A balance simulator for bicycling comprises a base (4) and a roller device. A guide rail (20) is provided on the top surface of the base (4), and a removable board (3) is mounted on the guide rail (20). A rotatable plate vertical shaft (10) on top of which a rotatable plate (2) pivots is provided vertically on the middle part of the removable board (3), and a groove (6) for holding the bicycle front wheel (1) is provided longitudinally on the top surface of the rotatable plate (2). A semicircular inner gear (5) is installed on the foreside of the bottom surface of the rotatable plate (2), and the central lines of the semicircular inner gear (5) and the rotatable plate vertical shaft (10) are collinear. The semicircular inner gear (5) is engaged with a small gear (7) on the top of a gear shaft (8) which is mounted rotatably on the middle front part of the removable board (3). A big gear (16) is provided on the lower part of the gear shaft (8) and is engaged with a long rack (19) which is mounted on the middle part of the base (4).