3DAero: Using the System
In the Beta release there are a limited number of settings to work with:
- Estimated Cd
- Capture period
- Estimated time and distance
Set the Cd based on the position style, we will be adding to the information around this in the near future -in the meantime:
Very low torso angle, head tucked in front of the Torso TT positions will be around 0.7. This rapidly increases with higher head positions and more upright torso angles. For a Road position start from around 0.9 for a drops position up to 1.2 on the tops.
The system has a default of 20s. We’d generally suggest 15-30s once the rider has settled in to their rhythm.
Estimated Time & Distance
This function allows you to establish a baseline for the riders performance - the system then calculates the change in time/power that results.
For example, this rider is focussed on the half Ironman distance and normally rides 2hrs14 at their key race. So we input 90km (metric only at this point) and 134 (time in minutes). If the rider has not raced before you may need to ask their normal training speed and target race distance.
Run 1 is the baseline.
Run 2 was sitting up on the hoods - which would cost 15.08mins or require another 97w to maintain the desired speed. This can be a useful illustration for why it is critical to have an aerobar position that can be maintained throughout the race.
Run 3 was ‘turtling’ - narrow elbows, shoulders shrugged in, head down. This would save 2.14mins or reduce the power requirement by 12.7w.
To begin collection press ‘Capture’ - the system will count down the defined period then save the average data. While capturing fill in the text box with a brief description of the position.
Repeat as many times as needed…
Clicking the save button will produce a .CSV file with the values shown in the table. You can then perform further analysis (if needed) and add to your fit report.
Getting the most from the system
Much of the value from the 3D Aero tool comes from educating the rider. Showing them that sitting up costs time. Pulling back on the bars (‘choking up’) costs time. Ducking their head and shrugging shoulders can save time.
For dialling in the position the tool allows you to assess the impact of different elbow widths (narrower not always faster), bar heights and saddle positions.
On the road bike you can demonstrate the difference between hoods and drops - sometimes it is faster to have have bent elbows on the hoods than to be in the drops.
Essentially - the best use of this tool is to to try a lot of scenarios to find the optimal solution for that rider. When combined with our 3D Motion system you can resolve a position that strikes a balance of aerodynamics, comfort and power.