Photo: Rocket Science Sports Rocket Bottle

Rocket Science Sports Rocket Bottle: Cylindrical bottle with a tapered bottom, rounded top and hundreds of six-sided, golf-ball-like dimples embedded in the surface, said to reduce wind drag by 16% over that of a smooth-surfaced bottle. (www.rocketsciencesports.com)

In bike racing and triathlons, aerodynamics can become an obsession. Because overcoming wind resistance is key, riders have for years shelled out big bucks for aero bike frames, aero handlebars, aero wheels and aero helmets — without giving a second thought to sticking a blunt, wind-dragging 3-inch-wide water bottle right in the middle of it all. Now, straight from the wind tunnel, the final piece of the puzzle has arrived: the aero hydration system.

— Roy M. Wallack

Slippery dimples

Rocket Science Sports Rocket Bottle: Cylindrical bottle with a tapered bottom, rounded top and hundreds of six-sided, golf-ball-like dimples embedded in the surface, said to reduce wind drag by 16% over that of a smooth-surfaced bottle.

Likes: Inexpensive compared with other aero bottles, and usable with a standard bottle cage. The dimples work by "adding more kinetic energy to the airflow" when it passes over the bottle, according to the company, ultimately reducing air turbulence/drag. The dimpled surface feels more secure in your hand than a normal bottle too. Weight: 3.5 ounces (a half-ounce more than a standard 20-ounce bottle).

Dislikes: At 17 ounces, it's the smallest bottle tested (note: It's advertised as 20 ounces).

Price: $11.99. (512) 782-4448.www.rocketsciencesports.com

Fast fin

Xlab Aero TT: Narrow, 20-ounce fin-shaped bottle held to the frame by a custom carbon-fiber bracket. Claims wind-drag reduction of 25%.

Likes: A psychological boost: It looks fast — so you feel fast. Also, its narrow, wind-cheating profile of 1.75 inches is very easy to grasp. The carbon bracket works well, pinching cutouts on each side of the bottle. Weight: Bottle is 4 ounces, and carbon bracket 1.2 ounces, making total weight lighter than a standard bottle/cage setup.

Dislikes: The price will stop you momentarily.

Price: $64.95 for cage and bottle; spare bottle $12.95. (760) 735-3215; http://www.xlab-usa.com

Humongous H20 hauler

Inviscid Design Speedfil: 40-ounce, triangular-shaped, foot-long reservoir with handlebar-mounted suck-hose that allows for hands-free drinking in the aerobar riding position.

Likes: It keeps you more aero, safer and better-hydrated than normal.

Whereas reaching for and raising a standard bottle causes huge aerodynamic and rhythm disruptions, you custom-position Speedfil's drinking tube near your mouth, allowing hydration while in an uninterrupted, two-handed aero position. Because of this, you drink more often. The neoprene-covered tube has a soft bite-valve that keeps fluid in the drink-ready position, eliminating time lag and gastric air bubbles. The large capacity eliminates a need for a second bottle and will also work well for long-distance bike tourists and mountain bikers. Triathletes will love its ability to refill on the fly; just dump an open bottle of fluid into the gasket-covered opening and drain it; an internal backsplash device keeps you clean. It's pictured here with an optional "Speed sock" neoprene jacket that keeps fluids cold ($25).

Dislikes: Expensive and heavy (15 ounces), although comparable with the popular behind-the-seat bottle carriers (which cause lots of air drag).

The weight is similar to that of any two-bottle setup.

Price: $99.95. (858) 605-6654; http://www.speedfil.com.

Funk-free fluidity

Clean Bottle: Not an aero bottle, per se, despite tapered ends, but it is the first water bottle with a screw-off bottom, allowing the thorough cleaning that is difficult with standard bottles.

Likes: Keeps your fluids free of the stinky, moldy funk most cyclists live with. Eliminates having to throw away old bottles and buy new ones. Fits in a standard bottle cage. See-through plastic. Weight: 4.5 ounces. Capacity: 22 fluid ounces (advertised as 24).

Dislikes: No speed advantage, unless you count sick days off the bike due to drinking out of a moldy bottle.

Price: $10. (650) 281-7681; http://www.cleanbottle.com

Wallack is the author of "Bike for Life: How to Ride to 100." roywallack@aol.com