Issues with adding a admin_menu on multisite

I'm working on a custom wordpress plugin
I have a hook to add the admin_menu and its working fine on my superadmin
however when I log in as just a regular admin the custom menu button is no longer available!
please help!

here is my code:
add_action('admin_menu', 'mainmenu');
function mainmenu() {
add_menu_page( 'New Menu', 'New Menu', 'author', 'tower-ticker', settingspage, menu-icon-generic, 100 );
add_action( 'admin_init', 'registersettings' );
}

this should allow the menu to show for author but its only showing on the superadmin!