Can someone with experience with the Powertap SL explain how to tell the Powertap that I am starting a new ride? It seems to me that if I don't clear the head unit (erasing all ride data) that each new ride I take just adds to the existing ride data. So, if I ride 50 miles on Saturday and 60 miles on Sunday it shows as one 110 mile ride on the next download. I don't want to have to download each time I ride but I will if I have to. Does anyone have any experience in using the Powertap that they can share?