Add climbing to Unity Standard Assets 3rd person controller?

I'm prototyping a project using the standard assets Ethan controller right now and I want to add climbing. Currently, I'm using the following script:

 public class ClimbableSurface : MonoBehaviour
 {
     public GameObject player;
     public bool canClimb = false;
     float speed = 5;

     void OnTriggerEnter(Collider other)
     {

         if (other.gameObject == player)
         {

             canClimb = true;
             player.GetComponent<Rigidbody>().useGravity = false;

         }
     }

     void OnTriggerExit(Collider other)
     {

         if (other.gameObject == player)
         {
             canClimb = false;
             player.GetComponent<Rigidbody>().useGravity = true;

         }
     }

     void Update()
     {

         if (canClimb == true)
         {
             if (Input.GetKey(KeyCode.E))
             {

                 player.transform.Translate(Vector3.up * Time.deltaTime * speed);
             }
             if (Input.GetKey(KeyCode.R))
             {

                 player.transform.Translate(Vector3.down * Time.deltaTime * speed);
             }
         }
     }
 }

I have successfully invoked the class (public ClimbableSurface cS;) within the ThirdPersonCharacter script and the buttons that I've assigned to climbing up/down work, but it's more like a jump right now. What I believe is happening is that the player starts climbing and then registers as airborne, so then the ThirdPersonCharacter script treats it like a jump and forces the character back down to the ground. Is there a way to make the TPC script ignore raycasting while cS.canClimb == true? Or does anyone have other ideas for successful addition of climbing to this controller?