Cycplus AS2 e-pump range review – easy battery-powered tire inflation

Traditionally if you needed to inflate your tires on the go you had two options to choose from, the trusty mini pump or the quick and efficient CO2 inflator. Recently a third option has been creeping onto the market in the form of small portable battery-powered air compressors.

Cycplus sent me its full range of e-pumps and I have been putting them to the test to see how they compare to each other and whether they have the performance to leave the best mountain bike pumps out of breath.  

Design and specifications

All the AS2 models have the same black alloy construction and feel well-made and sturdy enough to be joggled around in a framebag for hours. They all have a similar layout with a stubby press-on nozzle, a USB-C port on the top, and controls on the rear. The nozzles are compatible with both Presta and Schrader requiring a small “pillar” component to switch the nozzle from Presta to Schrader.

The AS2 range has three different models starting with the smallest AS2, then the AS2 Pro, and finally the big boy AS2 Pro Max.

The AS2 is the most portable of the three measuring 46.5mm x 65mm x 28mm and weighing in at 115g (including the silicone case) and is primarily aimed at road cyclists. It has a single-button operation, one press to wake it up and show the green, amber, and red battery indicator followed by a double press within three seconds to start inflating. Cycplus claims the AS2 is capable of inflating a tire up to 100psi and the 300mAh battery is said to be capable of inflating two road tires up to 80psi.

The AS2 Pro isn’t much bigger than the AS2, measuring 49mm x 28mm x 70mm and weighing 138g (including the silicone case), but it features an upgraded motor, pressure gauge, and a larger battery. On the back, there’s a screen showing pressure and battery life and three buttons are used to set a target pressure (psi or bar) when inflating. Max pressure is upped to 120psi and inflation should be faster too. The larger 420mAh battery is claimed to take 30 minutes to charge and is quoted to be capable of inflating two road tires up to 110psi. 

Lastly, the AS2 Pro Max has all the same controls and features as the Pro but gets a considerably larger battery. The 600mAh battery also has a higher voltage output which massively speeds up the inflation time too. So much so that CycPlus suggests that the AS2 Max Pro is capable of inflating motorbike tires and even topping up 195 car tires. This bigger battery does increase the size significantly though, with the AS2 Pro Max measuring 60mm x 32mm x 81mm and tipping our scales at a hefty 231g (including the silicone case).

All the pumps come with a Silicone case to protect against heat build-up. CycPlus advises using an adapter hose if you’re pumping up TPU tubes as heat from the pump could melt TPU stems. The AS2 Pro and Pro Max include an adapter hose that screws into the e-pump nozzle and is Schrader compatible, or can be fitted with an included Presta chuck. The AS2 isn’t compatible with the adapter hose.

Performance

All the stated inflation times are for road tires, so I put all the pumps to the test on 29x2.5in mountain bike tires and 700x40mm gravel tires to find out how they would perform for off-road riders. I choose ballpark numbers so inflation speeds and counts will differ depending on your own tire size and pressure. Smaller or lower pressures see better battery life and faster inflation times whereas larger tires or higher pressures will take a bit longer and require more power.  

The AS2 Pro and AS2 Pro Max excelled when it came to MTB tires, inflating tires up to 25psi in under a minute. Both were able to get a 40mm gravel tire quickly up to pressure and ready to ride. I was impressed with the number of flat to full inflations too, with the AS2 Pro’s battery having enough capacity to pump up five MTB tires or gravel tires. The AS2 Pro Max dominates here, the considerably bigger battery has enough juice for nine mountain bike tires or 10 gravel tires. The AS2 performed impressively well when inflating a gravel tire, achieving close to 40psi in a minute although it struggled a bit with the high-volume MTB tires. 

From the results, there are a few things worth noting too. The smallest AS2 e-pumps performance depended on the battery charge. The pressure it achieved in a minute fell off the emptier the battery got. Pressures also appeared to significantly affect the AS2’s performance, with higher pressures putting more strain on the motor generating more heat and draining the battery faster. The AS2 Pro and Pro Max with their upgraded motor offered a more consistent performance on both MTB and gravel tires.

After inflating a 2.5in tire to 25psi with the AS2 Pro and Pro Max I verified the pressure readings with my digital pressure gauge. It indicated between 23 and 24psi, while there is a discrepancy between the e-pumps and the pressure gauge I can't confirm which is more accurate. It's probably within the claimed 1psi accuracy though and unless you're particularly specific about your pressures, I think it's accurate enough for tires.

I found the charge time for all the e-pumps took a lot longer than stated to reach full battery from empty. Using a standard smartphone charging block and supplied cable, all the e-pumps took around double the time to charge to full according to my timings. Using a more powerful charger will obviously get closer to the official stated times but if you are bikepacking in the middle of nowhere you can’t guarantee fast charge times.

The biggest weak point of the Cycplus inflators is that none of them are waterproof so they are at risk from rain or sweat if you store them in your jersey pocket. The silicone cover will help keep the worst off and Cycplus provides a little zip-lock bag with the pump although this isn’t a very practical solution.

Have you ever been in a scenario where you have a puncture, you can hear it hissing when you're pumping but you can’t locate the hole when there isn’t air going into the tire? I found that if I was careful I could use the AS2 and AS2 Pro hands-free, leaving me free to inspect the tire while it's being inflated. That said, the pumps are noisy so you will be feeling for the puncture rather than trying to hear the hiss.

Verdict

Cycplus’ e-pump range offers a genuine third inflation option and there are some real stand-out benefits for the Cycplus e-pumps over traditional means no matter what cycling tribe or outlook you have. Pumping up a tire with a mini pump, particularly a high-volume MTB tire, takes time and energy. Even the smallest Cycplus AS2 takes away all the effort, quickly inflating tires with ease so you can get riding again. 

It may not be as fast as a blast of the racer’s favorite CO2 but it is also more convenient and less wasteful too. On a packability front, AS2 and AS2 Pro also offer a less fiddly package than CO2 unless you're taping it to the frame where it could get wet. Compared to the 138g AS2 Pro, a large CO2 canister weighs 76g plus around 27g for the inflator head and you only get one bit out of the cherry with that.

The human-powered pump still has the trump card of unlimited inflation should you get struck by multiple flats, that said the USB-C charging means that all is not lost if the Cycplus runs out of battery. If you're bikepacking with a battery pack you can charge it on the go and even one of those ultra-small 5000mAh battery packs is enough to charge the AS2 Pro Max eight times. Alternatively in a pinch, a top-up in a coffee shop is also an option assuming you have a cable and there's a communal USB socket available. Some e-bikes even have a USB-C charging port so you could charge the e-pump from your e-MTB, assuming you have power to spare. Cost will be a deciding factor too as a good mini pump is significantly more affordable than the cheapest Cycplus AS2, which retails for $89 / £70.11 / €82.31   

I think the AS2 Pro is the one to pick for all off-road applications. It's only marginally larger and heavier than the AS2 but has a longer battery life and faster inflation. Being able to set your desired pressure is a big positive for me, removing the faff of guessing and saving battery life as you won’t over-inflate by mistake. Unless you ride with a backpack or have lots of bikepacking bag space, the AS2 Pro Max is a bit big for general riding. That said, if you are only looking for quick trailhead inflation and don’t have space for a floor pump, the AS2 Pro Max is the one to go for.

Cycplus pumps are available from Amazon.

Tech specs: Cycplus e-pump range

• Price: AS2 - $89 / £70.11 / €82.31. AS2 Pro - $129 / £101.62 / €119.30, AS2 Pro Max - $129 / £101.62 / €119.30
• Weight: AS2 - 115g, AS2 Pro - 138g, AS2 Pro Max - 231g
• Colors: AS2 - Black / Silver, AS2 Pro and AS2 Pro Max - Black