http://www.universalcycles.com/shopp...29&category=58

http://www.universalcycles.com/shopp...32&category=58

depending on what you get, you'll need some longer chainring bolts and bolt spacers to space it out far enough to be able to use said big ring. obviously you'll also be decreasing your large ring clearance over obstacles, which may or may not be an issue where and how you ride.