Tom Bihn Synapse 25 review: Upsizing a classic laptop/iPad backpack

Nearly four years ago, I reviewed Tom Bihn’s Synapse, a fantastic and versatile compact backpack for those times when you don’t need to carry everything but the kitchen sink. I liked it so much that I bought the review sample. The Synapse remains my everyday backpack, and apart from looking a little worn, it’s in nearly as good condition today as when I reviewed it.

The Synapse is now called the Synapse 19, because Tom Bihn has since introduced a version with 30 percent more volume for all those people who loved the original’s design but complained that they needed more space (or—true story—felt that the 19 simply looked too small on them). The result, the $170 Synapse 25, maintains the Synapse 19’s versatility and clever design touches, but adds the company’s popular “rail” feature (more on that in a bit), making the Synapse 25 perfect for those who want a larger bag that they can use all day, every day—whether they’re carrying a laptop, an iPad, both, or neither.

Built to last

Like the original Synapse, the Synapse 25 uses exceptionally sturdy nylon on both the exterior (your choice of either 420d HT nylon Classic Parapack or ultralight 400d Dyneema/420d nylon ripstop fabric) and interior (200 denier Japanese Dyneema/nylon ripstop fabric). Tom Bihn offers ten different color combinations of olive, black, navy, or steel on the outside, and steel, wasabi, Iberian, solar, or ultraviolet on the inside. It’s not going to win any fashion awards, but the Synapse offers classic backpack style, and it doesn’t scream “laptop inside!”

The Synapse 25 also uses the same straps and padding as its smaller sibling. The straps are comfortably shaped and include 10mm of closed-cell foam with “an underside of ETC knit to keep you cool and comfortable.” The company says that the back of the bag (the side that sits against your back) is covered in “Dri-Lex Aero-Spacer mesh and 400 denier nylon” that won’t snag clothing, with a quarter inch of closed-cell foam for padding. When empty, the bag weighs roughly 1.7 pounds, which is fairly light for a well-made backpack.

Over four years of use, I’ve found the Synapse 19 to be quite comfortable, even when loaded, and in my testing of the Synapse 25, it feels much the same. You also get adjustable sternum and waist straps that are removable if you don’t want to use them, along with a nylon handle at the top of the backpack. The bag’s zippers are all water repellant.

Stores more

The Synapse 25 is roughly 20 inches tall, 13.4 inches wide, and 9 inches thick, with its 25-liter (1526-cubic-inch) capacity split across a large main compartment and five exterior pockets. That main compartment is where the 25 gains most of its additional space over the 19, although the bottom pocket (described below) is also larger. Inside this main compartment, towards the front of the bag, is a full-width pouch for large items; you also get a couple O-rings for attaching keys or other similar items.

Instead of a simple mesh water-bottle pocket on one or both sides of the pack, the Synapse hosts a zippered, vertical center pocket that’s deep and wide enough to hold a 32-ounce water bottle; an O-ring lets you hang a hydration bladder. Besides being much more secure than a short, open-top, mesh pocket, the Synapse’s central compartment keeps your bag balanced on your back, no matter how heavy the bottle. Just in front of this pocket is a smaller zippered pocket that’s perfect for your phone, a wallet, your earbuds, or other small items.

On each side of the water-bottle pocket are two sizable vertical pockets, each large enough to fit a small umbrella or even a light windbreaker. Each of these pockets includes an O-ring and one or more organizational pouches: three pen/stylus holders in the left-hand pocket, and a larger, soft-lined pouch for your phone in the right-hand pocket. The company includes one removable, 8-inch key strap that attaches to any of the bag’s O-rings.

Across the bottom of the bag, in the front, is the fifth zippered compartment, this one also significantly larger than its counterpart on the Synapse 19. In fact, on the Synapse 25 it’s large enough for a sweater or light jacket, or even some gym clothes. This pocket also includes three O-rings—sense a pattern?—for attaching one of Tom Bihn’s many organizational accessories. On the outside of this pocket is a webbing loop for attaching a safety light while walking or biking.

Everyone has their own pocket/organization preferences, but I’ve found the Synapse’s design to offer a great balance between enough pockets to keep everything organized, but not so many that you end up obsessing over where everything goes (or trying to remember where you put it).

On the rails

Speaking of organization, the big feature addition compared to the Synapse 19 is that the Synapse 25 incorporates two sets of webbing loops for Tom Bihn’s clever “checkpoint friendly Rails system.” This allows the Synapse 25 to accommodate not one, but two Cache seeves. These sleeves, which are available in vertical and horizontal orientations for pretty much any size tablet and laptop (up to 15 inches), don’t offer any rigid panels, but they do offer decent shock protection.

But the best part of the Cache/Rails system is that the combination makes it easy to get your laptop and/or tablet out of the backpack, and turns the Synapse 25 into a TSA-checkpoint-friendly bag. Each $30 Cache sleeve includes two full-length, nylon-webbing strap that Tom Bihn calls rails, as well as (for $5 more) a pair of Gatekeeper Rail Clips. Attach one end of each clip to a rail, and the other to one of the Synapse’s webbing loops, and the sleeve is held securely in the bag. But when you get to an airport checkpoint, you just open the main compartment and slip the Cache sleeve right out of the bag—the clips slide freely along the rails until stopping at the bottom of the sleeve. The Cache remains firmly attached to the Synapse, but the sleeve is now completely exposed so that TSA agents can clearly view your laptop in the X-ray.

Besides being great for TSA checkpoints at the airport, this modular design means that when you need to carry both your laptop and your iPad safely, you can. When you need to carry just an iPad, you can leave the laptop sleeve behind. And when you’re traveling technology-free (or as close as we can get these days), you can quickly remove everything and have a comfortable, roomy backpack that weighs considerably less than a traditional permanent-sleeve laptop backpack.

Of course, a Cache (or two) adds to the cost of the Synapse 25, but keep in mind that the cost of the Synapse plus a cache (~$200) costs less than buying a high-quality laptop/iPad backpack for when you need your tech, along with a separate standard backpack for when you don’t. And having a single, versatile bag has other advantages, as well, such as not having to move all your “everyday” stuff between bags every time you switch.

Bottom line

When I reviewed the Synapse 19, I wrote, “As long as you tend to travel light, and you’ve got a 13-inch (or smaller) laptop, this is a superb, and superbly versatile, bag.” With the Synapse 25, those caveats no longer apply: It’s just a superb, versatile bag. The Synapse 19 is still my everyday bag, because I like to travel light and its smaller size forces me to do so. But I have to admit that I’m envious of the Synapse 25. It’s a little bit more of everything that’s great about the 19, and the Cache/rails system is fantastic. The 25 is one of the most versatile bags I’ve seen, and though it’s not inexpensive, my experience with its smaller sibling—four years of heavy use and still going strong—suggests that you’re getting what you pay for.