Milkit Tubeless Valve Kit
Riding tubeless is great. It allows you to get away with lower tyre pressures and virtually eliminates pinch flat punctures. Of course it’s not all beer and skittles. The initial setup can be a hassle and you need to keep tabs on the sealant level inside to ensure that it’s still liquid. Modern tyres and 'tubeless ready' rims are making life easier but how do you know when the sealant has dried up?
You can deflate the tyre and remove one bead to check inside, but this can be messy and it’s a hassle that many people try to avoid. You can also shake the wheel and listen for sealant sloshing around but this tends to be hit and miss.
Swiss company Milkit has developed a system that aims to take the mess and guesswork out of the process. The kit sells for around $70 (ordered online) and consists of two special valves, a large syringe and all the necessary connectors. You can also buy spare valves for $37 a pair if you want to run the system on additional wheels.
A unique valve design lies at the heart of the Milkit system. It looks normal enough but has a secondary valve built into the grommet that sits up against the rim—it’s like an extra flap of rubber built into the bottom of the valve. The presta valve core is removable, just like most good tubeless valve designs. The only difference here is that the air won’t escape with the core removed, as the secondary valve keeps the system sealed. To let any air out, you need to have the main valve in place; pushing on the core then opens both valves at once to let the air out.
To check the sealant level, you place the valve at the bottom of the wheel, remove the presta core and fully insert the Milkit applicator tube with the inline stopcock closed (that last bit is important). Open the stopcock and the sealant will flow up into the syringe. You can see how much fluid is in there and top it up if required. Push the sealant back in, remove the applicator and refit the main presta valve—job done!
Under Pressure
It works as intended and is certainly easier than half removing the tyre but there are a few points that take away from its ease of use. First up, you need to have less than 22psi in the tyre to check the sealant level. Personally this isn’t an issue as I run wide rims that allow me to ride with 20-22psi all the time. If you generally run higher air pressures, you’ll need to partially deflate the tyre before using the kit and then reinflate before riding again. Not a huge issue but it is an extra step in the process. Sealants with larger than average particles – True Blue Goo and eThirteen for example – tend to block the thin applicator tube. It worked fine with Stan’s and most other sealants though.
The other more troublesome part comes when there’s not much sealant left in the tyre. With plenty of sealant inside, the fluid flows smoothly into the syringe when the stopcock is opened. If you’re low on sealant, you’ll get a bubbled mix of fluid and air and even at 20psi this rushes back into the syringe with a fair bit of force. It took me by surprise the first time, blowing the plunger straight out and covered me in sealant! If you suspect the sealant is low, take great care to open the stopcock cautiously or just let the tyre right down before checking. Fully deflate the tyre to check your sealant level and the benefits of the Milkit system are partially lost.
So it’s not perfect but there are some additional benefits too. The secondary valve does a good job of keeping the sealant away from the presta valve, ensuring the mechanism doesn’t get bunged up over time. It’s also easier to mount the tyre initially; remove the presta core and you’ll have good airflow for seating the bead but it remains airtight once the pump is removed—this proved quite handy.
Once I’d learnt of the idiosyncrasies, the Milkit system did make life a little easier. I suspect that many people will see the $70 asking price as being excessive for a plastic syringe and a couple of modified valves. If the price dropped, it could gain broader acceptance as it goes some of the way towards solving the hassles of living with tubeless tyres.
