CodeIgniter 3 - Accessing data in a view from 2 db's

Apologies for my nebie like question but i'm trying to lea a lot here, new to MVC and CodeIgniter.

I have a simple CRUD that i'm building, but i'm stumped on what I think is a very simple thing if you know what you are doing.

I have a View that is being used to Update a Tyre to the db into a table 'tyres'. In that View I want to display a dropdown of Brands that are held in a seperate db table 'brands'. In my Model I have a class of Tyres and in that I have a function :

public function get_tyres($id = FALSE)
{
if ($id === FALSE)
{
    $query = $this->db->get('tyres');
    retu $query->result_array();
}
$query = $this->db->get_where('tyres', array('id' => $id));
retu $query->row_array();
}

This allows me to access the Tyres data in my Controller and send the data through to the View using :

$data['tyres_item'] = $this->tyres_model->get_tyres($id);
$this->load->view('tyres/update', $data);

In my View I access the $data['tyres_item'] so that I can prefill the form with db data.

BUT

How do I access the Brands data from the db to build a dropdown list of all Brands in my view? I have separate Model and Controller for Brands but I can't access them in the View.

I tried adding

$data['brands'] = $this->brands_model->get_brands();

to my update function in my Tyre Controller but i understand that this won;t work because I am inside the Tyres Controller and not the Brands Controller.

How can I accomplish this, I know I must be missing something straightforward...

Here's my View : and what I want to accomplish :

     echo form_open('tyres/update');
    ?>

    <label for="tyre">Tyre</label>
    <input type="input" name="tyre"  value="<?=$tyres_item['tyre']?>" />

    <label for="brand">Brand</label>
<?php
    echo form_dropdown('brands', $data['brands']);
?>

...