Many road racers, time-trialists, and triathletes wear special aero helmets that look different from standard road helmets. But do they actually make you go faster? If so, then by how much? The answers to these questions and whether you should actually buy an aero helmet can be found in this article.
Aero helmets have fewer vents and a more aerodynamic shape that reduces drag and allows you to go faster. According to various sources, you can gain anywhere from 30 seconds to 3 minutes over a distance of 40 km by wearing an aero helmet instead of a regular road helmet. That’s around a couple of seconds every kilometer. Of course, this is for an equal amount of pedaling effort put forth by the rider.
Road, TT, and Aero Helmets
You probably already know about the traditional road helmet – lightweight lids with plenty of ventilation. Although a large number of vents keep your head cool throughout the ride, they do cause some aerodynamic drag. These helmets are great for normal road cycling and long distances but may not be ideal for racing events.
Time-trial or TT helmets are the ones you see on the heads of some triathlon or time-trial athletes. They usually do not have any ventilation holes and often have a tail to give them a more streamlined shape. The design of these helmets minimizes drag as much as possible. However, there is more heat buildup and the extra material makes them heavier.
➥ Also, know what kind of helmet should you get for the triathlon?
An aero road helmet is basically a combination of a regular road helmet and a TT helmet. Aero helmets have few vents compared to a road helmet to maximize speed. But those vents are strategically placed to ensure adequate airflow. The shape of aero helmets can vary, with some being quite round and others having a tail.
Time saved with an aero road helmet
The fact that an aero helmet helps to reduce air resistance has been proven multiple times, both with tests in a wind tunnel and out on the track. The vents of a regular road helmet create turbulence within the helmet and this actually produces a significant amount of drag. The design of aero helmets ensures the laminar flow of air over the helmet. The exact amount of time saved can vary for the bike, body position, and even clothing. According to Michael Hutchinson, British cyclist and multiple national time trial champion, an aero helmet can save around a minute over a distance of 40 km compared to a regular road helmet.
A wind tunnel test conducted by the magazine 220 Triathlon on several helmets found that aero helmets were noticeably faster than standard road helmets and only slightly slower than TT helmets. You can also get widely varying data from manufacturers themselves. Specialized, for example, showed that over 40 km, their Evade aero road helmet had a 40-second advantage over their standard Prevail road helmet. Meanwhile, tests conducted by Louis Garneau showed a gain of a whopping 2 minutes 40 seconds over 40 km for their Course helmet when tested against a regular road lid. Regardless, it is evident that an aero helmet will make you go faster when pedaling at the same power.
Data from Louis Garneau tests on Course aero helmet | Credit: bikerumor.com
Aero helmet disadvantages
An aero helmet might very well give you the edge you need to emerge triumphant in a race. However, this comes at a cost. There is less breathability and hence, your head will heat up more. Additionally, fewer vents mean more material which means that aero helmets are usually heavier than normal road helmets. The good news is that as designs improve, manufacturers can make aero helmets with better ventilation without losing any speed.
Ventilation of aero helmets
These days, many aero helmets can provide a decent amount of airflow. While they are not as airy as fully vented road helmets, they are way better than TT helmets. This is due to design improvements and strategically placed vents brought forth by meticulous testing. Various configurations for the ventilation are tested to see which setup minimizes drag while maximizing airflow.
Another innovation that has actually been around for some time is the use of adjustable vents. Sliders or panels on these helmets allow you to adjust the opening of the vents or even fully close them for maximum aerodynamic efficiency. This type of helmet might be a good option for those who partake in both racing, cross country road riding, and casual road cycling.
Adjustable vents | Credit: road.cc
Tail vs No Tail
As we have mentioned, aero helmets might or might not have a tail. In general, the tail is not as long as in a TT helmet. When you are sitting in a position such that the tail is behind you, your performance will be better than with a no-tailed helmet. Conversely, if you happen to look down and the tail points towards the sky, there will be turbulence behind the helmet and the aerodynamic advantage will be lost.
With a fully round aero helmet, there is no such issue. Hence, the positioning of a tailed helmet on your head is very important to get right. So, if you are doing a lot of high-speed riding in a straight line, a helmet with a tail will be better. Whereas, a helmet with no tail works better in a wide variety of angles and positions.
Weight, price, and safety
When compared to a standard road helmet, an aero road lid will almost always be heavier. However, this difference keeps getting smaller and they are still more lightweight than mountain bike helmets. Aero helmets are also pricier. You can get road helmets for less than $40, whereas finding an aero helmet less than $100 would be a bit difficult. In terms of safety, aero helmets have to meet the same safety standards as any other type of bike helmet.
➥ On the flip side, if you’re on the lookout for a mountain bike helmet, then, have a look at our selection of MTB helmets.
Q1. Can I use a cover to make my regular road helmet more aerodynamic?
Ans.: A bike helmet cover made of synthetic fabric or plastic is very useful in rainy or snowy weather. Now you might assume that using one will cover up the vents and essentially transform the road helmet into a TT helmet, right? Well, it doesn’t work like that. This might reduce the drag a bit but not by much as the shape and contours of a helmet majorly affect the aerodynamics of the helmet. To really improve your speed, instead of buying a cover, just buy an aero helmet.
Helmet with cover
Q2. Should I invest in an aero wheelset?
Ans.: Another way to go faster is to replace your wheels with a set of aero wheels. However, keep in mind that 70-80% of the drag is caused by the rider’s body, and only the remaining 20-30% is caused by the bike. Therefore, getting aero wheels will not be as effective as using an aero helmet. The speed gains will be greater with the helmet. Moreover, buying a new set of wheels is much more expensive than buying a new helmet. For initial improvement in performance, definitely invest in an aero helmet. If money is not an issue then by all means, get some aero wheels as well.
Q3. Is a time-trial (TT) helmet better?
Ans.: TT helmets are great for high-speed riding as they produce very little aerodynamic drag. If speed is your only concern, a TT helmet is perfect for you. However, they have little to no ventilation and are heavier which results in more heating and discomfort for the rider. Aero road helmets offer a better overall package, enhancing both speed and airflow. Regular road helmets are the best for keeping yourself cool. So, none of them can be called the best since each has its own upsides and downsides. Ultimately, which one you should choose depends on your specific requirements.
Q4. What other ways can I reduce drag on a bike?
Ans.: We have already talked about aero helmets and aero wheels to gain an advantage in a race. There are multiple other ways to reduce drag and improve speed. Try out some of the following to take your racing to the next level:-
- Wear skin suits that were made for bike racing.
- Install tri-bars that have a low profile and allow you to tuck in your arms.
- Ride in a low, forward-leaning position but not too low. The head should be in line with the body and you should not have difficulty in looking forward.
- Shorten the cranks so that your knees do not come too close to your chest.
- Buy a racing or TT-specific bike which is optimized for speed.
- Shaving body hair, especially where the skin is exposed, also helps.
To conclude, aero helmets do make a difference. This difference might not sound like much, but in a high-speed competition, every second matters. If you are looking to get into racing, then you might want to invest in a suitable helmet. After all, this is one of the easier and cheaper ways to gain a few seconds over your opponents. Be sure to purchase a helmet that fits your head well and has the proper design according to your needs.