Tubeless gets easier with new MilKit system

Neat Swiss invention lets you check sealant levels without deflating your tyres

Love riding tubeless but hate some of the hassles that go along with it? New Swiss company MilKit feels your pain, launching a new valve stem and syringe system that lets you check sealant levels without taking everything apart.

The key component of the MilKit system is the special valve stem, which incorporates a secondary one-way valve at its base. When the proprietary core is installed, the MilKit valve works as any other Presta valve stem – you can attach a pump and add air as usual, or depress the end and bleed off air as you see fit.

What makes the MilKit system interesting is what happens when you pull that valve core out. Normally, pulling out a Presta valve core (as you would normally do when seating a tubeless tyre for the first time or adding sealant) releases the air out of the tyre all at once. A secondary valve at the base of the MilKit valve stem, however, keeps the system sealed.

MilKit says its new tubeless injector kit will let users check sealant levels without having the deflate the tire:
MilKit says its new tubeless injector kit will let users check sealant levels without having the deflate the tire:

The key to MilKit is the secondary valve at the base of the valve stem, which keeps the system sealed even when the core is removed

Also included with the system is a syringe with a long needle – dubbed an ‘applicator tube’ by MilKit. This is inserted down through the tubeless stem through that secondary valve, allowing you to pull out the sealant inside to check on the remaining volume and condition. From there, it’s easy to inject that sealant back in or add more as needed – all without letting any air out of the tyre.

Impressively, MilKit says those secondary valves will even hold up to the higher pressures used in tubeless road setups.

“No air is lost when the applicator tube is pushed through the valve into the tyre and it prevents the air from escaping from the tyre when the valve core is removed,” said MilKit media relations representative Anna-Julia Lingg. “The kit as it is now can already be used for road tubeless. The valves work with high pressures as well.”

Moreover, that secondary seal will prevent valve stem clogging – a common side effect of tubeless systems.

With a milkit tubeless injector kit, all you have to do to check the amount or condition of sealant in your tire is remove the valve core from the proprietary stem, insert the applicator tube, and then suck out whatever fluid is in there with no additional disassembly required. thanks to a clever secondary valve system, there's supposedly no air lost from the tire in the process, either :
With a milkit tubeless injector kit, all you have to do to check the amount or condition of sealant in your tire is remove the valve core from the proprietary stem, insert the applicator tube, and then suck out whatever fluid is in there with no additional disassembly required. thanks to a clever secondary valve system, there's supposedly no air lost from the tire in the process, either :

MilKit will supposedly allow users to check sealant levels and conditions, and add more as needed, without removing the tyre

“I think the ability to measure the remaining quantity of sealant inside the tyre without partially dismounting it is cool, but what is even cooler is a side effect of the dome seal at the bottom of the valve,” said Alberto De Gioannini, founder of tubeless sealant maker Effetto Mariposa. “The valve stem and valve mechanism don't get any sealant inside, so that you don't have the occasional valve clogging we all experienced once in a while.”

According to Lingg, that the first round of kits unfortunately won’t allow users to re-inject sealant into high-pressure road tubeless setups since the syringe bodies are too big. Also, MilKit will initially only offer 35mm-long valve stems, which will prevent their use in deeper-section rims. Lingg says both issues are being addressed with both high-pressure syringes and longer valve stems already in development.

The milkit valve stem has the same external dimensions as a standard valve stem so there are no rim modifications necessary:
The milkit valve stem has the same external dimensions as a standard valve stem so there are no rim modifications necessary:

The MilKit valve stems have the same external dimensions as standard valves so there is no rim modification needed

Even before that happens, though, we can already see MilKit’s applicator tube being very handy for cyclocross racers who want to remove sealant from their tubulars at the end of the season.

MilKit isn’t available in stores yet but you can jump the brick-and-mortar line by supporting the company’s crowdfunding campaign on Indiegogo.

For more information, visit www.milkit.bike.

James Huang

Former Technical Editor, US
James was BikeRadar's US tech editor from 2007-2015.
  • Discipline: Mountain, road, cyclocross
  • Preferred Terrain: Up in the Colorado high-country where the singletrack is still single, the dirt is still brown, and the aspens are in full bloom. Also, those perfect stretches of pavement where the road snakes across the mountainside like an artist's paintbrush.
  • Beer of Choice: Mexican Coke
  • Location: Boulder, CO, USA

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