Ruota libera 1 velocità

    ****   *******    ****    *****     ****    *****   
   *       *         *       *     *   *       *     *  
  *        ******   *        *        *              *  
  ******         *  ******   *        ******       **   
  *     *        *  *     *  *        *     *        *  
  *     *  *     *  *     *  *     *  *     *  *     *  
   *****    *****    *****    *****    *****    *****