Many road riders encounter a dilemma when upgrading their bike's wheelset. With so many options available on the market, it can be challenging to determine which type of wheel best suits their needs.
Broadly speaking, we can categorize the options into lightweight or aero if you're upgrading your wheels. You're either trying to reduce your bike's weight or help it cut through the wind.
It's important to note that not every wheelset can be neatly categorized, and the distinctions between categories can often be unclear. For instance, the emergence of mid-section rims offers riders an all-in-one solution that balances aero efficiency and low weight. However, depending on your goals, you may be better off selecting a set of wheels that leans more heavily towards one end of the spectrum or the other.
Should I go for aero or lightweight? That's the question.
Aerodynamic Wheels
Rolling resistance and aerodynamic drag are the two factors that slow down cyclists on a flat road.
At low speeds, rolling resistance is the most significant force affecting tire resistance. However, as the speed increases, aerodynamic drag becomes the dominant force. Considering an average road position with decent tires, we can expect a 50/50 split between the tire and aero-resistive forces at a speed of 12.5mph.
Aerodynamics still plays a crucial role even when cycling at a relatively low speed. As the speed increases, the proportion of effort required to overcome aerodynamic drag becomes much higher. For example, at a more realistic speed of 20mph on a flat surface, about 75% of your effort will be needed to overcome aerodynamic drag.
An aerodynamic rim with greater depth can help to decrease the resistance caused by airflow for both the rider and the bike. Since aerodynamic drag is the primary force that riders need to overcome, an aerodynamic wheelset can offer a "free speed." When combined with other aerodynamic benefits, the case for using an aerodynamic wheelset becomes even more convincing.
Lightweight Wheels
When cycling uphill, weight becomes a significant factor in the amount of effort required. On a ten percent incline, a 75kg rider will consume around 90 percent of their effort in overcoming gravity.
To maintain a speed of 10mph on this incline, the rider weighing 75kg would have to generate about 415 watts. For every kilogram of weight reduction, roughly five watts of effort are saved.
When you're climbing, weight is more important than aerodynamics. However, if you're cycling on flat roads, rolling terrain, or a mountainous course with long valley roads, aerodynamics may become more important during your ride. It's essential to balance the demands of cycling with your wheelset choice.
Is The Mid-Section An Optimal Compromise?
A rim with a mid-depth offers a great balance between weight, responsiveness, inertia, and drag reduction.
For an average rider weighing around 75kg, a wheelset with a 45-55mm diameter is considered perfect. It's light enough for a 75kg rider to climb yet deep enough to feel the aero benefits.
The majority of the riders of Team Dimension Data consider the Enve 4.5 (45/55mm) as their primary wheel for all-day use. However, on flat or rolling stages, some riders like Mark Cavendish prefer the deeper 7.8 (70/80mm) wheelset to take advantage of its full aerodynamic benefits. The Enve 3.4 (38/42mm) is only used by heavier riders during climbs.
Alloy Or Carbon Rims
Carbon road wheels will consistently outperform any other wheel you use. As a long-time rider, I know how significant bike components can affect the performance of a bike. Two bike parts with the same price can perform with a vast difference. Carbon road wheels are the components you want to have on your bike. I'll list the features that make carbon road wheels better and why you should choose them:
Weight: Carbon road wheels offer the lightest weight for bikes despite newer technologies seeking to make aluminum wheels lighter. Carbon fiber is the most lightweight material used in producing bicycle components and serves the purpose of helping the bike maintain a constant speed.
Aerodynamics: Aerodynamics is one of the most important things to consider when cycling. Carbon wheels are exceptionally aerodynamic, helping you maneuver air resistance and drag pressure. They ensure that you reach higher speed with less effort regardless of the road terrain you are riding on.
Impact Absorption: Impact absorption is a very important factor in having a smooth and comfortable ride, and you may want to go for carbon wheels for that reason. The impact absorption capabilities of a bike mean that the rider does not feel the impact from landing at small heights, on rough terrains, etc. Carbon fiber is the perfect material to absorb the impact of cycling.
Other features include efficiency, versatility, and design. Carbon road wheels generally offer the best features you could get out of bike wheels, and there's hardly a substitute for it.
The Right Wheel For You
To select the perfect wheel for your bike, consider your riding style. If you mostly ride uphill, a lightweight wheel would be suitable. However, a mid-depth wheel would be ideal if you enjoy riding downhill or on flat terrain.
Generally, we suggest increasing the rim depth between 30-50mm, which provides significant aerodynamic benefits that outweigh the slight increase in weight. Besides, the wheels are more stable with this configuration.