I’ve been a vocal proponent of floor pumps with a secondary chamber for seating tubeless tires. It’s a great way to avoid buying a compressor. It’s also a great way to find yourself visiting your local bike shop (in my case, walking the 50 yards to visit Breakaway Bikes here in Santa Rosa), every time so much air has to be delivered at high speed that the pressurized chamber runs out before it has delivered sufficient air or can’t deliver said air quickly enough to actually seat the tire. The crazy part is that I can’t guess in advance which tire/wheel combination is most likely to result in problems.
The short end of this particular straw is that I haven’t been able to get along without the help of a compressor … until now. This spring, when I was at Sea Otter, I saw some products from a Swiss company called milKit that the innovations were so rational, so well considered that I shook my head and muttered, “Of course they are Swiss.”
The milKit Booster is an aluminum water bottle that comes with a special, air-tight head. The head has a presta valve on top for charging and a release valve on the side to fill the tire through the presta fitting. The Booster comes in two sizes: 1.0 liter (34 oz.) and 0.6l (20 oz.). I’ve been using the smaller unit and have found it to succeed where my pump fails. And while 0.6l may not seem like a giant volume, the issue in seating tubeless tires is less how much air you deliver than how quickly you deliver it.
MilKit specifies that you can pump the Booster up to 160 psi. With mountain bike tires (like the 29 x 2.3-inch Vittorias I recently mounted), I’ll pump the Booster up to 160 psi, though with gravel tires (such as the 700 x 38mm Panaracers I mounted), I’ll only go up to 100 psi.
Fundamentally, that issue of delivering air quickly to mount a tire comes down to hose diameter and chuck architecture. You can have a gigantic chamber pressurized to 1000 psi, but if the combination of hose and chuck will only allow .1l of air to pass per second, you’re never going to seat that big tire. The Booster has no such bottleneck (pun intended?).
That a solution can be so simple and seemingly obvious has the power to simultaneously make me grin and blush. Whether or not you think that’s a good luck depends on whether or not you are my mother. And maybe other factors.
I’m going to admit that the first time I leaned on the handle of the pump to take that tiny aluminum can up to 160 psi, I did so with some trepidation and anxiety. At this point, I’ve taken it up to that pressure enough times to no longer be nervous. I wouldn’t mind knowing what pressure must be achieved to blow the thing apart, but I’m guessing I don’t own a pump that will go that high.
Because the Swiss and efficiency go together like unicorns and glitter, the Booster can double as a water bottle (I was unsuccessful in squeezing it; see the previous ‘graph.) and milKit includes a top for the bottle and a small drawstring bag to keep the Booster chuck clean while out on the road or trail. No more asking around if someone has a 25g CO2 cartridge.
The 0.6l version goes for $47.95 while the 1.0l goes for $49.95. I’d say the big advantage to the smaller edition is if you want to take it on the trail with you; it will fit in a bottle cage.
Final thought: This thing would be amazing at cleaning dust out of my lenses.
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