Upgraded tires have been established by the manufacturer as tires that will work without any modifications needed for installation. Generally this refers to the width of the tire. For example the stock tire on the rear of a V Star 1100 is a 170/80/15. The Metzeler 200/70/15 is 30 mm wider (just over an inch) and slightly taller than the stock tire (which will lower RPMs) and will fit with out any modifications needed. Upgraded tires are extremely popular to install, and we have chosen to list them as an available option. As always, we recommend double checking all clearances before riding, but you should have no problems with installing these upgrades.