How do I use my bike fit measurements to get my drag calculations?
Drag is the largest limiting factor when it comes to moving your bike forward. It is also one of the hardest factors to measure. We provide some general drag estimates based on the drop down racing and climbing position selections on your bike profile, but in an effort to help further refine an accurate drag estimate we have created an advanced Fit-Based drag calculator.
This calculator takes specific measurements about your body and position on the bike to help refine your drag profile. You can always override your final drag profile with your own calculated data from velodrome or wind tunnel test data, but the fit based calculator should give more accurate results than our standard drop downs without the costs associated with aero testing.
The following guide will help you through your measurements:
Width in centimeters from the edges of your shoulders while in your racing position.
Width in centimeters at the widest portion of your hips while standing.
Hand Width (Racing)
Width in centimeters of your typical hand (road) or elbow (TT/Tri) placement while racing.
Hand Width (Climbing)
Width in centimeters of your typical hand (road) or elbow (TT/Tri) placement while climbing.
Hip to Shoulder
Length in centimeters from hip to top of shoulder while standing.
Hip to Head
Length in centimeters from hip to top of helmet while standing.
Seat to Handlebar Drop
Length in centimeters of drop from the center of your seat to your handlebar tops or arm pads (if no drop use 0 centimeters).
Torso Angle (Racing)
Angle from hip of a perpendicular line forward and a line through your shoulders in your racing position (sitting straight up is 90 degrees).
Torso Angle (Climbing)
Angle from hip of a perpendicular line forward and a line through your shoulders in your climbing position (sitting straight up is 90 degrees).
Seat Tube Angle
Effective seat tube angle (Road is typically 74-76 degrees and TT/Tri is typically 78-80 degrees).