Wohoo! I’ve solved it.
$image_link = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), ‘large’);
$hiresimage_image_link = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), ‘full’);
Get’s me an array and the first item in the array is the image url so I just use
$hiresimage_image_link[0]
$image_link[0]