Downtube Packs


The Downtube Pack is our solution for adding extra storage to a frame without traditional cargo mounting points thanks to patented V-Mount hardware that create a truly solid, reliable, and repeatable connection between bike and pack.

Downtube Packs allow you to utilise free space for carrying the essentials whether on a mountain bike trail ride, bikepacking adventure, or road tour. Available in two sizes, 1.7 litre, and 3 litre. Optimised to maximise space regardless of frame geometry.

Each pack ships with 2x Tailfin V-Mount Straps, designed to work with your frame.



1.7 v-mount spec
3l v-mount pack

1.7L V-Mount Pack


3L V-Mount Pack

Riding Style

Road & Gravel

Riding Style






Maximum Load


Maximum Load


Bag Construction Material

420D Hypalon/Ripstop Nylon

Bag Construction Material

420D Hypalon/Ripstop Nylon








The 1.7 litre Downtube Pack has been specifically designed and shaped to work with the geometry of a typical road or gravel bike.

Both 1.7 litre and 3 litre Downtube packs are suitable for use on a typical mountain bike - it just depends on how much extra kit you want to carry (see Packing Guide below).

We do not recommend fitting a Downtube Pack directly to the forks of your bike.

We do not recommend fitting a Downtube Pack directly to the arch of your Rack or AeroPack.

Absolutely. We designed the Downtube system around the dimensions of most common cargo straps such as Voilé. We would always recommend using the straps that are supplied with the V-Mount Pack as they have been designed specifically around use with bike tubing.

Yes. The soft rubber boot covering the V-Mount is designed to conform with frame tube shaping so will cover a boss if required. Each pack is also supplied with four rubber boss covers that can be used instead of the existing bolt in order to increase grip.

On paper a Downtube Pack is heavier. However when you take into account the additional straps and cargo cage required to mount a Cage Pack the actual weight difference is very minimal.

We created the Downtube pack primarily for riders with bikes without additional mounting points on their frames but also for mountain bikers who require a little more weatherproof storage. It is aimed primarily for use in and around the main frame of the bike and requires no additional parts to attach, unlike a Cage Pack. We would recommend a Cage Pack over a Downtube Pack anywhere you would normally fit a cargo cage, i.e. on forks and the arch of a Tailfin Rack/AeroPack.

Capacity is measured by filling a test sample with water and setting the closure to the minimum setting required for complete waterproofing (two folds of a roll-top closure) and then measuring the volume held.

The Packing Guide images below will give you some idea of what can fit in each size. For example, the smaller 1.7 litre has dimensions that will fit a standard 750ml waterbottle, or you could fit a lightweight packable waterproof, multitool, inner tube, pump and trail snack. The larger 3 litre version has dimensions that will allow a 1 litre Nalgene style bottle to fit or you can fit a standard size gas cannister, stove, cook kit and even some food.


Packing guide


Media Reviews

Additional Product Imagery


Top tip: Try searching for your bike make/model below to find others using this product on your bike.

Customer Reviews

Based on 78 reviews
Christian Lutz (DE)
Bike: Cube NuRoad Pro
Riding Style: Road / Ultra-endurance, Bikepacking
Great gear with premium support

The pack is, as every other gear is, well thought out and from great quality. If you have any requests, the tailfin guys are very helpful in solving the problem.

Mr. Norman Macleod (GB)
Bike: Cotic Flaremax gen5
Riding Style: Bikepacking, MTB
Down Tube Bags are Rock and Roll-top!

Wow, these are seriously good frame packs which I can swap them between bikes and use them wherever I want. I mainly use them on my full-suss where space is tight inside the frame, I now have an option to store essentials on my top-tube or down tube.

The 3l pack, I use to store a jacket, tools, first aid, gels and sweets when mountain biking. The 1.7l is smaller and I use it for rides when I don’t need an extra layer and need a pack for fuel, tools and first aid.

Stefan Tirtey (DE)
Bike: Specialized Divergen 2019, Roubaix 2020, JLaverack, open.mind
Riding Style: Bikepacking, Touring
Some of the best cycling products out there!

Every now and then you buy a product that seems expensive, but you buy it anyway. Then, after years of using it, you realise it wasn't expensive after all, because you love using it every time you touch it. That's my experience with Tailfin. Tailfin's products are excellent, with designs that reflect deep thinking, great engineering skills, good processes and listening to customers.

And I would add that the quality of the company and the business can really shine when things go wrong. It's that moment of truth that creates lasting customer loyalty. Tailfin has helped me out of a jam more than once, in impeccable style, and I would add that the quality of the company and the business can really shine when things go wrong. It's that moment of truth that creates lasting customer loyalty. The good people at Tailfin have bailed me out more than once in impeccable style.