isport wattage readings are low - help

[Aaron]

I've had the isport for about 1 month now and am consistently getting low wattage readings. One example - on the flats at 22mph with a minor head wind I'm registering 130 watts. Also, it seems that any time i maintain my speed the wattage drops steadily. Readings seem to be pretty good going uphill maybe a little high. They are very low going downhill. I'm 72inches, 170lbs, ride on the drops, bike and gear weigh about 30lbs (still have winter stuff mainly in NE).

I'm looking for a way to troubleshoot this. Is there a prescribed systematic way to get to the cause of the inaccurate readings?

Thanks,
Aaron

[Velocomp]

You need to be sure your aero and fric numbers are correct, your total weight is correct, and also that you completed a good cal ride.

When you ride, what does your wind speed say?

Please post aero, fric, and some wind speed numbers while riding, and corresponding bike speed numbers.

[Aaron]

Hi,
Thanks for your reply. Total weight is correct = 201. Aero = 0_490 Fric = 8_497. Do those numbers look right?

I will look at the the wind speed vs bike speed on my next ride on Monday.



Thanks,
Aaron

[Aaron]

Thanks for your reply. Total weight is correct = 201. Aero = 0_490 Fric = 8_497.

Do those numbers look correct?

When you ride, what does your wind speed say?

Went for a ride today. I did a cal wind at the beginning and about 30 minutes into the ride. I also redid my tilt calibration.

Having done this, when I looked at the ride speed vs. windspeed, I was seeing a big difference. Ride speed 22 windspeed 16 This is with a head wind of around 8mph. Riding into the wind most of my numbers were like this.

Thanks,
Aaron