Yeah..probably getting dry. Also, do get any post nasal drip? You'd think that would keep it from getting dry, but usually it just irritates. Physical activity raises adrenaline...rushes of adrenaline open sinuses, then all the trapped gook runs out. Isn't this pleasant?? I've had serious sinus/allergy problems for 16 years now so I'm all up on the 'gook' info. Definitely try the gum thing, and even better, drink more water if possible. Not just before/during/after the ride, but all the time.

Natbug