I don't know how they can get away with that, there is no way the section width or the tread width are the same between those two tires.
Section width is obviously way different between the two.
Also the aspect ratio cannot be the same either looking at the pic, (dividing a tire's height off of the rim by its width) Certainly looks like the new R1 has a much higher ratio and they likely did it by shorting on the section width of the carcass, or the section width of the old tire is more eight inches?
Measure section width on both tires 'bulge to bulge' of the side wall is either one 8 inches?
I need to replace both front R1's on my tractor soon and hoping they are not narrowed down either.
Already wish they were a bit wider than what was supplied new. Sure seems like these companies are fudging the numbers today, of course only in their favor as far as material costs.