Track is the width at the tire centerlines. It is the same for B110 and B210 at 1245 mm.
Track: center of tread-to-center of tread
Front Track B110: 1240 mm (49.0 inches) B120: B210: 1245 mm for 13" wheel models B310: 1330 mm Front for North American models B310: 1305 mm Front for Canada A12A (12" wheel) models
Rear Track B110: 1245 mm rear B120: B210: xx for 13" wheel models B310: 1300 mm Rear for North American models