Tested: milKit Tubeless Booster
For reasons beyond me, I haven’t invested in a good compressor yet, and instead stick to the tried and true, “why use your head when you can fight it” motto. Luckily, there’re companies like milKit out there that recognize my plight and come to the rescue with products like the Booster, a small and portable tubeless inflator that costs about as much as a nice floor pump.
Retailing for $60 in the U.S., the milKit Booster is an inflation system that is essentially a miniature, human-powered can of compressed air. The Booster is composed of two parts, an aluminum bottle and the Booster valve head. The bottle is, well, literally just a bottle, and the valve head is no more complicated itself. A presta valve (with the same removable core as the valves in your rims) is used for inflating the Booster, and the outgoing air port for inflating the tire is of the press-and-play variety—it’s about as simple as it gets. In case you need directions though, milKit has kindly printed them on the bottle itself, including the max pressure (160 PSI). Step 1: Inflate Booster. Step 2: Remove valve core. Step 3: Inflate Tire.
If you forget, the directions are printed on the bottle. Step 2 is optional, but I recommend you do it.
While the graphics on the bottle show a hand pump being used to pressurize the Booster, I wouldn’t recommend it (even if you can find a hand pump that is willing to do 160 PSI). That being said, while traveling I did use the Booster with the Stumpump, which goes up to about 90, and in a pinch at the trailhead that could be enough to seat a stubborn tire if you don’t have a floor pump around. Inflation with a floor pump is certainly the proper way to go, and the .6-liter version I tested (there’s a 1-liter version too) only took about 30 seconds to pressurize.
The Booster head has been updated to address some previous issues. It’s been trouble-free during testing.
Of course, given that you’ve only put in 30 seconds of labor, it’s obvious there isn’t going to be a whole lot of wind coming back out. The .6-liter volume of the smaller Booster exhausts itself in just a few seconds—not much more than your average C02 cartridge. That’s why it’s more important to remove your tire’s valve core when using the Booster than if using a proper compressor. You’ll need all the help you can get. But those few seconds were all I needed to at least seat the bead on every tire I tried, including those from Schwalbe, Maxxis, e*Thirteen and WTB in a variety of sizes from 2.3 to 2.6, though I haven’t had the chance to try it with fat bikes. It should also be noted that the Booster only works with Presta valves, but that shouldn’t be a problem for most people as I can’t remember ever seeing a tubeless tire with a Schrader valve.
The internals are very simple, essentially there’s just a small check valve.
I used the Booster primarily while traveling internationally, and the .6-liter version has proved to be a perfect size for packing away. I still had to go seek out a floor pump, but asking to borrow a pump in a country with a language barrier is a lot easier than explaining that you’d please like to bring your sealant-dripping, half-seated tire into their shop to use a compressor they may, or may not, have. The pantomime for “floor pump” is far more universally understood. While the smaller size was nice for my uses, and fits in most bottle cages for those looking to boost on the go, the large 1-liter size is probably more practical for most people. It’s still quite small, but offers a bit more punch when it comes to inflation. It’s the same price too, so unless space is a premium for you, there’s no reason not to go big(ger).
I never used the Booster out on the trail, but it’s light enough that if you have space in your bag for it, it wouldn’t be a burden. However, since it really needs 160psi to be useful, it’d be a one-shot deal unless you have a floor pump with you (which I would guess you wouldn’t). Bringing a couple CO2s, or better yet a mini-pump, or even betterer yet a mini-pump and CO2, would be the smartest option. Chances are you’re riding out with a tube anyway, and you don’t need high pressure for a tube. Plus, the space you save in your pack by not bringing the Booster could be taken up with Oreos, Gummy Bears, special edition Gummy-Bear-Flavored Oreos or whatever your trail snack of choice is.
You can use the bottle as a water bottle if you want, the kit even comes with a regular top, but wash before use.
MilKit recently redesigned the valve head on the Booster after they experienced some issues with the previous version last summer. The new head has proven to be solid and reliable during testing—at one point I pressurized the Booster, forgot about and accidentally left it for a week. To my surprise, there was still quite a bit of pressure left. The aluminum bottle has survived flights in a duffle bag without damage, but if the bottle or head do get damaged, milKit sells both as replacement parts.
There are, of course, floor pumps with larger integrated charging cans that are easier to use and pack more of a punch than the Booster. But they’re impractical to travel with and impossible to ride with. The milKit Booster is a nice, compact alternative to keep in the back of the car for those infrequent (or frequent) times you need it. Or even to keep in the garage if, like me, you’re still too stubborn to just buy a compressor.