Place the corn on the grill and roast, turning often, until golden brown on the outside, about 15 minutes. When it cools, cut the kernels off into a bowl. Add the onions, beans, jalapeno, red pepper, and cilantro. Combine the oil, lime juice, chile powder, and cumin in a smaller bowl. Pour over the corn and bean mixture, and toss to mix. Let sit in the refrigerator for half an hour before serving. Makes 4 servings.