Thanks for all the info. It sounds like most are about the same. I have been using 500mg of calcium supplements and 250mg of magnesium daily since I first posted. I also started using Gatoraid Endurance during extra hard or long rides and then taking another 250mg of magnesium when done. I also use the old fashion after ride drink of chocolate milk. So far so good, no more cramps either during or after rides. Though if I pull my legs up behind me without using my arms to stretch them they will start to cramp. After riding the STP "Seatle-to-Portland" ride in one day and no problems I figured things must be working for now.