Muddymoles mountain biking in the Surrey Hills and Mole Valley

How to: repair a tubeless (UST) tyre

Posted by Matt | April 15, 2008 | 6 comments so far

Sunday’s ride saw one puncture. Me. Odd you might think given I’m running tubeless tyres but there is a simple reason for it. Originally my Orange Five came equipped with Panaracer Fire XC Pro’s in their tubeless incarnation, to go on the Mavic 819 UST wheelset.

All functioned perfectly for about 400 miles until I got a rip in the front tyre that the latex couldn’t seal. No problem, at the time I just put in an inner tube to get home. But somehow there it stayed, with me thinking ‘I’ll repair the tyre properly next time I puncture’. Except I didn’t puncture again until Sunday, by which time I’d clocked up 968 miles!

So, shamed finally into working out how to repair a UST tyre, here’s what I found:

  1. Take out the inner tube and attempt to reinflate the tubeless tyre without it, in order to find the tear in the tyre.
  2. Realise that you need a really good seal on the tyre bead, so take the tyre back off to clean the bead thoroughly of any dried latex sealant.
  3. Put tyre back on and reinflate. Pump like mad with your track pump in order to get enough pressure to seat the tyre on the rim. This may take some effort.
  4. Use the sharp pointy thing from the tyre repair kit to slightly enlarge the hole you have now been able to find.
  5. Take tyre off and push a strip of repair patch (covered in rubber cement) through the hole using the pointy thing again.
  6. Gently ease the pointy thing back out, which has the effect of cutting the repair strip in half so that the two halves are now sliced and wedged alongside each other in the hole.
  7. Wait five minutes, put tyre back on and fill the tyre with about 60-80mm of latex fluid, (easiest with a syringe from the chemist). Trim off the excess repair strip too.
  8. Pump the tyre back up. Pump like mad etc. in order to do this, which as mentioned may take some effort.
  9. Make sure the tyre is properly seated before pumping up to about 50psi, then spin the wheel to ensure the latex is evenly coating the inside of the tyre.
  10. When you are happy with the repair (like, next morning), set the tyre pressure to your normal operating pressure.

That’s it. Actually the process was a lot more straight forward than it sounds and not even particularly messy. You could even complete steps 5 to 7 without removing the tyre again I guess which would ‘save you some effort’ and avoid some mad pumpage.

Be sure to carry that old inner tube with you on the trail though as there is zero chance of you repairing a tubeless UST tyre on the trail, simply because you’d never get the air into the tyre without a track pump. You might even find you need a tyre boot if it’s a bad cut.

Filed under Tips in April 2008

Matt

About the author

Matt is one of the founding Molefathers of the Muddymoles, and is the designer and main administrator of the website.

Having ridden a 2007 Orange Five for many years then a 2016 YT Industries Jeffsy 29er, he now rocks a Bird Aether 9 and a Pace RC-627.

An early On-One Inbred still lurks in the back of the stable as a reminder of how things have moved on. You can even find him on road bikes - currently a 2019 Cannondale Topstone 105 SE, a much-used 2011 Specialized Secteur and very niche belt drive Trek District 1.

If you've ever wondered how we got into mountain biking and how the MuddyMoles started, well wonder no more.

There are 6 comments on ‘How to: repair a tubeless (UST) tyre’

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  1. Dunc says:

    Thanks very much for the advice. Worked a treat on my tubeless tyres.

  2. Biggles says:

    Provided you’re quick you can fix the puncture with the Panaracer kit before the tyre goes flat and the bead comes away from the rim.

    I’ve done it a few times on the trail. Works best if a friend sticks a finger over the hole while you prepare the tool. I carry my pointy tool preloaded with a rubber strip for speed.

  3. Muddymoles says:

    Going Tubeless: A sealed deal?

    Just how easy is it to convert to tubeless tyres using UST rims? Well, there’s a number of factors involved…

  4. Andy says:

    Before going UST I was all prepared for inflation with a track pump. But as a home test for trail side repairs I first tried with my backpack handpump – the beads located and the tyres inflated no problems without the use of latex.

    Early days for me using UST at the moment and I may end up eating my words but I don’t forsee trailside puncture repair of UST being a problem.

  5. Matt says:

    Andy, you must be built like an Ox! From what I’ve witnessed and experienced so far the idea of seating a UST tyre with a handpump is pretty daunting.

    If you’re confident you can inflate a tyre reliably trailside then go ahead but without latex you’re at risk of punctures and I’d suggest carrying a spare tube ‘just in case’.

    Good luck!

  6. andy says:

    Matt,

    Here’s proof…

    Inflating UST tire with a hand-pump

    It isn’t me but it is the same wheel tyre combination.

    QED

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