jQuery(document).ready(function($) {
    // Show default image
    $('#large-image.oma-opa-fiets').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
    
    /*************************************************************************
    * This is for the template-bikes.php image hover swapper
    *************************************************************************/
    
    /* OMA & OPA FIETS */
	$('#thumbnails * > img.thumb1.oma-opa-fiets').hover(function() { //mouseover
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/1.gif")'});
	},function() { //mouseout
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
	});
    
	$('#thumbnails * > img.thumb2.oma-opa-fiets').hover(function() { //mouseover
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/2.gif")'});
	},function() { //mouseout
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
	});
    
    $('#thumbnails * > img.thumb3.oma-opa-fiets').hover(function() { //mouseover
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/3.gif")'});
	},function() { //mouseout
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
	});
	
	$('#thumbnails * > img.thumb4.oma-opa-fiets').hover(function() { //mouseover
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/4.gif")'});
	},function() { //mouseout
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
	});
	
	$('#thumbnails * > img.thumb5.oma-opa-fiets').hover(function() { //mouseover
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/5.gif")'});
	},function() { //mouseout
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
	});
	
	$('#thumbnails * > img.thumb6.oma-opa-fiets').hover(function() { //mouseover
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/6.gif")'});
	},function() { //mouseout
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
	});
	
	$('#thumbnails * > img.thumb7.oma-opa-fiets').hover(function() { //mouseover
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/7.gif")'});
	},function() { //mouseout
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
	});
	
	$('#thumbnails * > img.thumb8.oma-opa-fiets').hover(function() { //mouseover
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/8.gif")'});
	},function() { //mouseout
        $('#large-image').css({'background-image':'url("/wp-content/themes/mydutchbike/images/bikes/oma-opa-fiets/0.gif")'});
	});
});

mdb jQuery code - image swapper

jQuery