Estimated reading time: 9 minutes
A note on terminology: This guide references our Rear Systems – a new way to describe everything Tailfin that you mount to the back of the bike. The CargoPack, (formerly known as the AeroPack), the SpeedPack, and our modular Pannier Rack range comprise our Rear Systems.
Introduction – what is a Rear System?
Rear Systems refer to a Top Bag + Rack combination, and the perfect starting point for the type of adventure that requires carrying gear. We offer both a CargoPack (formerly AeroPack) and a SpeedPack Rear System. The CargoPack is made to go far and loaded, the SpeedPack for going fast and light. We’ll go into more detail below.
Like a seat pack, only better? The truth is, seat packs suit plenty of people for a variety of reasons, but for us, there were always limitations to strapping a bag to your seatpost with velcro. So, we looked at what was out there and smoothed out the inherent and reported issues: swaying on the bike, access to your gear, mounting, abrasion issues, and more, to create a solid, stable, and light accessory.
Both CargoPack and SpeedPack comprise a waterproof bag with a rigid base, connected to the seatpost with a clamp and stabilised by connection to the axle or rack mounts of your bike with a rigid Arch. Their capacities are 18L (CargoPack) and 10L (SpeedPack) internal storage, with 3L of external mesh pockets – perfect for stashing goodies.
Video Complete Guides
CargoPack (formerly the AeroPack)
SpeedPack
CargoPack/SpeedPack vs a traditional seat pack
Where the CargoPack and SpeedPack differ from a standard seat pack is in how they mount to the bike. A custom-made quick-release skewer or Thru Axle with mounting points form a stable tripod for the CargoPack between the ends of the axle and the seat post. It is this unique setup that gives the CargoPack its incredible ride performance and a stable platform to support the top-opening bag. The same goes for the SpeedPack, and our Racks.
Whilst traditional seat packs offer advantages in weight, they fall short in almost all other areas. The core benefits are as below:
- The CargoPack will not rattle or sway behind you – creating a stable, forget-its-there, ride
- A top-opening bag ensures easy and fast access to your belongings
- Engineered connections won’t damage or rub your frame or seat post (even if it’s carbon)
- Optional pannier mounts allow you to add panniers for bigger trips
- More pockets give additional storage options
- Dropper-post friendly – the Speed Connect seatpost connector requires only 30mm of available seatpost
What to choose, how to fit
CargoPack, SpeedPack, or Rack?
For an in-depth look at this question, visit our ‘Rack or CargoPack – which one is right for me?’ article.
If you want the simple answer, it can be summed up well as this: If you plan to take your bikepacking off-road a lot of the time, we would recommend a CargoPack or a SpeedPack, as it’s the most simple of our rear systems. It has a less intricate mounting system than a Tailfin Rack and Top Bag combo, which makes it lighter and provides complete reliance when off-road. As an additional benefit, as the bag is an integral part of the structure, noise and rattle are eliminated when really pushing the boundaries of where you can explore.
If weight is also a high concern for you, for instance, if you plan on undertaking an ultra-distance race, want to do some fast touring on your road bike, or simply want the lightest Tailfin setup we produce, then you need to go for a SpeedPack.
Rack – Made for modularity.
Add and remove panniers, cages, mounts, any of our Top Bags, you name it – there’s a Rack option for you. Ideal for riders who want to use their setup for commuting, loaded touring, utility, and everything in between.
CargoPack – Made to go far and loaded.
Ideal for long-distance adventures, commutes or bikepacking trips where carrying capacity and durability are key. Top-opening bag with cavernous entrance and generous 18L capacity, plus two 1.5L expandable stretch-mesh pockets.
SpeedPack – Made to go fast and light.
Tailored for performance-focused riders who want to travel light without compromising efficient load carrying, stability or handling. Rear-opening bag for ultimate stuffing and minimal weight. Capacity of 10L, plus large external 3L stretch-mesh pocket.
Rear System Options:
Carbon or Alloy Arch?
This is purely down to weight and cost. The Carbon CargoPack is just as strong as the Alloy version (just ask our racers doing 2000+ km off-road MTB races).
The easiest way to decide which is better for you is to weigh up how much you wish to spend on the setup, and how much of a factor weight is upon your objectives.
Bigger budget, high weight concerns = carbon
Medium budget, low weight concerns = alloy
The other main difference between Carbon and Alloy Rear Systems is the triple bosses, which are on the Alloy version but not the Carbon. These allow you to run Cargo Cages with Cage Packs or water bottle cages, further expanding your carrying capacity.
Non-Pannier and Pannier-Mount Versions
We also offer a range of pannier bags, specially designed to fit our Rear Systems, using our X-Clamp technology to offer a secure, robust, and rattle-free ride.
When selecting the options for your Rear System, you’ll be asked to choose whether or not your Arch will have pannier mounts. It is not possible to add these onto the Arch later, so it’s important to decide now whether you’re going to want to use side panniers with your Tailfin setup in the future. The non-pannier version of the Arch is the sleekest and slimmest version, whilst the pannier-mount version allows you to carry more, using pannier bags.
Standard or Extended seatpost connector?
If you use a small frame size or a low saddle height, we’d recommend using the extended seatpost connector, as this allows your chosen Rear System to sit further back, allowing better access to the bag and volume-carrying capability.
The extended seatpost connector can be selected when choosing the options for your Rear System. Due to the modular design of our systems, you can always add this later by purchasing it as an accessory.
Fitting to your bike
Our Rear Systems are designed to fit 99% of bikes on the market – whether that’s road, touring, gravel, hardtails, or even full-suspension mountain bikes.
We do this by offering a variety of ways to mount to your bike, so our systems even fit bikes without rack mounting points:
For a more detailed explanation of mounting options for your bike, read our Mounting Your Rack or CargoPack Guide.
Whilst all mounting options will work well, we would always recommend Axle Mounting (Option 1) as it provides the most robust and weight-bearing mount. If you’re unsure of your axle type, use our handy tool here.
Please see this Video Guide on properly attaching the Seat Post Connector.
Modularity
A unique feature of Tailfin products is modularity. Components have been designed to be replaceable and can be swapped over. So if you purchase an Alloy CargoPack and panniers for your commuting and then want to save weight for an upcoming ultra-distance road race, it’s possible to buy a Carbon Arch on its own and swap it over in a matter of minutes, ready for the start line.
Alternatively, if you wanted to swap your CargoPack out to become a Rack, you can do so by purchasing a Top Stay and AP18 Connector Part, then simply remove your CargoPack connector parts, and now you have 2 separate setups to choose from.
Repairability and other details
Repairability
The other distinct advantage of being completely modular is that damage to one part of the system doesn’t mean the end of your Rear System, as each component can be replaced easily. Our Rear Systems are guaranteed for 5 years for equipment failures/defects, but in theory, they should last a lifetime of use.
All individual parts for Tailfin Rear Systems can be found and purchased in the Accessories and Spares section of the website.
Which accessories can I use with a Tailfin CargoPack?
Further information
For another deep dive into the CargoPack (formerly known as the AeroPack), check out Cass Gilbert’s in-depth review on Bikepacking.com.
If you can’t find what you need here, you can always contact our friendly Customer Service team.
CargoPack FAQs
If you can’t find what you need here, you can always contact our friendly Customer Service team.
