After riding my old pair of Contintental Terra Speeds for 2 seasons, I slashed the rear tire and replaced it with a new one. During setup I replaced the rim tape, cleaned everything, mounted the new one, filled it up with 60ml of sealant. After the first night it went from 3 bar (43 psi) of pressure to below 2 bar (29 psi). After a second ride and a second night it happened again, so I started my sponge test and covered the whole wheel in soapy water. It had 3 micro leaks right on the tread, that hadn't sealed. Now after more then 2 weeks, 2 of them had selad and one re-opened, leaving me with 2 micro leaks again.

What are my options here? I don't really want to use repair strips on a brand new tire.

  • 3
    Put the inner tube in Jun 18, 2023 at 13:11
  • 3
    @ArtGertner personally, I like tubes, but tubeless is widely used and has its benefits. New, tubeless-ready tyres, with fresh sealant should work. The OP should be entitled to get what they paid for, if they haven't done something silly.
    – Chris H
    Jun 18, 2023 at 17:16
  • 1
    What sealant are you using?
    – MaplePanda
    Jun 18, 2023 at 19:56
  • @MaplePanda at I've switched to Stans with the new set of rubbers, was on some no name from a local bike chain before hand, because I needed to top up "now".
    – Marco
    Jun 18, 2023 at 20:54
  • I'd be concerned that the sealant isn't doing its job at all - imaging getting a fresh puncture while riding.
    – Criggie
    Jun 19, 2023 at 2:47

4 Answers 4


Continental have a bit of a history of leaky tubeless casings, although it seems to be less of a problem on their more recent tyres. As a last resort you can speak to your retailer or the Continental distributor to investigate a refund/replacement.

However there's a number of things to try first.

  1. Just keep topping up the air and riding it for 7-10 days. Leave the bike parked with the problem area at the bottom so the sealant is pooled on it.

  2. Try another brand of sealant. Some sealants seem to do better at different air pressures and with different sizes of holes.

  3. Take the tyre off, clean it and try again. I've found in the past that some tubeless tyres have something (probably mold release agent) that prevents sealant sticking to the inside. I find i get better results when I give the insides a quick wash with water+sponge.


Are the leaks distributed around the circumference of the tyre, or clustered together?

For a single leak I'd say pump up the tyre and leave the leak at the bottom. This might still work if they're close together. If widely spaced, you may need to repeat this process for each leak in turn.

If you've lost more than a tiny amount of sealant in the process, it would be worth topping it up.

  • They are placed around one quarter of the circumfence.
    – Marco
    Jun 18, 2023 at 20:53
  • That would mean leaving each leak at the bottom, with pressure applied, for some time (with how long depending on the sealant)
    – Chris H
    Jun 19, 2023 at 6:15
  • Already tried. One sealed and then reopened. I've marked every one of them with a pen on the tan wall.
    – Marco
    Jun 19, 2023 at 6:21
  • AndyP's mention of trying different sealant might be worth a shot in that case, but you might have to clean very well first
    – Chris H
    Jun 19, 2023 at 7:00
  • 1
    During travelling yesterday I transported the bike in my boot and lost all air on the tire, because of "stupid me". The sealent dried out and now the tire is roughly air tight. Just need to refill some and test over the course of the week.
    – Marco
    Jun 19, 2023 at 7:06

If the tire has cracks, the OP should ask for a replacement. Of bigger concern is why the sealant didn’t plug the leaks…the OP really needs to review their install process. It’s important to shake the sealant immediately prior to application, so the micro fibers are thoroughly distributed. After mounting, the wheel should be spun to coat the inside of the tire. I’ve used tubeless for several years, and the threat of flats due to thorns and the like has been virtually eliminated. The increased peace of mind is definitely worth it.


One thing that has helped me seal tubeless tires successfully is to give a freshly mounted tire a ride soon after mounting it. The flexing of the tire including the bead area along with efficient distribution of the sealant helps to fill and fix many of the small leaks better than just letting it sit, especially at the bead interface. It sometimes takes a few rides to address persistent small leaks.

Other answers regarding ensuring the sealant used is well shaken before being added and the possibility of a defective batch of sealant are also worth considering.

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