Abstract: A transmission ratio control device for a controllable, continually variable V-belt transmission for motor vehicles includes a primary hydraulic line carrying the clamping pressure for the V-belt from the primary pressure chamber, a check valve opening against the pressure in the primary pressure chamber, a secondary hydraulic line carrying the clamping pressure for the V-belt from the secondary pressure chamber, and a second check valve opening against the pressure in the secondary pressure chamber. An adjustable pump is installed in a line connecting the first line, between the primary pressure chamber and the first check valve, to the second line, between the secondary pressure chamber and the secondary check valve. The adjustable pump is dependent on a control signal to control the continually variable gear ratio by pumping hydraulic fluid between the primary pressure chamber and the secondary pressure chamber.