Aero bars are proven to help enhance overall speed, economy, and long-distance comfort on the bike.
Designed to achieve an aerodynamic “time trial” position (or “aero position,”) aero bars have become mainstream across many facets of cycling, including triathlon, gravel, touring, and bikepacking.
Here we discuss the science behind aero bars, how much time savings you can expect, and what the best options are depending on your needs.
If you looking for product recommendations, see our page on clip-on aero bars.
The Basics: What are Aero Bars?
Aero bars are a specialized type of handlebar extensions with padded forearm rests, allowing cyclists to achieve a more forward-facing, aerodynamic time trial position.
They come in many styles, ranging from clip-on aero bars that attach to most road bike setups to custom-molded, 3D-printed aero cockpits.
What’s the benefit? Rather than having the arms positioned at shoulder width (as in the case with traditional drop bars,) aero bars enable are more narrow arm position that minimizes wind resistance and aerodynamic drag.
In other words, aero bars enable triathletes and time trialists to access an aero position, which is characterized by drawing one’s upper body and arms forward and inward into a more tucked position.
This position has been proven to significantly minimize wind-resistant drag, especially at high speeds.
Understanding the Science of Aerodynamics
There’s a reason why cyclists use aero bars, aero helmets, and tight-fitted clothing. Aside from the gravity felt when climbing, aerodynamic drag is the greatest barrier to cycling speed, accounting for 70 to 90 percent of the resistance experienced while pedaling.
While advancements in triathlon bikes have been pivotal in improving speed on the bike, the cyclist presents the most significant barrier to minimized aerodynamic drag.
The human body is not very streamlined, and in turn, rider positioning is critical to reducing drag and maximizing speed and efficiency.
Cyclists use drop bars and aero bars to position themselves to reduce exposure to their frontal area, which helps minimize the degree of wind resistance they must overcome. Reducing the frontal area helps riders increase their speed and their efficiency over time.
One of the best sources of information on the subject of aero bars and time trial positioning is an MIT Chemistry of Sports lecture titled “Cycling Aerodynamics: Clearing the Air.” The lecture highlights a series of wind tunnel studies that tracked eight professional cyclists, including Alberto Contador and Ivan Basso, and the amount of drag they experienced while making micro-adjustments to their time trial positioning.
The wind tunnel studies were compelling, showing aerodynamic improvements ranging from 2% to 17% less drag across all athletes. One of the key takeaways from the studies is that a 5% improvement is easy to get, and a 5% gain means significant results in aerodynamics.
How Much Faster are Aero Bars?
Aero bars, which enable athletes to achieve an aerodynamic time trial position, generally provide speed gains ranging between 5-10% or more. For an athlete traveling 20 mph (32 kph), that’s a difference of traveling between 1-2 mph (1.6-3.2 kph) faster at the same degree of energy output.
It’s important not to discount the aerodynamic gains that today’s time trial bikes deliver. Next having an aero helmet, bike technology has advanced by leaps and bounds in drag reduction, weight, and rider positioning.
Aero Bars vs Drop Bars and Hoods
A common question that arises when assessing the aerodynamics between road bikes and triathlon bikes is: how much faster are aero bars versus drop bars on a road bike?
Several studies comparing aero bars with traditional cycling postures found that aero bars outperformed both drop bars and brake hoods in terms of aerodynamics, VO2max, and heart rate efficiency.
It’s important to note that a lot of this work is focused on trained athletes who have experienced cyclists. Conversely, a study testing VO2max in untrained athletes found an upright cycling position performed best over an aerodynamic time trial position.
Using aero bars is a proven way to improve aerodynamics on the bike. However, any additional gains in VO2max and heart rate efficiency will significantly depend on the individual athlete.
In most cases, beginner triathletes can get their bearings by building fitness and confidence on an entry-level road bike, using the drop bars to get into an aerodynamic position. As training progresses and cycling skills advance, an athlete can yield greater performance improvements using aero bars and aggressive time trial positioning.
Known for their unique look and function, aero bars are a standout component that distinguishes most triathlon and time trial bikes from typical road bikes. That’s not to say road bikes can’t be retrofitted as a time trial machine with the addition of aero bars.
How to Choose the Right Aero Bars
Today, aero bars are used for more than just triathlon and time trailing. You’ll often see clip-on aero bars being used in gravel bike racing, ultra-distance cycling, and bikepacking.
Enabling cyclists to tuck into the conducive time trial position, there’s ample science that supports the use of aero bars in substantially minimizing aerodynamic drag while maximizing speed.
Aero bars come in two primary types:
- Clip-on aero bars that bolt onto standard road bike handlebars
- Full aero handlebars, which include both base bars and aero bars
Most road bikes and some beginner time trial bikes are well suited for clip-on aero bars. As the most popular place to start, clip-on aero bars are the most versatile and economical option that typically ranges between $100-300.
Unlike clip-on aero bars, full aero handlebars come as a complete unit with integrated stems and aero bars. If you’re riding a higher-end triathlon bike or time trial bike, a full aero handlebar setup is likely more suitable.
This performance upgrade is proven to be significantly more aerodynamic than clip-on aero bars with road bike handlebars. But they come at a price of $400-$1,000+ and require a completely different break and cable system – which can be quite the mechanical overhaul in itself.
Other Aero Bar Upgrade Considerations
Other things to consider when finding the right type of aero bars are:
- Bar Extension – One of the primary differentiating features in aero bars is the extension at the very end, or where you place your hands most of the time. Some athletes feel faster with shorter and less angled extensions, while Ironman and ultra-endurance athletes may prefer longer extensions.
- Risers – Almost all aero bars allow you to use risers to elevate the arm pads. Generally, beginner athletes will typically use risers as they progress their time trial position.
- Arm Pad Position – The width, narrowness, and angle of the arm pads may also dictate your choice of aero bars. There’s no clear science supporting a more narrow arm position than a wider position faster, so comfort is a priority here.
- Brake Levers & Gear Shifters – For athletes using full aero handlebars, the braking and shifting system is an added consideration, especially when upgrading.
- Total Weight – Most aero bars are made of lightweight carbon fiber and/or aluminum material, but the added componentry (i.e., Risers) can also add weight.
Although it’s always advised to choose fit and function over aesthetics, there is, of course, the actual look of the aero bars that undoubtedly plays a role. Get a better visual look at the different aero bar options by checking out some of these aero bar products.
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1. K. B. Blair, “Cycling Aerodynamics: Clearing the air,” MIT Open Course Ware, 2013. [Online]. Available: https://ocw.mit.edu/courses/experimental-study-group/es-010-chemistry-of-sports-spring-2013/lecture-notes/MITES_010S13_lec10.pdf
2. Sheel AW, Lama I, Potvin P, Coutts KD, McKenzie DC. Comparison of aero-bars versus traditional cycling postures on physiological parameters during submaximal cycling. Can J Appl Physiol. 1996 Feb;21(1):16-22. doi: 10.1139/h96-002. PMID: 8664843.
3. Ashe MC, Scroop GC, Frisken PI, Amery CA, Wilkins MA, Khan KM. Body position affects performance in untrained cyclists. Br J Sports Med. 2003;37(5):441-4. doi: 10.1136/bjsm.37.5.441. PMID: 14514538; PMCID: PMC1751358.
4. Peveler, Will & Bishop, Phil & SMITH, J & RICHARDSON, M. (2005). Effects of training in an aero position on metabolic economy. Journal of Exercise Physiology Online. 8.
Endurance athlete, professional off-road cyclist, and avid blogger, Tyler Tafelsky participates in long-course multisport and cycling events. Today, Tyler competes in ultra-distance cycling races at the professional level. Since starting Better Triathlete in 2014, he has been the head of content for the site's editorial team. Learn more about Tyler