Holes in Zipp carbon rim

Just wanted to make sure I’m not crazy. These holes aren’t good right? There’s at least 20-30 all along the edge of the rim. I emailed Zipp but haven’t heard back.

This is the second post in the last week I’ve seen with new messed up Zipp wheels. Not good, Bob.

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@CaptainThunderpants I have two opinions about that wheel:

Opinion the First: Do not effen ride those wheels

Opinion the Second: The manufacturer should replace those wheels at no cost to you. I guess they are not new wheels so Zipp probably won’t. Just FYI, I bought some dimpled zipp 404 knockoffs from C-Razy Carbon on aliexpress in 2017. No holes in the bead.

Carbon Wheels Track | Track Carbon Rear Wheel | Carbon Wheels U Brake - Brake Track U - Aliexpress

Does Zipp have quality control or not? Because this makes it seem like they don’t.

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Yeah, pitting is no bueno in composites.

Indicates problems with tool prep, layup, bagging, etc.

I worked aerospace composites for a couple years and something like that wouldn’t pass QC.

Edit: my opinion is that high end commercial products should be visually flawless.


Less than 6 months old. Probably 300-400 miles on them, never crashed.

My opinion…you should already have new wheels.


At first I thought you were trolling and making a joke about the dimples. Yea, that’s bad! Get those replaced!


:astonished: Even if its just cosmetic (don’t assume that though) they should be replaced,


That’s what I thought when I saw it, but I’m not a materials guy. You don’t get bubbles in carbon fabric so the fact that there are little bubbles around the bead indicates to me that it’s all resin & no carbon. Also indicates that there wasn’t enough vacuum to get the air out of the bead…so if there are that many voids around the periphery the laminate itself is probably riddled with voids. But even if it wasn’t, the bead…the thing that keeps your tire attached to your wheel…doesn’t have the proper laminate stack. It looks like the bead is more resin than carbon and even the resin is permeated with voids.

Yikes. I would be scared to ride those wheels.

I wouldn’t be scared of those wheels. Those tiny voids look larger when you take a close up picture of them. They are so small that it took six months to notice them.

Youtubers like Hambini and Luescher would go on and on for an hour about those voids telling us how horrible Zipp is. Let’s face it, we don’t get aerospace grade carbon in the cycling industry. If we did, everything would cost 10x as much as it does.

Now, when you pay top dollar for Zipp wheels you expect perfection so send them back for peace of mind.

I don’t know where you are from but in Europe warranty is usually handled through the store for the first 1-2 years (depending on the product) not the manufacturer

I was wondering if anyone has any opinions on this. These are 454’s max 4000km old. Doesn’t seem right? Especially for a £3000 pair of wheels.

that is normal, it’s a drain for water that makes it into the void inside the rim

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Not talking about the drain hole the cracking above near the tyre, its hard to photograph.

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Those cracks at the edge of the rim?

This is also a cavity relief hole, I.E if the wheel combination is tubless and the rim becomes pressurized it stops the side of the rim from being blown out.

To OP, looks like scuffing from bottoming out or hitting a pot hole, not sure if its actually “cracked”

Those are the ones! There are loads more at other point in the rim too.

I wouldn’t say cracked it more delaminated you can get your nail into the little hole / cracks.

Those look like minor voids from manufacturing. You can find a lot of tiny imperfections in carbon when you take pictures with a zoom lens and magnify them.