5

It's my first time setting up tubeless. The tyre seems to have seated fine, but I'm losing air through three of the spoke holes when I go much above 20 psi. Details:

  • new rim, new tyre (new bike in fact)
  • 29" DT Swiss M 1900 Spline - tubeless ready
  • 2.3" Minion DHF - tubeless ready

I've added more sealant (must be getting near 200ml now) and shaken it about, concentrating on the leaking areas; air has stopped leaking but that might be the loss of pressure - down to 10-15 psi I think. Will leave it to sit overnight at the lower pressure and see what happens in the morning when I add air.

But in my limited reading so far I haven't seen this specific problem mentioned. Wondering if I'm wasting my time trying to seal this, and instead have a problem with the rim tape or even a defective rim?

EDIT: just for clarity - it's a tubeless-ready rim, factory taped, which I'd have hoped would rule out any errors of tape selection or technique.

2
  • I made a mistake of putting the tubeless tape over the normal rimtape on one wheel. It took some time to seal overnight, but sealed in the end and I still use it. I just later added another layer of the tape.
    – Vladimir F
    Oct 30 '20 at 13:28
  • I’m not sure, but just because the air is coming out of spoke holes doesn’t necessarily mean that the rim tape is leaking. With double walled rims, air could also escape around the valve stem, enter the inside of the rim and exit through the spoke holes. On my DT Swiss rims the factory installed tape looks very good and tight.
    – Michael
    Oct 31 '20 at 9:38
12

It seems like there is a problem with the rim tape. The tape should seal the spoke holes without milk. Try cleaning the rim and replacing the tape if it is still loosing pressure.

5
  • Agreed. I would add that the OP could check if the rim tape is wide enough. I think people usually recommend two layers of it as well.
    – Weiwen Ng
    Oct 30 '20 at 11:29
  • 1
    Yeah the rims came tubeless-ready, which rules out bad tape selection or technique on my part. Disappointing that things aren't as they should be out of the box.
    – Adrian
    Oct 31 '20 at 4:29
  • The factory rimtape might be standard rimtape for use with inner tubes. The rim might be tubeless ready but does the description specify that the rimtape is included in that? Also adding 200ml of sealant is way too much. It cancels out the weight saving from going tubeless
    – Carel
    Oct 31 '20 at 15:44
  • Yep the tape has "tubeless ready" written all over it (literally I mean, not figuratively)
    – Adrian
    Nov 1 '20 at 6:57
  • So I pulled the tyre, and there's a hole in the rim tape. Guess I must have poked it with something. "Fixed" with random black plastic tape - goodness knows how long that will last, but wanted to prove nothing else wrong. For now, it's staying up and I'm carrying a tube :-) Thanks everyone.
    – Adrian
    Nov 1 '20 at 7:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.