An objective look at tubeless tires

Biking Skills

October 18th 2019

The mountain bike market is a thriving source of new technologies and developments that often, after a few years, filter over into the road bike world. Tubeless tires are a perfect example of this. Today, we’ll take a look at the pros and cons of this technology and what alternatives may solve the same problem.

What are tubeless tires?

In a tubeless-tire setup, the inner tube is replaced by some high viscosity fluid–OK, goop—that finds its way into any punctures and clogs the holes. This setup requires an airtight rim, with no internally visible spoke heads, and a very tight tire-rim connection.

TRADITIONAL CLINCHER TIRE

There are a lot of call-outs here, but the main idea is that you have a Rim (1) that holds the tire in place with the Bead (4), inflated by an Inner Tube (5), protected against internal flats by a plastic Rim Strip (2).

 

TUBELESS TIRE

Tubeless tire cross section

With a tubeless tire, the Rim (1) becomes more important, often requiring more of a lock to hold the bead in place. The Rim Strip now has been replaced by more airtight (and waterproof) Tape (2). You’ll want a Tire (3) that works well with the rim, and relatively fresh Tire Sealant (4).

It’s possible to convert a tubular set-up to a tubeless set-up, and we’ll go into that shortly, but your biggest success will be with tubes and rims designed to work together in a tubeless design.

But first, the all-important question…

Why are we considering this?

Here, in no particular order, are some of the common reasons for switching to tubeless, which we’ll inspect with an immediate sniff test.

FEWER FLATS.

Mountain bikers ride in all terrain, including jagged rocks and around plants with aggressive thorns, such as goathead thorns and cactus spikes. The appeal of a self-healing tire in mid-ride is evident. MTB bikers also like to ride with more traction, at lower tire pressures, leaving them susceptible to self-inflicted flats called “pinch flats”, where the rider’s weight in the rim pinches a hole in a thin inner tube.

goathead thorns

Goathead thorns (Acanthospermum_hispidum) are not a cyclist’s best friend.

Road bike riders have fewer obstacles, but may encounter broken glass. There’s no reason on a road to underinflate tires, so any pinch flats are typically due to inadequate tire pressure.

Assessment: True.

EASIER FLAT REPAIRS.

If you have a hole that’s too big for the tire sealant to fix, and you find it bubbling out–you found your puncture already!–you can just stick a bit of foam into the hole with an insertion tool, spin the wheel to stir up the sealant, and reseat the tire with a CO2 cartridge. If that doesn’t work, or you have a sidewall flat where the sealant doesn’t help, Game Over; it’s time to use that spare inner tube you’re carrying and ride the conventional way.

Overall, using sealant sure beats flipping the bike for tube work every time.

Assessment: Often true.

LESS WEIGHT.

So…you’re swapping out a 200 gram inner tube for 160 grams of sealant, a 7 gram stem, and an 80 gram single-use CO2 cartridge/adapter pump combo. Plus you’ll still want a spare tube for those bad repairs. How is this a weight reduction?

Assessment: Myth.

MTB RIDE QUALITY.

Sometimes you’ll see it described as a “less harsh ride.” This often the result of riding flat-free at lower tire pressures, which absorb more of the microvibrations on rugged trails. This improvement is also described by users of tire inserts–which also help with fewer flats.

Assessment: Often true.

LESS MAINTENANCE.

The idea here is that you spend less time fixing flats and more time having great rides. But if your sealant isn’t fresh enough, you’re going to spend some time dealing with stuff like this, either before your ride or during it. There’s even an informal name for it–Stan’s Coral, named after one of the leading brands of tire sealant.

Stan's Coral

To avoid this, you’ll be pulling your tires off even between flats, to either check the viscosity or replace the sealant.

Ultimately, to ride safely at lower tire pressures and spend less ride time fixing flats, you’re signing up for more maintenance time back at home and in the shop. In the absence of better  alternatives, that may be a valid tradeoff to make, shifting maintenance to a more convenient time and place.

Assessment: Myth.

Is there a better alternative?

For years, Tannus has made a completely airless solid tire, and we’ve considered it but haven’t offered it yet. But now they’ve taken tire inserts to a whole new level with the Tannus Armour, and we have to give it a try as a dealer. Here’s how it works.

Tannus Armor cross-section

The Tannus Armour fits around the inner tube, protecting both against significant thorns like goathead and cactus, as well as sidewall dangers.

Tubeless enthusiasts will be quick to note that this set-up still includes a tube, so…more weight! Yes–not that weight savings was much of an advantage anyway–but this is clearly more weight. However, you don’t need to carry that pump or the extra tube, so it’s a wash again.

And you can run your MTB tire at lower pressures, for higher grip, just like with tubeless. In fact, all the way to flat, if you need to, because the foam inset protects your rim from damage and your inner tube from pinch flats.

Run flat with Tannus

Tannus Armor: Safe at any pressure.

Ultimately, this insert provides all the benefits of flat protection and better ride with a tubeless tire, but without the need to maintain fluid quality inside your tires. We are starting the process now of becoming a dealer for Tannus Armour inserts in 26″ and 27.5″.

Will Flatbike be selling bikes with tubeless tires anyway?

Flatbike’s solution to flats on MTBs will be Tannus Armour as an add-on option. On road bikes, we’re going with Gatorskin tires as a default, with the possible later option of Tannus solid tires as an optional no-cost swap-out. We don’t see a move to tubeless yet, although we may eventually build around a rim set that meets the UST (Uniform System Tubeless) standard, if we can find one that works well with standard clincher tires too.

There are lesser semi-standards, such as “tubeless-ready” or “tubeless compatible”–amorphous designations which mean that they are easier to convert but still may not work optimally with all tubeless tires. But if we do change rims to ease the tubeless transition, it makes sense to go directly to the gold standard for an optimal customer experience.

In the meantime, for current riders, CHANGE bike MTB wheels can be swapped out for tubeless rims or, with some degree of success, converted from clincher tires to tubeless. Here, compliments of SingleTracks, is an article explaining how to convert a wheel from clincher to tubeless at the lowest possible cost–with Gorilla Tape in the most professional way imaginable!: https://www.singletracks.com/blog/mtb-repair/tech-how-to-ghetto-tubeless-for-mountain-bikes/

Rim taped for tubeless tires

It looks like carbon fiber, but it’s just really, really good taping work.

And if you’re committed to moving to tubeless with your existing Mavic CrossRide rims–the rims that ship on all CHANGE folding rugged hybrid and folding mountain bikes–but aren’t convinced you can cut and lay down tape this accurately, you’re in luck. Mavic has a rim tape kit specifically designed for their 26″ or 27.5″ wheels, so you can start out with all the right tape sizing.

Mavic rim-taping kit

One kit that gets you part to tubeless tires on your existing bike. Yu’ll just need a valve, tubeless tire, and tire sealant like Stan’s.

Either way, whether you jump on the tubeless-tire bandwagon or go counterculture with Tannus inserts, you’re headed for fewer flats, more trail traction, and better rides.

 

Happy riding!

Bob Forgrave's Signature

Bob Forgrave is president of Flatbike, an
ecommerce company offering full-size folding bikes
and kits to make any bike take up half the space.

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425-985-6219


6 responses to “An objective look at tubeless tires”

  1. David says:

    When you say tubular you mean clincher.
    It is not possible to convert tubular to tubeless. They’re completely different wheel systems.

    • Bob Forgrave says:

      Thanks, David. You’re correct. Edit made. In the comparison between traditional clinchers and tubeless clinchers, I forgot about the old tubular design that involved gluing the tire to the rim! Never going there; never will…

  2. Ben says:

    I personally have tried tubeless and hate it passionately. Messy as heck requires more regular maintenance and top up, much more expensive, isn’t as easy to fix if you do get a flat that requires you to stop and it soaks through the side walls causing mold to grow on the tire castings during winter storage.

    • Bob Forgrave says:

      Thanks for a valuable perspective, Ben. We couldn’t agree more, which is why all our folding MTBs go out with Tannus Armour, instead of tubeless!

  3. Ron Williamson says:

    Tannus is really heavy and all rotational weight. Saying it’s a wash because you have to carry an extra tube is just not true. 200 grams in a backpack is much different than having to spin extra weight. Plus tannus adds tons of rolling resistance. Felt like I was pedaling uphill with the brakes on while on flats.

    • Bob Forgrave says:

      Ron, are you speaking about Tannus Armour inserts or Tannus airless tires? If the second, I’m with you and am planning to quantify the rolling resistance difference vs. inflated tires in a future article before we start (or not) carrying airless tires as a separate item. (We’ve used airless tires in limited capacity with success on one bike model).

      But Tannus Armour inserts are altogether different. First, it’s a light foam, so the rotational weight effect is limited. As for rolling resistance, that’s a factor of tire shape (knobs or not), surface area (wide or narrow), and tire inflation (soft or not)—all of which are about the tire, not what’s inside it. Two of the top uses for Armour are pro MTB riders who can deflated their tires for more grip and lateral stability on technical terrain, and e-bike riders who ride more inflated with less chance of walking a bike back.

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