Hinault/Genzling book. Long post.
The now out-of-print book “Road Racing Techniques and Training” by Bernard Hinault and Claude Genzling (ISBN 0-941950-13-1) addresses this ratio in the chapter “Morphology, Position and Frame Design.” The authors first define seven body measurements:
1. Height – no shoes.
2. Inseam E – 1.5 cm wide carpenter’s square raised as much as possible into the crotch, no shoes.
3. Thigh C – rider on stool, back and pelvis against the wall. Lower legs vertical. Put straightedge against two kneecaps, measure the distance from straightedge to the wall.
4. Lower leg J – same position as thigh measurement, no shoes. Put straightedge on top of the knees in front of the beginning of the thigh muscles. Measure from straightedge to ground.
5. Trunk T – rider on level stool, pelvis and back against the wall, shoulders horizontal. Place carpenter’s square on the bulge of the collarbone, measure distance mark on the wall at this height and the top of the stool.
6. Arm B – previous position. Rider grasps a small cylinder the same diameter than his handlebars. Without moving shoulders forward and back against he wall, rider moves his straight arm to a horizontal position. Measure from wall to edge of cylinder.
7. Forearm A – arm at 45 degrees, rider bends elbow to form a right angle between his upper arm and forearm. Measure the distance between the elbow and the cylinder.
The authors then address morphological differences, using the letters and definitions above. They state the norm of the ratio of thigh C to lower leg J as 1.11 in men, 1.14 in women. They claim that a larger C/J ratio has been observed in cycling champions: Coppi at 1.18; Merckx at 1.16; Hinault at 1.20.
Hinault and Ginzling then list a norms for trunk, arm and inseam ratios for men
T/E = 0.76
B/E = 0.87
A/E = 0.40
and explain briefly how these ratios (or variations thereof) can be used to figure a rider’s reach.
The authors don’t use the ratio of inseam to height because, in their words, “the size of the head and the neck, which have nothing to do with position, falsify the results."
Of course, the book is old, the translation from the French leaves much to be desired, and the norms are based on Western Europeans. It’s pretty much been relegated to the scrap heap of training literature, but I think it’s still a viable text. Somewhere in the beginning of the book, the authors say “the numbers propose, the rider disposes.” How true—at least for those riders who can hear what their body is telling them.
