Tubeless, or Not Tubeless? That is the Question.

By Mike Tierney

The sporting bicycle rider, when it comes to wheels and tires, is faced with this decision. And like many bike-related decisions, this one also seems to have been foisted on us by the bicycle industry.

It doesn’t take much of a skeptic to realize that the bike industry’s needs don’t always align with the needs of cyclists. But like most dilemmas, if we arm ourselves with knowledge and think for ourselves, we can choose what is best for us.

A Brief History of Tire Systems

When the cycling boom hit North America in the ’70s, no-one was prepared for the standard tire of the racing and sport riding masses in Europe — the tubular. This racing tire, with its inner tube sewn inside a light, supple tire that could withstand very high inflation pressures, and that had to be glued onto special rims, did not go over well in North America.

Dedicated racers understood the value and accepted the work involved in riding tubulars, but the masses of people attracted to the exercise benefits of road cycling wanted nothing of the ritualistic gluing and repair of punctured tubulars. Thus, they were forced to choose between heavy low-pressure 27 x 1 1/4″ tires or high-maintenance tubulars.

The cycling industry, not one to miss an opportunity, responded around the mid- to late 1970s with narrow, high-pressure clinchers, and cyclists everywhere experienced something they had barely heard of until then — the dreaded pinch-flat. The low-volume, high-pressure tire, when it hit a hard object like a pebble, would compress and pinch the tube between tire and rim, and tiny “snake-bite” slits in the tube would be the result. Still, this seemed to be a small potential price for what was practically a maintenance-free, tidy solution – and clinchers became the status quo, universally accepted by cyclists and all rim and tire makers.

In 1999, two tire companies and one rim manufacturer worked in collaboration to develop a tubeless mountain bike tire and rim system that prevented pinch flats, which were fairly common in the MTB world of low-pressure tires and tubes used in a rocky environment. They named their system “UST,” which stands for Universal System Tubeless. It featured a rim bed without any holes (no spoke nipple holes), a special inflation valve and a dedicated tire that was air-tight.

The system worked well, but no other manufacturers bought into the design. Another company developed its own version of the idea, marketing its own special hooked-bead rim, a sealing tape for its rim bed that had normal nipple holes, and a latex-based liquid that sealed the tire and plugged any small punctures. This was used with success by some but, like UST, never caught on for road bikes for the masses.

Along Comes Road Tubeless, And ‘Tubeless-Compatible’

Tire and rim companies Hutchinson and Mavic collaborated on a Road Tubeless standard in 2006, but it, too, never caught on with cyclists or other manufacturers. It was just about dead in the water, and the industry’s reaction to that was what we have at the present time — “tubeless compatible” rims with a special rim bead hook, and tires from a select few manufacturers that have the special tire bead that hooks into the rims.

Other rim designers, seeing a potential trend, have offered “tubeless compatible” rims and, while they are fine for the few people who went tubeless, the 70-90% who still prefer inner tubes (depending on whose survey you believe) are saddled with very hard tire installation and removal, if they decide to try tubeless-compatible rims but use them for clincher tires.

Rim-to-tire interface had to be made tight so as to allow inflation when no tube is there to help. This issue is quite variable due to rim and tire tolerances and temperature and humidity differences.

Complaints Have Been Legion

The complaints have been legion. Some people simply couldn’t install their tires or remove them when they did suffer a puncture. Lots of us wanted the benefit of the new 23-24mm-wide rims, but we were not pleased with the struggles of tire installation, even when we used proper tire installation techniques.

One rim designer, Pacenti Cycle Design, with their SL23 rim, had the same problems. They had a nice 24mm-wide rim that was widely accepted by the tubeless crowd, but it didn’t make the inner tube people happy. Company owner Kirk Pacenti listened, and for 2015 he came out with a modified version, one with a deeper bead well that made tire installation and removal a breeze in comparison to the previous version.

I have both versions of the Pacenti SL 23, and while a few hours of honing my installation technique make tire struggles less severe with version 1, the version 2 rim just about removes all the problems.

Pacenti explained the difference to me in an email: “Basically, the V2’s bead well is 1mm deeper. A 2mm smaller diameter doesn’t sound like much, but in reality it gives you a 6mm smaller circumference. That is a LOT.”

I’ve heard about two other rims that have gained the reputation of being easier to use than most, but since I haven’t used either of those rims, I can’t personally confirm this.

Another minor drawback, if it is one at all, is that we can’t use the very popular Velox cloth rim tapes on any tubeless-compatible rim and must use the newer style thinner polyurethane-type tapes. Pacenti markets its own tape.

Is this Really ‘Progress’?

But the biggest drawback to the acceptance of tubeless remains the fact that, unless we want heavy butyl-lined tires to prevent porosity, we have to pour a latex-based sealing liquid into the tire during installation. With clinchers, the “sealing” job has always been done by the inner tube, a nice, clean, easy solution.

So within a few years our options “progressed” from gluing tubular tires to rims, to pouring liquid concoctions into tires. Most of us stayed with the normal narrow tire and inner tube system, which for the most part works quite well and is effectively maintenance-free.

Wider Rims, and Wider Tires, Evolved

The good thing to come out of all this, though, is that at around the same time as road tubeless was introduced, rim designers realized that wider rims than the normal 19mm-wide rims allowed tires to hold a larger volume of air, and that allowed us to use lower pressures. This had two benefits: a lesser chance of the dreaded pinch-flat, and more comfort.

Also around that time, tire makers realized that the same benefits could be had by going with 25mm-wide tires, and these were quickly adopted by many cycling enthusiasts. After all, the 20-23mm tire width was first developed for European racers and not the average recreational road cyclist.

Almost all the cycling world, including top pro racers, is changing to 25mm tires — or wider, especially for rough roads. And the move to wider rims seems in full swing, as well, for clincher-only and tubeless-compatible alike.

What Does the Future Hold?

So what is the future of tires and rims for recreational roadies?

Wider rims that allow us to use lower pressures are a big step in the right direction, but collectively, cyclists simply haven’t embraced tubeless. It seems clear that most riders simply do not want to deal with the extra muss and fuss of using a system that requires extra work, different products and, potentially, a gooey mess in the process.

Can we hope that the industry abandons the dead-end tubeless system?

It’s interesting to note that most of the big cycling tire makers have chosen to sit quietly on the sidelines on this issue. They have not marketed tubeless tires as yet, but they do seem to be embracing the move toward wider clinchers to fit on those wider rims that are gaining in popularity.

25 is already the new 23. One wonders what the new 25 will be?

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Mike Tierney writes The Wheel Builder column for RBR. He is a life-long cyclist from the UK who has spent most of his adult life in Canada. Mike has been a passionate home wheel builder for the past 52 years and specializes in taking the mystery out of wheels and wheel-building for Newbies. Hundreds of cyclists have built their first wheels with online help from his wheel building website, MikeTechInfo.com. Send your questions about wheel building and wheel maintenance to Mike at [email protected]. Click to read Mike’s full bio.