Brand New Race-Driven Rear Steel Sprocket. You will receive a 39 tooth steel rear driven sprocket that has a 520 pitch and will fit the following: Kawasaki KX250F KX 250 F 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017. All Race-Driven sprockets are manufactured to meet or exceed OEM specifications and are produced using hardened S45C steel to give you years and years of trouble free service. Please make sure when purchasing sprockets you do so according to your ATV or motorcycle and riding style. You can also purchase sprockets that will give you more take-off speed or top-end speed. Race-Driven is committed to bringing the highest quality products to all riders at an affordable price. Customer Driven – Quality Driven – Race-Driven.