Purpose of ride analysis

[moethedog]

I'm trying to understand the ride analysis. I have a workout to ride in power zone 4, which is 244 to 284 watts. So I do my workout keeping in that range. When I download the ride file, the ride analysis drops my wind and lowers my power to 200 to 250 watts. This puts my whole workout in zone 3, which means I didn't do the scheduled workout.

It seems the if the ride analysis is correct, the power meter is not useful to use during workouts since the numbers it displays are very inaccurate. If the ride analysis is incorrect, why is it done upon download?

Is there some way I can get accurate power numbers while riding?

Thanks,
Darren

[Velocomp]

Please post a ride file that illustrates your question.

[moethedog]

Hi,

Here is the file I mentioned, but the same thing happens for most of my rides. Before each ride I let the iBike sit on the bike for a few minutes and then do a wind and tilt calibration.

In this file after a route analysis is done with "Ride has out and back" and "Ride ended where it began" checked, my average power drops from 197.7 watts to 164.2 watts. From looking at the chart, it appears to have dropped my wind speed for the entire route which lowers all my power numbers.

Thanks,
Darren

[racerfern]

I don't see the issue as being temperature or wind offset. You had a variation of a few degrees but nothing to skew things all that much.

I see the difference as being wind scaling. IMO your wind scaling is too high and the analysis feature adjusts for this. In fact your effort on the road may be less than what you're seeing. However, your FTP might be set too high, so since things are relative, you're doing the right effort at the wrong scaling. Does that make sense?

I lowered your wind scaling based on the ride you provided. Try out the attached profile and you should see your before and after numbers being much closer. Then do a fitness test with this profile and you'll see that number adjust itself. Finally, you'll find your zones adjusted to align with the new FTP. Note that your effort on the road will be the same for the same planned effort.

One more thing, you can apply this profile to your existing rides as long as you also adjust your FTP.

This profile might have to be tweaked; after all I'm just looking at one ride.