Using the software
Shrink the capture area around the rider – leave space above for sitting up but it can be tight on the sides and ground. Reducing the capture area significantly lowers the processing load on your computer and can help it run much faster. Only the capture area will be saved in images and video.
Setting a baseline distance and time allows the system to calculate increments in finish time for each position.
Measurement Screen Setup
Before you start capturing you need to set a Cd value. This allows the system to calculate a CdA and from there the time and power differences
This table offers a basic guide to selecting a Cd:
|Torso Angle||Position Style||Cd Estimate|
|< 15||TT / Tri||0.7|
|15-20||TT / Tri||0.75|
|20-25||TT / Tri||0.8|
|25-30||TT / Tri||0.85|
|30+||TT / Tri||0.9|
If you wish to only look at the impact of the Frontal Area change you would not alter the Cd over the course of the session. You should still choose a roughly appropriate Cd to give meaningful scaling to the FA value. If you make significant changes in torso angle you should also change the Cd in order to give a more sensible time change.
Setup – Educating the rider
It can be helpful to have an item or wall chart for the rider to look at. In any case, ask the rider to pick a spot on the wall or floor that feels like a realistic distance to look ahead and focus on that. If they change their focus point during the session you will most likely get invalid data.
Ideally you will find a position that allows the rider to relax their neck/shoulders (lowering the head) while looking the same distance forward.