The Right Pedal Ergonomics: More Power and No More Knee Pain

The pedal is the point on the bike where you transfer your power to the machine. This alone shows how important it is for you to choose the right pedals. There are many things to consider: material, design, frictional connection... and of course: ergonomics! Who wants aching knees, cramped muscles or inflamed tendons when your feet don’t fit right on your pedals?! There are two fundamentally different ways in which your foot is “connected” to the pedal: either clipped in, or standing freely. 

Clipless or Flat Pedal, that is the question

Whether you ride clipped in or place your foot freely on the pedal has many ergonomic facets: power transmission, freedom of movement, and safety, to name a few. Figuring out what is better or worse isn’t always clear, but one thing is certain: the efficient power transmission clearly favours the use of clipless pedals. Due to the firm connection between muscles and machine, you cannot only push but also pull when riding. This means you use every single pedal rotation on both legs and have almost 360° of power transmission. This also provides a rounder stroke that can be sustained for a long time at high frequencies. It doesn’t matter whether you’re tackling a trail with gnarly roots in an enduro race or the cobblestones of the “Hell of the North” somewhere between Paris and Roubaix: with clipless pedals, your power is always transferred to the ground surface, no matter how uneven that may be.
The question of whether to use clipless or flat pedals is particularly important if you ride a mountain bike or a touring bike, or if you use your bike mainly for commuting. On road bikes or cyclocross bikes, the question does not usually arise, as these disciplines absolutely require a rounder stroke for better power transmission.
Whether it is ergonomically advantageous that you can move your foot freely on the pedal requires a different answer. Advocates of flat pedals argue that the foot’s freedom of movement avoids pain caused by repeated stress, and stimulates the muscles in a more versatile way. The slight, mostly unconscious change of foot position during rides also changes the position of the ankle joint and the knee. However, freedom has its downsides: not every foot position makes physiological sense. Many so-called gentle postures do more harm than good in the long run. In particular, clipless pedals do not have this problem. The foot position is predetermined within certain parameters by the fixed connection. Modern clipless shoes do not allow you to install them in joint-damaging, unergonomic positions neither lengthwise nor crosswise. One crux, however, is the angle. If the cleats are adjusted to the wrong angle, any problems are exacerbated by the firm connection between the shoe and the musculoskeletal system. If you ride clipless pedals, you should therefore pay close attention to the correct cleat adjustment. Not only do the manufacturers’ specifications help, but also special templates such as the highly recommended Cleat Tool from the Koblenz-based ergonomics specialist Ergon.

Contact Surface

In regards to the size of the pedal platform, “more is more" is not such a bad motto for once. Particularly on a mountain bike, you stand firmly and securely and have enough space for technical riding. Most MTB platform pedals therefore have an almost square base. The largest of this kind are pedals for hardcore downhill, freeride and enduro use such as the legendary Saint Pedal from Shimano (10.5 x 10.9 cm), the DMR Vault (10.5 x 10.5 cm) or the Specialized Boomslang (11 x 10.8cm). Beyond the MTB, large pedals can help: if the soles of your shoes bend around the pedal at the front and back, you need a larger contact surface – or a harder shoe sole. In general, shoe size and condition play a role in finding a new flat pedal. The bigger your shoes and the softer the shoe sole, the bigger your pedal platform should be. If your shoes bend around the pedal (the so-called plantar flexion), this costs energy and leads to fatigue or cramps. Those who like to wear warm and waterproof but voluminous winter shoes will also be pleased with a large platform. The only real disadvantage of larger pedals: they are heavier.

Shoe Choice

Pedals and shoes belong together and influence one another. This is especially true for flat pedal shoes. Their soles are a little softer than their clipless siblings in two respects. First to consider is the midsole, which determines the overall stiffness of the shoe. Second is the rubber outsole, which determines grip on different surfaces. More flexibility in this area provides more control, grip and comfort while walking. Be careful, however: if the shoe is too soft and curls around the pedal like an overripe banana, it will cost you both power and control. A dedicated cycling shoe is therefore always the better choice over a pair of gym or skate shoes. Depending on your application, there are a wide variety of models from urban-inspired sneakers to touring shoes, from all-mountain shoes to downhill shoes. All-mountain, enduro or downhill shoes in particular have a very grippy sole and interlock so tightly with the pedal pins that you can hardly move them sideways or from front to back. This means you have to actively take them off the pedal and reposition them, which requires a fair amount of practice.

Inside the Pedals – MTB

For MTB, clipless pedals are usually designed symmetrically, regardless of whether they also have a cage or not. The best-known example is without a doubt the SPD pedals from Shimano, where you can clip in from above or below. This ensures that you can quickly attach to the pedal even in technically difficult situations. A large pedal platform, as offered by mountain bike pedals from the all-mountain, enduro or downhill segment, makes clipping in even easier. Simply place your foot centrally on the pedal and it will find its way into the clip-in mechanism. Until then, thanks to the cage and pins, you are sufficiently safe even when clipped out. Pedals from crankbrothers are a special case. Their clip-in mechanism, clearly seen in the classic Eggbeater pedal, allows you to clip in from all four sides. This is called 360° Engagement. Crankbrothers clipless pedals with cages also work in a similar way. Since the spring can rotate freely in the cage, the cleat always finds its way quickly and securely.

Outside the Pedals: Release Hardness and Angle

With most clipless pedal systems, you turn your heel outwards around the pedal mechanism to release. Shimano’s SPD system comes equipped with a multiple release function. In this case, you can also disconnect by tilting the heel. There are two parameters that influence how easy or difficult it is to do this, and they are not usually combined. Some systems let you change one parameter, some others:

• The release hardness is determined by the tension of the spring mechanism. The harder the spring, the greater the resistance when turning the heel. Many systems allow you to adjust your release hardness individually, such as both SPD systems from Shimano, both Time systems, Ritchey, HT or Look. This works either via a screw (usually with a hex bit) that changes the spring preload, or via exchangeable spring plates.
• The release angle depends on the interaction of the cleat and the spring mechanism. Some manufacturers, such as Time, design their cleats to have a different release angle depending on the direction they were mounted in, such as 13° or 17° for TimeAtac. Crankbrothers also follows a similar trajectory, but also offers three different cleats that allow release angles of 10, 15 and 20°.

A special case is again Speedplay, whose pedals have a very low release hardness but a high release angle. A good option for people with knee problems, but it takes some getting used to when one is accustomed to a "hard" pedal.

Q-factor and Axle Length

Speaking of standing wider: the bottom bracket width and crank design not only influence the Q-factor (also called stand width), but also the pedals. The longer the axis and the wider the platform, the further out you can or must stand. On a road bike, XC or generally on long distances, a narrow Q-factor is usually the norm. This is either out of pure habituation, as the efficiency is perceived to be higher, or because of aerodynamic advantages. Gravity mountain bikers in particular like to stand further out and wider for more pressure and control on the pedal when they are not in the basic position, but working from the thighs and hips. Naturally, your hip width also plays a role: people with narrow hips quickly find wide Q-factors uncomfortable, and vice versa.

The Shoe: Sole Hardness

The harder the sole, the better the power transfer – that is a fact. However, hard soles also have their disadvantages: they do not roll off well, and comfort and stability while walking or standing are miserable. They also transmit vibrations and require a good footbed to prevent fatigue. On a mountain bike, the lack of feedback and the reduced control can also be a disadvantage. Therefore, there is no such thing as the perfect cycling shoe, only shoes that combine your personal requirements in the best possible way. An indication of the sole hardness is given not only by the manufacturer’s specifications, but also by our application filter: shoes for road cycling, cyclocross, triathlon and track have the hardest soles, shoes for dirt jumping, slopestyle, downhill and city tend to have the softest – the rest fall somewhere in between. We have already pointed out another aspect: the smaller your pedal, the harder your shoe should be. Tip: Ergonomic insoles with different hardnesses are a great way to adjust the comfort or efficiency of your shoe and compensate for errors. This is not an ergonomic issue, but you should still pay attention to it: the shoe must also fit the pedal system in terms of the number of bolts.