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.