Bag maker Tom Bihn offers “a convertible organizer bag/shoulder bag/waist pack” called the Side Effect. I was looking for something that would serve as a multi-purpose bag to put in my carry-on; specifically, a tiny purse that could also serve as a non-liquid make-up case.

Optimally, I wanted it to be able to fit one of the front pockets on my new Tom Bihn Co-Pilot (which I will review sometime in the future), but alas, the Side Effect is just a tad too long. I can get it to fit, but it’s a real effort. So while the bag is a keeper, I’ll need to stash it in the Co-Pilot’s main compartment instead.

Tom Bihn’s Side Effect bag.

The Side Effect is in no way a big bag, though. Measuring in at 8.7″ x 5″ x 2″, it’s about the size of one of those “man bags” (or “a European” as they kept referring to it on a Seinfeld episode), but considerably more streamlined, without a bunch of unnecessarily flaps. The concept isn’t new. I’ve had similar bags of various sizes from companies like Eagle Creek and L.L.Bean, although with the Side Effect you get Tom Bihn’s superior workmanship, made in the U.S.A.

Tom Bihn’s Side Effect bag, as it compares in size to a pair of sunglasses.

The Nifty

This bag is truly versatile. What looks to be an innocuous shaving kit is actually a Transformer of bags. Flip the bag around and notice the two vertical “vents.” These openings house the waist strap, which is sewn into the back of the bag. Unlike some shoulder bags that you “convert” to waist packs by just looping the shoulder strap around your waist, the Side Effect has a reinforced strap that fits nice and snug around your waist. The strap stays in place with a plastic buckle, and although the snap is 1.25″ in size and not as big as some of the big snaps you see in rugged waist packs, if you want to go completely hands-free and have it secured in place, this is a great way to carry this pack.

The hideaway waist straps on the Tom Bihn’s Side Effect bag use a plastic buckle that snaps together tightly.

This waist strap is adjustable out to 56 inches. Most people will have no trouble getting this to fit around their waist. Some thinner folks may find too much leftover strapping. Since the waist strap doesn’t come with any adjustable holders or clips, I would recommend just tying the ends or tucking the leftover back into the pack panel.

In front of the hideaway panel is a flat zippered pocket that the manufacturer recommends for stashing your passport. If you wear this as a waist pack, the passport will be zippered up and right against you; probably the safest place to hide it short of wearing a hidden passport holder under your clothes. The Side Effect has a thin enough profile that you can wear it as a waist pack under your jacket, making it harder for pickpockets to get to.

The back of the Side Effect bag, when you’ve folded the waist straps and tucked them away in the side vents. You can see the vertical piping on the ends of the bag. The zipper is for a flat pocket in the back that is sized to fit a standard passport or two. You can also use this pocket to stash the shoulder strap.

As a waist pack, the Side Effect makes a great man bag as well.

In addition to the sewn-in waist straps the Side Effect comes with a detachable shoulder strap, and this is where we start moving into purse territory. While the waist strap webbing is 1″ wide, the shoulder strap is only 5/8″ (a tad shy of 3/4″). Trust me: the 5/8″ width makes the shoulder strap absolutely dainty. It’s actually a very nice change, because most of these convertible shoulder bag/waist packs I’ve encountered have always used 1″ webbing (same width as the waist strap), and it makes the bag look much more utilitarian and unisex. Guys—the strap might feel too skinny. One option is to use the much wider simple strap that Tom Bihn sells separately. It will give the bag a considerably manlier, albeit bulkier, look.

The shoulder strap that comes with the Side Effect.

This shoulder strap extends out to 59″, making the Side Effect a perfect cross-body shoulder bag. As far as sizing goes, I would say the Side Effect is small enough that you can carry your essentials in it, take it with you to meetings or to lunch, without feeling awkward that you’re carrying your purse around the office (for the men: Women, once we get to the office, usually stash our purse in a desk drawer, but it often means we don’t have an easy means to carry the essentials around during the day).  The Side Effect is also small enough that you can drop it into your gym bag and not have it take up a lot of space. Just unclip the shoulder strap and hide the waist straps and the Side Effect won’t even have anything to snag in your gym bag.

Buried in the product’s description is the fact that the Side Effect automatically comes with one of Tom Bihn’s 8-inch key straps. It’s snapped onto one of the small D-rings inside the bag, but you can easily clip that on one of the two exterior D-rings (where you would snap the shoulder straps onto), and clip the other end to something in your gym bag (or whatever larger tote bag or laptop bag you might use) so the Side Effect stays snug in place.

A close-up of the shoulder strap buckle shows how it is identical to the buckles on the Tom Bihn key strap. The ball that the buckle attaches to lets the strap swivel freely. Note the D-ring on the bag that the strap attaches to; it is only about a  half an inch in size. Just enough for one of these buckles, but not so large that it snags on things.

Ladies, you can definitely use the Side Effect as a make-up bag. It has a couple of slider pockets so you can slip a compact or mirror in them. Just be aware that this bag isn’t specifically designed as a toiletry kit, so while it’ll handle a bit of splashing just fine, it’s not waterproof. Guys, you can use this as your toiletry kit as well (using the shoulder strap to hang it in a bathroom while you’re traveling), but if you plan on flying, it does not qualify as a transparent 3-1-1 toiletry bag. For that you will either need to put all your liquids in a resealable plastic baggie and then put the baggie in the Side Effect, or get a transparent 3-1-1 pouch like the Tom Bihn 3D Clear Organizer Pouch.

Two final notes in the “nifty” category, and these are again for the ladies. When you hide the waist straps and detach the shoulder strap, the Side Effect actually makes a reasonable clutch for an evening out. The main thing that won’t fit the picture is the Tom Bihn label, which is sewn right onto the front center of the bag. My suggestion, if you can tear yourself away from removing labels (which is what I recommend for camera bags), is to carefully snip the threading from the label and remove it altogether. You will initially be able to tell where the thread was, but the fabric should “heal” itself over time. Just do it relatively quickly after you get it, so the fabric color behind the label matches the rest of the bag.

If you love Tom Bihn and cannot bear the thought of removing their label, consider getting a big broach to pin over the label to camouflage it.

Finally, if you have a detachable chain shoulder strap from another purse, you can swap the regular shoulder strap with the nicer one, and you’ll really be ready for an evening out.

The Not-So-Nifty

Fortunately there isn’t a lot of negatives for this bag, but I do have one main druther.

My biggest complaint is that, for its size, you really can’t get a lot of stuff in there. Part of the problem is that the fabric is very stiff and provides very little give when you’re trying to stuff things in there. The same 1000 denier Cordura that makes their bigger carry-ons so tough, also means considerable rigidity with the Side Effect.

The second reason it’s tough to get stuff in there is because the opening doesn’t open as much as I would like. The zipper goes all the way across the top and down the sides by about an inch, but when you unzip it completely and try to pry open the bag from the sides, the mouth doesn’t open quite so wide, and you wind up having to pinch your fingers to have to go in and pry stuff out. I’m sure it was designed that way to prevent stuff from falling out too easily, but the main compartment has two zippers that meet in the middle, so I would think you could have a wider opening.

The Side Effect, filled to the gills with stuff…

The contents of the Side Effect: Cell phone, iPod Touch (with earphones), Moleskine pocket journal, coin purse, nutrition bar, a pen, a tube of lip balm, and a set of keys. Note the keys are attached to the lanyard key strap.

Take a look at the two photos. I can easily grab the packet of tissues since it’s just resting on the top of the main compartment. I can also get to my cell phone, which I’ve slipped into the left slider pocket (you can’t see it because it’s nested itself lower in the pocket). I can also easily grab the iPod Touch out of the bag, although getting it back in is a bit of work since the earphone cords don’t want to go into the slider pocket. I can also take the purple wallet out, mostly because it’s very thin and just contains a few plastic cards and some bills. That’s about it.

In the shuffle of things, my pen and lip balm have probably fallen to the bottom of the bag. No way I can retrieve them unless I take everything out of the main compartment. Not very convenient. And surprisingly, the Side Effect doesn’t include a pen or lip balm sleeve anywhere, so there’s no way to secure it anywhere.

Some bag manufacturers, like baggallini, use a trick where the zipper opens up a lot along one size, but the contents don’t fall out because there’s a piece of fabric that adds a protective barrier/gusset; that is, the zipper pulls down below where the inside panel starts. Something like that would help a lot here. What particularly catches is the corners; the Cordura is very stiff, and because Tom Bihn reinforces all the internal seams with piping, the combination means less give. I could see how it might get really hard to reach in and get anything if you’re wearing the waist strap. And unlike other belt bags that have an extra zippered pocket in the front, the Side Effect lacks such a feature (but it’s also what makes this pouch so streamlined with a clean profile), so whatever you’re looking for is going to be in the main compartment.

Probably the easiest solution to the problem is to simply craft the Side Effect in one of their lightweight Dyneema nylon fabrics. The only thing you would give up is the ability to carry it as a clutch purse (since you’d give up a lot of the stiffness), but as long as the product is offered in both Cordura and Dyneema, people can decide which works best for their purposes.

In the end, though, I don’t think the difficulty in getting to your stuff is a showstopper; all the other features make this well worth considering.

Final Notes

The Tom Bihn Side Effect is a bag full of wellness—well-thought out, well-designed, well-constructed—and at $30, an absolute bargain that’s very competitively priced against other brand crossbody bags and belt packs. Tom Bihn has managed to design a really good multi-carry pouch that works well however way you choose to carry it. Most women probably don’t think of using a Tom Bihn bag as a purse (or they might just assume the Cafe bags are the way to go), but the Side Effect is a great option, especially for traveling. The Side Effect is still small enough to easily slip into your main carry-on or seatside bag (like the Co-Pilot) and keep your valuables in, but its versatility is what clinches it for me. The Side Effect gets my thumbs-up; I really like the utility of this bag.

The Side Effect comes in various colors, including (currently) Steel, Black, Plum, Indigo, and Olive. Tom Bihn is known for swapping in new colors and retiring some colors, so if there’s one you have your heart set on, get it sooner rather than later.

Available for $30 from Tom Bihn directly.