Yamaha 2007-14 WR450F / 2007-2009, 2014 YZ450F Blue Chain & Sprocket 13/51 116L OEM replacement Steel Front and Rear Sprocket and Blue Non O Ring Chain Average tensile strength of 7600 lbs Fits 2007 2008 2009 2010 2011 2012 2013 2014 Yamaha WR450F / 2007 2008 2009, 2014 Yamaha YZ450F