Heat oven to 400° F.
In a bowl, toss the potatoes and oil. Spread on a baking sheet and roast, stirring occasionally, until crisp, about 30 minutes. Sprinkle with ¼ teaspoon salt.
Meanwhile, heat a grill or grill pan to medium.
Shape the beef into four 1-inch-thick patties. Season with ½ teaspoon each salt and pepper. Cook to desired doneness, about 3 minutes per side for medium.
Transfer the patties to buns and top with the mayonnaise, pickle, lettuce, and tomato. Serve with the chips.