The adjustment of the saddle serves to enable the muscles to work optimally in
the longitudinal reach. As there is only one optimal longitudinal reach, there
is only one optimal saddle height. Most of the methods used at present to
determine the correct saddle height are far from optimal. We will briefly
discuss a few of these measuring methods.
First there is the so-called heel-method. The heel of the shoe is placed on the
pedal and the saddle is adjusted at such a height that the leg is stretched
while the pelvis is still in horizontal position. So far no evidence, empirical
nor scientific, has been found to justify this measuring method. More
importantly, this method does not take into account the fact that the modern
cycling or racing shoe has a heel jump. In reality this means that, as a rule,
with this method the saddle is adjusted too low.
The second method was developed by Claude Genzling. During the Tour de France of
1978 he measured the body sizes of the cyclists and the respective adjustments
of their bicycles. On the basis of these measurements Genzling arrived at the
following conclusion: the saddle height ( the distance from the heart of
the bottom bracket to the upper part of the saddle) = 0.885 x inner
leg length. Two critical remarks, however, should be made about Genzling's
conclusion. Nowadays the adjustment of the saddle height demands a different
approach, given the fact that in the course of time the cycling sport has
evolved from endurance sport to power endurance sport. Secondly, the Genzling
formula takes a relative size (see saddle height illustration size 2) and an
absolute size (crank length) as starting points. In this method, an incorrect
crank length would lead to an incorrect saddle height because the saddle height
is the distance from the saddle to the pedal axle (see definition above). In
other words: this method is inconsistent.
A third method is more scientific and was developed by Nordeen-Snyder (1977). In
determining the optimal saddle height, the use of oxygen was taken as a
starting point. On the basis of experiments it was concluded that the ideal
saddle height corresponded with 1.05 x trochanter height; however, this method
does not mention if the thickness of the sole and the height of the pedals are
taken into consideration. Depending on the pedal-shoe system that is used,
notable differences in saddle height can occur ( illustration size 1). A
practical disadvantage is that it is very difficult to determine the trochanter
height. Other surveys based on the same method determined the saddle height at
1.09 of the inner leg length (Hamley & Thomas, 1967).
Another method (Homes, Pruitt & Walen, 1994) starts from the angle of the
knee. When the pedal is in its lowest possible position, the knee should be
able to bend 25 to 30 degrees. This method is only applicable when a global
indication of the saddle height suffices. Other surveys, however, make clear
that an exact determination of the saddle height can have major consequences
for energy expenditure.
Gonzales and Hull (1989) showed that an optimal adjustment of the bicycle
depends on more than one variable, and that these variables are correlated and
interrelated. They are in favor of a multi-variable measuring method because
the single-focus approaches described above are too limited and do not lead to
individual optimization. However, no general conclusions and recommendations
can be made.