Tubeless road tyre buyer’s guide

What is a tubeless tyre?

Since time immemorial, road bike riders have used tyres with separate inner tubes. And, since then, you’ve seen them standing by the roadside, bike wheel off, trying to patch up a pin-prick hole in that floppy black rubber ring.

Tubeless tyre technology does away with all (or at least most) of that. Instead of the air in your bike’s tyre being held in the inner tube, a tubeless tyre makes an airtight seal with the wheel rim.

To do that, the tyre and the rim are made with closer tolerances than a tubed tyre and wheel, and the rim has a tubeless valve screwed into it to make an airtight connection.

The rim also has to be sealed to keep air in. Some are airtight by design, with no spoke holes in the rim bed, others achieve this using an adhesive rim tape applied to the rim bed.

To make sure air doesn’t leak, liquid sealant is poured inside the tyre when fitting (or injected through the valve).

Tubeless sealant is designed to seal small gaps between the tyre and rim, and deals with the majority of smaller punctures, healing them as they happen.

Tubeless tyre technology is the norm in other tyres, such as those found on cars and most motorcycles. It’s been slow to come to road bikes mainly due to the higher pressures used and the need to sort standards and tolerances.

Should I convert my road bike to tubeless?

Ride quality

Supple: it’s a word that’s repeated time and again in reviews. Without a separate inner tube, the overall thickness of the casing is reduced, leading to a tyre that deforms more easily in response to road imperfections, leading to a more comfortable ride.

Lower tyre pressure

You can run tubeless tyres at lower pressures, typically dropping 5 to 10psi from what you’d run with a tubed setup. That’s because there’s no risk of pinch flats if you run over a rock or other bump in the road. The ability to run lower pressures further improves comfort, too.

Puncture protection

As well as avoiding pinch flats, the sealant in a tubeless tyre protects against smaller punctures, often sealing the hole with minimal loss of pressure in the tyre. So hunting for those pin-prick holes in your tyre is a thing of the past.

But even the best tubeless sealants don’t always sort out larger holes or sidewall damage, so it’s still advisable to carry a spare tube and a pump, or a tubeless repair kit, just in case.

If your tyre does get a cut that the sealant can’t fix, we’ve got a guide on how to repair a tubeless tyre.

Lower friction and higher speed

The movement of an inner tube against the tyre’s casing causes significant friction, making tubed tyres slower as well as less comfortable. Butyl inner tubes have the most friction against the tyre; although latex and TPU inner tubes versus tubeless is a closer contest.

With no inner tube at all, and assuming all else is equal, tubeless is usually faster as well as more comfortable to ride.

Reduced rotating mass

Because you’ve done away with the inner tube, you can save a fair chunk of weight with a tubeless setup in some cases. That’s particularly true with the usual butyl tubes; the weight-saving with latex tubes is less, although latex tubes make up for that by being more fragile and leakier.

That saving is countered by the need to add 40ml to 60ml of sealant to your tyre to get a seal and benefit from puncture protection. Also, tubeless-ready tyres are typically heavier than their tubed brethren because they need to be airtight and usually have a heavier-duty bead for safety reasons.

Increased versatility

As modern road bikes offer ever-increasing tyre clearances, many tubeless tyres are available in widths above the standard 25mm. With larger air volumes, you can take in even rougher terrain, heading onto gravel trails to up your repertoire of available rides.

What are the disadvantages of tubeless road tyres?

There are a few things to watch out for if you’re thinking about going tubeless.

Tricky setup

We talked above about the tight design tolerances needed for tubeless to work at road bike tyre pressures. Many tubeless tyres can be set up on a wheel just using a track pump, but as tubeless standards for the road are still in flux, some combinations of wheel and tyre just won’t seat while others are excessively tight. You may need to use a tubeless-specific pump with an oversized air chamber, or a separate booster to seat a tyre.

The former is a pump where you pressurise a reservoir, then release the air into the tyre. That pushes more air into the tyre at higher pressure and faster, seating the tyre on the rim.

For more, read our detailed guide on how to set up road tubeless tyres.

Slow leaks

Once set up, you can often still get slow leaks from a tubeless tyre, due to incomplete sealing to the rim. Spinning the wheel can help distribute the sealant and stop the leak, but, if that doesn’t work, a quick ride up and down the road will often do the trick.

You may need to top up the sealant too, if you’ve lost a significant amount.

Sealant top-ups

The sealant in a tubeless tyre tends to dry out and set over time, so you need to keep an eye on whether there’s any liquid sealant still in there. If there isn’t, your tyre may not stay inflated if you get a puncture.

You need to monitor its level every month or so and keep it topped up. That usually means popping a tyre bead off the rim so you can see how much liquid sealant is left, adding more sealant if necessary and reseating the tyre. Or you can remove the valve core and squirt sealant through it.

Both can be slightly messy but Milkit has a system that lets you suck the liquid sealant out of the tyre, measure its volume, top it up and re-add it to the tyre. It’s a bit pricey but makes maintenance easier.

Non-sealing flats

Tubeless tyre sealant will often fix flats without you even noticing – we’ve had quite large thorn-induced punctures that would have otherwise stopped us in our tracks that have sealed up without us realising, and with a negligible drop in tyre pressure.

But some holes are too large for the sealant. Sidewall damage is often the cause.

You’ll either get a persistent leak or the plug of sealant will blow out if you have anything above minimal air pressure in your tyre. You might want to carry tyre levers, a pump and a spare tube to swap in if that happens.

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