How much pressure do I need in the booster?
The pressure needed in the booster depends a lot on the tire rim combination and whether or not the tire has already been inflated. With 6 bar / 87 psi in most cases only good tire rim combinations or tires that have already been inflated will work. With 8 bar / 116 psi most tires will work and only in a few extreme cases are the full 11 bar / 160 psi needed.
What booster size do I need?
One of the main advantages of the milKit tubeless booster is the very efficient air flow: unlike other tubeless boosters, the milKit booster doesn't have a hose and thus no pressure loss - the full air pressure is right by your valve. With so much air shooting into the tire in an instant, even the small booster is efficient enough to inflate any tire (except fat bike tires). Your choice of booster size is therefore a function of what bottle size you want: maybe a compact 0.6L / 17oz or 0.75L / 25oz to fit into your bottle cage or the large 1.0L / 34 oz to bring more water on your ride.
Can I use the booster with any tubeless valve?
The milKit tubeless booster can be used with any Presta tubeless valve. The milKit valves have the advantage (besides being able to measure and refill your sealant without releasing the air from your tire) of keeping air in the tire without the valve core in the valve stem – which makes inflating easier and more efficient.
Presta valves with external threads that do not reach to the top of the valve stem reduce the efficiency of the milKit booster.
Does the booster fully seat my tire on the rim?
The booster is meant only to pre-inflate your tire so it sits on the rim tightly enough to keep the air in. You then have enough time to insert the sealant through the milKit valve, using the milKit syringe and needle, screw the valve core back and to inflate the tire to full pressure until it fully jumps onto the rim.
If your tire doesn't hold the air well after pre-inflation with the booster, you might have to first screw the valve core in, inflate the tire to full pressure until it fully jumps onto the rim, then reduce the tire pressure to below 1.5 bar / 22 psi to add the sealant into the tire.
Do I have to remove the valve core before inflating my tire with the booster?
The milKit booster can be used with or without removing the valve core from your valve, although, removing the valve core does lead to a more efficient air flow, and is consequently always recommended.
milKit Valve System
What valve length do I need?
The standard milKit valves have a usable length of 35 mm (1 3/8 inch), and they work for most rims except some special high-profile rims. For high-profile rims, there are 45mm, 55mm and 75mm versions of the milKit valves available.
Click here to see the valve dimensions.
What tire and rim sizes does milKit work with?
milKit works with all common tire and rim sizes and widths, including 26", 650B, or 29", and road, mountain, or city bike wheels.
The standard milKit valves have a usable length of 35 mm (1 3/8 inch), and they work for most rims except some special high-profile rims. For high profile rims, there are 45mm, 55mm and 75mm versions of the milKit valves.
Click here to see the valve dimensions.
Can I get replacement valve cores?
Yes, we've made our valve cores (with valve core extensions) available at low cost so you can order them with your next order. Tubeless made easy!
Can I use milKit on my road bike?
The milKit valve system can be used with all tubeless tires including for mountain, road, and city bikes. We recommend using tubeless ready tires and rims for optimal performance and reliability.
How do I let air out of the tire when the valves are closed on the bottom?
The milKit valve core has an additional valve core extension that pushes open the rubber flaps at the bottom of the valve, if you want to release air from the tire. Releasing air during your ride is as easy as it was before.
How can I prevent the plunger from getting ejected from the syringe?
It is important to close the sealant regulator before inserting the needle into the valve.
Make sure to open the sealant regulator slowly, and let the sealant flow into the syringe. Be ready to close the sealant regulator once all sealant is in the syringe (you can hear, see, and feel the air bubbles coming through the needle). The plunger moves a lot faster if no sealant is in the tire and only air is flowing into the syringe.
How much air pressure can I have in my tire while measuring or refilling sealant in the tire?
It is best if you reduce the air pressure to 1-1.5 bar 14-22 psi before measuring and refilling. This is enough to keep the tire in place. It is also possible to measure and refill at higher pressures.
Can I use milKit with valves from other brands?
Our valves are custom made, as they have closed rubber flaps at the bottom. This has several advantages:
- The valves don’t get clogged anymore
- They keep the air in the tire, even if you remove the valve core (easier installation of tubeless tires)
- They allow measuring and refilling of sealant with the air pressure still in the tire
You can use valves from other brands, but you would not benefit from the best advantages milKit offers.
Which sealant can milKit be used with?
milKit can be used with most common sealants - although some have very large particles and cannot be filled into the tire through the valve. The large particles of these sealants clog the valves while riding more than the other sealants. We recommend using milKit valves to prevent your valves getting clogged by the sealant.
We recommend using the new milKit sealant which has specifically been designed to offer the best performance and work best with the milKit valve and syringe system.
Read more about the superior performance and advantages of the milKit sealant here.
milKit Tubeless Sealant
How much sealant do I have to fill into my tire?
Many factors can influence your decision about how much sealant to add into a tubeless tire. Some tires "soak up" a lot of sealant and a few days after installation a significant part of the sealant is gone. This is where the milKit valve and syringe system comes in handy: we recommend always checking the amount of sealant left in the tire a few day after installation.
Choosing the right amount of sealant also depends on the priorities of the user: adding more sealant will result in a better puncture protection but make the tire heavier. With the milKit valve and syringe system, that makes the measuring and refilling of the sealant quick and easy, the right amount of sealant can be tested and optimized step by step without a hassle.
We recommend starting with the following amounts and then optimize the right sealant level from there:
- Road / gravel 30-50 ml / 1-2 oz
- 26” MTB 60-80 ml / 2-2.7 oz
- 27.5” MTB 80-100 ml / 2.7-3.4 oz
- 29” MTB 100-120 ml / 3.4-4 oz
Can I make the sealant thinner by adding water?
Our sealant is a little bit thicker than the one you might have used. It always stays homogeneous so you don’t have to worry about shaking the bottle before use or particles not being distributed evenly in the tire.
The sealant covers the inside of the tire nicely, but that also means that less sealant flows to the bottom, which can then be measured using the milKit syringe. As a result, the “mobile” part of the sealant that you measure will be smaller when compared to the total amount of sealant in the tire.
If you prefer your sealant to be thinner, you can add up to 40% of water to the sealant. This will increase the lifetime of the sealant and make it flow to the bottom of the tire better, however, it will also slightly reduce the puncture fixing ability of the sealant.
It’s always a trade-off between longevity and puncture fixing capability when it comes to sealants. You’ll have to find out what is the right balance for you. But hey, that’s exactly what the milKit syringe system is here for, right? To help you understand what’s happening with the sealant inside your tire.
An important thing to understand when installing a new tire is that a significant amount of sealant “disappears” into the pores of the tire. We recommend measuring the amount of sealant left in your tire, a few days after installation – that will be the amount of sealant for best performance.
When do I have to replace my sealant?
There are two reasons why you should regularly check your sealant:
- Sealant drying up
- Sealant getting old
You should always have the amount recommended by the sealant manufacturer in your tire. You will develop a feeling, over time, of how frequently you have to check your sealant. It's always good check your sealant before a long ride or a holiday to have the peace of mind that your tubeless system will be all right.
Sealants also get old and lose their functionality. Old sealant can be recognized by a change of color or when it starts dissolving and the consistency is more like water than like new sealant. Old sealant should be extracted from the tire with the syringe and disposed of. Mixing new with old sealant is not recommended.
milKit sealant does not dissolve and just gets thicker over time. Still the sealant has to be replaced regularly to guarantee the best performance.
More about the new milKit sealant can be found here.