I: A simple diagram can help you determine the size of mountain bike you need
II: Formula Calculation
1. Measure thigh length (i)
It is best to wear cycling clothes when measuring, stand on a flat, hard surface, and have someone assist you. Stand upright with your feet about ten centimeters apart. Place a book or similar object flat against your crotch and apply slight upward pressure (less than what you’d feel on the saddle), then measure the distance from the top of the book to the ground: i
2. Measure body length (t)
Use the same posture and steps as in step 1. Measure the distance from the bottom of the V-shaped groove between your collarbones to the top of the book: t
3. Measure arm length (a)
Stand upright with arms extended horizontally and palms facing forward. Measure the distance from the webbing between your thumb and index finger to the plane of your ribs: a
4. Measure shoulder width (s)
Stand upright with arms relaxed, and measure the width at the shoulder joints: s
Take each of the above measurements three times and use the average value
Based on the above data, you can determine the frame size you need:
Road bike frame size ＝ i * 0.67 (cm)
Mountain bike frame size ＝ (i * 0.67 - 11.0) * 0.394 (inches)
Stem length ＝[(t+a)/2+x] - et
Road bike x＝4; Mountain bike x＝8;
et＝effective top tube length (the effective length of the top tube on the frame, which is the “o” in the first diagram)
The crank length suitable for you:
Drop bar width: (the width of the drop bar refers to the center-to-center measurement)
