Sweet! I just measured the same way you did, outside to outside including the chain, and I got about 6 3/4 on my '06. It sounds like that's pretty close, probably within about 1/8 of an inch, to what you measured.
I think this shows some real promise. I am going to see if I can make those wheels fit!
/ Colorado 2010
"Both the man of science and the man of action live always at the edge of mystery, surrounded by it." -Oppenheimer
2007 Monster S2R / 2006 TE610 / 1999 KDX 200 / 2000 DRZ-E