BY CHRISTOPHER KAUTZ & ERIC PARDYJAK

However, many athletes worry about giving up their aerodynamic advantage by carrying bottles on their

bike, and have therefore experimented with different ways to minimize drag while staying hydrated. But

for many athletes the question still remains: Where do I carry bottles in order to minimize aerodynamic

losses while still being able to access my drinks?

Our goal in running this experiment was to measure the drag differences between the following drinking

systems: no system at all (to determine a baseline), bottles on the frame, an aero bottle between the

handlebars, a behind-the-saddle bottle carrier, and a prototype of the new NeverReach drinking system.

Each of these systems was tested, with the athlete sitting on the bike then not drinking, and with the

athlete taking a drink.

So, after spending all of the hours at the track, what did we discover?

First, we learned that the most obvious effort athletes undertake to reduce drag— namely removing the

bottle cages from their frames—is probably not worth the effort. Having established a baseline number to

compare against, we found that we could not measure a drag difference by putting bottles on the bicycle,

nor by putting an aero bottle between the handlebars. This held true both with the athlete drinking and not

drinking (Note: the test rider we used is a professional cyclist who was able to take drinks from his frame

while staying in the aerobars with one hand, not having to break his aero position to drink). An obvious

advantage of the bottle in the aerobars is that any athlete can take a drink without breaking the aero position.

We were quite surprised by this, as we would have predicted that both of these systems would have

increased the drag on the rider a fair amount.

Second, we learned that while putting bottles in a carrier behind your saddle is a convenient way to carry

extra fluids (and gear) on long training days, it is not a good idea from an aerodynamic perspective. Our

testing showed that having bottles behind your saddle is akin to the flap being up on an airplane wing,

which you probably know is the technique used to slow down planes. We found that simply having

bottles behind the saddle slowed the athlete down by approximately 1 second per kilometer, or about

three minutes over an Ironman! However, the time losses become much greater as an athlete begins

reaching for his bottles and has to break his aero tuck. The idea that the aero advantages of putting bottles

behind you is negated by sitting up did not surprise as, hut the fact that the bottles slowed you down so

much simply by being back there was surprising.

Lastly, we reconfirmed what was tested in the early l990s with cyclists, which is that if you change the

airflow off the back end of an athlete in the right way, you can significantly increase the speed of that athlete.

The new NeverReach system is a teardrop that sits behind the athlete’s saddle. The athlete drinks

from a tube that runs from the system to the front of the bike. The positioning and shape of the

NeverReach is such that it works much like a fairing and significantly smoothes out the airflow coming

off the athlete’s back. This leads to a timesavings of about 0.9 seconds per kilometer or about two minutes

over an Ironman.

The bold numbers on the chart indicate measurements which are statistically significant. All

other numbers are within measurement error of the testing and therefore cannot be differentiated

from the baseline drag number. Once the above numbers were calculated, they were converted

to velocity and time differences for those that were significant. The velocity and time

predictions were calculated using a power output of 200 watts. The predicted velocities and

time are listed in the lower chart (with the behind-the-saddle drinking system assuming five

drinks per hour for these calculations).

Once the above numbers had been calculated they were converted to velocity and time differences for

those that exceeded measurement error. The velocity and time predictions were calculated using 200

watts.

In all, it was an interesting experiment, and one that taught us that putting your drinking system in the

wrong place has a significant negative impact on performance Undoubtedly, many people will be

surprised by the aerodynamic advantage one can gain (or lose) from proper placement.

Christopher and Eric make up PK Racing Technologies a research-based company specializing in bicycle