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It’s no secret that I’m a fan of the Fumpa portable air pump, a handheld device that lets you accurately check and top up tire pressure with the press of a button. As one of my most loved products of 2019, I regularly use it instead of a floor pump, it’s become my go-to travel pump/gauge, and it’s the common envy of other tech editors. And so when I stumbled across the bargain-priced Xiaomi Mijia (or “Mi” for short) electric tire inflator, I ordered one and put it to the test.
If you haven’t already, please check out my in-depth review of the Fumpa and miniFumpa air pumps which goes into detail about what these devices do and don’t do.
An intro to the Xiaomi Mi
- Xiaomi Mijia digital tire inflator
- What: A low-cost compact digital tire inflator.
- Weight: 439 g
- Price: From US$35
- Highs: Impressive price, accurate gauge, easy to use.
- Lows: Slow to attach, slow to inflate, noise, can unwind Presta valve cores.
Xiaomi, a Chinese consumer electronics company, offers products from mobile phones and e-scooters, to TV streaming devices and smart desk lamps. The Mi Portable tire inflator is a relatively new addition and is designed for inflating car, motorcycle and bicycle tires in addition to sports balls.
The Mi offers a maximum pressure output of 160 psi, has a digital pressure gauge which I verified as being accurate to within 1 psi across a wide range of pressures, and has an auto cut-off function for once the desired pressure is reached.
It’s a product supplied in retail-friendly cardboard packaging and includes a soft bag, a micro-USB charging cable, a Presta-Schrader valve adapter, and a needle for inflating sports balls. It’s easily and cheaply sourced from a number of online retails such as AliExpress, eBay and Amazon. I paid AU$70 (shipped, approximately US$45) for mine, however, they can be found for as little as US$35. Compare that to the Fumpa at US$179 / AU$249 and you can see the attraction.
With dimensions of 124 mm (L) x 70 mm (W) x 45 mm (D), the Mi inflator fits in your hand, but it’s still noticeably larger in form factor than the Fumpa (42 mm x 73 mm x 87 mm). And really, the looped hose makes the Mi closer to 183 mm in length when stored. It’s a similar story on the scales, where the Mi unit comes in at 439 g versus the Fumpa at 380 g. Neither are intended for riding with (although the miniFumpa is) and are more designed as replacements for a floor pump.
Like the Fumpa, the Mi features an internal rechargeable battery, and because it’s internal, there are no worries about flying with this device, whether in your checked baggage or not.
Turning on the device is as simple as pulling the hose out, something that automatically triggers the power. And unlike the Fumpa, the Mi has an auto-off function in case you leave the hose out. The hose itself is threaded to the unit and features a Schrader valve at the other end. The provided Presta adapter twists into this seamlessly and can be left in place during storage, meaning there’s little risk of losing this key component.
There are five inflation modes which, in theory, let you pre-configure the pressure so the unit can easily inflate different things. However, only the manual setting lets you go above 65 psi, and even the dedicated bicycle mode is limited to a range between 30-65 psi. Meanwhile, the car and motorbike modes are pre-configured to a limited range of Bar pressure.
These modes could actually be quite useful if they were more customisable, and in theory, you could then have one setting for your road bike, and another for your off-road bike. But nope, you’re best to manually dial in the pressure you need – and thankfully the device defaults to the last pressure used.
Longer lasting but slower than a Fumpa
Given the Mi is noticeably heavier than the Fumpa, I’d expected a fair bit of power from it. However, it’s clear the Fumpa has been designed to draw significant power from the 11.1 V battery, while the Mi and its 7.4 V battery is relatively chilled.
Two issues I have with the Fumpa are the noise and vibration (seriously, it really rattles that air in), and both are unavoidable as the device only pumps while you’re manually holding down the power button. It’s a different story for the Mi which allows you to set the device and let it do its thing, hands-free. And even if you did choose to hold onto the device, it’s noticeably smoother-running. However, where the Fumpa rips the air into your tire at a rapid rate, the Mi can be a little tiring to watch.
For example, the Mi took 1 minute and 24 seconds to inflate a 700×25 mm tire to 80 psi, while the Fumpa hit the same pressure in just 20 seconds. Similarly, the Mi took 2 minutes and 5 seconds to put 35 psi into a 650B x 1.9 in tire, while the Fumpa ripped through it in 29 seconds.
However, the Mi and its substantially higher-capacity battery clearly wins in longevity from a full charge. The Fumpa ran out of juice after seven full inflations (to 80 psi) of the 700×25 mm tire, while the Mi kept ticking until 15 full inflations. The larger volume 650B wheel saw the Fumpa switch off at five full inflations (at 35 psi per inflation), whereas the Mi did it 10, almost 11, times.
Do keep in mind that both units are rechargeable via a Micro-USB port, and so easily topping up the battery while travelling is of no concern with either. Likewise, both units offer some form of battery-level indication, although in both cases it’s only a rough guide, and you may get caught off-guard if pushing the units to extreme tire pressures.
From a speed point of view, the Mi is the three-legged turtle in a race against the rapid-rabbit that is the Fumpa. I love the Fumpa for being able to quickly squirt a little pressure into a tire, while the Mi almost had me questioning why I don’t just reach for my floor pump.
At this point it’s worth noting that I’ve never successfully setup a new tubeless tire with the Fumpa. I recently re-tested this exact thing by setting up some eight wheels with Continental tubeless tires for the Gravel Bike Field Test, and the Fumpa failed to get a single one to bead (while a couple of generic floor pumps managed the majority of them). And with that, the Mi’s lower production of air volume means it’s hopeless for this task. That said, both units will top up the air of an existing tubeless setup without issue.
As expected, the raging Fumpa is noticeably noisier than the slower Mi, but neither are hotel room friendly. I recorded the Mi at 85 dB, while the Fumpa has a wake-the-neighbours 99 dB output. In both cases, you’ll want to reinflate your tires the night before you sneak out for your early-morning ride.
A fiddly valve
The Mi’s threaded valve offers a simple sealing o-ring and this design is sure to remain leak-free for ages. However, one of the main perks of an electric inflator is speed of use, and the basic valve design really hampers such efficiency.
This is most apparent when using the Presta valve adapter. I found myself having to be extremely careful to ensure the valve was threaded on straight. Similarly, and as covered in the mega mini pump shootout, such threaded pump valves do have a tendency to undo removable Presta valve cores without welcome. By contrast, the Fumpa is designed specifically with Presta valves in mind and simply pushes on with a friction fit.
That said, if you have bikes with both Schrader and Presta valves, then you’ll like the Mi’s multi-purpose design. And this design does mean you can easily thread on a high-quality Presta pump head to the Mi, such as a Silca Hiro, although such an addition will make it noticeably more cumbersome in portability. Similarly, the Fumpa offers an aftermarket dual-head valve and hose for its pump, although it’s less convenient in terms of size, too.
Not what I want
I fell in love with the Fumpa for its ability to push it onto a Presta valve, give the button a quick squirt and within a few seconds know that I’ve got my tires set to exactly the right pressure. In this way it’s more convenient and faster than any high-end floor pump, and as a result, I get a heap of use from it.
And it’s with this speed that the Mi falls apart. Threading on the pump head is comparatively tedious, and from there the inflation speed is a trickle. It’s not faster to use than my favourite floor pump and so it doesn’t enrich my cycling life. Sure changing the pump head will go a long way to making the Mi faster to use, but the Fumpa is still more compact and more powerful.
The Mi is clearly aimed at the casual user who wants a device to inflate a variety of things. It’s easy to use, well-priced, long-lasting, and does indeed offer accurate pressure setting – all very impressive things given that low price. However, it’s multi-purpose design is also exactly why it’s not the ideal zap-and-go inflator that I’d hoped it would be.