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Top Tube Bags
The Tailfin Top Tube Bag range took us two years to design, from the initial planning and prototyping phase to production. The reason for this? Perfection. Every part, from material choice to the Flip Pack’s Mag-Lock magnetic closure, has been honed and perfected in-house. We have had a lot of help along the way thanks to our R&D Division riders. Lachlan Morton, Josh Ibbett and Gail Brown, plus our other test riders, all have been integral to the testing process. Thanks to their feedback, we have ended up with a full complement of five top tube packs, meeting the needs of every type of rider.
Video Complete Guide
Creating the perfect Top Tube Bag
As with all our products, we aim to create the ultimate solutions. In this respect, our Top Tube Pack is no exception. Taking on board the critical features/problems of existing top tube packs, we set about creating the ultimate version.
After two years of product development and well over twenty different prototype stages (not to mention all the variations and adaptations to each prototype), we are happy with the results and we think you will be too.
Watch Tailfin founder Nick explaining what makes the Top Tube Bag so special
Fitting to your bike
All Tailfin Top Tube Bags can be mounted using the supplied TPU straps or bolt-on attachments with compatible frames. The V-Mount hardware provides two bolt-on positions to place the pack exactly where you want it. In addition, the rubber boots of the V-Mount system are pre-cut to retain and allow the bolts to pass through neatly.
Using the V-Mount in this way provides market-leading stability for a bolt-on top tube pack. This also allows for the load to be spread away from the frame’s riv-nuts, minimising any potential damage when carrying heavier loads in your top tube pack.
The Tailfin Top Tube Bag also has removable straps; this improves pack life, something sewn-on velcro straps can’t compete with. We also ship all packs with an additional 36cm long TPU strap enabling setup on bikes with a large top/head/downtube union. You can even use two straps together for even larger applications. As we set out to do with all Tailfin products, increasing the number of bikes the Tailfin Top Tube Pack is compatible with.
Curing instability – V-Mount technology
Without a doubt, the number one issue with all top tube packs is the propensity for unwanted movement. This movement can come from terrain-based vibrations or rider interaction (knocking to the side when getting on and off the bike, for example). Many existing packs fit well when the bike’s top tube matches the pack’s base width, but often need an additional stabilising strap around the fork steerer.
They stop working well when it’s either trying to grip narrow-diameter steel tubing or oversized carbon and alloy tubes. Luckily we already had the basis for the solution in the form of our proven V-Mount technology (found on our existing Downtube Packs). The V-Mount system combines many parts, all working together in harmony.
From the tacky rubber pads to the abrasion-resistant and grippy TPU straps to the welded V-Mount tunnel/garage to how we transfer the rigidity to the internal HDPE ‘Taco Shell’. It’s the unification of these parts that create the magic.
Knee rub – which pack is right for me?
Every rider is different. Through extensive research and body mapping, it was obvious that one of the limiting factors of a rider’s use of top tube packs is the tendency for the pack to interfere with knee tracking.
Slow motion video capture and anecdotal field testing indicated that if the goal is maximising the amount of storage available, each rider and bike combination has a ‘maximum pack size’ before causing obvious knee rub. Just as with a shoe, glove or even bike frame there is an optimum ‘sweet spot’ in terms of the shape. One size most certainly does not fit all. As a guide if you’re unsure:
If you suffer from knee rub with other packs or have a narrow gait on the bike, then 0.8L Zip Top Tube Bag is the pack for you
If you ride mainly gravel or road bikes and don’t suffer from knee rub with other top tube bags, then go with a 1.1L (zip or flip) Pack
If you ride mainly mountain bikes you will want to order a 1.5L (zip or flip) Bag
Top Tube Bags (Flip) – what’s unique?
Our Flip Lid Packs have 2 unique features:
1) a functional flip-top shape constructed using 3D welding and
2) a secure and reliable closure mechanism (Mag-Lock technology).
3D Welding our signature Hypalon and Ripstop Nylon panels ensures a watertight construction which is why we construct all of our softgoods using this method. This method is relatively straightforward when creating simple packs, but the tapered shapes and rounded edges of the Top Tube Packs meant that consideration had to be taken to design all angles and radii to perfection in order not to introduce any awkward folds or too tight an angle and in order to keep a clean and good-looking aesthetic.
Mag-Lock Technology – We are firm believers that latches and mechanisms offer a better experience when they have a ‘positive action’ – just like the X-Clamps of our pannier bags. What we mean by this is we want these mechanisms to be actively opened and closed; this way you 100% know that the operation has been done.
The Mag-Lock is designed to offer a repeatable closure, be simple to operate even with winter gloves, provide noticeable feedback to eliminate second-guessing, be self-adjusting and user repairable. This last part is of vital importance with this style of closure. We utilised shock cord to allow the pack to stretch but we are well aware that even though this is the best material for the job, it has a finite life span. To counter this, rather than just attach it permanently with glue or stitches we developed a cunning little clutch mechanism that allows for easy replacement of the cord without additional bulk.
Top Tube Bags (Zip) – what’s unique?
Zips are often the weak point of a top tube pack, both from a waterproofing perspective and also as they tend to fail over time if a bag is either overstuffed or the angle and support of the zip are not enough to overcome friction introduced when opening or closing the bag. In order to ensure our zips stay reliable for the lifetime of a pack we had to incorporate the following features:
- The internal HDPE structure of the pack supports the zip, allowing for easy, one-handed operation.
- The V-Mounts hold the pack with enough stability to ensure the pack doesn’t move whilst operating the zip.
- The top radius of the pack is constant to ensure even tension throughout the entire length of the zip.
- We haven’t removed the secondary metal zip puller to save weight. We found incorporating it alongside our cord pull ensures that the zip is operated at the correct angle and the operator isn’t pulling it away from the direction of the zip.
- Most manufacturers opt for a standard No.5 sized zip. We went oversize to reduce failures.
Cargo Straps
All of our Small Packs secure to your frame using our Cargo straps, and each pack ships with them included as standard.
The new Tailfin Cargo Strap pays homage to the ever-popular, incredibly effective ski strap system yet boosts the design to 11. We created it to deal with the demands of bikepacking specifically. But rather than just copy and paste the classic design, we invested in considerable R&D to offer specific advantages from our Load Lock Buckle design and material selection.
The buckle shaping has bicycle frame tubing profiles in mind, and the whole strap utilises non-scratching materials. The version supplied with the Downtube Packs has a unique shortened prong designed to eliminate snagging on clothing or skin and sits flush with the strap when engaged:
Protecting your frame
When you combine slippery materials with velcro straps or other inherently unstable attachment methods, you get movement. Put a top tube bag with these features on your fresh new bike frame, take it for a ride and even when riding on dry and clean roads, this movement will eventually damage the finish of your beloved bike. Mix in some rain and dirt, and in some extreme cases, this unwanted movement can cause actual damage to the frame itself.
We spent a lot of time testing our V-Mount system when fitted with dedicated TPU straps, on our ‘wiggle rig’ (see video at the top of the page). The results speak for themselves, but if you’d rather not watch the video, the bottom line is this: V-Mounts and Cargo Straps eliminate movement completely when attached correctly, even without a front strap, and thus you will have zero frame rub with our packs. No matter how wet and muddy.
Waterproofing
Our entire Top Tube Pack range uses a revised, lighter version of Tailfin’s signature Hypalon/Diamond Ripstop Nylon* mix to create a waterproof pack. All packs feature our 3D welded construction process (no mean feat on such a small yet complex design), eliminating any potential weak points for water to get in. On top of this, all zips used are genuine, fully waterproof versions.
*Due to the lower wear and stresses placed on a top tube bag, we could incorporate a lighter-weight 210D Hypalon material without impacting durability.
Downtube Packs
What are Downtube Packs
Tailfin Downtube Packs allow you to carry your essentials in complete security, even if your bike doesn’t have dedicated mounting points. They’re available in two sizes, 1.7 and 3 litre – The 1.7L is designed around road and gravel Q-factor. 3L for MTB Q-factor. Both are fully waterproof and use our clever V-Mount technology to secure snugly to your frame, without any worry of damage.
The secret to just how stable and secure the Downtube Pack performs is a clever mix of our unique V-Mount system, accompanying internal aluminium frame alongside Tailfin’s own bike-specific TPU Cargo Straps. These unique features provide the Pack with a formidable grip, far superior to its competition. Delivering a performance we feel is unrivalled.
Pack size – 1.7L & 3L
Two distinctive sizes enable you to fine-tune the amount of storage you need. The 1.7-litre version is perfect for carrying tools, pumps, spare tube, water bottle, or lightweight jacket, and fits more with road and gravel bikes.
The larger 3-litre Downtube Pack utilises a shape that accommodates larger loads. Comfortably fitting larger Nalgene style bottles, gas stoves, roast chickens, or whatever you want to carry. This pack is better suited to MTB frames.
V-Mount technology
Our unique patented V-Mount is the real MVP of all of our Small Packs. This unique piece of mounting hardware is responsible for an attachment performance so good we can guarantee a 100% non-slip and non-marking attachment when mounted correctly.
The V-Mount is typically Tailfin in being an innovative piece of hardware providing a performance advantage far superior to standard soft bags. In essence, the V-Mount is a simple concept comprised of an aluminium base plate and a removable, soft and compliant rubber boot, but its function is far more than the sum of its parts. The angled channel (hence the ‘V’ in the name) enables the V-Mount to cradle typical bicycle tubing profiles in such a way as to achieve double line contact, This solves the classic ‘two circle problem’ that plagues traditional round packs – that when meeting a rounded frame tube a round pack only creates a single line of contact. The result of this interaction is an increase in the likelihood of slippage. In addition, the highly grippy, removable rubber boot also aids in grasping frame tubes without a hint of slip, even on gloss paint finishes.
Each Downtube Pack has two V-Mounts, individually adjustable with twin mounting positions. A feature that allows fitting of the Pack on a full range of tubing shapes regardless of obstacles such as cable guides. V-Mounts are also sized proportionally for the two Downtube Pack sizes, providing the same grip irrespective of load size and weight. All parts are modular and replaceable if damaged.
Internal frame and material construction
Each Downtube Pack features a size-specific internal CNC machined 6061-T6 aluminium frame housed in an internal pocket. This provides rigidity without significantly increasing weight. The frame’s pared-back shaping creates enough stiffness to hold the pack stable without increasing rigidity to a level that limits the bag’s ability to pack effectively. The structure also acts as the connector between the pack and the V-Mount attachment system, allowing for a solid and stable platform blending the hard and soft components.
These Packs take inspiration from the larger bags in the tailfin range and share materials. They use Tailfin’s signature, 100% waterproof mix of durable 420D Hypalon in high-wear areas and thinner, more flexible Ripstop Nylon to create a conformable shape. Roll-top closure provides easy, weatherproof access. Each Downtube Pack also ships with additional T Hook compression straps. These provide added performance and can reduce the length of the bag or compress soft contents.
Cargo Straps
The Downtube packs secure to your frame using our Cargo straps, and each pack ships with them included as standard.
For more information on the cargo straps, visit the product page now.
