How To Measure Sit Bones For A Bike Saddle. Your sit bones will leave an indentation on the paper. This can mean the rider has a forward rotated pelvis, with the sit bones typically up, off the saddle surface.
Your sit bones should crush the corrugated cardboard slightly and leave two indentations. Most shops will have a device to measure the distance between your sit bones without being intrusive: Bike saddle width is the measurement of the widest part of a saddle, onto which your sit bones will rest when you are sitting down.
If your sit bones measure 135mm, go with a 155mm saddle.
Step 3 select your right sitting position from the positions shown above and add the corresponding value to the measured sit bone distance. A larger saddle is always better than one that is too small. Bike saddle and sit bone width isn’t the holy grail. Make sure you are sitting upright, which will push your sit bones into a vertical position.