all photos: Jeff Barber

Tubeless tires are a godsend to mountain bikers when it comes to performance. But maintenance can be a hassle. So Milkit decided to come up with a solution.

The Milkit Valve System ($59.99 MSRP) consists of a syringe, tubing, and valves in a single kit. As you can see in the photo at the top, the whole kit fits inside the syringe for easy storage and access when you need it.

Starting with the valves, Milkit has put a ton of thought into the product and improving the tubeless tire experience. The removable core is longer and sturdier than most. But what really sets these valves apart is the use of a one-way flap at the bottom (inside the tire) that lets air in, say from an air compressor, but prevents air from escaping when the valve core is removed. The idea is to allow users to check sealant levels and top off without having to fully deflate the tire which risks unseating the tire bead.

Note the blue gasket on the valve collar.

Even the screws that hold the valve tight to the rim from the outside feature fancy little rubber gaskets to prevent air loss at the rim hole. I usually just trash the plastic valve caps when I install a tube or a new set of valves, but the Milkit caps are actually really nice and have a good feel to them.

The hose inserted into the valve, showing the one-way flap that keeps air from escaping when the core is removed.

The real star in the Milkit Valve System is the syringe which is designed to serve two purposes. First, it makes measuring and adding sealant a breeze. Just dip the hose in a bottle of sealant and slurp up the amount you need (generally 2 ounces for regular tires, 3 ounces for plus, and up to 4 ounces for fat tires.) Remove the valve core, insert the hose into the valve, and push the sealant inside.

Not only is the syringe useful for filling a tire with sealant, it can also be used to measure the amount of liquid sealant available inside a tire, without unseating the bead. Rotate the tire so the valve is at 6 o’clock, insert the straw, and draw the sealant into the syringe. I imagine it’s not really possible to get every last drop, but it’s a good way to estimate. If the tire is low, use the syringe to add more sealant.

Now, about that one-way flap on the valve. The idea is it allows the user to remove the valve core without letting all the air escape, but use some caution here. Milkit recommends you have less than 20psi in the tire before inserting the hose, and with good reason. I mounted a new tubeless tire and jacked up the pressure to 40psi to get the bead seated before I added sealant. Without thinking, I removed the valve core, inserted the tube, and POP! Sealant everywhere, including my face, as the pressure blew the entire stopper out of the syringe. Lesson learned.

The hose is actually pretty stiff and has a nice pointy tip which allowed me to poke through my tire inserts to get sealant in place. Without the hose, getting sealant into the tires when running certain inserts requires removing the bead from the rim.

Compared to my primitive system of shaking tires and using a crusty, used Stan’s 2oz. bottle with a nozzle to add sealant, the Milkit Valve System is a huge improvement. It makes the whole process cleaner, more precise, and faster. While the price could be a deterrent, there’s certainly a lot of value in having the right tool for the job when working on a mountain bike.

Buy from Treefort Bikes

Thanks to Milkit for providing the Valve System for review.

# Comments

  • Brad Beadles

    i prefer to ride until all the sealant dries up and I get a flat 10 miles from the car and i’m all like “why did i get a flat?? i thought tubeless is never supposed to get a flat” and then i open up the tire and realize it’s dry af #shredlyfe

    • Jeff Barber

      That’s certainly another method, and one with which I am well accustomed. Ha!

    • Phonebem

      While I don’t prefer this method, it’s usually the one I use…

  • Noggus

    Whenever I have my tires off the bike I give them a shake. If I can hear the sealant sloshing around in the tire I figure I’m good to go. If I don’t hear anything, I’ll add 2 to 4 oz of sealant.

  • Sean Gordon

    This is really not a knock against this particular system, but I discourage use of an obturation ring at the valve nut. We all use double walled rims, and we need the seal to occur at the rim bed. Air escaping from the exterior valve hole indicates compressd air and sealant is entering the interior of the rim where it will slowly leak from the spoke holes, corrode the nipples, and fill the rim with latex. I recently purchased a set of bontrager rims that have a deliberately drilled hole in the sidewall to serve as an indicator- if your rim bed is not fully sealed it will vent audibly. In short if you think you need an o-ring, what you really need is a new tape job.

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