The million-dollar question: Why on earth are you still using inner tubes?

​The advantages of tubeless systems have been clear for years. This has been confirmed by laboratory measurements and practical experience, in both amateur and professional cycling. And yet, countless cyclists ride along roads, gravel tracks and trails whilst turning a blind eye to the facts and continuing to rely on traditional inner tubes. Is this merely nostalgia, or is there a rational decision behind it?

Rolling resistance: evidence from the laboratory

From a purely technical point of view, tubeless tyres have long since won the battle. As there is no inner tube rubbing against the tyre, rolling resistance is reduced. Standardised laboratory tests carried out by BIKE and TOUR clearly show the difference, depending on the category:

• Road bike: Compared with a traditional butyl inner tube, a tubeless setup saves just under 4 to 5 watts per tyre at 35 km/h. Extrapolated across two wheels, riding tubeless therefore makes you about 10 watts faster.
• Mountain biking: Even in a cross-country setup, tubeless tyres save a full 4 to 5 watts compared with butyl tyres. Even in a more demanding trail setup, going tubeless still saves a good 3 watts per tyre.

Puncture resistance: there’s a world of difference

In the so-called ‘guillotine test’ carried out in the laboratory – in which a blade is dropped onto the tyre from various heights to simulate impact with a hard stone – the wheat is separated from the chaff. Whilst a butyl inner tube on a mountain bike often suffers the dreaded ‘snakebite’ even at low drop heights, tubeless tyres, by design, do not have this problem. In the laboratory, tubeless set-ups have been shown to withstand almost twice the force of butyl. Minor punctures caused by thorns or glass are usually sealed by the integrated sealant whilst riding, often without the rider even noticing.

More importantly, because the tubeless system is so puncture-resistant, the tyre pressure can be reduced significantly. This results in noticeably greater comfort off-road, a massive improvement in cornering grip and traction, and even more efficient, energy-saving roll behaviour.

So why the reluctance? The obstacles

If the system is so superior, why are so many cyclists still hesitant? The main reason is the maintenance involved, coupled with the initial cost. Initial fitting of tubeless tyres is not for those who dislike visiting the workshop: the rim must be perfectly taped with special tape, and often a compressor or a special boost pump is needed to force the tyre into the rim bed.

It also adds up financially: a tubeless kit comprising valves, rim tape and sealant initially costs between 30 and 50 euros. Then there’s the issue of durability: the sealant dries out after 4 to 7 months and needs to be topped up regularly at a cost of around 5 to 10 euros a year. For occasional cyclists whose bikes sometimes sit unused for weeks at a time, tubeless tyres thus become a fiddly and expensive maintenance hassle.

Whilst salami repair sticks can save most rides in the event of larger cuts, if the tyre really can’t hold the air any longer, the only solution is to fit a spare inner tube – a sticky mess by the side of the road.

What’s more, inner tubes have come a long way: modern TPU (thermoplastic polyurethane) inner tubes are extremely lightweight and offer minimal rolling resistance, whilst remaining as easy to handle as ever. Although they cost a hefty 15 to 30 euros each, in road bike lab tests their rolling resistance is often only a hair’s breadth behind that of tubeless tyres. Many riders therefore prefer to avoid the hassle of tubeless maintenance.

And yet: it’s all down to the milk!

Plenty of advantages, just a few minor drawbacks – so what are you waiting for? Throw that butyl ballast over the side! With milk in your tyres, the dreaded rock garden suddenly loses its terror: drop the tyre pressure, focus on the road ahead, and off you go through the rocky terrain! And on the road or a gravel track, too, tubeless tyres mean the road is clear ahead: whilst the inner-tube brigade risks frantic evasive manoeuvres at the sight of cracked tarmac, the ‘milk’ brigade rolls right over it with ease. If you want to be faster, you’ve just got to ride smoothly!

A comparison of systems by bicycle category

Conclusion: Who needs what?

• Mountain biking: There are no more excuses. Anyone riding on rough terrain without an inner tube benefits so significantly from puncture resistance, cornering grip and traction at low pressure that the occasional maintenance and running costs are absolutely justified.
• Gravel bike: The perfect use case. The combination of improved comfort on gravel thanks to lower tyre pressure and protection against thorns makes tubeless tyres the logical upgrade for anyone who cycles regularly.
• Road bike: The bastion of the inner tube. Modern TPU inner tubes are hardly any heavier or slower than tubeless systems. So it’s no wonder that the classic tyre set-up still dominates the scene. But, fellow road cyclists, aren’t the days gone by when we used to pump six bar or more into our narrow tyres? Wider tyres and lower pressures are now the order of the day on the road too – offering greater comfort, better cornering and grip in wet conditions. The pros in the peloton have known this for a long time.