Running with inner tubes equipped with sealant liquid, should we remove visible thorns etc or not?

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  • This question was separated out from a different one about thorns and tubeless. This one is specific to tubed tyres and road junk like thorns.
    – Criggie
    Feb 7, 2017 at 4:39
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    Damned if you do, damned if you don't? Out of the fire into the frying pan? The last flat I got with a liquid sealant tube was caused by a minute piece of glass that made a pinhole. I removed the glass and checked the inside of the tire. But the tiny pinhole leak wasn't stopped and had a slow leak, flat again in 20 minutes. Replaced with a regular tube. Rolled up the sealant tube to put it away and the green stuff came spurting out of the valve all over everything. Feb 7, 2017 at 6:08

1 Answer 1


You should always remove the thorns as soon as you see them. There's a good chance that if you're diligent about it, you'll get them before they even get through the tyre to put a hole in the tube. For ones that are already embedded deeply enough in the tyre to puncture the tube, removing them will prevent them from making the hole bigger than it already is.

You should remove them carefully in a way that allows the sealant the best chance of fixing the puncture. To do this, begin by resting the wheel vertically such that the thorn is at the bottom, near the ground. You then leave it like this for a few minutes. Gravity will cause the liquid sealant in the tube to pool at the bottom, near the thorn. Once you pull the thorn out, the sealant should plug the hole almost immediately, but it's still best to leave the wheel with the puncture at the bottom for a while for best results.

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    And don't do what I did and spot a giant thorn and pull it whilst the bike is lying on its side in the car boot. Sealant doesn't work when its all pooled on the sidewalls......
    – Andy P
    May 28, 2019 at 14:10

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