Cyclepedia.org Wiki | Fit / Huggi Guimard

Proper bike fit is the process of balancing comfort with efficiency, while taking into consideration the riding style, type of riding, flexibility, injuries or condition of the rider. Current fit methodology is nothing new, it’s based upon proven industry standard theory and formulas. To make bike fit simple to understand, it can be broken down into five areas using the Huggi and Guimard formulas made popular by Greg Lemond’s book “Complete Book of Bicycling”.

A) Saddle Height— a function of inseam and type of riding.

B) Saddle Setback— a function of femur length.

C) Reach— a function of torso and arm length and type of riding.

D) Handlebar Drop— a function of flexibility, comfort or effect desired and type of riding.

E) Frame Size— typically measured from crank center-to-top of seat tube.¹

excerpt from: theBikeBiz

Frame Size:
Inseam x .65 = center-to-center frame measurement (Wilfried Hüggi’s formula)

Baseline Saddle Height:
Inseam x .883 = saddle height, measured from the center of the crank (bottom bracket) to the top of the saddle (Guimard’s formula)

Baseline Saddle Setback:
Is measured from placing the rider at proper saddle height with shoe and cleats set up with the ball of the foot directly over the pedal axle. Then taking a plumb line off the front of the kneecap with the crank arm at 9 o’clock, the plumb line should intersect or fall behind the pedal axle by no more than one centimeter.

Baseline Reach:
(Sternal notch height – inseam + arm)/2 + 4cm

Baseline Drop:

Recreational Riding= +3 to −3cm
Sport Riding= −3 to −7cm
Racing= −7cm or greater

¹ this is different from the Hüggi frame size calculation, which is center-to-center. (↑)