How to return the value from a class ?

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using program1; //My progrm file
static void Main(string[] args)
        {
            program1.bike_details details = new bike_details ();  //First class
            program1.userdetails datum = new userdetails();  //second class
            details.bikedata(@"D:\solution");
            Console.WriteLine("Your output were extracted.......");
            Console.WriteLine("Press any key to exit.......");
            Console.ReadKey();
        }

My first class file:

 class bike_details
     {
            public string Nameofbike { get; set; } //Variable declaration
            public int bikeIssued { get; set; }
            public int currentusage { get; set; }

            public void bikedata(string path)//Input from program
            {
                     userdetails udetail = new userdetails();//My another class
                       string bikname;
                        int no of bike;
                        int currentbike;
                       //do something....
                      udetail.userdata(Nameofbike);
                     //get the elemnts  from userdata and return it to main function
            }
}

My Second class file: 

class userdetails
   {

       public string UserId { get; set; }
       public string Username { get; set; }

      public void userdata(string nameofbike)//Input from class1
       {
            string userid;
            string name;
        //do something....
        //Add it in a array and return the values
       }

 I have a main function.I have created two classes in separate file .Initially i sent the input for class1 from main function.And from there i sent a data to my second class,Where some operation performed and I want to get that data in class2 file in my current class and return to main function.Give me some guidance.