Sometimes strap issues- sometimes just heart rate is ambient! Ambient heart rate is totally normal, and you did note that once you get to the meat of your ride, your heart rate is a bit more consistent. I wouldn't worry about it unless it was like that consistently throughout your entire ride, or if your heart rate was consistently too high throughout your ride (see a doctor) or consistently low throughout your ride (perhaps a strap issue). I think you're cool. If the saliva/lotion thing still yields the same result, I don't think you have anything to worry about.

koffee