Ruote csc carbon 40x30 Craked

[Specialf.]

Good morning everyone, I'm writing here to get your opinion on what happened to me.
I live in Italy and ride a road bike for about 4,000 km a year.
In March 2025, I decided to purchase a set of CSC carbon wheels via AliExpress, with a 40mm profile, 24mm internal rim width, and 30mm width.
They arrived quickly, were immediately taped, and 30mm Pirelli tires with internal latex were mounted.
Everything was fine; the wheels seem very smooth and sturdy.
Now, after a year and a half of use, the front rim cracked due to a small pothole. The wheel instantly lost pressure, and I had to walk home.
I removed the wheel and mounted a spare.
I emailed CSC and purchased a new front-only wheel without any fuss, paying $100 for shipping alone, because they said they didn't have any stock in their European warehouse in Spain.
Today, a week later, the rear rim also broke.
I was left breathless.
No potholes, nor any strange, unusual routes.
How is it possible that they both broke within a week of each other?
I only have one question:
Italy is currently experiencing an exceptional heat wave with temperatures of 40 degrees. Could this have compromised the structural strength of the rim, perhaps by softening the resins or something similar, or is the lifespan of these cheap wheels really that short?
Has anyone had experience with this company's warranty?
I've contacted them now to see what to do; I'm desperate.
Thanks.

[Jaaniusss]

Most likely the same original pothole that cracked the front wheel also left the rear wheel with a micro crack - that now developed over the week to a failure?

[momento]

I had a similar experience with the 50×32 model with 5.5 mm carbon spokes and 28 mm tyres. I hit a manhole cover and it cracked. I opened a claim because they were only 3 months old, and after a lot of effort I won the dispute and got a full refund. I then bought a new set from them — the 45×32 with 3.3 spokes. Just to be safe, I inflate them to 5.5 bar.

[ZacItaly15]

I own exactly the same wheels 40x30 (they're effective 42mm) CSC and I used +- 3500km so far without any trouble,
The only issue was connected to heavy drag of ratchet that I reduce with different springs and different setup of ratchet and a lot of grease.
I'm selling this wheelset because I improved my ride with the carbon spoke version 45mm tall with 23,5mm inner width.

I think that the warranty is very difficount to get, the responsability is connected with pothole (in Italy we have very bad road condition) and...bad luck.

[Lotnik]

Did you hit both wheels the same pothole? Maybe rear was also damaged slightly during same ride and didn't showed up right away?
Temperature has nothing to do with carbon and resin. Carbon layups are heated to very high temps to harden properly.

[Specialf.]

Tom Xiang just replied and said that after a year the warranty is no longer valid and that I also need to buy a new rear wheel. Do you think it's possible to return the front wheel even if I purchased it directly from the website? Is there a return procedure?

[momento]

Tom Xiang just replied and said that after a year the warranty is no longer valid and that I also need to buy a new rear wheel. Do you think it's possible to return the front wheel even if I purchased it directly from the website? Is there a return procedure?

With “WEBSITE” do you mean the CSC Wheels website? Out of ALIEXPRESS?
Anyway, it’s difficult to get a warranty:

A lot of time has passed.
It would be hard to prove that the product is defective, because it cracked after an impact.

If I can give you some advice: try to reach an agreement with the seller to get the best possible price for buying the rear one.
They had offered me to ship only the rim and let me handle the mounting myself.

[Da11as]

Does the wheel has pressure release channel?

[Da11as]

What do you mean? What do you understand by "air vent"?

There should be a hole on a side of the rim, between nipples level and the rim tape level. It serves the purpose of releasing the pressure buildup from a tire in the otherwise enclosed space.

[dolph]

There should be a hole on a side of the rim, between nipples level and the rim tape level. It serves the purpose of releasing the pressure buildup from a tire in the otherwise enclosed space.

I dont think it's relevant in this situación when using latex tubes, those holes are useful to avoid spoke nipple corrosion and for tubeless safety, a non tubeless tyre and innertube are "open" through valve stem and leaky tire.

[Specialf.]

Most likely the same original pothole that cracked the front wheel also left the rear wheel with a micro crack - that now developed over the week to a failure?

Actually, now that you mention it, it might have actually happened that way.
I might not have noticed because the tire didn't lose pressure anyway.

[Specialf.]

I had a similar experience with the 50×32 model with 5.5 mm carbon spokes and 28 mm tyres. I hit a manhole cover and it cracked. I opened a claim because they were only 3 months old, and after a lot of effort I won the dispute and got a full refund. I then bought a new set from them — the 45×32 with 3.3 spokes. Just to be safe, I inflate them to 5.5 bar.

Where did you buy it? From the website directly or from AliExpress?
Didn't you consider using an internal sausage?

[Specialf.]

Did you hit both wheels the same pothole? Maybe rear was also damaged slightly during same ride and didn't showed up right away?
Temperature has nothing to do with carbon and resin. Carbon layups are heated to very high temps to harden properly.

exactly, I think that's exactly how it went, I'm only realizing it now.

[Specialf.]

There should be a hole on a side of the rim, between nipples level and the rim tape level. It serves the purpose of releasing the pressure buildup from a tire in the otherwise enclosed space.

I think I understand what you're talking about. Is it a small hole visible on the outside of the rim? I should check more closely, but yes, I seem to remember it because I've always wondered what it was for.
I'll check further.

[Specialf.]

I dont think it's relevant in this situación when using latex tubes, those holes are useful to avoid spoke nipple corrosion and for tubeless safety, a non tubeless tyre and innertube are "open" through valve stem and leaky tire.

I mounted them tubeless with puncture-proof liquid inside, 30mm tires inflated to about 4 bar.
I weigh 90 kg.
If I were to reassemble them, I already have some inserts at home to fit inside, like the ones used for mountain bikes; we call them "sausages."
With those, if you get a puncture, the rim doesn't immediately touch the ground, and even if you hit an edge, it's less likely to hit the rim edge and crush the tire.