The folks at SRAM know how much of a pain it can be to inflate a tubeless tire. Seating a tubeless tire properly can mean the difference between awesome ride quality and a quick pit stop on the site of the road. So SRAM’s patent shows a redesign to the inflation valve to make it easier to get tubeless tires to seat.

How inflation valves work now

Tubeless wheels come with inflation valves that you pop through the valve hole and seat into place. And the valve is generally held there by a threaded nut.

The inflation valve — assuming it’s a Presta valve, which is most common on bicycles these days — has a small threaded barrel at the tip. Unscrewing this barrel opens the inflation valve’s air chamber.

The part of the valve that sits within the rim itself has an opening. Once you attach your pump to the barrel end and start pumping, air flows through the valve and into the rim/tire interface.

The force of the air from the pump shoots directly through the valve. That means the air gets blasted at one spot on the tire. This is essentially a force on the radius of the tire.

Since air needs to apply pressure to the entire tire circumference in order to seat it on the rim, current tubeless inflation valves are inefficient at the seating process. If you’ve ever tried to seat a tubeless tire with a hand pump, you probably already knew this.

What SRAM’s valves change

inflation valve fig 5

FIG.5 shows an illustration of how SRAM’s inflation valve would work. A tube lives inside the rim/tire interface and redirects the air blown through the valve itself.

SRAM’s patent outlines an inflation valve that’s all about that sweet circumference.

The outside of the valve, in this patent, remains largely the same as what we’re used to. The real magic lies inside. The part of the inflation valve that sits inside the tire and rim features an additional aspect.

A  body that sits perpendicular to the valve itself (and is attached to the valve itself) helps redirect some of the inflation air around the circumference of the wheel. That should make it easier for you to inflate and seat your tubeless tires, even with a hand pump.

The patent outlines several versions of what may ultimately become the finished product. The simplest version features a tube-like structure attached to the valve itself. This would likely be made of rubber, like an inner tube.

Other versions outlined in the patent expound on this simple concept. The tube itself may feature reinforcing ribs or structures inside, for example. These could serve a dual role. First, such structures would help keep the tube itself open at all times. Second, the structures in the valve channel can help redirect air more efficiently.

Is it cool?

Presta valve variations

These illustrations show two different variations on the valve shape and function. The one on the left features an internal latticework to provide structure, and to help redirect air more efficiently.

If it works, yes! And SRAM’s not the only company chasing this unicorn inflation dream.

Tubeless tires are only becoming more prominent in all disciplines in cycling. Mountain bikers have long suffered through the finicky nature of inflation valves and tire/rim combos. Now, with road riders and gravel riders cottoning onto the advantages of tubeless, it has only become more important to have easy inflation methods.

So SRAM’s invention would certainly make life easier for cyclists of all stripes. It would eliminate, or at least reduce, the need for an air compressor when seating tubeless tires. It could indeed make it very easy to inflate and seat tubeless tires with a hand pump, too.

Another nifty advantage to SRAM’s potential inflation valve system is its adaptability. A lot of mountain bikers have caught onto the benefits of tire liners like Cushcore. Similarly, gravel riders have begun using such inserts to help prevent flats and improve cornering stability.

The downside? Installation is a huge pain. And once you get the inserts inside your tire, you still need to inflate the tire and get it to seat. SRAM’s inflation system can help there by blasting air along the circumference of the tire and liner, rather than directly at it.

This should, in theory, make it much easier to seat tubeless tires even with inserts inside. My blood pressure just dropped thinking about it.

Patent research assistance provided by Wheelbased.com. Check them out for deeper dives on some of these patents and more.

19 comments

      • Dockboy on

        I bet a butyl tube would redirect air just fine. Take an old, small for the tire tube, cut out these six inches, and I bet you get a good bit of this innovation.

        Reply
        • David on

          …and while you’re at it, add a couple of lightweight plastic rings to keep the tube from collapsing. A couple of zip ties held in place on the inside of the tube with a dab of super glue would do it.

          Reply
        • mudmudmud on

          That’s easy enough to find out. I have a tire that stubbornly refuses to seat on the rim. I’ll try it next time. Don’t see why the tube section would collapse.

          Reply
  1. Joenomad on

    The Tour of Flanders was won on clincher wheels with regular tires with latex tubes. Most of my issues with road tubeless has been between the tire and rim interface and not the valve.

    Reply
  2. Shafty on

    This is a mostly useless device, as it fails to address the the most common issue with tubeless tire installation. It’s not “defeating the leaking air with high flow”, it’s *prevent air leaks at the start of installation*. I don’t believe different valves can accomplish that.

    Not only must the bead seat area be optimized and standardized, but the trough of the rim must be as well. Several manufacturers have successfully produced rims that don’t leak air from the moment the tire is mounted. That’s key, and allows a user to seat the tire, even without sealant, and often with only a hand pump. If you can’t deal with issues on a long ride or trailside, you could be stranded.

    I don’t think “it’s possible to seat your tires” is a high enough bar. It needs to be easy and similar in behavior to inner tubes.

    Reply
  3. Henry Krates on

    This story and the fact that some pro teams are using inner tubes are validating my decision to not go tubeless. If I’m going to work that hard on my tires I might as well ride sew-ups again.

    Reply
  4. Kieselguhr Kid on

    But… The tire itself is a tube that redirects air around its own circumference…
    How does adding a section of inner tube (rigid or not) help in any way?
    Also, tire inserts, while making it difficult to install and remove tubeless tires, seem to make them easier to inflate as they help press the bead against the rim forming a seal.

    Reply
  5. WorkOnSunday on

    thought Zipp (sram) did a good job with their latest 303 series wheels, mounting were super easy (i came across 3 sets so far, none broke a sweat…..or thumb).

    for this solution, i would be very worried about the wheel balance and also those unsealable puncture where you need to replace this with inner tube (logistically how is it going work, put that device back into your back pocket when it’s all soaked in sealant?

    Reply
  6. dangerseals on

    Definately a solution that nobody is asking for. They’re trying to say that your tire won’t seat because there are air forces pushing your tire away from the valve (push it with your hand stupid) but the issue is 100% hoop design. Most manufacturers have dealt with this in recent years, and almost all new wheels seat up with no problem – it’s every “tubeless ready” hoop from before 2014 that needs to be burned in a giant pile.

    Reply
  7. Ant'ney on

    The seat with a compressor or CO2 cart is a 1 time per tire thing for me on every modern MTB tire/ wheel combo I have tried over the past few years. Foldable Kenda, Bontrager, Maxis trail tires on WTB, Ibis and no-name rims. Maybe this is targeted at road/gravel, but I think it’s a non-issue for mountain.

    Reply
  8. Jason on

    Why are we still using presta valves? A move to schrader valves would make all this tubeless stuff so much easier. With all the rims getting a lot wider in the last decade there’s plenty of room for it now.

    Reply
  9. typevertigo on

    The tubeless valves that come with Vittoria’s Air-Liner Road tire inserts use basically the same concept, but omit the perpendicular extensions. There are additional perpendicular holes on the base of their tubeless valve that help divert the air sideways. That seems to me like a more elegant approach.

    Reply

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