You are reading a single comment by @EdwardZ and its replies.
Click here to read the full conversation.
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
@EdwardZ
The page presents hardly the basis for bicycle fitting as used by the British National team... Heel over pedal generally results in a position that is sub-optimal low. It neither prevents injury nor optimizes power. Heel on pedal is not unlike factor*inseam or inseam-factor models for saddle to center of bottom bracket. The main difference between the heel on pedal and something like Guimard’s 0.883*inseam is that the former nearly always produces a lower saddle. Genzling's 0.885*inseam produces an even higher saddle height and these are generally lower still than a number of other "formulas". Back in the 1980s a popular formula for saddle height in the US-- attributed to Eddy B.-- was 0.96*trochanter height + shoe/pedal stack height (center of pedal axle to foot sole) - crank length. Eddy's model while resulting in positions quite close to the Guimard height was derived from his own faulty research. Despite being bad science the work was still taken quite seriously given the success of the US team. The most popular formula currently used in the scientific literature is Hamley and Thomas' 1.09*inseam - crank length. Their seminal paper "Physiological and postural factors in calibration of the bicycle ergometer" from 1967 is really the basis for the French factors. The Genzling and Hamley models, however, only intersect when crank length is 20.5% of inseam. That only occurs when a rider has an inseam of 83cm and selects a 170mm crank. If we look at most of the studies (including Hamley's) we'll see that most of the cyclists are not far removed from this median. The Genzling model results in saddle heights for shorter cyclists being put higher, resp. lower for taller, given the observation that road cyclists tend to keep more or less to cranks in the band 170-172.5-175mm in length--- 165 and 167.5mm really are only popular on the track while 180mm is very much a time trial sort of thing. Right now the so-called Holmes method is probably the biggest trend in elite fitting. The current state of research seems to indicate that such heights are perhaps not the best for performance but do provide a good basis for the minimization of injury.