Single Handed (4 of 6): Pack Hack Reconfigures Roomy Rucksack for Crossbody Carry

I’m a backpack person. Whether for everyday carry or for travel, I’ve always preferred backpacks to sling, messenger, duffel, and, above all, roller bags. But after I severely injured my right arm, I was forced to cycle through alternatives, particularly for day-to-day purposes. I found smaller, single-shoulder bags uncomfortable to wear for long periods; most also lacked space (and padding) to safely carry stuff I regularly need, like a laptop. Absent an off-the-shelf solution, I began thinking on custom designs. Ultimately, I figured out a way to hack a backpack to work like a crossbody bag (so my “bad” shoulder wouldn’t need to carry weight), while retaining the look, feel, and functional advantages of its original design. The key to this reconfiguration is in the pack’s straps.

The “base” bag I started with is the Techonaut from Tom Bihn. There is a larger 45L version, but even the 30L carries more than the vast majority of slings or messengers. Techonauts are also designed to convert from backpacks (via hideaway straps) to duffle bags (via a built-in side handle and removable shoulder strap).

This bag’s crucial design detail (for our purposes) is the way each backpack strap unclips at its base, allowing it to be stored in a slot above. I realized I could repurpose this functionality to serve another goal as follows: instead of tucking both of them away, I could stow just one of the two straps, then run the other strap across at a diagonal and clip it into the buckle at the opposite corner – taking the strap that starts at the top left, for example, and buckling it in at the bottom right.

In effect, this created a kind of sling bag — but one that wears and works more like a backpack, conforming to a similar space. While messenger bags of similar capacity bulge out to one side, this hybrid rests like a turtle shell against a wearer’s back, much as it would in its regular two-strap mode. The shoulder strap (upon which this design hack hinges) is comfortably wide and padded, too, since the bag was designed to accommodate a large range of loads. Of course, even my uninjured shoulder still has limits that demand accommodation. Thus, shifting the bag from two shoulders to one was just the first step. I also made other modifications to manage weight distribution and improve accessibility.

Below, we’ll consider adaptive hacks and assistive accessories that can be applied to crossbody-modified Techonauts as well as other kinds of bags. Later, for those still looking for a straightforward, ready-to-wear bag, we’ll go over an array of off-the-shelf slings and messengers — ones I researched and tested before resorting to a custom hybrid.

Supplemental Support & Magnetic Buckles

The Techonaut comes with a slim waist strap. Normally, this thin default option is sufficient. But to better distribute the load in this new sling configuration, a padded one is preferred. Tom Bihn also sells padded straps separately that use the same gatekeeper clips.

TB waist belt modded w/magnetic V-Buckle

As an aside: after searching for other solutions, I’m still not sure why companies don’t make higher-volume sling bags. But my best guess is that you really need something like a waist belt to make 20L+ loads practical — it’s hard to carry that much gear for long relying only on a single shoulder for support.

For one-handed access, you can replace a plastic waist belt buckle with a magnetic alternative. Personally, I took one of each belt type from Tom Bihn (normal and padded) and replaced the plastic buckles with a magnetic Fidlock V-Buckle and Slider, respectively (to try out both).

To operate a V-Buckle (like the one on the right in the above image), you pull a corded tab, raising and releasing one part from the other with surprising ease. To lock them back up: just bring the two pieces close together and the magnets will snap them back into place.

Two Sliders (LL) and three different V-Buckles

With a Slider, as the name suggests, you slide the top of the buckle to one side. There are reminder arrows that indicate which direction to push the pieces in order to uncouple them, which is easily done one-handed. Like a V-Buckle, reconnecting the paired parts is easy: put the pieces close to one another and they’ll snap right back into place.

For the most part, Fidlocks are bought by businesses to be integrated into consumer products, like purpose-built straps. That said, you can buy sample sets online or bundles from their manufacturer. There are minimum purchase quantities when you buy direct, but that may be fine if you’re retrofitting a bunch of stuff– which I, for one, continue to do. For instance, I’m working to swap in a pair of 25mm (1″) magnet buckles at the bottom corners of my Techonaut where the shoulder straps connect to the bag. I’ve even gone beyond bags to put magnetic buckles on medical slings and braces for my injured arm.

More Magnets, Padded Straps, & Zipper Pulls

Despite my general preference for backpacks, I do also own both a messenger bag and a shoulder sling from Tom Bihn — they do have some use cases, but also limitations (more on those below). I modified both bags post-injury with 25mm (1″) Fidlocks for easier access. For belts and straps, I’ve found (through testing) that I generally prefer the lift-and-pull mechanism of a V-Buckle, while the smoother sideways release action of Sliders works better for fastening bag flaps.

I’m bringing these two bags up largely to highlight hacks and accessories that can be useful both on and beyond a reconfigured Techonaut. But I would also recommend each bag, with caveats. In terms of capacity, the 13-liter Maker’s Bag has space for a large laptop but no padding for electronics. For its part, the 9-liter Ristretto has a padded space for a small laptop, but this bag is sadly no longer in production. So the Maker’s Bag isn’t padded and Ristretto is hard to find. Nonetheless, these bags are useful backdrops for exploring a series of modifications.

On both bags, I’ve traded the default straps for padded Mini SOS alternatives that are much more comfortable for everyday carry. This strap is also a great option when using your Techonaut as a duffel bag. I would also recommend getting some strap holders to go with it.

I also like to add double-swivel carabiners as ‘bridges’ between shoulder strap clips and attachment points on bags, for two reasons: (1) the swivel action lets straps rotate freely without twisting up, and (2) they make it easier to take straps on and off one-handed — just unclip the bigger biner from the pack rather than the strap’s smaller built-in clip. And since the TB shoulder strap connection points are consistent from bag to bag, I can save money on straps by swapping them around.

More Fidlocks, including some that I swapped onto different TB waist and chest straps.

Clearly, this will only apply to bags being worn in fully dual-shoulder backpack mode, but when sternum straps are called for: I recommend either adding a magnetic clasp to whatever option comes with a bag or just buying a strap pre-fit with a magnetic closure. Be sure to double check, but backpack chest straps generally employ 20mm (¾”) buckles.

The Techonaut already comes with a set of nice, heavy-duty zipper pulls, but depending on your dexterity you might prefer smaller smaller ones you can hook with a finger or larger ones that work as handles. You can also roll your own DIY alternatives out of paracord.

As mentioned above, Tom Bihn’s sling and messenger options are limited, so I tried out a lot of other bag brands as well. If all of this modifying stuff feels like too much, or you need to fill a different usability niche, hopefully the results of my research into (and testing of) various options explored below can speed your own search.

Single-Sided & Ambidextrous Sling Bags

If you’re leaning toward slings (and happen to be newly left-sided) like me, Nomatic makes a pretty solid array of small and medium sized sling packs – I actually have a 6L Navigator– alas, their laptop-sized bags are all two-strapped, and their largest sling is 10L. Still, they have space for a tablet or a very very small computer. They are all made for left shoulders, which works for me, but may not for you. Pacsafe also builds good, left-oriented options (alas, also capping out at 10L), such as the Vibe. There are many others, such as the Atom sling bag, I’d have liked to try if they weren’t exclusively designed to sit on right shoulders. (Naturally, if your problem mirrors mine rather than mimicking it — as in: your right side works — just invert all of the recommendations and lamentations above.)

There is also a subset of slings that can sit on either shoulder, thanks to straps that unclip at the bottom and tether to attachment points on either side of the bag. On the whole, though, these tend to be even smaller than one-sided slings. That said, of those I tried, the Osprey Daylite Sling felt like the best in class, as far as materials and workmanship, though it only carries 6 liters. The biggest I found that can be shifted to sit on either shoulder is the Patagonia Stealth Sling, but it has a 10-liter limit and is made for anglers (not computer users).

There’s a Case to Be Made for Messengers

If you’re comfortable with a bag that sits off to the side, but can bulk out your spatial footprint in public, messengers may suit your needs. Overall, I found Timbuk2 and Chrome Industries to have the most compelling ones. Chrome has slings up to the 16L Kadet Max as well as messenger options all the way up to a 24L Citizen, but they start to seem uncomfortably bulky beyond the 20L Midtown.

I will say this for messenger bags: since the straps cross your body and put the bag on your injured side, you can use it as an arm rest. It can, however, also get in the way if you’re wearing an orthosis.

A note on sidedness: some messengers offer easier access to certain pockets when users rotate their bag from their back or side around to their front, which allows the wearer to avoid taking the bag off entirely. However, some such bags are optimized for rotating in one direction or the other, though they may appear ambidextrous at a glance. If you can’t try a bag out first in person, look at the images associated with listings for clues, such as models shown wearing a bag on only one shoulder, or rotating it in only one direction for frontal access.

“Missing Middle” of Inclusive Bag Design

Analogous to the gap between small and large housing stock in many cities, my search has convinced me that accessible baggage has a “missing middle” problem. Slings tend to fall in the 8- to 12-liter range, while messengers range up to 24L, but only in rare cases. By comparison, a Techonaut can also be used to carry smaller loads, but has a capacity that can reach up to 45 liters. One-handed users seeking something in that range are generally going to be stuck looking at duffels or rollers — nothing you’d want to carry or cart around all day.

Wearing a backpack-style bag is (in my opinion) more comfortable in public compared to aforementioned alternatives. I hate being in cramped spaces like subways or buses with a bulging side bag or awkward roller, which expand my physical footprint and jostle those around me. My injury has compounded these concerns.

Wearing a bag that conforms to the space of a backpack feels more stable and allows me to move more freely. Hence the reconfigured Techonaut, enhanced with assistive mods and accessories. I still also bring a shoulder strap with me, and use the side handle at times, but those are secondary options for short-haul situations. When I need something with the functional range and comfort of a backpack, my best current option remains my crossbody-modified hybrid.

I feel fortunate to have arrived at a solution that largely fits my needs. But really, pack makers should recognize this “missing middle” problem and design accordingly. People shouldn’t have to single-handedly create their own adaptive solutions. I also firmly believe that users with two working shoulders would benefit from such inclusive bags as well, which offer them a greater range of carry options, too.

Strap In: Further Stabilizing the Slingback

Meanwhile, the main drawback I’ve experienced with my reconfigured Crosspack, or Slingback, (or … I’m still working on a name for this modded Techonaut) has to do with the curvature of the strap. It simply isn’t designed for crossing a chest diagonally, which can lead it to ride up on the shoulder. To pull that strap back down (and better brace the bag), I’m experimentally running a stabilizer strap (with a magnetic buckle, naturally) from the left backpack strap’s sternum strap attachment point (shown below) down to the bottom left corner of the bag, which has an unoccupied left shoulder strap clip in this crossbody configuration.

I’m also in the process of swapping out the shoulder strap buckles for magnetic ones. If all goes well, the new clip-in points at the corners of the bag will ultimately accommodate either a shoulder or a stabilizer strap, depending on how it’s configured to be worn at any given time. So although I find my bag already works well as-is, it also remains a work in progress. Should you choose to emulate my approach, you can of course stop short and opt out of these more intensive modifications.

If I seem obsessively bent on iterating upon the Techonaut in particular, the reason is simple: I haven’t yet encountered any other viable starting bags. Most hideaway straps I’ve seen on other backpacks don’t detach at all, making a crossover mod impossible. And I’ve looked around quite a bit.

At this point, it would take a really ideal candidate (or great purpose-built option) to cause me to change course. Still, you may yet find another backpack base model that can work with this kind of customization — perhaps even one on which the straps unclip at both the bottom and the top, which would allow the wearer to swap straps entirely, making for an even more personalized fit. If you happen to come across such a unicorn, I hope you will follow my lead and share your find widely to help others still searching for an ideal design solution.

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