I've recently noticed something odd with my Polar 725 HRM. Currently I've got it set up for speed and cadence on my roadie. Now particularly at the beginning of a ride, and always with headwind the heart rate goes nuts, spikes to 110% or more of max. But as soon as I turn off the headwind, the HR goes back to normal. Initially I thought low battery power in wearlink transmitter, changed it a few rides back. I then thought interference with other things but have been taking things off and no change. I also thought the electrode pad things were too dry, wet them, tired ECG gel. Then thought not salty enough (salts can increase electrical current tranmission) so I didn't clean transmitter for a few rides (eew!). Too much hair on chest--> been attacked with shears, no change. Still did it today. It settles down once I've done about 10 miles and then is all fine but it looks very strange when I download. Anyone else have similar oddities with their HRM's? Or ideas what it is that causes this flutter. I know for sure there is no way known I peak my max HR at 235bpm, like I did this morning and can hold it for five mins.