Just received this specialized carbon hardtail, and discovered a fine crack at each side of the bridgestay where it joins seat stay. Unfortunately seller didn’t mention this in description and I was unable to inspect in person before purchase (some distance away). Just cosmetic in the paint? or worth making a fuss over?
Bridgestay crack 3 by Captainsideburns, on Flickr

Probably just a crack in the lacquer.

or worth making a fuss

er yeah,

can’t see properly from that pic, but the line seems to start and end in a manner where it looks more like paint damage than a crack in the structure. if it was a structural crack, i would expect it to extend around the curve of the bridge.. might well be wrong though.

Weep gently

Not worth taking a chance over imo

Don’t chance it. Make a fuss and get your money back.

Is it just me, or does anybody else find it impossible to tell anything useful from “crack” pictures like this? I’m fairly sure if I had the frame in my hands I’d be able to tell whether that was a crack or just paint damage, but not from a picture.

did you buy this as a bike or a frame?

i only ask as the photo shows the bike built up. if it was sold as a frame, you surely should have spotted this before you began building? if i was the vendor and had GENUINELY not spotted it myself, then i would think twice about refunding… with all i know, it could have occurred whilst you were riding it.

just playing devils advocate…

did you buy this as a bike or a frame?
bought it as a bike, received today, noticed before all wrapping came off. Very fine hairline continues nearly all the way around the seat stay.

Refund.

…oh, but notwithstanding not being able to tell from the picture, IME the majority of “cracks” where people aren’t sure whether or not it’s a crack aren’t.

its a sticker…..

how would you get a crack there?… some form of twisting force?

I’d send it back – it’s not worth the risk.

even better if it’s not fully unwrapped yet.

seller may say it was damaged in transit but that’s for them to take up with couriers. Get a refund.

Sorry mate, I think that’s definitely a crack. Should you decide to get it mended this guy is great:

Carbon Cycle Repairs

Its going to be very difficult (or impossible) for anyone to determine whether or not this is small crack in the paint or something more serious from a picture. Some kind of non destructive testing equipment would be required. Other than that you would probably need to take the paint back to the bare frame and or course by then its going to be too late.

One method of non destructive testing used to test the integrity of composites in aero and other such applications is the tap test. Some of you may laugh at this for such a “hi-tech” material, but is is a bonafide method of non destructive testing. To how does it work ?

In this case I would take something metallic, like a 5 or 6mm drill bit. Wrap a thin layer of electrical tape round the end (the side that fits in the drill) hold the other and proceed to tap the frame. I would remove the parts which might interfere with the sound. Any way you would be looking for changes in tone in the different parts you tap.

You could start there.

My opinion is that to have a crack like that, you would probably need some quite serious damage underneath if it was immediate carbon below. However, having said that. Most bike manufactures have still not mastered moulding these more intricate parts of bikes, as a consequence they often need a fair bit of finishing so areas like this can have quite a bit of filler slapped on there. It would not surprise me if this was filler heavy and some flexing in this area would have caused the filler to burst.

Just to join in and further the comments by chief9000. I’m an aerospace NDT engineer and spend my professional life looking for cracks in aircraft structures both conventional and composite.

It is true to say that we use tap testing on composites, though we have a device called a woodpecker that taps at an automated frequency and triggers and alarm if a problem is found. We tend to use this technique to look for disbond in the lay up, or when we suspect a composite skin to of come away from a honeycomb core. Unfortunately it’s not so good with cracks, but then composites really don’t crack how you would expect them to. They tend to shatter down through the composite layers and the better way for us to pick that up is with shear-wave or through transmission ultrasonics.

As for the OP’s pic, it’s pretty hard to tell what’s going on without seeing it in person but the first thing I would be doing is getting the paint off. Carbon fibre is able to flex a lot more than the paint and lacquer on top, and removing the paint in the area will tell you a lot more about what is going on below. If the indication is still there then you may have a problem but again it’s hard to tell without looking at it.

Looks like a witness crack where some filler or the very hard brittle lacquer has cracked with the flexion of the frame.

My Specialized Roubaix has had this crack for about 4000 miles of rough roads and it hasn’t grown at all. There’s a more alarming one on the fork crown, also been there over 3000 miles.

I wouldn’t start removing lacquer etc until you’ve had a discussion with the seller. Very poor form not to mention any such defect in the selling description and if you’re unhappy then ask for a full refund.

If it is a crack im sure the seller could have it replaced via spesh warranty?

Thanks all. Yes, I’m inclined also to think that it is probably filler/paint. It’s just the lack of real knowledge that concerns me, and that the warranty doesn’t apply to me. I think prev owner probably hadn’t noticed. As she was a member of her lbs race team she shouldn’t have had any problems with warranty if needed. Still waiting a response from her.

Thanks again.