Has anyone compared a size S to an XS on a Hardcore, is there a big difference? I originally thought I was gettting an XS but it looks like it will be a S and I just want to know what I am getting into. I have tried an XS and it hugs you in there nicely, I dont think a S will be much more roomy. I am 6'0" and 175lbs

Let me confuse you.......
Hardcore XS comes with XS size rails and S size seat. You will notice the rails are wider in the clamp area and then get narrow at the rail peak before going down to the axle.
Tried to call you.