In large mixer bowl, combine 1 1/2 cups of the all-purpose flour and the yeast. Combine water, sugar and salt. Add to dry mixture. Beat at low speed with electric mixer for 1/2 minute, scraping bowl constantly. Beat 3 minutes at high speed. By hand, stir in the whole-wheat flour and enough remaining all-purpose flour to make a moderately stiff dough. Turn out on a lightly floured surface and knead until smooth, 8 to 10 minutes. Cover; let rest for 15 minutes. Cut into 12 portions. Shape each portion into a smooth ball. Punch a hole in center of each with a floured finger. Pull gently to enlarge hole, working each bagel into uniform shape. Cover; let rise 20 minutes. In large kettle, combine 1 gallon water and 1 tablespoon sugar; bring to a boil. Reduce heat to simmering. Cook 4 or 5 bagels at a time for 7 minutes, turning once. Drain. Place on greased baking sheet. Bake at 375° for 30 to 35 minutes. Remove from baking sheet; cool.