think someone leaned that bike against something and screeked the paint, is all that is. But if it drinks up a few drops of oil then yeah, explore further.

I vote razor blade or scraper as a more sure way to diagnose. I'm going to be an optimist and guess that if that were a crack in the metal then the paint crack would likely propagate beyond the ends of the crack, which does not appear to be the case.
But by all means, remove some paint and check. Small area, is on the least visible area on underside of the bike. You can touch it up. Will be painless.

[ultraman6970]

U have to sand that down to know what is going on, either way never seen a crack in that area either so IMO is hard to tell w/o looking at surface.

The good news is that is under the tube and the bike wont explode, worse can happen is that the crack (if there's one) will continue growing. Once the paint is off just put a vinyl sticker in there. till you decide or can paint the whole stay.

IMO that's a paint crack, probably is the primer that failed. Either way you have to peel the paint off by sanding of a razor blade.

[weisan]

I bet it's a scratch. I have tons of these in my bikes especially the ones that get ridden, not garage queens.

Clean it up/rub it off real good and see what happens...

[AngryScientist]

under side of the chainstay?

my best guess is that you, or someone rode over something that scraped the paint enough to get some rust starting and the rust is growing linearly along the paint scrape. i doubt it's a crack in the middle of the tube like that. bottom of the chain stay would be an easy place for a stick or rock to scrape the paint too.

it would bug the hell out of me too though, and i would just immediately take a dremel with a barrel sandpaper attachment and take a few mm's down to bare metal and check. it's a white bike in a spot out of general sight, would be easy to do a basic touch up and would give you confidence that it's not a big deal.

moving forward though, if that is rust coming up through the paint, even if it is just from surface rust on the tube, you've got to stop it, or it will continue to grow, which means removing the paint, removing the rust and covering it with new paint.

[AngryScientist]

oh, and i agree with weisan, step one is to scrub that spot good, potentially with something very mildly abrasive, like automotive polishing compound to see if it's just something on the surface of the paint.

[Tickdoc]

Nothing duct tape won't fix ;~)

Really weird. on a carbon frame I would bet money there was a crack under the paint, but not on a steel frame.

It doesn't look like a scratch.

Weird.

[JAGI410]

I agree with AngryScientist. It’s just a scratch. Hopefully you can prove us right!

[R3awak3n]

woah guys, I just went online this morning and SOOOOO much good advice.

THANK YOU ALL SO MUCH, seriously.


It really is strange to me, just such a weird place to have a crack. So much that I am not really worried about it. OBviousy I am curious and definitely do not want it to rust. Is there a way to prevent it from rusting without removing paint first? Even if I remove paint I might just do a tiny little bit (the line is quite long, inch and half maybe) really just to see. Also, the line is not perfectly straight but its also not crooked, its very straight to be a crack.

here is another image to really show where it is, NDS and not touching any point where I would think a crack would start

[gary_a_gooner]

I actually had a bike develop a crack in the same location. It was closer to the BB and was made of titanium. Builder acknowledged that the tubing had to be defected but it was OK to ride as a replacement was being working on.

[ColonelJLloyd]

Originally Posted by weisan

Clean it up/rub it off real good and see what happens...

+1 I would use some Meguiar's Scratch-X lightly and see what happens. No need to sand or cut into the paint before trying to remove it like a normal scratch.

[Wilkinson4]

Goo gone or other suggestions here first. Is there a local builder you can take it to for a quick inspection?

Be careful J. I had a recent crash due to a failure. No fun at all.

m

[David Kirk]

Do you have any idea what brand/model of tube we are talking about?

dave

[ColonelJLloyd]

Nm

[R3awak3n]

Originally Posted by ColonelJLloyd

+1 I would use some Meguiar's Scratch-X lightly and see what happens. No need to sand or cut into the paint before trying to remove it like a normal scratch.

I just got this for my car. It does seem deeper than the clear coat though. I think I will remove a bit of the paint with an X-Acto knife and take a look.

I do love this bike too much, I would probably just have hampsten build me a new one instead of fixing this one (into having a custom bike made by hampco)

[R3awak3n]

@David Kirk - From the ebay listing, mix of True Temper OX platinum and Reynolds 853.