Is this a paint crack or frame crack?

[sefe2022]

Hello fellow cyclists and carbon experts.
I want to purchase a second-hand carbon frame road bike. The owner was very honest and told me the bike was involved in a crash and sent me these images with the crack near the bottom bracket area.




Is this by any chance a paint crack or is this frame not safe to use anymore?
Thanks to all.

[rareposter]

Very few people are going to commit and tell you it's fine or it's not and frankly, you'd be insane to take the say-so of a bunch of strangers on an internet forum regarding the material strength of a frame based on nothing more than two photos.

Why is the guy selling it? Is it *because* it was crashed and he has a crash-replacement frame or he simply doesn't trust the bike any more?! That in itself is a bit of a red flag although at least he's up front about it. See if the seller will give you a full description of the crash as well - it'll be a big difference if it was slid down the road at 40mph or clipped a kerb at 5mph...

I would get it to a carbon repair place and have them take a proper look at it, then make an offer based on their advice. Contrary to popular belief, modern carbon frames are actually relatively straightforward to repair but there's not much point fixing a broken bit of carbon if the frame is out of alignment or similar.

[Paradiddle]

I wouldn't personally buy a second hand carbon frame that has been crashed. Even if that's not anything, you might not be able to see other micro fractures elsewhere.

What I recently did with my cracked carbon frame was to shine a strong light from behind the crack. If you can see the light come through then it's bound to be structural. Not sure if you can do the same with this bike considering the paint and position of the crack.

[iandriver]

The line looks like it is around the metal insert that is bonded into the frame to receive the external bottom bracket. Can't tell from a picture how well joined to the frame it still is. Like the last poster, needs a proper pro assessment.

It is quite common for metal parts to be bonded into carbon frames, such as dropouts etc.

[sefe2022]

Thanks for replying so fast.

I understand it's hard to determine the condition of the frame from a picture, but I just wanted your "first-look" opinion, and I will not make my purchase just based on that

In the meantime, I had a further conversation with the seller and he told me he had ridden the bike since the crash, and the crack it's still the same, and had not grown bigger. He even gave me his Strava profile and had loads of pictures with the bike rides (the last one at the end of May this year). - The crash was last year - he said he was hit by a car coming from the front.

Anyway, today or tomorrow I am going to meet with him (he's from the same town as me) and take the bike on a 30-40 km ride, with steeper climbs, and see how well it performs. I plan to put some real pressure on the pedals to see if something goes wrong.

I also sent some pictures to some carbon shop repair, and they all told me it's something fixable for a small amount ( around 50-70 pounds ).

I will keep you posted. Thanks again. Fingers crossed

[Jamesh]

If hit from the front then it's the forks / headtube that's likely to fail.

Check these out.

That crack looks like a loose BB sleeve.

[sefe2022]

If hit from the front then it's the forks / headtube that's likely to fail.

Check these out.

That crack looks like a loose BB sleeve.

Thanks for the heads-up.
I will check that as well

[gxaustin]

Why is a paint crack as wide as that and flakey?
My guess would be movement under the paint.
I wouldn't risk it without a professional opinion.
Last week a car hit me and I can confirm there's a lot of energy to dissipate. My carbon forks (Ti frame) look ok and don't creak but I'm not sure if I can trust them. My wheel still runs true though I don't know if that means all the shock went into the fork or whether the impact wasn't big enough to damage anything. I don't know because I blacked out as I hit. I was incredibly lucky. You can bet I'm not going to take any risks with the bike.

[fastpedaller]

Why is a paint crack as wide as that and flakey?
My guess would be movement under the paint.
I wouldn't risk it without a professional opinion.
Last week a car hit me and I can confirm there's a lot of energy to dissipate. My carbon forks (Ti frame) look ok and don't creak but I'm not sure if I can trust them. My wheel still runs true though I don't know if that means all the shock went into the fork or whether the impact wasn't big enough to damage anything. I don't know because I blacked out as I hit. I was incredibly lucky. You can bet I'm not going to take any risks with the bike.

If a wheel is hit 'straight on' it will take a very large load, as that is it's strength whenever it's being used/hits potholes.

[gxaustin]

[/quote]
If a wheel is hit 'straight on' it will take a very large load, as that is it's strength whenever it's being used/hits potholes.
[/quote]
The impact wasn't straight on and the wheel was turned to the left in relation to the bars. But as I said, maybe all the shock passed through to the fork - hence my concern.

[brumster]

Walk away, don't even consider purchasing.

[rmurphy195]

Walk away, don't even consider purchasing.

+1 - never, ever buy a frame that's been in a crash, irrespective of material. Only exception would be to buy it (cheap) for the components.

[PT1029]

I don't think I would purchase a carbon frame if crashed.....
It looks like the metal BB insert is loose/no longer bonded securely in the frame. If you lean over the bike, flex the pedals hard from side to side by hand, you might see movement at the crack in the paint. I would do it out of curiousity as I would not be buying anyway (unless priced so could buy for the parts).
If the frame had not been crashed, I professional carbon repair place could probably re bond/glue the metal BB insert back securely (and hopefully the right way round!).

[sefe2022]

Thanks, everyone for your input.
I took a chance and bought the bike at a good price, after taking it on some serious elevation ride, and abuse it like a maniac.
The crack seems to be the same, and there is absolutely no play when I flex the pedals from side to side.
Anyway, today I plan to remove the bottom bracket completely and have a more in-depth look.
If there is something cracked, I already have a carbon repair shop ready to do the fix.

Here it is, waiting to be stripped

[sefe2022]

I removed the bottom bracket and made a thorough inspection, and the news are great. It seems that the crack it's just on the surface(paint area).

Will continue to ride like this, and keep a close eye on the bottom bracket just in case.

Thanks to everyone who took the time to reply.

Keep on riding!