What to Know When Buying Aero Road Bike Wheels
If you want to go fast on a road bike, there are two main ways to get faster. One is to train and train hard. The other way is to go aero. We can't help you with the first one, but we can help you get aero. One of the best places to go aero is with your wheels. When you're out riding, your wheels and tires will be the first part of your bike and yourself that has to break through the air. Now, the easy bit, sit down, and we'll guide you through all the knowledge you need to buy a set of aero wheels for your road bike.
The Truth About Aero Wheels
Road bike wheels tend to come in two varieties, lightweight and shallow rimmed wheels and deeper, more aero wheels. It may come as no surprise to hear that lightweight, shallow rimmed wheels are better for climbing. Aero wheels prefer more rolling and flat terrain. They also bring additional benefits if you're riding by yourself or in small groups.
If you're riding along the flat, you'll have to main things to overcome as a cyclist. You'll be fighting against rolling resistance and aerodynamic drag. At around 20 mph, you can expect overcoming aerodynamic drag to be approximately 75% of your effort. The easier you make it for your bike to slice through the air, the faster your go for the same effort.
ICAN AERO Wheelset
The good news here is that relative to cost, and wheels are the best way to lower aerodynamic drag. A deeper aero rim will then help to reduce aerodynamic drag. Some people like to consider this to be "free speed," which is not to do with the cost of the wheels but to deal with your energy cost. Saving energy and going faster, what is not to love?
What Depth of Aero Wheel do I Need?
As we mentioned above, deeper aero wheels help to reduce aerodynamic drag. If it were as simple as this, we would all be riding full carbon fiber disc wheels. We also have to think about side winds. Deeper section rims don't like crosswinds. They can also add weight to your bike, which is less critical if you're riding a flat course.
The majority of us will not be riding a flat course all the time, and will possibly have a few climbs in most of our rides. If that describes how you ride, then we have the solution for you.
40 - 55 mm Aero Road Bike Wheels
Pros, and aerodynamicists, consider 45 to 55 mm deep aero road wheels (also called midsection depth) to be the perfect meeting point between lightweight and aero advantage. The extra weight won't be an issue on a climb. The added stiffness may also be of benefit when the road hairpins at high gradients. You won't lose any forward momentum to wheel flex.
60 mm Plus Aero Wheels
Aero wheels over 60 mm will bring you more significant aero gains. They will also be slightly heavier and be more susceptible to crosswinds. They make a great choice if you're going to be riding time trials or races where you want to sprint off the front of a bunch.
ICAN AERO 86mm
Wider Aero Wheels
We used to believe that going narrow was the way to go aero. Everything got made thinner. Now we know that sometimes a little girth is helpful. The reason for this is your tire affects how air hits your wheel rim.
The air hitting your tire can be stalled or detach from your bike. As such, there is no point going aero at the moment where your rim hits the tire. The wider rim can then be used to help direct the airflow.
Tire Width on Deep Aero Wheels
We should now all agree that aero wheels will make you faster. There is one other part of your bike that you should consider to maximize your aero gains. Your tire will hit the air before your aero wheel rim, so you need to pick a tire that will work with your rim.
Thankfully there is a simple rule for picking the correct tire. Pick a tire that is 2 mm narrower than your outer rim width, making sure the tire doesn't sit like a mushroom on top of the wheel. It is also worth noting that a slick tire will cause the airflow to stall, make sure you pick tires with a tread pattern.
Tubulars, Tubeless, or Clincher?
You'll need to make sure that you pick the correct style of tire for your aero wheels.
Tubulars, or tubs, are tires that are stitched shut, and you glue or tape them to your rim. For years they were the choice of pros, as you could keep going if they punctured and were faster than clinchers. They have been falling out of favor in recent years as they are a pain to set up and have a higher cost.
Clinchers are the tires that the majority of us will be used to be. Clincher tires are called, so as the tube pushes the tire into the hook of the rim, they then clinch to this hook.
Tubeless tires are also technically clinchers, but you don't use tubes, just air to help them clinch. You fit special tape to your wheel rim to make the rims airtight. You then add some sealant. The lack of tubes makes the tires as fast and supple as tubular and more puncture resistant than clinchers.
2-Way Clincher Tubeless.
Construction of Aero Wheels
Aero wheels need a lot more material than box section rims. Extra material will then add weight. Carbon fiber is then the best material for constructing wheel rims. With the advances in carbon wheel manufacturing, the weight penalty is coming down every year.
The Brake Track, One of the issues with carbon fiber wheels is the brake track. There are two main issues with carbon fiber brake tracks. They don't brake as well in the wet. They can also overheat when coming down Alpine descents.
Some manufacturers get around this by building a carbon fiber fairing on an aluminum rim. Using this method adds weight and is a cheaper way to fix the issue. Other manufacturers have spent time and money on developing carbon fiber braking tracks. The quality of these tracks now surpasses some aluminum brake tracks and keeps your wheel lighter.
ICAN AERO 45 Brake Trake
Spokes,If you're building your wheels, make sure you get a hub with the same number of spoke holes as your rim. New carbon fiber rims will generally use fewer spokes than older box section aluminum rims. The wheels can use fewer spokes as the deeper rims, as the distance the spokes have to travel shorter, and you can build a stiffer wheel with fewer spokes.
One thing many people forget is that not all spokes are created equally. You'll be looking for spokes that are butted. Butting removes material from non-critical areas. The butting makes the spokes lighter but keeps them just as stiff as non-butted spokes.
Aero or round? Spokes also come in round or aero variety. Round is cheaper and easier to fit as it doesn't matter how they are aligned. Aero, or bladed, adds to the aerodynamic properties of the wheel. They are harder to fit as you need to keep them properly aligned so that they are not causing more aerodynamic drag.
Hubs, You need to make sure you order the correct hub for your bike. For disc brake hubs, you'll need to make sure that they match your rotors, either Centerlock or 6 bolt. What type of axle are the hubs using? Is it quick-release or thru-axle? Your cassette also matters. Are you running Campagnolo, Shimano, or SRAM cassettes, make sure your rear hub has the correct freehub.
What Aero Wheels Should I Buy?
Now is the time to be honest with yourself. Will you be using the wheels recreationally, or are you going to be racing?
If your using wheels recreationally or are a beginner, then go with a midsection aero wheel that is for clincher tires. Midsection means your less likely to have issues with the wind while you learn bike handling skills. Clincher tires are also the easiest to fix at the side of the road.
If you want to race, you'll be best fitting deeper section aero wheels. It would be best if you try tubeless or tubular. Both will let you carry on if you have a puncture, with the tubeless, hopefully, self-healing, and only losing you a few PSI.