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.

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 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.