On the Hunt for Wasted Watts: Why Shoes Matter

Frame, wheels, tires, aerodynamic position… Riders are constantly on the lookout for every watt that could improve their performance. But power can also be lost at an often-overlooked interface: the foot, the shoe, and the pedal. Stiffness, shoe size, support, and the fastening system play a much more important role than it might seem. Here’s why.

By Guillaume Judas – Photos: ©3Bikes.fr, DR

On a bike, you don’t gain watts solely through better training or lighter equipment. Part of your performance also depends on the interfaces between your body and the bike. Among these, the connection between the foot, the shoe, and the pedal is essential, yet often underestimated. A well-chosen shoe—one that’s sufficiently stiff and properly fitted—can help improve power transfer while providing greater comfort and stability.

In the constant quest for more watts, professional teams seek out every possible advantage: aerodynamics, tires, riding position, drivetrain, bearings, and even effort management. But before we can even talk about gaining a few extra watts, the power generated by the legs must first be efficiently transferred to the pedal.

The Importance of Cycling Shoes

The shoe is one of the key points of contact between the cyclist and the bike. With every pedal stroke, it must transmit the forces exerted by the foot without unnecessary deformation. This is a major reason why high-end road cycling shoes use very stiff soles, often made of carbon. A sole that is too flexible can absorb a small amount of energy by deforming under pressure, even though the actual difference between two shoes is difficult to quantify under normal conditions.

However, stiffness is not an end in itself. A shoe that is extremely stiff but poorly fitted to the foot can cause pressure points, numbness, or discomfort and ultimately hinder performance. The right shoe is therefore one that combines stiffness, support, and comfort.

The right shoe is one that combines stiffness, support, and comfort.

Finding the Right Size: A No-Brainer

Before considering the lacing system, the first adjustment to make is simply choosing the right size. The foot must be properly supported without being compressed. A heel that lifts with every pedal stroke causes unwanted movement and forces the foot to compensate. Conversely, a shoe that’s too narrow or too short can cause compression, especially when the foot swells during a long ride.

You should also take foot shape into account. Two shoes of the same size can have very different volumes in the forefoot, instep, or heel. Some brands therefore offer different widths or volumes. But sometimes you have to accept that a particular shoe model simply isn’t right for your foot shape. That’s why it’s important to try them on before buying.

The positioning of the cleats also plays a major role. Even with an excellent shoe, a poorly positioned cleat can disrupt your pedaling mechanics and create unnecessary strain. Power transfer therefore does not depend on a single component, but on the entire system consisting of the foot, the shoe, the cleat, and the pedal.

Power transfer does not depend on a single component, but on the entire system consisting of the foot, shoe, cleat, and pedal.

Proper tightening to prevent unwanted movement

Once you’ve chosen the right shoe, its lacing system should hold the foot securely and evenly. The goal is not to tighten it as much as possible. Excessive pressure can create pressure points and disrupt blood circulation. Instead, the fit should prevent the foot from moving inside the shoe—particularly at the heel and midfoot—while allowing sufficient freedom at the forefoot. For many manufacturers, one of the latest trends is precisely to offer models with a wider forefoot, so that the toes can spread out comfortably at the front of the shoe and aren’t compressed.

But the greater the forces exerted on the shoe, the more noticeable internal movement can become. This is particularly important during phases where power output increases: sprints, accelerations, steep climbs, or pedaling out of the saddle.

Consistent support also helps maintain a constant feeling of contact with the pedal. This is likely one of the main benefits of modern fastening systems: allowing the cyclist to quickly find the right tension and easily replicate it.

Laces, Velcro, buckles: each has its advantages

Choosing a fastening system is, above all, a matter of compromise. Laces remain a simple, lightweight, and highly effective solution when properly adjusted. They provide a relatively even distribution of pressure and often offer an appealing aesthetic. Lace-up systems are aerodynamic and lighter than any other fastening solution. Their main drawback becomes apparent once you’re on the bike: they cannot be adjusted while riding. They also require lacing that’s precise enough to avoid areas that are too tight or too loose.

Velcro strap systems are quick and easy to use. They allow you to easily adjust the tightness, even during a ride, but their precision is generally more limited. They remain particularly appealing for certain recreational or triathlon shoes, or for cyclists who prioritize simplicity.

Micrometer buckles or dial systems, on the other hand, allow for very precise adjustments. They’re especially handy when foot volume changes during exercise, particularly on long rides or in hot weather. You can then adjust the tension without having to take off your shoe.

At 3bikes, we each have our own preferences. Jeff loves laces for their clean, minimalist look. Pierre-Maxime appreciates the simplicity of Velcro straps for quick transitions in triathlons. As for me, I only use micrometer buckles because the volume of my foot changes during exercise. And I often need to tighten the shoe at the end of a ride because my foot feels looser inside. So there’s no single system that’s universally superior. The key is to achieve consistent support tailored to your foot shape.

When your foot swells, the fit becomes even more important

On a ride lasting several hours, the foot can increase slightly in volume—or decrease, in my case. A perfect fit at the start can then become too tight after two or three hours. That’s why I just can’t get used to laces.

This is one of the reasons why systems that allow you to easily adjust the tightness can be a practical advantage. It becomes possible to slightly loosen the pressure on the forefoot or instep, then tighten the shoe again before a climb or a more intense effort.

Some professional runners even say they adjust their lacing during a race. This is particularly true of Kasia Niewiadoma-Phinney, who says she adapts the tightness of her shoes depending on the stage of the race: looser at the start, then tighter when she needs more power.

Up to 3% more power in tests

This issue of fit has recently been the subject of research conducted by the BOA Human Performance Fit Lab. In cycling-specific tests, researchers compared different shoe and lacing configurations to evaluate their impact on power transfer, energy efficiency, and speed.

According to the results reported by the lab, certain configurations improved power transfer by up to 3 watts under the conditions studied. Over the duration of the effort, the efficiency gain reportedly reached 4.5 watts. These results obviously depend on the testing protocol, the shoe used, the rider’s body type, and the test conditions. They therefore do not mean that a simple adjustment to the tightness will allow all cyclists to consistently gain a few watts.

But perhaps the most interesting finding lies elsewhere: the quality of the interface between the foot and the shoe can have a measurable impact on performance.

The quest for watts sometimes starts with the details

For the amateur cyclist, there’s no need to rush out and buy the most expensive shoe or the stiffest carbon sole. Before chasing a hypothetical gain of a few watts, it’s essential to get the basics right: a shoe in the right size, suited to the width of your foot, stiff enough for your intended use, with proper heel support, even tightness, and correctly positioned cleats.

A comfortable, well-fitting shoe also makes it easier to maintain a stable position over hours of riding. This is particularly important on long rides, when small movements or pressure points eventually become bothersome. Stiffness, too, must be considered in the broader context. A very stiff sole can be beneficial for sprints and intense efforts, but extreme stiffness does not necessarily offer an advantage to all riders. Comfort, support, and the ability to maintain an efficient pedaling stroke for several hours are just as important.

In the quest to eliminate wasted watts, it’s therefore sometimes more effective to start with what you already have. A poorly adjusted shoe, a foot that moves around, or a strap that’s too tight all result in losses in comfort and potentially efficiency—issues that are much easier to correct than changing your frame or wheels.

The connection between the cyclist and their bike isn’t limited to the pedals. Between the foot and the crank, just a few millimeters, a sufficiently stiff sole, and the right amount of tightness can make all the difference. Not necessarily in a dramatic way, but enough to remind us of an essential rule of cycling performance: before looking to gain watts, you must first avoid losing them.

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