Going tubeless: sealant, plugs, and what to actually carry

Tubeless seals small punctures on its own, lets you run lower pressures without pinch flats, and rides better for it. What it doesn't do is let you stop carrying repair gear. It changes what you carry, from a spare tube to a set of plugs, and you still want the tube as a last resort.

Here's what matters, in the order it matters.

What tubeless fixes, and what it doesn't

Sealant handles the small stuff. Thorns, glass, wire, the punctures that would otherwise end a ride. Most of the time you won't know it happened. You'll spot a dried patch on the tyre days later and that'll be the only evidence.

Because there's no tube to pinch against the rim, you can drop pressure. On gravel and mountain bikes that's the real win: more grip, more comfort, fewer flats. On the road the gain is smaller, but it's still a gain.

What sealant won't do is close a sidewall tear or a cut much beyond a few millimetres. For those you need a plug. If the plug won't hold, you need a tube. Knowing that hierarchy in that order is what keeps you riding instead of calling someone.

Setting it up

The parts list is short: a tubeless-ready rim and tyre, tubeless rim tape, a valve, sealant. Where people come unstuck is the tape and the seating.

Tape properly. It has to be the right width for the rim and laid without wrinkles or bubbles, with decent overlap. Air escapes through a bad tape job and no amount of sealant fixes that. If you're chasing a slow leak nothing seems to solve, it's usually the tape.

Seat the tyre before you add sealant. Get it to pop onto the bead shelf with air alone. A tubeless inflator or compressor will do it; a track pump sometimes will, depending on the tyre. Once it's seated and holding, deflate, add sealant through the valve, re-inflate. Doing it in that order keeps sealant out of your inflator and off the floor.

Then go and ride it. Sealant has to get thrown around inside the tyre to coat properly, and a short ride does more than leaving the wheel standing overnight.

How much sealant, and how often

About 60ml a tyre for road, 90 to 120ml for gravel and mountain depending on tyre volume. More isn't better. It's just weight sloshing around.

Sealant dries out. In Sydney you're looking at every three to four months, sooner over summer. Checking is easy: pull the valve core and dip something thin in, or take the wheel off and listen for liquid as you rock it. If it sounds dry, it is.

A tyre with dried sealant is worse than a tube, because you're running a setup that can't self-seal and you've probably stopped carrying a tube for it. This is the most common tubeless failure we see, and it's completely preventable.

The repair order on the road

1. Let the sealant try. Spin the wheel so the hole ends up at the bottom and let it come round. Most punctures seal in seconds.
2. Plug it. If it's still spitting, get a plug in. Push the tool in, leave the plug, pull the tool out. Don't be gentle about it, because a plug that's too shallow works its way back out. Trim the tail once it holds.
3. Tube it. If the cut is too big for a plug, pull the valve out, fit a tube, ride home. Accept that you're getting sealant on your hands.

So the kit is plugs and the tool, a tube, tyre levers, and a pump or CO2. Not much more than you were already carrying.

The mistakes we see most

Letting sealant dry out, by a distance. After that it's cheap or wrong-width rim tape, which causes slow leaks that get blamed on everything else. Then not carrying a tube, on the assumption tubeless abolished flats rather than reduced them. And running pressures so low the tyre burps off the rim in a corner.

Learn it hands-on

We run Fix a Flat and Go Tubeless as a Thursday evening Skills Night at the Annandale workshop. 90 minutes, $90, six riders maximum. You work on your own wheels: tube changes done properly and at speed, a tubeless conversion start to finish, sealant, and plugging a cut we make on purpose so you've done it once before you have to do it in the dark on a wet road.

Doing it once with someone watching beats reading about it five times.