Accessing Static variables

public class Bicycle {
        
    private int cadence;
    private int gear;
    private int speed;
    private int id;
    private static int numberOfBicycles = 0;
        
    public Bicycle(int startCadence, int startSpeed, int startGear){
        gear = startGear;
        cadence = startCadence;
        speed = startSpeed;

        id = ++numberOfBicycles;
    }
       // ...
}

Source of code : https://docs.oracle.com/javase/tutorial/java/javaOO/classvars.html

I learned in my class that Static variables should be accessed by calling with class name. i.e. ClassName.VariableName

But in the code above, how is this statement id = ++numberOfBicycles; compiled without errors, even though the variable numberOfBicycles is static