Just for fun this morning I mocked the rim up again, this time using 07-earlier axle spacers. Since they are a larger diameter than the 08-newer they slid on the 09 axle I have. In comparing axles, both axles are turned in 3 different diamers. The center section is either 1" (07-older) or 25mm (08-newer). The section of the axles that ride in the forks are the same diameter which makes sense since the font forks are the same from 00-current. The threaded ends of each axle are different which also explains why front axle nut covers either fit 08-later or 07-older. Another difference is in the spacers. On the 07, the spacers are not the same size, one is longer than the other and it matters what side of the wheel it is mounted on. The 08-later are the same length. I also stacked the spacers side by side and the total length of both 09 spacers are about 1/8" longer that the combined length of the 07's. This was also evident when I mounted the wheel. I used the 09 axle with the 07 spacers and installed the wheel. The first thing I noticed was the 1/8" gap between the spacer and the fork before I tightend the axle nut. I installed the brake calipers and they fit but I still had the gap. I'm sure I could have squeezed the forks together by tightening the axle nut but then the brakes would bind for sure. Not a good situation for sure. After installing the wheel two different ways I have concluded that you need to use:
2010 SG rim
09-later axle
07-older brake disks