For inquiring minds.
Wheel / tire widths measured in this manner.(http://fjowners.com/gallery/3/150_21_03_12_5_37_16_0.jpeg)
Front
120/70 - 17 tire mounted on an FJ 3.0" wheel = 4-5/16"
120/70 - 17 tire mounted on an FZR 3.5" wheel = 4-11/16"
+ 9%
Rear
150/80-16 tire mounted on the FJ, 3.5" wide, 16" wheel = 6"
170/60-17 tire mounted on the GSXR 5.5" wide, 17" wheel = 6-3/4"
+12%
Granted, the change in profile is more of a drastic than the change in width, especially on the back tire. IMHO.
Rear
(http://fjowners.com/gallery/3/150_21_03_12_5_37_17_2.jpeg)
Front
(http://fjowners.com/gallery/3/150_21_03_12_7_41_48.jpeg)
Nice write up, good comparison of tire and wheel sizes. Just cuz the tire is wider (vs wheel width) does not mean you get the best size of contact patch. Put the right size tire for the wheel.....
Please keep in mind that every tire makers tires will be different then their competitors in the same size. The Avons that I like run wider than the marked size ( their 170/60-17 Storms actually measure 175mm wide).
Keep going. Even the same manufacturer will have width variations between their lines. For example, a BT-023 will be different than a BT-015 of the same nominal dimensions.