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Speedfil Hydration: The Evolution of Hydration Systems

By Tom Demerly for TriSports.com

Speedfil's A2 is a practical and effective hydration system for improving bike and rider aerodynamics and making hydration on the bike easier.

During previous seasons Inviscid Design has expanded their line of hydration systems from their original, frame mounted Speedfil now called the “standard”  to their frame mounted, conventional bottle cage carried Speedfil F2. The Speedfil A2, a handlebar mount unit, is one of the simplest, least expensive and most efficient hydration systems in the industry.

The Speedfil A2 is more than a well engineered bike bottle top threaded to screw onto a standard bike water bottle. The new top integrates a patent-pending fill port that is likely the envy of every other hydration system manufacturer. The simplicity and elegance of the refill-on-the-fly closure continues with the easy to drink from straw design and the high degree of flexibility for mounting the system.

The fill cap on the Speedfil A2 is simple, elegant and foolproof. You simply rotate it open, fill from another water bottle, then rotate it closed. It is the industry best design and 100% slosh-proof.

Speedfil begins the design of the A2 with a standard threaded water bottle cap as its basis. This is the threading standard found on Specialized brand water bottles and virtually every other plastic bike bottle in the industry. There are a few bottles that do not work with the Speedfil F2 top including Polarbottles insulated water bottles. Incompatible bottles are in the absolute minority though, making the Speedfil A2 cap as close to “universal” as anything in the bike industry. The Speedfil cap works on 21 and 24 ounce size bottle and is supplied on a larger 24 ounce bottle.

This cap houses the unique, patent-pending “fill ball” opening. This ingenious design is effectively a rotating ball with a hole in it. Rotate the ball smoothly with one hand to open it, rotate it the opposite way to close it again. There is absolutely no sloshing or leaking and actuating the opening to quickly refill the system after passing through an aid station is easy. Once you learn to use the system you simply rotate the filler ball opening to the “open” position as you approach an aid station, grab a full bottle from the aid station volunteers on the fly, squirt the contents into the Speedfil A2 through the open cap, quickly discard the bottle back into the approved/race legal bottle dumping area at the end of the aid station and then easily close the cap. With this system you could do an entire Ironman distance race using only a Speedfil A2 and one standard bottle cage on your bike.

With the Speedfil A2 you do not lose time by leaving the aero position to reach your drink system as these athletes do using removable handlebar bottles and behind the saddle systems.

The Speedfil A2 bottle mounts horizontally between the aero extensions on your cockpit. Wind tunnel tests conducted by, among others, Cervelo found this orientation to be the optimal way to carry hydration from an aerodynamic perspective. Some wind tunnel findings suggest carrying a bottle horizontally between the arms is actually more aerodynamic that carrying nothing at all in the same space. In addition to being the most aerodynamic orientation for the bike itself, it also keeps the rider in the aero posture. While it is difficult to test how much aerodynamic benefit this may provide at a given distance, it is easy to suppose that never leaving the aero position to drink will net a substantial time saving over the entire length of a bike course. The longer the bike leg, the greater the time savings.

The Profile Design HC Mount carries the polymer/composite Profile cage and will mount the Speedfil A2 well forward on the cockpit. Other options enable a more rearward mounting orientation.

Speedfil does not supply mounting hardware with the A2 and this is a good decision since there are already so many cockpit hydration mounting options available. Different mounts can carry the bottle in a forward orientation, as with the Profile Design system we rigged or a more rearward orientation as with the elegantly simple King Cage system that replaces the top cap on your stem and angle the bottle very slightly upward facilitating easier filling and emptying.

The King Cage top cap mount for a bottle cage combined with the excellent X-Lab Gorilla Carbon Cage provide an excellent rearward mount in the cockpit. The mounting tabs on the King Cage mount can be bent carefully to slightly alter the angle of the Speedfil.

Assembly of the Speedfil A2 is simple. The system is supplied with a long length of tubing and a right angle elbow connector. You slide the tubing into the bottle and leave enough protruding for the elbow connector to slide into. The rest of the tubing goes on the other end of the ninety-degree tubing elbow and will protrude upward. This section can be covered with the neoprene sleeve. A bite valve style mouthpiece attaches to the end of the drink tube and keep fluid in the tube so your first “pull” on the drinking tube delivers liquid into your mouth.

Assembly of the Speedfil A2 is simple. This is cutting the tubing to insert the ninety-degree elbow.

Another benefit to the Speedfil A2 design is a non-rigid straw. While there may be an aerodynamic cost to this design versus the more rigid, airfoil shaped drink tube on a Torhans system there may be some benefits to the straw being flexible. There certainly is a benefit to the bite valve design since you do not have to suck fluid up from the fluid level inside the straw.

To fit the bite valve you simply cut the drink tube to length and insert the bite valve assembly.

The Speedfil A2 is a simple and elegant design with the industry best refill cap. Speedfil deserves credit for a well executed design with the A2 that not only improves bike and rider aerodynamics but is also easy and quick to fill and does not slosh or spill. Additionally, the system is not reliant on any one mounting optioin but highly adaptable to a wide range of mounting systems already available. You may already have a cage mount hydration system on your aerobars that a Speedfil A2 will fit. In every regard this is elegant engineering, and the A2 moves Speedfil to the top of the short list of industry best hydration options.

Speedfil's A2 is simple, elegant, functional and inexpensive. It is among the very best hydration options in the industry.