This is an apology to Lorri Lee Lown. I was wrong about something and insisted that I was right. Doubts arose and I had to check my assumptions (based on experience). That is that the increased friction caused by heavier riders and the increased drag due to their size overcame the increased gravitational pull. I was wrong enough that I couldn’t even push the numbers to fake it. I’m man enough to admit it. It doesn’t happen all the time. This time I was wrong.
Simply put, given similar parameters, a heavier bike and rider will go faster coasting down a hill than a lighter rider.