Comfort is the least investigated factor in the matrix. This parameter is predominantly based on rules of experience and is subject to years and years of trial and error. Even the most well-known manuals, such as Science of Cycling, present the reader with a number of general statements that provide little basis for a more systematic approach. In reality, the aspect of comfort is taken into consideration only when the adjustment of the bicycle leads to inconveniences or complaints.
We will discuss a number of aspects that deal with comfort, taking the parts of the body which actually make physical contact with the bicycle (i.e., saddle, handlebars, pedals) as our starting point. It should be noted that these three parts of the body are of crucial importance in the adjustment of the bicycle, rather than the size of the frame. Many cyclists and bicycle dealers are fixed on the size of the frame, and the size of the frame only. The frame geometry (which is more than just the size of the frame) is only important when adjusting the bicycle, in order to get the three contact parts of the body in the right interrelated proportion. This aspect is irrespective of the fact that the frame geometry can have consequences for the cycling properties of the bicycle.

The saddle.
A saddle should fit comfortably. Having said that, this is the most difficult aspect when trying to adjust the bicycle. On the one hand, the width and shape of the saddle depend on the distance between the seat-bones and the shape of the pelvis. The larger the distance between the seat-bones and the rounder the pelvis, the wider the saddle should be. On the other hand, the width of the saddle also depends on the position of the upper body on the bicycle. When sitting on the bicycle with a very curved spine, a narrow racing saddle is more comfortable and more functional ( grating of the inner legs). When sitting upright, a wider saddle is generally more comfortable (Van Hulten, 1999). As far as is known, no practical measuring method has been developed yet which takes into account both width and shape of the saddle, as well as the position of the upper body on the bicycle. The only possible advice that we can give here is to find out through trial and error. At this point, we should make a few remarks about saddle tilt, i.e., whether the saddle should be placed in a horizontal position or not. In principle the saddle should be placed horizontally. In case of a "positive saddle tilt" (i.e., saddle pointing upwards), the cyclist runs the risk of numbing certain parts of his body. As a consequence, the cyclist will be inclined to tilt his pelvis backwards which results in more pressure on the lower back. If the saddle is pointed downwards ("negative saddle tilt"), the cyclist will tend to slide forward. This is very uncomfortable not only because the narrower front part of the saddle gives too little support, but also because the arms, wrists and hands are subjected to too much pressure as a result of the cyclist trying to maintain a normal position on the saddle. The height of the saddle plays an important role in experiencing the bicycle as comfortable. If the saddle is placed too high, the cyclist runs the risk of overstretching his muscles; if the saddle is placed too low, however, the pressure on his quadriceps might become disproportionately high. Also see the chapter on efficiency: height of the saddle.

The handlebars
Research has been conducted into the relationship between the adjustment of the handlebars and a comfortable position on the bicycle (Bremmer 1994). The most important conclusion of this survey is that the distance between saddle and handlebars is very much a matter of personal preference. The disadvantage of this kind of practical research is that the element of habituation can have a substantial effect on the measuring results. The experience of bikefitting.com is that a cyclist does not experience an adjustment of distance and difference in height between saddle and handlebars as comfortable when the advice on this matter deviates from what the cyclist is used to. Our experience, however, also shows that eventually the majority of cyclists believes the new adjustment to be an improvement. The handlebar-width should correspond with the width of the shoulders. Handlebars that are too wide automatically increase the frontal surface area of the cyclist and lead to loss of aerodynamic advantage. An additional drawback is that the cyclist will also show a sagging between the shoulder blades. In the long run, this will lead to complaints of the neck and shoulders. Contrary to common belief, handlebars that are too narrow will not result in loss of oxygen intake; however, narrow handlebars often lead to more nervous steering than wide handlebars and, hence, to loss of comfort. The steering angle should be adjusted in such a manner that the lower arm and hand are positioned in one line, as much as possible. It is clear that a correct aerodynamic position and a comfortable position of the torso do not always go hand in hand. Depending on the discipline the cyclist is engaged in and the speed he develops, he will decide on his position accordingly.

The pedals.
Together with the cycling shoes the pedals form a unity through which the cyclist transfers movement to the bicycle. For matters of comfort it is important that shoes and pedals offer sufficient stability, enabling the movement of the knee to remain in line-of-force with the hip and foot. Contrary to popular belief, the cyclist has to adjust himself to the movement imposed on him by the bicycle. This implies that the link shoe-pedal (shoe cleats) is subordinated to this imposed movement. The position of the shoe cleat ensures that the foot is positioned straight on the pedal, so as to give stability to the knee joint. This explains why the link shoe-pedal should be stable in itself. The pedal should also be sufficiently wide because the entire front part of the foot must be supported. In order to cut back on weight and to decrease air resistance, pedals are often made as small as possible. So small, in fact, that stability depends entirely on the rigidity of the shoe and shoe sole, and on the link with the pedal. In reality this stability leaves a lot to be desired. With respect to the adjustment of the shoe cleat and complaints as a result of instability of the front part of the foot, we refer you to the Shoe Cleat Adjuster and the FAQ.