mavic ksyrium pro carbon sl UST tubeless road bike wheels and tires

When mountain bikes first moved to tubeless, the primary standard was UST. It promised a standardized rim and tire interface, and tires that would essentially lock into place and hold air without sealant. While it worked, many brands ended up using a non-standard “tubeless ready” design that was far lighter, but required sealant and had wide variations between rim profiles, tire beads and abilities to hold air on its own. And that wild west is what’s largely prevented road tubeless from taking off. We covered this saga in two parts here and here.

Now, however, Mavic is standardizing things and doing it big, bringing virtually all of their road wheel and tire systems into the UST fold. The new standard promises easy installation and inflation, better performance, and run flat safety…

UST works by creating a defined bead hook shape and size, then matching the tire’s bead shape to it. This lets the tire bead pop into the bead socket and stay there, even with extremely low or no air pressure. So, where some tubeless setups risk losing the tire if you have a sudden blowout, UST shouldn’t pose the same safety risk. With the tire stuck on the rim, even when flat, you retain more control to safely pull over and fix it.

Other benefits of the system include lower rolling resistance and better grip. The reduced rolling resistance comes by eliminating friction between tire and tube. In Mavic’s tests, they reported a 15% reduction at the same tire pressure. Even when reducing tire pressure by 15psi, it still showed a 5% improvement in rolling resistance while also making the ride more comfortable without worrying about pinch flats.

This system also saves weight. Despite the UST tire weighing about 45g more than the non-UST version, their UST wheel/tire system with sealant comes in 40g lighter than a comparable tire with tube. And with their FORE drilled rims, which don’t break the surface of the rim bed to insert the spoke nipples, you won’t even need rim tape.

Mavic’s new Yksion Pro UST tires use a Kevlar bead, are more pliable than carbon beads, making them easier to install and remove. They also get a new rubber compound called 11Storm that, they say, is a good blend of grip and lower rolling resistance. They’ll be available in 25mm and 28mm widths.

Mavic Cosmic Elite UST wheelset – All photos c. Mavic
Mavic Pro Carbon SL Disc UST
Mavic Pro Carbon SL Disc UST

US pricing and availability for all of the new UST road wheel and tire systems is:

  • Comete Pro Carbon SL Disc–$1899, 1755 grams (available Q3)
  • Comete Pro Carbon SL–$1799, 1635 grams (available Q3)
  • Cosmic Pro Carbon SL Disc–$1899, 1570 grams (available Q3)
  • Cosmic Pro Carbon SL–$1799, 1450 grams (available Q3)
  • Cosmic Elite Disc–$499, 1770 grams (July availability)
  • Cosmic Elite–$449, 1850 grams (July availability)
  • Ksyrium Pro Carbon SL Disc– $1899, 1510 grams (available Q3, shown at top of post)
  • Ksyrium Pro Carbon SL– $1799, 1390 grams (available Q3)
  • Ksyrium Pro Disc–$1099, 1620 grams (July availability)
  • Ksyrium Pro–$999, 1420 grams (July availability)
  • Ksyrium Elite Disc–$799, 1690 grams (July availability)
  • Ksyrium Elite–$699, 1520 grams (July availability)
  • Allroad Pro Disc–$1099, 1660 grams (available Q3)
  • Allroad Elite Disc–$799, 1720 grams (available Q3)
  • Allroad Elite RB (rim brake)–$799, 1600 grams (available Q3)
  • Open Pro Disc–$99, 420 grams (available Q3)
  • Open Pro–$99, 420 grams (available Q3)
  • Yksion Pro UST (tire)–$69, 260 grams
The Mavic Allroad family was already available as a UST system and carries over.

Technically, the system doesn’t require sealant to hold air, but Mavic recommends adding about 30g of sealant per tire as a defense against punctures. They say the new Road Tubeless UST standards are being approved by ISO and ETRTO, which define the rim contour designs and diameters. By using an ETRTO standard for defining UST for road, they’re opening the door for others to follow suit and create an ecosystem of compatible wheels and tires. And their tires are made for them by Hutchinson, so perhaps we’ll see UST tires from them soon, too. Mavic helped create the UST MTB standard in 1999 along with Hutchinson and Michelin, and for a time those companies and Shimano were working to create a road UST standard before abandoning the process in 2005. Fast forward and new manufacturing processes and a growing interest in road tubeless and the standard is now set.


  1. When are the Open Pro Exalith rims coming out? It seems to be the only known new product not included in the list above, and all of the other stuff is up on Mavic’s own website as well. I hope they haven’t decided to not release it…

    • Exalith…the only Mavic “innovation” I’m interested in. They’re so late to the wide rim party and once they come, they’re still years behind.

      • I don’t agree, Mavic will provide reliable and easy to install tubeless to the mass. That’s something huge. I was a UST user for years and never considered tubeless to be some kind of dark magic. It just worked. Now i use TR on all my bike because i’m racing, it’s lighter, and mtb ust is essentially dead. While it works it’s a true headache. I need a lot of tools and accessory to make it work and still some tire will make me loose sometime easily 30 minutes to be correctly seated (try to install and fail, remove valve, inflate with chamber, remove chamber, add valvle without core, seat, add sealant with syringue, add core, reinflate…).

      • I will add that exalyth in my opinion is not interesting. I had mavic ceramic, it brake marginally better in some situation but it will wear too, can do horrible sound from time to time. Rim and pad are super expensive. It’s not money wisely used. Standard rims are very good tho.

        • This works FAR better than their ceramic rims…yes, they surely chew up pads though.

          I haven’t had any issues with my other tubeless wheels. Magic is doing nothing special but offering another set of tires

          • Veganpotter – really recommend you go deeper into the story. what we’ve introduced is truly a game changer in terms of offering something safe and easy to use while retaining all of the benefits of road tubeless. the best part, the ideas and technology are available for anyone to adopt into their products … for free.

            • Working in the field, everything else is already easy to use;) Except owning Mavic hubs…or ordering Mavic spokes

    • Hi, Chad from Mavic. I can offer a little more on this. Indeed, the Exalith is not quite ready. However, James is correct in that we are still working on the Exalith versions and they will come in the future. After the initial testing we were not satisfied with the results since the dynamic of the rim and tire interface is very different with tubeless vs. tube-type.

      So, rest assured that’s it’s coming and we’re working quickly to have the best solution.

    • blah blah blah – no, you aren’t “stuck” with Mavic tires. However, the easy of use and safety are only guaranteed with Mavic tires. We found enormous variances in other tubeless tires that can make a tubeless system hard to use, unsafe or both. so, one of the main benefits of our “system” is that by using our wheels and our tires you end up with a very solid and high-performing solution for road tubeless.

      not t mention that our new UST tires have tested to be a great compromise between high grip and low rolling resistance. whereas, with others, you only get one of those two things.

      i hope this helps.

      • Hi there Chad,

        Do you think that these new wheels could be used for cx with say a Clement tubeless cx tire? ( at much lower pressures of course) also, a bit off-topic, but does Mavic have any plans to update its venerable Reflex tubular rims ( or should they just be kept in their current venerable model?)


        Ted S.

        • Hi Ted – of course you can use a Clement CX tire but we cannot make any claims about how it will perform in terms of safety and ease of use. It might be OK, but without doing any of our own testing it is impossible to know. As you’re running lower pressures the risk is lower but again, we can’t guarantee safety and that it’ll be easy to intall / uninstall.

          For the Reflex rims there aren’t any short term plans but I’ll ask about it to the product guys. I’m sure you’re not the only one who would like it. That said, have you seen the new Open Pro UST?!

          • I have indeed seen the new Open Pro rim, it’s looks really nice and looks great on that Campag equipped bike that I saw on this Website.

            • As a shop guy, I’ve rarely seen a loose fit and rarely too tight of a fit. I wouldn’t want a rim with such a narrow internal measurement and dealing with your antiquated freehub isn’t fun either…easy enough to do but annoying when you rarely need to touch other hubs.

    • Hi Lewis. It is a 40g savings over a tube-type system and that INCLUDES the weight of the sealant. So, the UST road tubeless system is 40g lighter than the similar tube-type system.


    • Great question. When using tubeless, our recommended maximum pressure is:

      25mm on 17mm internal width rim – 7 bar / 100 psi
      28mm on 17mm internal width rim – 6 bar / 87 psi

      25mm on 19mm internal width rim – 6 bar / 87 psi
      28mm on 19mm internal width rim – 5 bar / 70 psi

      30mm on 22mm internal width rim – 5.8 bar / 85 psi
      40mm on 22mm internal width rim – 4.5 bar / 65 psi

  2. No one cares about the performance benefits compared to tube system. What are the advantages over tubeless ready? That you can skip sealant and that the bead stays on at 0 psi. Not groundbreaking, and not necessary IMO. Sure a tri guy will skip sealant to save weight, but you can go super light on sealant with tubeless ready and have the same performance gains. Bead staying on, a bead popping off during a flat would be scary, but since regular tubeless ready virtually eliminates or slows flats, I doubt this is an actual gain either. Mavic, late to a game as always, but this time no one is going to play.

    • Rideifbikes – I encourage you to look a little deeper into the story. Until now, road tubeless (any kind) has totally ignored how the wheel, rim and tire work together. That is why there are so many stories of tires blowing off of rims / wheels and so many storeis of roadside nightmares because the tire wont come off after a flat.

      You’re right, road tubeless is not something new. And you’re also right, we’re late. But, what we’re bringing is a “standard” or benchmark for the tire specifications and manufacturing consistencies. That, along with the UST rim profile, most certainly is something new for road tubeless. We are the only brand that will say that our system is totally safe and as easy (or easier) to use than a tube-type system. So, you can have all of the benefits of road tubeless (however you prioritize them) with the added confidence that it is safe and the added benefit of it being very easy to use.

      We guarantee you that you will not find a tubeless ready system that is as wasy to use as ours with the added benefit of total confidence in the performance and safety.

      Happy to discuss further in a constructive way if you like. Not every product innovation can be sexy, but the technology behind our UST road tubeless system will hopefully define the future of road tubeless and ensure products (from all brands) perform as expected in a safe and user-friendly way.


      • Chad,
        It’s not true that Road Tubeless has ignored how the rim and tire work together.

        It’s always been designed as a system. It wasn’t until the ‘home brew cowboys’ started cobbling together their own B Fit ideas that things started to go wrong.

        The Hutchinson/Shimano system, which was the first system launched, was designed around a mechanical fit between the tire and rim. The tire will not come off unless you release the bead all the way around the rim.
        Campagnolo/Fulcrum, Easton and others use the same system.

        • Thanks Mint Zebra, totally understand where you are coming from. However, things have changed so much since the initial Hutchinson / Shimano work that it is a bit like comparing apples and oranges. The materials are so much different and, maybe, what would be more accurate is to say that what we’re offering is CURRENTLY the only system that has been truly designed together from the ground up. Even though the orignial Hutchinson / Shimano system was designed around a mechanical fit, it’s only half of the story. What we’re offering is the fully integrated solution that goes beyond the fit.

          There will be an “engineers talk” on our website soon. If you would like to discuss more after reading that I would enjoy the discussion.

      • Rant incoming –

        “Until now, road tubeless (any kind) has totally ignored how the wheel, rim and tire work together. ”

        I must respectfully disagree with that. The Shimano/Hutchinson “RoadTubeless” standard correctly identified how important it was for the rim and tire brands to design to a common standard, many seasons ago, and it works. Mavic chose not to implement it, perhaps because of “not invented here” syndrome, high licensing costs, sour grapes, or some other reason we aren’t privy to.

        Kudos to Mavic for getting on board now. It’s better than tires with inner tubes in just about every way and seems well thought out.

        But given how long ago Mavic had the solid rim bed needed to make this work without rim tape, it is frustrating that they wouldn’t make a small change to the rim extrusion shape to match the Shimano/Hutchinson specs and enable tubeless use like 10 years ago. Mavic was so far ahead with the solid rim bed but never did anything with it! As a result the industry missed an opportunity to have dialed road tubeless rim/tire compatibility.

        So now with the introduction of Mavic “Road UST” we now have at least 3 different rim types called “tubeless” that are all different – the old Shimano/Hutchinson type, the new Mavic UST type, and the Stan’s type, (which doesn’t match the rim shape specified by Shimano/Hutchinson, but still claims compatibility with the tires). And probably more variants too! I would not want to be the rider trying to figure out which tires (Hutchinson RoadTubeless, Mavic UST, and others that just say “tubeless”) will work on my rims without blowing off at high speed. Does a Schwalbe One Tubeless tire work on #1, #2, or #3? Some? All of the above? Who knows. It’s pretty scary actually that tires and rims with the same ETRTO size label don’t work together in some cases.

        In particular cyclocross has great potential for tubeless if someone can make it work without burping, seal up easily, and handle low PSI. Riders could change tires for race conditions easily instead of buying multiple wheel sets with tubulars. But with multiple competing rim and tire interfaces it seems like we are moving away from that rather than closer toward it…

    • Hey Rideifbikes, How often would guess the sealant would need refreshing in a tubeless-ready road tire system? You know, just as a practical matter for regular, everyday riders? Our household has 4road and 4cx plus 2-700c commuters(not counting mtb or bmx or beater/cruisers). Cuz, we all want performance gains.

  3. Chad, I see on the website that the internal width for the new UST versions is 19mm vs 17 mm for the non UST versions (ksyrium and cosmic pro carbon for example). did the external width also change ? will the non-UST versions disappear ?

    • Jan – the external rim width will stay the same even thought the internal width is increasing. The alloy non-UST wheels are being phased out now and the carbon non-UST wheels will sell out later this year and we’ll have the UST version exclusively moving forward.

  4. Chad, by releasing a dimensioned rim profile, is Mavic allowing other manufacturers to use the UST profile without licensing?

    • The patent on UST expires in the very near future. So, it will be open and free for anyone to use. In addition, there is an ETRTO working group that will come with an established “norm” / recommendation for rim specifications in 2018 and it (most likely) will be the UST dimensions. We truly hope the UST specifications will be adopted by those who are not already using it to ensure safety for consumers. After that, the tire manufacturers have their own work to do to be sure their tires are working within the norm in “real world” consumer scenarios. That is the bigger work since there are no standards for tires in either tube type or tubeless. They simply must reference the ETRTO standard for the rim without any other considerations. This is the reason why we can be 100% confident in the safety and ease of use of our system … we’ve designed them together.

      • How far into the future is the near future in which the UST patent will expire? Will Mavic seek to renew the patent where possible? There’s little motivation for other rim, wheel, and tire manufacturers to produce UST products until that patent expires. That kind of puts a big brake on UST as a standard.

        I’m not sure that ETRTO making UST the standard for rims will change much in terms of other manufacturers. ETRTO has already proven itself to be behind the times and the current state of the art when it comes to tire size vs. internal rim width.

        In the long run, it’s hard to see the industry coalescing around one tubeless tire standard. As an example, look at what we have with BB standards.

        • Raymond is right, we can’t renew the existing patent. But, we could have evolved the patent to protect our patent for 20 more years if we had wanted. Instead, one of our goals was to make this information available to all brands at no charge. We want to support the consumer as a partner in moving the industry in a direction to provide the best solutions for cycling. So, next year, when the patent expires … it’s totally open. Also, FWIW, the cost for licensing the UST technology in the past was minimal ..

  5. Excellent news – well done Mavic. It sounds like many of the qualms I’ve had about road tubeless have been addressed. Could we have some 650b rims too, please?

  6. Alas. Now for somebody OTHER than Mavic to give it a try. Sorry–I still remember the Velonews Editor and his magical exploding Mavic spokes.

  7. Used to mtb race with mavic tubeless on 26ers, yes 26ers, and never had a problem with flats, punctures, or tires rolling off rim with hutchinson pythons on Mavic UST. Have not tried 29er tubeless with their wheelset, but when I first tried stan’s those things were scary, flexy, burped like hell, and have not looked back. Have used tubeless Shimano tubeless for road for 5 years without a single catastrophic failure, burp, or cut so bad that I could not get home. If they are as good as those then everyone will benefit, as it is just as easy to put these on as putting in a tube.

    • I’m actually pretty impressed with the Schwalbe Pro Ones and G-Ones. They’re easy to mount and ride great IMHO. Interestingly I, personally, was never able to get the Mavic Yksion Elites to mount tubeless on the Mavic Allroad wheelset they came with. But I did install the G-Ones tubeless on those wheels in about 15 minutes with a track pump. The G-Ones on the Allroad wheels have worked great for six months. The Pro Ones on my Ultegra wheel set have also worked well, though I’ve had one puncture–which didn’t seal too well with Stan’s, so I had to put a patch on the inside of the tire.

    • Exactly. The Ultremos were garbage, the Ones were pretty good but the Pro Ones are garbage.

      I’m intrigued by the $69 price point on the Yksion. That should mean that the discount sites are selling them in the $40-$50 range which is unheard of except for the garbage Schwalbes.

  8. How will Road UST being ETRTO compliant mesh with the wider (19-21mm internal) road rim trend?

    From here:

    “Example of reading: a 23mm tyre can be safely mounted on traditional rims of 13mm to 16mm (internal width). On any rim wider than 16mm, it is not possible to use a 23mm tyre safely.

    On the other hand, a rim that is 21mm wide internally, can only accept tyres from 35mm and above.”

    For instance Specialized CLX rims have 20.7mm internal width and were optimized aerodynamically for 26mm tire shape. A 23mm Pro ONE on the CLX rim makes a 26mm tire shape but this is outside of ETRTO norms. Granted the CLX aren’t UST but the trend towards wider road rims (in part popularized by Hed) seems is ignoring ETRTO.

  9. Is there a reason there is no 23c option? I”m a biggish dude and ride 25s, so not that I care, but I assume there are folks who still want/need 23s?

  10. The problem with the old standards was that the ETRTO didn’t adapt when rims and tires got wider.

    Since rims with internal widths of 21+mm are already a thing, here’s hoping the UST standards will be able to adapt.

  11. Skimming the article, it seems that Mavic has fixed several flaws with the original UST (weight) and spotted a good segment for this to work. However, for this to truly work, more companies (both wheel and tire manufacturers) need to pick up the tech.

    • Fortunately for us, Mavic is a tail that wags a pretty big dog. In the bike industry, they have probably the biggest install base of any one brand of wheels.

  12. The mavic hate is strong in some posts. I for one welcome our new tubeless road overlords.

    Seriously, this is better than a +1mm rim for most of us. I’m been using ghetto tubeless on road for a long time now and its been great. I’m glad a big brand is jumping all in. More choices. better tire interface, etc.

  13. As long as I can keep buying replacement Open Pro C’s every few years, then im happy, still the best all round rim.

  14. A proper standard for road tubeless is welcome after several failed attempts. Though I’ve ridden tubeless for 1.5 years with DT Swiss wheels and Schwalbe Pro One’s with zero issues.

    Sad that Mavic is always a couple millimeters behind the competition in rim width!

      • Hey Chad, I’m also a bit worried about rim width. I really don’t have any data but have been riding 23mm (external) rims with 23c (and now 25c) tires for years. Specifically, if I mount a 28c tire on your Ksyrium rim, will it clear the brake caliper? (Given that I’d have to set the pads closer for the narrower rim)

  15. I like the reported benefits regarding ease of installation and the safety from not having tires blow out on a puncture. I’d really hope that Mavic ups their game with even wider rims and also would really hope that Michelin, Continental, Victoria, and others adopt UST so that their tires fit better on Mavic rims too, and those benefits are available to people who prefer those tires.

  16. Man…I’d hate to be a consumer in these markets. Good thing tubes still work great and 99% of the riding population still wants them. Carry on. Let me know when all you gals and guys get this stuff figured out.

    • A lot of things still work, but that doesn’t mean that consumers don’t want something different or better or that the industry can’t make something better. A rim/tire combo that is much more flat resistant than a clincher with a tube stuffed in it? Who wouldn’t want that, especially when tubeless tires are coming out with rolling resistance as low or better than clinchers?

  17. I’m glad you guys have made the effort to innovate on this….. and I can see the potential of various improvements in installation in flat-tire retention working and how that might be attractive to a good segment of the market…. Getting the current road tubeless to seat on two different sets of wheels (Pacenti and Roval) has been a huge pain for me, and in the end every tire but one required c02.
    In one case after a local tire shop tried to blast it on with their high-pressure system and couldnt.
    And your improvements to that kind of think, I hope, will win over some segment of the market share.
    But for me, the differences between this UST, existing tubeless approaches and standard, tubed clinchers are narrow enough, that whether the tire/wheel combinations are actually fast is by far the biggest driver in deciding and right now, except for gravel, I’m on clinchers with latex tubes.
    The differences in a really fast vs simply decent tire are some of the biggest, yet least visible, in all of cycling equipment.
    A road tire with UST has to be down in the 11-12 watt rolling resistance range before I will consider them. And they should NOT be round in section as that shape can essentially make deep carbon wheels useless aerodynamically in off-axis winds.
    Conti has this right at no serious penalty to puncture resistance and no compromise to longevity.
    Others are close one one way or the other, but typically getting rolling resistance right but shape all wrong.
    Chad, not sure how your UST road tires stack up, but if they don’t cut it in this first round with RR and aero, just ask your engineers to get it right in the refinements for the 2nd gen.
    Until UST is shown to be fast for road, or in the general ball park, I’d hold off.
    If they are 10-20 watts off for RR and aero combined that would not be at all unusual for new tires, so common in fact that I would not risk it until Mavic or some other company is clearly making fast ones.
    I can’t risk it, can’t afford to guess at whether Im giving way 5-7 percent of my FTP for no reason.

  18. Chad, I see the Mavic tubeless tires will use a conventional aramid bead. Mavic emphasizes that the size of tire relative to the rim is the critical component. Can I interpret that any brand of clincher tire with a aramid bead, if sized properly, would then work with the new Mavic UST rims? Therefore, a non “tubeless” clincher tire could work? Not approved of course but as an academic inquiry.

  19. I like the mavic rims but lets be honest those freehub bodies are NOT for serious riders who put down decent power or do decent mileage.

    Is there a hack where I can fit a DT Swiss freehub body to a mavic rear wheel?

  20. Chad are you still replying??? Thanks for the great info on the Mavic UST system…very interesting..i have been using tubeless ready now for bout 4 years primarily on a set of Campy Shimal Ultra tires and s set of Reynolds as well. I really haven’t had any problems installing and changing tires, but i appreciate this step toward standardization. I am getting a new bike that comes with these wheels and tires and i plan to try this out, But i am very picky about the tires a I use, . Can i use any tubeless tire on the market on the Mavic
    UST system without risk of a rolling failure??? i am fine if its hard to install..

  21. Mavic does deserve a lot of the credit for pursuing tubeless tech in the bike realm from way back (not just this latest venture). I’ve been mountain and road tubeless for over a decade, UST and Road Tubeless.

    Mavic is overstating the “problems” of current real Road Tubeless… the trouble comes from Idaho-Engineering and cobbled tubeless setups. I used Shimano”s system initially, no problems. Since then I’ve been on Fulcrum 2-way fit Zeros and have had ZERO problems. No sealant, no air compressor, and average a flat every 2-3 years.

    I’m glad to see Mavic admitting that Tubeless is the future, frankly most of the industry has been too busy changing bottom bracket standards, often with performance losses, while this very obvious ‘better mousetrap’ technology sat largely unused for a decade.

    It’s about time this goes mainstream. The problems have been drastically overstated by a bunch of yahoos not using actual tubeless products then blaming tubeless systems when their s#!t burped or blew off the rim.

    Thank you Mavic for reinvesting in this tech, it will be a positive for the industry. Now go back to your engineers and FINALLY ADDRESS YOUR FREEHUBS! You make great wheels and ruin them with bad freehubs. Quit letting a certain Swiss company make it look so easy while you make it look so hard.

    Life’s a journey, gotta enjoy the ride 🙂

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