Inaccurate wind measurments

[sergei]

I need an advice, what I might be doing incorrectly.

I installed my iBike Pro on handlebars initially, did all calibrations as per instruction and did couple of rides, everything seemed to be perfect.

Then I got my TT handlebars, ordered handlebar eXtender as it was advised in manual, installed everything,
having iBike above the handlebars trying to avoid anything which would prevent air from flowing in. Did a ride and already during a ride noticed that power measured is much lower then durning previous rides. After downloading data I saw, that wind was measured being always from behind although I did the same route back and fourth and on one way there was a pretty strong wind against me.

Decided to change location of iBike, now installing it under the bars, although I can not monitor numbers on the screen, I decided to give it a try, did a short ride and results were the same, wind registered being only from behind although I did a circle of 10 miles.

I did calibrated tilt and wind offset after every repositioning.

Finally I removed TT handlebars and installed iBike back same way it was installed initially. Just came back from the ride and results are not good, there has been sections with pretty strong head wind, but it was registered as almost no ground wind.

Does anybody have an idea, what should I try next?

P.S. Because of this trouble my power numbers are very low, which demotivates me a lot

[R Mc]

1. It's not clear from your post: Did you do a new set of coast-downs and a cal ride to make a new profile for the tt position? It sounds as though you did not--which means that the wind scaling number the ibike uses to calculate wind will be massively wrong.

2. Before everyone tells you that you need the remote wind sensor (and you might), be aware that positioning the ibike between your arms is not good for accurate wind readings.

The key is to make sure that the wind port is directly exposed to the wind and NOT shielded by the aero bars (or sitting in a turbulence zone). I get good results with the unit mounted below my aero bars (and since it's between them, I can see it while I'm riding).

[sergei]

Indeed, I didn't do coast-downs and a cal ride, but after I removed TT bars and placed iBike on the same spot as the coast-downs and cal ride were done, results are totally different from the first ride, looks like something wrong happened to the wind sensor.

Here is the picture from todays ride


And this is a picture of the first ride


Note, that setup for both rides were the same, and I swear, I experienced pretty strong head wind today

[coachboyd]

It sounds to me as if your wind scaling might be off. If you are doing a wind offset before your ride, and you are always showing a headwind or tailwind, that is a sign that your wind port is not calibrated correctly.

If you go into the cal ride in your setup screen and start a new cal ride, this should fix the problem. I would do this without the aero bars on the bike so that you know nothing is blocking the wind port.

Let me know if that solves the problem.

[sergei]

Thanks, will try tomorrow and post results. (bow)

[coachboyd]

Great,

if you want, you can send one of those files to me at boyd (at) totalcyclist dot com and I will check it for you. If it was a solo ride that started and ended in the same place I can figure out what your wind scaling number should be.

[sergei]

Did calibration ride today and it seems to be corrected the problem, at least the short ride afterwards registered wind in both directions. See picture below