Busted Carbon Rim - Thoughts?
 

A little over a month ago I bought a set of Superteam Carbon 50mm deep wheels (these: Amazon: Superteam Carbon Wheels) and rode them for a few hundred miles with some specialized clincher tires, nbd. The specialized tires were a used pair I had, and they were getting a bit worn out, so I pulled them off the wheels and popped on a set of Schwalbe pro one tubeless tires. I seated them with one of those air dump tanks you pump up, and they seated fine. So I went to pump the front tire up with my track pump, and they're pinging and thumping as the tire is popping onto the bead, but when I hit ~50 psi something cracked and the air rushed out.... I looked over the wheel, and the wheel itself actually cracked between the tire and braking surface; it looks like several of the carbon layers separated.

So that wheel is ruined. I'm 2 days outside my 30 day Amazon return policy so I contacted the seller, and to be quite clear, they emailed me back promptly, and it looks like they're going to cover it under warranty.

But my question is, what should I do going forward? The tubeless tires were installed with little to no fuss, using park tool plastic levers, so definitely nothing out of the ordinary. These wheels are really highly reviewed and lots of people are using them with no issues. Many have set them up tubeless and are happy. However, even if I get a replacement wheel, I'm not sure I want to ride something that fragile.

• Should I chalk it up to a defect with this one wheel, and give them another shot?
• Should I ditch the tubeless tires and run a set of clinchers and be happy?
• Should I sell this set (once I get a replacement front), and stick with tried and true aluminum (because I can't afford a brand name set of carbon wheels)

Just needed to get my thoughts out so I could try to think through this like a sane person.

That's what I would do..

Would you give the tubeless tires another shot, or bail on them?

It's not the fault of the tires. I would use the same tires, set up tubeless.

For something like cf wheels, I would either buy a name brand or stick with aluminum rims. That's not really a place where I want to take a chance.

Without seeing a picture of this, I would safely (I think) guess that there was a leak in the tape or valve interface that allowed a bunch of air to get into the rim chamber. What then happened is that you inflated the rim along with the tire. Since the rim is not engineered for this direction of force, pop went the weasel. This has happened before on a few brands of rims (as "name brand" as you can get). You can specify a drain hole in the replacement rim and that will prevent what I've described from happening.

If it's covered under warranty, get the new wheel and move on. If this happens again, then it's time to look for another brand of wheel.

Aren't you running lower pressure in your tubeless tires vs. clincher? Not sure how a tire makes the difference in your situation. Good to hear that ST is going to cover it under warrantee though.

Do you have a picture of the crack?

That's very interesting; I hadn't thought of that. That would be a problem that is specific to tubeless, so would most "tubeless compatible" wheels come with a drain hole? I think this could definitely be the issue; when I inflated the rear tire it blew the O-ring out between the tubeless valve stem and the nut that holds the stem against the rim so prob the same issue but the air got out there in that case. I have a hunch the wheel vendor will not be willing to drill this hole as they are a vendor and not the mfg. Seems like maybe I should just run it with a clincher.

I don't have a pic yet. It was late last night when it happened, and I didn't have time to get a pic before work this evening. I'll ultimately (assuming I continue with this endeavor) try to run about 85 psi on the tubeless compared to 100 psi I was running on clinchers.

I'll try to get some pics this evening after I have some more time to mess around with it.

This happened with a track pump?

Yep, around 40-50 psi.

That doesn't sound like a tape issue to me. How much pressure was in the tank when you dumped the air for the initial seating? The only thing I can think of is:

1. Defect in the carbon which caused the separation
2. You dumped an extremely high volume of air during initial seating and it caused the crack, and when you used your track pump it didn't take much pressure to open it up.

Yeah, I'd say your experience with the rear confirms what I thought about the front. At the very least you need to replace the tape as it's compromised.
I would at least ask the vendor about drilling a drain hole. Rims have lots of holes in them already, and there are plenty of places on a rim that don't see much if any loading. A small pin hole place correctly should not affect the rim.
This is an issue that we've heard of just recently, and I believe that we will be spec'ing our rims with drain holes in the future just to be safe. We're investigating it.
Though tubeless and carbon rims have gone together for a long time, there is always the chance for new and "interesting" issues as adoption gets more widespread.

Regarding item 2, I started from 100 psi in the dump tank. The dump tank is 2' L x ~2.5" ID, so that's ~118 in3 and I'd estimate the tire volume at ~41 in3 (I can show the math if curious). So that means when I dump the tank from 100 psi it should end up at ~70 psi gauge maximum before leaking off.

Just out of curiosity, where are you vendors placing the drain hole? Just in case I hypothetically have to place my own....

I wish that my rims had drain holes... not because of this issue, but because I got caught in torrential rains twice over the summer and the rims took on a bunch of water in the inner chamber. I had to remove the tire and valve to drain 'em. :notamused:

OP - if you do have to re-tape, try to get your hands on some DT Swiss tape in the appropriate width - that's the best stuff I've used, yet. It has just enough stretch that it conforms to the rim bed much more easily and cleanly than stuff like Stan's.

Weeeeeeell... I got some Stan's but I didn't actually use it the first go round as the wheels already had some tape in there. But I'm going to pull the existing tape out and try the Stan's. And if that doesn't work, I'll try the DT Swiss tape.

I wouldn't drill my own holes, I want to keep my teeth, but maybe that's just me? :p

Having two similar failures setting up tubeless, I would just run them with clinchers and call it good. But I agree with other assessments that it's like the tape job allowing air to enter the rim cavity. I've had good luck with this tape, I use two layers. You want to make sure that the width covers the entire rim bed, from wall to wall, so that you get a really good seal, and make sure that the tape is smooth and tight, no bubbles or wrinkles.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Checking the listing you posted, they're not advertised as tubeless ready, did you tape them when you went tubeless or use the tape that was on them already? Just wondering because some wheels will come with tape on them that is really just to cover the spoke holes and isn't meant to be used with a tubeless setup. That could def have been the issue.

I use the tape that was in there based on an answer in the "questions" stating it was tubeless tape. However, I'm pretty sure that is not the case now.... That said, if the only difference between me and a compromised wheel is the seal between tape and wheel, I think I may bail and run clinchers.

Oh, I thought these were tubeless ready.

OP, the Amazon Q&A section explicitly says these wheels are not tubeless compatible.

Just because you can put rim tape on and get a seal doesn’t mean it’s safe. Carbon tubeless wheels require additional carbon to support the extra stresses.

To be fair, one guy in the Q&A says it's not "tubeless compatible", however several other people comment stating they are running them tubeless. Regarding carbon tubeless wheels, yea, I didn't know that at the time. Do you know if aluminum wheels can be converted to tubeless without being "tubeless ready/compatible"?