Whether you are doing a Sprint or an Ironman distance triathlon- at the very minimum, every race you are spending at least 50% of race time on the bike!!!! So clearly, there has been a significant amount of information thrown out there on aerodynamics... not just based on the fit, but aerodynamic research has been done on bottle, bento box/ food storage, and flat kit sizing and placements.
Today, instead of simply 'barking up the same tree'... let's look at function versus the 'concept of aerodynamics' of bottle placement on the bike, for both short course and long course!
BOTTLE PLACEMENT ON THE BIKE
1. BETWEEN THE AERO BARS BOTTLE
AERODYNAMICS: Reduces drag behind the riders hands
FUNCTION: Constant reminder to drink- its in your face you can't ignore it :), Easy to refill at bottle hand-ups in long course
A. Short Course- This absolutely depends on the person. In an Olympic, we have seen several athletes really appreciate and not sacrifice speed and skill by utilizing the aero bottle. For the sprint, if you must use a bottle the aero bottle not a bad option- but then again, not having a bottle on the bike for a less than 30min bike will be your most efficient option.
B. Long Course- Get this now if you have trouble with your bike handling skills as you drink, struggle with hydration reminders as you fatigue.... you catch my drift- get the aero bottle, it makes life very easy come race day!
2. BEHIND THE BIKE
AERODYNAMICS: Less drag, it is in the slip stream of your own body and positioning
FUNCTION: (or shall we say many possible malfunctions) can cause issue with mount/dismount ease (esp in long course bc of less mobility and response after hrs on the bike), difficulty to grab and must sit up to get hydration (think of shoulder tightness and once again, less mobility through the upper body), many times this bottle position is called the "missle launcher"- hit a bump and know it is likely to shoot out the back
A. Short Course- you don't need the added weight on your bike, 1 bottle should be plenty, and why the heck are we slowing down to grab it- the point in short course is go hard and fast!
B. Long Course- don't do it, as you can see above- its not functional- I don't care if it sits in "your slip stream"... You either have to sit up and get it (um, not so aero anymore as soon as you sit up) or you could cause a potential wreck if you decide to stay in aero while getting it by weaving across the road as you stretch to reach behind you.
It is has been said, "Weaving down the road with advanced dehydration is not aerodynamic."
DOWN TUBE VS. SEAT TUBE
AERODYNAMICS: There is far less drag when the bottle is placed on the down tube. Air actually moves out and around the natural body's positioning and knee placement.
FUNCTION: Placing a bottle on the seat tube, can be very difficult for some riders to reach down and almost behind them. The down tube bottle does not require you to look down to grab it.
A. Short Course- if you have to have a bottle, and want to put one in the frame itself- choose the down tube
But consider if it is just a sprint- skip the bottle all together and take some more weight off that bike (1bottle of water roughly weighs roughly 1.5lbs).
B. Long Course- put the bottle on the down tube. Suggestion, use this bottle simply to refill and/or to spray on your body to keep you cool during racing. This is the bottle you will replace during hand-ups.
So what is the perfect aerodynamic and functional set up for
A. Short Course- Consider not putting a bottle on the bike if it is less than 12miles to really save some efficiency with those watts.
But when you do need a bottle, use only 1, either the aero bottle between the bars or on the down tube.
Otherwise, strip off all other cages- why waste the energy and create more drag.
B. Long Course- Front aero bottle between your bars and one on the down tube.
SIDE NOTE HERE ON BOTTLES: Utilizing any bottle, bottle hand up system, etc requires cycling skills/drills- Regardless of aerodynamics and the next latest and greatest of any product, the most important aspect for you to access your full potential and watt efficiency on the road takes practice!!! (See pic attachment!)
I hope this helps you understand that aerodynamics is an incredible tool and honestly, it looks cool a lot of the time...
BUT IF IT IS NOT FUNCTIONAL- IT WON'T MAKE YOU EFFICIENT AND FASTER!!!