Dramatically Improve your Aerodynamics: Become a Human Water Bottle Cage

800 792 Patrick McCrann

If you’re on the quest for a performance-enhancing edge without breaking the bank, we’ve got exciting news for you. The folks at Triathlete.com wrote the definitive piece on this trend. According to that article, the latest trend of stuffing a simple cycling water bottle down your tight racing top with a zipper, aptly known as the “chest fairing,” has shown the potential to reduce drag by a staggering 9%.

The best part? You already have everything you need!

In this article, we’ll delve into the science behind this aerodynamic hack, explore the essential equipment, and provide step-by-step guidance on how to practice and use it safely and effectively on race day.

Prepare to maximize your performance with minimal investment!

chest fairing at IMLP

Chest Fairing in action at IMLP

Understanding the Science

The idea behind the chest fairing trend is rooted in aerodynamics. Research conducted by experts, including aero-tester Jim Manton and researchers from KU Leuven, has shown that positioning a water bottle strategically on the chest can significantly reduce drag on a triathlon bike.

The bottle acts as a fairing, leading the air around and below the pelvis, thereby decreasing overpressure that pushes the cyclist back. This drag reduction effect has been observed to be as high as 9%, resulting in potential time savings of minutes over an Ironman distance.

Minimal Equipment Needed

One of the most appealing aspects of the chest fairing trend is its simplicity and low cost. To get started, all you need is a tight racing top with a zipper, a standard cycling water bottle, and your trusty triathlon bike.

No need to invest in expensive aero gear or high-tech equipment—just grab a bottle you already have and get ready to make the most of it.

Remember to “right-size” the bottle by your torso. The taller you are, the larger the bottle opportunity.

Practice Indoors First

Before hitting the open road, it’s essential to practice your chest fairing positioning on the indoor trainer.

This serves multiple purposes: ensuring safety, finding the most comfortable and efficient setup, and getting accustomed to the feel of the bottle against your chest during the ride.

Set up your bike on the trainer and experiment with different bottle sizes and placements until you find the ideal configuration that works for your kit, your body type, and bike geometry.

The last thing you want to do is just mess around while riding on the open road because you had a brainstorm.

Taking It to Race Day

On race day, once you’ve fine-tuned your positioning through indoor practice, you’re ready to take the chest fairing out on the course.

Here’s a step-by-step guide on how to use it effectively:

1️⃣ Pre-Race Check: Before starting your race, ensure that the water bottle is securely positioned inside your racing top, and the zipper is appropriately closed.

2️⃣ Safety First: Always prioritize safety. Make sure the bottle placement doesn’t obstruct your view or interfere with your ability to breathe comfortably. Test your setup during training rides to avoid any surprises on race day.

3️⃣ Focus on Comfort: During the race, pay attention to your comfort level with the bottle in place. It should not cause discomfort or distract you from your performance. If you find it uncomfortable during the race, consider adjusting the positioning or ditching it altogether (at an aid station).

4️⃣ Stay Hydrated: Don’t forget the primary purpose of the water bottle—to keep you hydrated. Make use of the chest fairing during the biking leg, and if you’e got a flexible straw, you could possibly access the bottle as needed for sips without losing your aero position. #nextlevel

5️⃣ Post-Race Evaluation: After the race, assess your experience with the chest fairing. Did you feel a difference in your performance? Did it help you maintain a more aerodynamic position? Use this feedback to fine-tune your setup for future races.


With the chest fairing trend, triathletes have the opportunity to unlock a 9% drag reduction without spending a dime on expensive equipment. Embrace this simple yet effective race-day hack by strategically placing a water bottle inside your racing top.

Remember to practice indoors to ensure safety and comfort, and gradually incorporate it into your race-day routine.

Stay focused on your performance and make the most of this innovative technique in your next triathlon!

    • Patrick McCrann

      That’s a great question. It depends how you want to use it. If you need additional fluids, you could put fluids in there but have to make sure the bottle stays in place. Right now most athletes seem to be using this bottle empty. If the rules change such that the bottle actually needs to be in use, then water would have to be in there.

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