Aer City Sling 3 Review

A third sequel usually carries with it a unique kind of pressure. Once you try and reach for that golden “trilogy” status, the third cannot be anything but solid. Fortunately, Aer is a brand that’s really good at that kind of consistency. From their signature all-black zipper-in-the-middle styling to making sure they use nothing short of the most tried-and-tested materials and hardware, every product line that’s achieved the “trilogy” status we’ve tested from them has been travel-worthy.

So, is it the same story for the Aer City Sling 3? With a noticeably sleeker shape and lots of subtler tweaks in materials and layout, we’re looking closely to see if the changes they’ve made sum up to a solid sequel or just a passable summer flick.

External Components

Compared with the City Sling 2, the City Sling 3 has a narrower design, almost as if Aer pulled on the sides to really stretch out the shape. Instead of boxy and rectangular, it’s more tapered, and we like it because it’s less cumbersome, at least in appearance. That said, the City Sling 3 may have undergone some slimming down, but the core materials are more or less the same. That means the usual 1680-denier CORDURA® ballistic nylon, as we’re testing in this review, as well as black X-Pac and black Ultra colorway options. Topping off materials are YKK zippers, Duraflex and Woojin hardware, as well as Hypalon accents.

At the top is a carry handle when you need to grab the sling quickly but don’t feel like clutching the entire thing. On the City Sling 2, the top handle was a convenient way to carry it in pouch mode since you could stuff its strap into the back panel. It’s a similar case with the City Sling 3, but instead of a stowable strap, it’s now completely detachable via side-release buckles.

On that note, the first significant change we noticed with the City Sling 3 is the strap system. Whereas the City Sling 2 used aluminum adjusters for compressing the sides, the City Sling 3 uses a more passive mechanism. Namely, the side-release buckles on either side cinch the front and back closer together, using the sling’s own weight to keep things tightened while wearing it. It’s a clever design we’ve seen on Bellroy slings as well, and it cuts back on extra straps and slack, making for a much cleaner-looking setup. That said, this also means you lose compression as soon as the strap is no longer under tension (i.e., once you put the slings down).

Having two side-release buckles means no more central magnetic FIDLOCK for the City Sling 3’s strap. We like this change because we often use a sling while also wearing a backpack, and having the buckles near the sling itself means we can actually reach for them. We also dig that Aer included a small loop on one of the buckles so you can hang the City Sling 3 on a restroom stall hook, for example, without it dangerously hanging a few inches from the dirty floor.

Fit Notes

The City Sling 3’s overall carrying comfort is superb, as expected of a sling that’s undergone two iterations. The strap, while not padded, is wide enough to distribute the weight evenly, and that passive compression mechanism works to minimize sag. That said, the City Sling 3 feels somewhat large for a two-liter sling. Perhaps it’s the narrower shape, though it is worth noting that the ostensibly larger 2.5-liter City Sling 2 is 4.75 inches tall, while the City Sling 3 is 5 inches. We can’t help but notice a difference since we have both on hand to compare.

Adjustment while wearing is quite tricky, as the adjuster always rests on a tricky spot for us to reach, namely just behind the shoulder or behind the hip in crossbody mode. It’s doable, but our convenient compromise is removing the sling, making the adjustments, and fine-tuning until we get the fit right.

Inside The Sling

At the back is a slim zippered pocket for correspondingly slim items, including passports, tickets, and transit cards. But for everyday use, chances are you’ll use this for a smartphone, in which case we’re happy to report that a Max-sized iPhone fits, if only barely. Try not to put anything too bulky, though, like a wallet bulging with cash, because it can also misshape the back panel.

The front pocket still features a middle zippered opening, the same style we’ve seen with the City Sling 2. Our primary gripe there was that small items could fall out since the opening sits in the middle, resulting in a shallower bucket space. While still true with the City Sling 3, the situation is somewhat mitigated by having dual zippers with one on each end. This ambidextrous design means you don’t have to hang the sling on just one specific shoulder to keep the zipper opening at the top, as required with the City Sling 2.

Using the front pocket is still a challenge because of its middle-split design. As we’ve noted with the City Sling 2, this style presents a relatively shallow floor for storing gear, so you’re mostly limited to small accessories. Even just trying to fit a set of keys onto the built-in key leash inside was always an awkward experience since half of it fits into the bottom of the pocket, but the rest sticks out. It also doesn’t help that the pocket generally feels small once you fully pack the main compartment.

The first thing we noticed about the main compartment is that it doesn’t have YKK AquaGuard zippers, unlike the front pocket. That to us is strange since the main compartment’s opening is facing up, so it’s more likely to get rained on than the front pocket. To be fair, the zippers here are still reverse-coil, so liquids should still have a hard time seeping through, but it’s just interesting to note.

The main compartment houses all of the City Sling 3’s organization. On the front side are twin stretchy mesh pockets, while the back side has dual stretchy mesh pockets (one is narrower than the other), followed by a zippered pocket for loose accessories. At the backmost is a divider pocket, which is, unfortunately, not big enough for a Kindle but fits a Max-sized iPhone.

With four mesh pockets in total, it’s easy to accommodate a lot of accessories, such as chargers, cables, and wireless earbuds. That said, it takes some figuring out where exactly items fit the best because you have to consider a few other factors. For example, while we found that a minimalist wallet can fit in the smallest mesh pocket, there isn’t enough height clearance for the zipper to close smoothly. Additionally, the front pocket can cut into the front-side mesh pockets, so that needs consideration as well.

There is a decent amount of floor in the main space in the middle. However, if you lean more towards using the pockets first and getting everything organized, what you can fit in the middle will mostly depend on whatever leftover space there is. In our case, there’s just enough to fit a pair of sunglasses in its hard case, a medium-sized power bank, and a pair of lightweight gloves.