I had the same questions when i oredered mine like that from,them but have rode on it for about 3 months and had no problems.The reason it is so short is because the chain guide roller design is to be used for swingarms that are running a skid plate,the other design with two rollers is designed to be used without a skid plate. Here is the link to explain..... http://www.tmdesignworks.com/index.php?main_page=product_info&cPath=67_184&products_id=333