Milkit tubeless sealant measuring device mountain bike  (1)

If you ride mountain bikes, you probably ride tubeless. Or you’ve tried it. Or you have a friend who has used it. These days its fairly ubiquitous, but it’s not fool proof. Getting the sealant into the tire can still be a messy process. It’s one thing to add sealant to a brand new tire that is being installed onto a wheel, but adding sealant to a tire that is already mounted is where it gets tricky. You don’t want to break the bead so removing the tire is out. Without removing the tire, there is really no way to tell how much sealant is left – at this point it could be one big sealant urchin rolling around in the tire. After all of that, installing the sealant through the valve can leave a clog which can make airing up the tire a hassle in the future.

While it seems these are annoyances we’ve all learned to live with,  engineer Pius Kobler and entrepreneur Sven Rizzotti thought there could be a better way. As often happens, necessity was the mother of invention after a flat tubeless tire in Moab caused Pius to rethink the ability to measure how much sealant was actually still in a tire. That quest to manage the amount of sealant led to the new valve design as well that could change tubeless as we know it…

11188351_1587564754862490_8703715173354892332_n Milkit tubeless sealant measuring device mountain bike  (2)

On the 6mm presta valve itself, the biggest improvement is the addition of a rubber flap at the bottom of the valve. When combined with the straw from the syringe, it makes it so that the sealant can be installed or measured with the air still in the tire. Of course when you pull out the syringe, the flap closes up and prevents sealant from entering the valve so in theory it should never clog. According to MilKit the valves will fit any standard mountain bike wheels. *Update: As pointed out below, the valve core has an extension built in that opens the flap in order to adjust air pressure.

Milkit tubeless sealant measuring device mountain bike  (1)

milKit_compact_print_small IMG_6389

To use the applicator, MilKit recommends inflating the tire to 22 psi and then removing the valve core. The rubber flap will keep the air from escaping and then you can insert the syringe into the bottom of the tire. If you are checking the amount of sealant left in the tire, opening the valve on an empty syringe will cause the left over sealant to flow into the syringe due to the air pressure in the tire. At that point you can either push it back in if there is enough, or add additional sealant and top it off. This whole process can be done without breaking the bead, losing air pressure, or gumming up the valve. Seems like a huge step in the right direction.

milKit-compact-pkg milKit_Release-milk

Currently in the process of an IndieGogo campaign, the tubeless kits start at $49 for the complete MilKit with two valves and the refiller, but for the first three days there is a $39 Early bird option for the MilKit. Jump up to the $63 pledge for the kit with sealant. Kits are estimated to arrive in June.


  1. I guess some kudos for trying to solve a problem. But… I haven’t really had a problem with this before. The little valve stem wrenches are easy enough to pack, little bottles for OrangeSeal/Stans… what am I missing. Am I just lucky?

  2. Not buying into this was ever a problem. Sounds like an engineer had too much school loans and needed to come up with a problem that he had a “solution” for. Make a protoype, have a bunch of poor schmucks crowdfund his solution and….. pay off his loans.

    Really, is it that tough to pop the bead and check, or even unscrew the valve and use an old spoke as a dip stick to check if there is liquid sealant left?

  3. Who puts the sealant in through the valve?
    I have always just put one tire lever on to stretch the tire bead open enough to inject the sealant.
    It is a lot easier.

  4. Why would anyone look inside the tire when you can just swish around and say “yup, there is Stan’s” or “nope, let me add some more”.

    I just don’t get it. High five for trying to innovate, but this seems more like a solution looking for a problem.

  5. Adding Stan’s through the valve is awesome simple. Pick up those little 2oz bottles with the tip so you can shoot it directly into the valve to refill. Just pull out the valve core and bam. No mess, takes 2 seconds. Not sure why anyone would deal with injectors, syringes, dripping stans onto your work bench, etc.

  6. Until you can pull the Stan’s urchins/tumors out thru the valve, I don’t see how this is that helpful in the long run.

  7. @Hank Hill… They forgot to engineer that in. We just hope that when air flows back out the rubber seal, no sealant will go with it and clog the valve. DOH!

  8. I agree with Tom on this, turn off the music in the garage, hold tire to ear and shake it around. When I pull the valve stem which takes something like 10 seconds each to add sealant with the little Stans bottle, I throw away the old core and put in a fresh. Done.

  9. I guess I’ll be the first post in favor. Adding sealant through the valve stem is much less hassle than popping a bead and partially unseating a tire. Especially when you’ve got a valve core removal tool. And I have many times had sealant clog the valve itself when air is being let out to decrease air pressure. This may solve that; however, it leads to my question. With what is basically a check valve being mounted on the interior end of the valve stem, how does one allow air pressure to escape the tire? Does depressing the valve core head open the check valve somehow? Seems like a neat system to prevent sealant clogging the valve core, but creating a new problem if air pressure can’t be carefully released from the tire.

  10. Although I don’t currently have a problem removing the core to add sealant, I do love that the whole system comes packaged inside the syringe itself. It would be handy to have spare valves and everything right there in one kit. I do think the flap on the bottom of the valve is unnecessary and a little overkill. Maybe re-market as less of an “innovative answer to tubeless problems” and more as a useful spare valve/injection kit.

  11. Seems like a creative way to make life easier. I wouldn’t say adding stan’s before was a problem but for a lot of people who don’t have air compressors it’s a pain to break the bead. I don’t think the convenience is quite worth the cost, but still a good idea.

  12. With UST no sealant required. Duh. Been riding for a decade in rocky socal with UST and no sealant on mavic rims. One (1), flat. The flat was fixed with a peal and stick park patch on the trail by unseating one side of the tire (without removing rim from the bike), sticking that patch on the inside of the tire and inflating with an anemic pack pump. Fastest flat I ever fixed.

    Sealant is for wimps! (Or for tubeless “ready” rims/tires whatever those are?)

  13. Sealant is for anyone who lives near cactus, bull briar, prickly pears, thorns etc… Growing up where I did, flats and torn up shins from briar was a daily thing. Sealant, even just for tubes, was a godsend.

    That said, if air can’t be bled from the tire without breaking the bead…I don’t get the point.

  14. How do a let air out of my tire? I have to remove the valve core and push in that hose? Kind of prohibits modifying tire pressure while out on trial.

  15. Just a short answer to some questions above:
    – The valve core has an extension that pushes open the rubber flaps to release air
    – There is a new kind of valve core tool included

  16. Their valve core appears to have a needle that goes beyond the second valve to allow the adjustment of air pressure. Look at the tail by the “1” in their illustration.

  17. @jlrichar Sealant is for anyone who wants lighter rims and tires. Aside from getting one set of Nobby Nics seated I’ve had great success with all the tubeless ready tires I’ve used.

  18. I’m with Ed – this actually looks like it’ll be super handy. If you bikepack or if you ride with a backpack, this would be the bee’s knees. I’ve had situations where I’ve shaken the tire, thought I heard sealant, and then been proven wrong. If you need to be self-sufficient and you’re riding stuff that nigh demands tubeless-ness, this would be really spiffy. I’ll be buying one before my next bikepacking trip, definitely.

  19. @FoolCyclist

    Judging from their accents (and the IndieGogo website) they are from Switzerland. Student loans don’t exist there as high level education is free. So, great conspiracy theory you got there.

  20. Buy light tire. Add sealant. Buy light rim, add rim tape. Or just get UST tires/rims. Which is lighter? Its probably pretty close. Here’s the thing though. The system that is just a rim/tire is simpler, and thus better. Also, my mavic crossmax slr’s are pretty light, as are my nobby nic’s. Back when I rode tubes in socal I got flats all the time. After switching to UST tires/wheels only one frickin flat in almost a decade with thousands of miles/year. Perhaps tubes just sucked back then?

    Now lets discuss wheel size…

    (yes I am old).

  21. Look it’s Dieter & Helmet from the Sprockets Show, They look as happy
    as little girls. 🙂 :0) They like inserting MILK through their stems.

    Nice clean design and a great package. Answer to a problem that can be fixed by going to to your local medical supply for allot less. Save your old MTN valve stem and make new tubeless stems out of them by cutting them down and leaving the rubber ring around them.
    Also caffelatex sealant is a option other than Stan’s and it comes with a nice big syringe to PUSH milk through the STEM 🙂 🙂

  22. Given how quickly we go through sealant here in the desert (death by a thousand papercuts- or something along those lines), I can see the appeal of the idea. I can’t count the number of times I’ve popped a tire off only to realize that two scoops’ worth of Stan’s had been put to use sealing hundreds of little cactus holes.

    Maybe it’s not for everyone/everywhere, but it sure beats unseating a tire every week or two just to check or blindly adding sealant when none is needed.

  23. I’m with Lindarets on this one. I think this is brilliant. I am going to their website to support this. I use a syringe now but the valve and its base is perfect.

  24. Jlrichar, you obviously do not live or ride in the Bushveld, an acacia karoo thorn is the length of your middle finger and a lot more rude, Devil thorns in the Karoo will let you ride about 50m with your setup. In some areas, sealant is essential. I find refilling with a small Stans bottle pretty simple.

  25. If you don’t want to gum up your valve with sealant then always inflate, or bleed, with the valve at the 12 O’Clock position. Add sealant with the stem at the 3 O’clock or 9 O’clock position. You won’t gum up the works that way.

    I guess with low pressure tires unseating a bead to check/add sealant isn’t a big deal, but on road bike tires it’s a pain in the ass to re-inflate after a bead has been popped.

  26. Not as crucial a product for mountain tires. This will be awesome when it is available to work with higher pressure of road tubeless. Much more difficult to inject sealant through the tubeless road valves as they are quite a bit smaller.

  27. Reading the comments it seems that not everybody has had a lot of varied experience with Tubeless tyre systems and that is fully understandable. Many combinations of rims and tyres and circumstances would see no major benefit from such a system to easily justify the on-cost. In my experience, however, there can be some VERY awkward tyre/rim combinations and/or circumstances. On one of my wheelset/tyre setups the fit is ludicrously tight. I have had numerous problems with them but I still want to run them. Problems include:- Very difficult to mount tyres and I don’t want to use too much force with tyre levers on carbon rims too often if it can be avoided to dismount/remount even part of the bead to check sealant. When ambient temperature is cold multipy that problem to impossible. When I first tried to pry the bead open just a little, on a day of cold ambient temperatures, I instead had to cut the tyre off. Nect problem: these rims do not have a proper UST channel to retain the bead and when they are left aside unused for a while they also deflate enough for the tyre bead to slip into the middle gutter of the rim. Doh. Anyway, when that happens the tight beads also have a tendency to drag the ‘tubeless’ sticky rim tape down into the central gutter with them, wreck the seal, and leave the wheels un-rideable until I’ve done an hour or two’s work to carefully clean every speck of rubber remnant off the rims and replace the tape. Grrr. I am not saying that these valves will solve my problems in all circumstances but they sure could help a lot. I can’t imagine me fitting them to other wheelsets but, hey you never know. Congratulations to the designers. I’m in.

  28. Re: Who puts the sealant in thru the valve?
    I do. And the valve is one cut out from a Continental Schrader tube that you can buy for $6. Remove the valve core, inject in sealant, install valve core, pump up, ride. Don’t be scared. Grab a 9.5 mm bit, drill out your rim and install a Schrader valve stem. In addition to using threaded Schrader valve stems cut from Conti tubes, you can find aluminum Schrader stems for [auto] racing wheels.

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