Tailfin Long Top Tube Bag Review: Function Over Form

Recently, a few of us editors found ourselves deep in conversation about the rise of looonnnggg top tube bags. Why are they suddenly so popular? Which brands make them? Who loves them, who doesn’t, and what makes them useful? We debated their best use cases and ultimately agreed that when it comes to these peculiar-looking accessories, “function over form” is the operative catchphrase. While undeniably practical and potentially indispensable in certain scenarios, their aesthetic appeal—especially for those of us who gravitate toward classic bike stylings—leaves something to be desired.

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For me, top tube bags often sit in a gray area for me when it comes to bikepacking setups, no matter their size. I genuinely enjoy their at-hand pragmatism and accessibility, but they don’t always win me over aesthetically. It’s not that I find them unattractive, but they often feel like visual clutter, especially given my minimalist preference to keep the profile of the bike relatively unencumbered—particularly for photography. For this reason, I tend to skip top tube bags unless I’m tackling a touring with a sense of urgency type of trip or simply need more space because of other limitations. That said, I’m fortunate to usually have ample frame triangle space, which makes leaving them out an option. Not everybody has that, so in once sense, the long top tube bag might be a revelation for a large percentage of the bikepacking population.

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Looking at them from a strictly utilitarian stance, top tube bags are among the most user-friendly and accessible storage solutions available, and the longer varieties significantly expand their utility. The all-new Tailfin Long Top Tube Bag is an excellent example. Despite it not fitting perfectly into my visual style, I thoroughly enjoyed using it, and it actually allowed me to go without a frame bag on one bikepacking trip. Read on for specs, details, and my take on its performance.

All About Problems

Tailfin approached the design of their Long Top Tube Bag in the same manner they do with all their bags: with a clear focus on solving challenges commonly faced by riders. Packing space was the obvious impetus. The Long Top Tube Bag aims to provide a solution for folks (and certain bikes) who simply lack enough storage volume within the frame triangle. Similarly, it provides more immediate space for riders, particularly ultra-endurance cyclists, for calories and other items that can be accessed quickly and easily.

The Right Sizing

Tailfin’s Long Top Tube Bag comes in three sizes: 1.6L, 2.2L, and 3.0L. The two smaller sizes are derived from Tailfin’s 0.8L Top Tube Bag and have a thinner form factor designed for road and gravel frames, catering to riders who want or need to minimize knee rub. The largest 3.0L iteration is a little wider, and Tailfin claims it’s made for mountain bikes with an inherently wider Q-factor but is technically also compatible with road and gravel bikes for folks with a naturally wider stance—Tour Divide Boost-spaced drop-bar bikes come to mind, although I’ve personally never had an issue with knee rub on a top tube bag. Similar to their frame bag, Tailfin did their homework to make sure each size is specifically tailored in length to fit a variety of different frame styles. Having a flat top tube is one critical factor, although the elevated V-mounts could make it work with slight curves, depending on placement.

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Tailfin sent all three for comparison. I didn’t test each of them on a hundred different bikes, but I found the 2.2L version to be a good fit with a couple of bikes I had in the stable at the time. As seen here, I used it mostly on the full-suspension Specialized Chisel. I didn’t have a frame bag that fit that bike and decided to forego having a custom one made. The Tailfin Long Top Tube Bag was perfect, and quite frankly, a boon in this scenario. Note the flat top tube on the Chisel where the Long Top Tube fit perfectly.

For bikepacking, I was able to outfit the frame triangle with a small accessory triangle by Stealth Bags I had on hand, a small water bottle, and a DrJ0n cage that held my Vargo BOT and nested cook kit. The Long Top Tube Bag took up the slack and held two 12-ounce cans, tools, a water filter, a couple of snacks, a headlamp, and most appropriately, my relatively new MSR Long Spoon. All told, the contents in the triangle and the Long Top Tube Bag amounted to what I could fit in a relatively large full frame bag on a hardtail. That’s the ticket.

Stability and Battle of the Bulge

Stability and structure was another top priority for Tailfin when designing these bags. Typically, higher-volume or overloaded top tube bags often wobble and shift, which is annoying and gets in the way. To address this, they carried over their patented V-Mount tech used on their normal-sized Top Tube Bag and the V-Mount downtube bag. You can read more about those in the associated links. In a nutshell, these three V-shaped fittings on the bottom of the bag provide a port for each TPU strap and have a rubberized V-shaped cap that grips the frame tube. I had used the V-mounts on their down tube bag; they’re impressively stable and do a great job of keeping the bag from rotating or sliding. It works just as well for the Long Top Tube Bag and eliminates the need for extra stabilizing straps.

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Each bag also features diagonal carbon struts sandwiched between the fabric layers on the interior to shore things up, prevent bulging, and maintain a slim and streamlined profile. Even when I overloaded it with the heavy double 12-ounce can load I mentioned above, it preserved its shape and didn’t shift or rotate.

Organization and Access

Like all of their products, the Tailfin Long Top Tube Bag is packed with innovative little details. One of the standouts is the suite of organizational accessories. Each bag ships with a moveable stretchy divider that velcros in place to each side and allows you to create two separate compartments. This is a nice touch, especially with the double-entry zipper that provides access from the front or rear of the bag. I placed the divider to create a rear cavity that took up about a third of the bag and reserved that for snacks to access while riding. Everything else I needed at camp was stored in the remaining portion of the bag.

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Tailfin also offers optional accessory pockets to hold items like your phone or wallet and internal loops to secure a battery bank, tools, or pump. I used one of the pockets for my phone, and it worked great. The Accessory Pack sells separately for £20/$30/€25.

The Features We Need

Other features include a hooded wire port at the front of the bag for charging devices mounted to the bars and a patented rain gutter on the rear zipper assembly. The latter essentially allows water to flow in and drain out of the zipper stop to keep it from pouring into the bag. The fully 3D-welded construction and water-resistant zippers further enhance the bag’s weather resistance. That being said, several of us on the team have experienced complete failure with this style of small coil zippers. It wouldn’t retain its near waterproof status, but I think I’d still prefer a large molded-tooth zipper for the sake of durability. Fortunately, Tailfin offers a solid five-year manufacturer’s warranty that guarantees they’ll replace or repair it if it does break.

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One last thing to note—although I didn’t test this—is that the placement of the V-Mount strap keepers integrate seamlessly with other Tailfin bags. This allows you to use a single strap to mount both the top tube bag and their frame bag.

• Model Tested: Tailfin Long Top Tube Bag 2.2L
• Weight/length/price (1.6L): 206g, 370mm, £85/$115/€110
• Weight/length/price (2.2L): 250g, 470mm, £100/$130/€125
• Weight/length/price (3.0L): 265g, 500mm, £115/$150/€145
• Place of Manufacture: Taiwan
• Manufacturer’s Details: Tailfin

Further Reading

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