I don't know where the previous answerer 04758...gets it from but his numbers sure show the lack of much between the ears....To the asker: You either have a XC bike and I hope a good one and not dept store brand? Your bike is just under 5 inches of rear travel and you do not want to get a 160mm fork as it will not likely (im guessing a little here) fit your head tube and the angle of it either and it will take your front end up too high which will effect your steering and the responsiveness of the rear triangle and the fork overall....basically it will create a mess for you to handle and you likely will not handle it, I know I could not. I have a bike with a 160mm travel fork (GT sanction 1.0 2009) and it is set up for this size of travel fork and you generally only see this size on DH bikes and few mountain specific bikes and NEVER on any XC bike that I know of.... Do NOT do this!