Try taking mustard. I take a pack of yellow mustard (that you get at a fast food restaurant) or a tablespoon before each ride and have not experienced cramps. A couple of guys that ride with us swear by it. The one gentlemen even keeps a bottle of mustard in his night stand for night leg cramps. I've even seen them stop and buy it at a convenience store on a ride if they did not take it. I've also heard of drinking pickle juice.