Still don't get Downhill tailwind figures

[spangelsaregreat]

Hi,

I recently re calibrated all the profiles on my bikes with new out and back calibrations etc. The PowerPod is now working really well with similar Power on all the bikes. I know its been discussed before about how downhill power figures can be affected by riding on the drops etc. However, I get different results on different rides. I would say in general the power is fine, it drops when riding down a steady downhill as I would expect. However, I notice the overly high power figures on some rides and mainly when I start to press on.

I have attached a file for a recent Threshold type ride. It is a circuit ride starting and finishing in the same place. Quite a windy day but the wind speed was similar throughout the ride. If you look at the Power figures from about 2 miles to 14 miles the average is about 285 watts which about right as my FTP is around 290 at present. You can see my heart rate is pretty constant in that part of the ride at 148. However, when I hit the last 4 miles which is downhill, steady descent which you have to pedal on with a tail wind the power jumps up. My heart rate average is 150 so it is a similar effort as the previous section but the average power jumps to 446! I rode in pretty much the same position (I ride on the hoods with arms bent)so it can't be an aero thing.

Wondering why it is when you ride steady down a gradual descent with a tailwind you get consistent power figures but when you push on the power appears to increase more than your actual effort.

Regards

[Velocomp]

One thing I notice in your ride file is that the slope correction is pretty significant. This means that your calibration angle is quite different from the angle at which you've reattached your device. your unit is working pretty hard to get your slope corrected. This might be a problem.

Downhills are really tricky because speeds are high and calibration errors are magnified. You might want to try a recalibration, but I don't see anything else obviously wrong with your file.

[spangelsaregreat]

Okay, where can I see the difference in the tilt factors? Would slight adjusting the mount not do the same thing?

[Velocomp]

Okay, where can I see the difference in the tilt factors? Would slight adjusting the mount not do the same thing?

You can't see the tilt factors; it is in a hidden screen. To get the tilt factor minimized, you will need to do a new cal ride, then afterwards make sure you reattach your device at the same angle (according to the instructions).