I wanted to get rid of all variables for my short tire life.

I did the string thing and found the marks on the swingarm to be perfect, (I was surprised) but my front tire is offset 4.5mm to the left.

I've read that this happens a lot. When Motorcyclist interviewed GMD Computrack they said all GSXR's are offset 8 to 10mm.

Oh well at least now I know. Geuss I'll keep getting lousy mileage. :roll:

My crude measuring system has always shown me that the swingarm marks are right on, too, so your findings don't surprise me.

The offset in the front tire may be due to the forks being pinched at the axle. Loosen off the left side pinch bolts, and pull the fork out. Either that, or raise the front tire off the ground after loosening the pinch bolts to see if the forks "spring" outwards, or feel like they're bound inwards.

Use the feeler gauge to check for caliper clearance, as well.