Making the bike pedal

[jinglylime]

hi, im trying to make a bike move by using the pedal() method, the method will move the bike forward a distance of half the circumference of a wheel. ive tried creating the pedal() method however when the method is invoke the position of the bike is still the same. please help me. thanks.

public class Wheel
{
    private double position;
    private double radius;

    public Wheel()
    {
        position = 0.0;
        radius = 50.0;
    }

    public void setRadius(double newRadius)
    {
        radius = newRadius;
    }
    
    public void setPosition(double newPosition)
    {
        position = newPosition;
    }

    public void rollForward(double distance)
    {
        position = position + distance;
    }

    public double getPosition()
    {
        return position;
    }
    
    public double getRadius()
    {
        return radius;
    }
    
    public double getCircumference()
    {
        double circumference;
        circumference = 2*radius*Math.PI;
        return circumference;
    }
     
}

public class Bike
{
    private Wheel frontWheel;
    private Wheel backWheel;

    public Bike()
    {
        
        frontWheel = new Wheel();
        backWheel = new Wheel();
        
        frontWheel.setPosition(50);
        backWheel.setPosition(-50);
    }
    
    public double getPosition()
    {
        double position;
        position = (frontWheel.getPosition() + backWheel.getPosition())/2;
        return position;
        
    }
    public double pedal() // here's my problem
    {
        
        double position;
        position = getPosition() + frontWheel.getCircumference()/2;
        return position;
    }
}