Jack up back tire. Mark a link with twist tie or black marker. Count the links (a link has two pins connected by a side plate [link]) Should be as Mud Puddle says unless you have a modified counter sprocket or rear sprocket. You can count the teeth on the sprockets then, if your link count is correct for your year.I replaced my chain on my 08 wee last year and I can't remember how many links I ordered. The problem is my chain is a little too tight even when the wheel is all the way forward..How do I count my links and what does factory recomend?