Itween Path change speed

Hi, I'm making a bicycle simulation. It is made using Arduino and Unity. The bike speed measured at Arduino is transmitted to Unity. and I want to change the speed in itween path in real time. What should I do?

using UnityEngine; using System.Collections; using System.IO.Ports;

public class asdasdasd : MonoBehaviour { SerialPort sp = new SerialPort("COM3", 9600); //set Serial port string bikeSpeed;

 void Start () {
     sp.Open(); //Serial port open
     sp.ReadTimeout = 1; //set Serial timeout
 }
 
 // Update is called once per frame
 void Update () {
     if (sp.IsOpen)
     {
         try
         {
             sp.Write("s"); //send start data
             bikeSpeed = sp.ReadLine();
             print(bikeSpeed);
             float chbikespeed = float.Parse(bikeSpeed);

             Debug.Log(bikeSpeed);

             transform.Translate(Vector3.forward * Time.deltaTime * chbikespeed);
             
         }
         catch (System.Exception) { }
     }
 }

}

using UnityEngine; using System.Collections; using System.IO.Ports;

public class MoveBike : MonoBehaviour { SerialPort sp = new SerialPort("COM3", 9600); //set Serial port

 // Use this for initialization
 void Start () {
     iTween.MoveTo(gameObject, iTween.Hash("path", iTweenPath.GetPath("Path1"), "orienttopath", true, "speed", 10));
 }
 
 // Update is called once per frame
 void Update () {
     
 }

}