Stand the bike on level ground
Measure the seat tube length from the center of the bottom bracket to the top of the seat tube
Measure the effective top tube length from the center of the head tube to the center of the seat tube
Measure the actual top tube length from the center of the head tube to the center of the seat tube along the tube
Measure the head tube length from the top to the bottom of the head tube
Measure the seat tube angle from the bottom bracket to the top of the seat tube
Measure the head tube angle from the ground reference to the head tube line
Measure the chainstay length from the center of the bottom bracket to the rear axle
Measure the wheelbase from the front axle to the rear axle
Measure the standover height from the ground to the top of the top tube
Measure the reach from the center of the bottom bracket to the top center of the head tube
Measure the stack from the center of the bottom bracket to the top center of the head tube vertically
Check the manufacturer’s geometry chart for the frame size
Use a tape measure and a level for accurate measurements