Taking Your Bike Measurements

A. Effective Toptube Length

Horizontal top tube frame (some road bikes): Measure from the center of the head tube at the head tube / top tube junction to the center of the seat tube at the seat tube / top tube junction.
Sloping top tube frame (compact road bikes and mountain bikes): Measure from the center of the head tube at the head tube / top tube junction horizontally (parallel to the ground) to the center of the seat post or seat tube.

B. Stem Length

Measure from the center of the steerer clamp to the center of the bar clamp, along the stem’s extension. Most stems are only available in 5mm increments and typically range from 90 – 140mm.

C. Saddle Tip to Bar

Measure from the tip of the saddle to the center of the stem clamp where it holds the bar.

D. Saddle Tip to Brake Hood

Measure from the tip of the saddle to the tip of the shift/brake lever hood. This measurement applicable to bikes with drop bars (road bikes and cyclocross bikes).

E. Saddle to Floor

Measure from the top of the center of the saddle (at center line of seat post) to the ground vertically. A plumb line dropped from the center of the saddle helps accuracy.

F. Bar to Floor

Measure from the top of the bar (next to the stem clamp) to the floor.

G. Saddle Height

Measure along the seat tube from the center of the bottom bracket to the top of the saddle.

H. Saddle Setback

Drop plumb line from the tip of the saddle and measure from the plumb line horizontally to the center of the bottom bracket.

I. Saddle Length

Measure overall saddle length

J. Seatpost Offset

This is the measurement from the center of the seatpost to the center of the clamp. This information is usually available from the seatpost manufacturer. If you cannot find it let me know the post make and model, I have most offsets recorded

K. Crank Length

Measured from the center of the bottom bracket to the center of the pedal spindle. On most cranks this measurement is stamped on the inside of the crank arm right at the pedal hole.