Tailfin, designer and manufacturer of high performance cycling equipment, has launched the AeroPack S and AeroPack X: fully-integrated rigid seat packs aimed at the performance cyclist who wants to go fast either on or off-road. Uniquely the AeroPack integrates a rack directly into the seat pack to increase stability for minimum weight and maximum aerodynamic advantages.
Tailfin’s AeroPack is available in four formats: the Carbon S, Alloy S, Carbon X and Alloy X. The S series is purely for carrying gear on top while the X series has additional side mounting capabilities. They share the same high frequency welded, 100% waterproof, roll-top bag with a 20L capacity and 9kg maximum load, and offer either a carbon or alloy supporting arch. It fits everything from road bikes to mountain bikes – even the majority of full suspension bikes. It is also a great option for those with dropper posts because it attaches to the post, rather than the saddle.
Where the AeroPack differs from a standard seat pack is in how it mounts to the bike: a custom-made quick release skewer or Thru axle with mounting points form a stable tripod for the AeroPack between the ends of the axle and the seat post. It is this unique set-up that gives the AeroPack its incredible ride performance and a stable platform to support the top opening bag.
Designed for fast-paced, self-supported events, the AeroPack has class-leading aerodynamics: during development, it was tested back-to-back against alternatives and achieved similar or better performance. One notable conclusion from the aero testing was that bar bags, although functionally useful, tended to incur around a 10-20W penalty, meaning that aerodynamically-speaking, riders are better off with a larger seat pack rather than splitting their gear front and rear.
Following last year’s successful Kickstarter crowdfunding of the prototype, the AeroPack has since undergone extensive engineering changes. There have been a number of developments since the original product, to improve durability and serviceability. Should an accident happen, the modular construction means that owners will be able to replace the minimum amount of parts possible. Over 1,300 pre-orders have already been taken and fulfilled, including the original Kickstarter pledges.
Tailfin founder and engineer Nick Broadbent explained, “With the AeroPack, our aim was to take the idea of a traditional seat pack and make it better. 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.”
The AeroPack S is the fastest and most aero way to carry gear on any bike and has been tested by riders in multiple editions of the Transcontinental Race and Bike Non Stop in arduous real-world conditions across mixed terrain. It is the product of choice for Ben Davies, who came second in this year’s TCRNo7, and Peter Anderson (2018 TransAm winner), who came second in Bike Non Stop racing across the USA. In total the AeroPack was used by seven riders in this year’s Transcontinental, clocking up 28,000km between them.
Ben commented, “For racing in the Transcontinental, equipment choices are incredibly important and having quality kit, that makes you faster on and off the bike, is crucial. The AeroPack performed flawlessly and I didn’t need to give it a second thought. What’s important is that it’s lightweight and has a ride quality that gives it an assured feel on the bike.”
Peter commented, “The AeroPack performed perfectly, I did not have a single issue with it during Bike Non Stop. I was aware that the course was 30% gravel, but I was under the impression that it would be mostly groomed “rail-to-trail” roads. It was not: some of the sections were better suited for mountain bikes with full suspension. Tailfin’s AeroPack survived these incredibly rough conditions along with a high-speed crash. It speaks volumes about the quality and design of the product.”
The AeroPack S
The AeroPack Carbon S is the lightest and fastest model in the range. Aimed at the performance cyclist, who wants to go fast either on or off-road and who won’t compromise on weight, aerodynamics or ride quality, it features an integrated top bag with no side pannier mounts
The AeroPack Alloy S is for those who wish to stay light and fast, but without breaking the bank. Aimed at performance riders who treat their gear with less care, it’s the ideal companion for MTB, longer touring rides, rough bikepacking and commuters.
The Aeropack X
The AeroPack Carbon X is identical to the Carbon S but adds side mounts for increased versatility for carrying side panniers and side cages.
The AeroPack Alloy X is identical to the Alloy S but adds side mounts for increased versatility for carrying side panniers and side cages.
Additional information on compatibility with full suspension bikes
Tailfin believes that the best bike-packing bike is the bike you already own. Therefore it was important that the AeroPack could be used with full suspension bikes. Using a unique tri-pivot design each pivot contains replaceable plain bushings which allow it to adjust position as the suspension compresses.
Carrying any gear behind the seatpost of a full suspension bike is challenging. With regular fabric seat packs there are three issues. Firstly, they impede dropper post use; secondly, they must be kept small (sub 7 litres) in order to avoid the rear wheel driving into the bottom of the pack; and thirdly, they are often in the way of the rider’s rear end when making steep descents.
The AeroPack does a fair job to resolve those issues: however, it is still not without its compromises. The weight of the gear sitting directly on the wheel changes the unsprung mass of the wheel (similar to URT suspension system in the 90s), which will change the suspension dynamics and create more chatter on rowdy trails.
The majority of our in-house testing has been done with a Santa Cruz Bronson which has 150mm rear travel. The results were generally positive with the positives outweighing the negatives.