Campagnolo Bora 35 break track problem

[snaxez]

I bought a pair of used Campagnolo Bora 35 tubulars with 3Diamant break track.
I was told it was only used for races and for about 1000-1200km. But tonight at a closer inspection i`m not so sure anymore. The rear wheel break track seems more worn down. (I can feel the difference under my finger between the track and gloss rim side). First wheel seems better.
On the rear rim I noticed some damage or missing epoxy in one spot. How worried should I be about this?

I made some pictures:
https://imgur.com/8iOHP3p
https://imgur.com/lsLpn1o
https://imgur.com/K4H3SHm
https://imgur.com/ufqeWTv
https://imgur.com/ck7CrCk

[pdlpsher1]

You're OK. That's a carbon void. It's not common to see voids that big but you should be OK. As for the finger nail test between the brake track and the glossy part, yes you will feel the difference in height even on brand new Bora 35s. This is because a thin latyer of epoxy is removed to expose the bare carbon that makes up the 3Diamant braking surface.

Other than the carbon voids I don't see a lot of wear on those brake tracks. When brake tracks are magnified they often look way worse than in person without magnification. You have plenty of life left in those brake tracks, perhaps even 90% life left or more.

[Calnago]

I take it you didn’t know the seller personally? I’ve had Boras going back 10 years and none look like that. From the pics and what I can see, I’d agree that it doesn’t look good. Have you ridden them to test how they actually work. Can you actually feel a concave indentation in the brake track. If so, they have to have a whole lot more than 1000km to 1200km of use. Or some really extreme constant braking in extremely harsh conditions.

[snaxez]

Yeah, I did not know the owner personally, but I was told by the guy that they were used by his son who is a 15year old pro CX racer (Won mini Paris–Roubaix last year). He said they were only used for races on the road bike, and the kid was 67kg or something like that so, should be light. Was told they were bought one and a half years ago, but had no papers. I wonder if this would go under the 3 year campa warranty?
It`s winter and snow here, so it will be at least 2 months before I can ride them.

[pdlpsher1]

The reflection of light on carbon brake tracks can make the brake track look far worse than what it really it. One has to look at multiple pictures from various angle to judge it accurately. And remember these are under high magnification. Brake tracks that look perfectly normal/fine will look horrible under magnification. From my own eyes I honestly don't see any heavy wear on those tracks. But I'd agree with Calnago that the wheels most likely have more than 1.2k km of use. Maybe 4k km. But I honestly think you have nothing to worry about.

[Calnago]

Hmmm... funny because I was going to say as one of my caveats “... unless those miles were exclusively cyclocross in muddy, sandy and wet conditions”.
So I wonder if “only used for races on the road bike...” means he didn’t have a proper cyclocross bike so just used his road bike . You just never know when you buy used. Could be great. Could be not so great. But can you feel a divot (concave spot) in the brake track.m? I guess you just have to go forward and decide whether you got a screaming deal (and now know why), or whether you paid a good amount for a set of wheels in supposedly very good condition, in which case I’d argue they’re not in great condition and you want your money back.

I’ve seen enough Bora brake tracks to say that no, those are not in good shape. I looked at your pics again and particularly pics 3-5, either those wheels were flawed from manufacturing (highly unlikely), or were put through the ringer consistently in terrible conditions. There’s no way those only have 1200km of “road use” on them. I’d want to see the “roads” if that’s really the case.
Oh, and as for warranty, that would only apply to the original purchaser and even then not include normal wear and tear, which, although probably not “normal”... that certainly seems more from very hard use than a manufacturing defect.

[pdlpsher1]

The open space is definitely carbon void, not something caused by CX, improper braking, or high mileage. If your concern is solely on the void I would take it up with Campagnolo as that's a manufacturing defect. Very small voids are more common and unavoidable. Large voids are uncommon and they should have been caught by QA. Personally if I bought the wheelset new and I see a void like that, I would take it up to Campagnolo. I told you not to worry about it since you bought the wheelset used, and presumably at a very good price.

Apart from the void I don't see any other issues with the brake track.

[snaxez]

I guess I have to see if I can notice it when braking during the ride. If it feels ok, and I can`t notice it during the ride, then I will live with it, and keep them.

[snaxez]

Still snow outside, so can`t do a test ride. Asked campa support about this, and got a response:
Dear Customer,

it seems like a principle of delamination, which will worsen with atmospheric agents and with the use ...

And when I asked if it is a defect from manufacturing or does this happen with use? Then I got a response back:
it's not a production fault, all the carbon braking tracks are delicate, if you use unsuitable pads or if it incorporates material in them it can be detrimental to the life of the braking track.
Moreover, during long braking the temperature reached inside the rim is very high, this can alter the carbon fiber characteristics.
Use in the race accentuates this wear and tear.