^ What rubber came on your bike? IRC roadwinner? Bridgestone BT45? I haven't heard good things about the IRC; however, the BT45 is a decent tire and very suitable for new riders.
-To the newbies thinking about "cool looking" over sized tires please be aware of what is going on. The ex250 has a 3.5" rim. The 160/60 was made for a 4.25" rim. The tire must be "pinched" onto the smaller rim contorting the tire shape from which it was designed. "Pinching" a tire on to a smaller rim is a hazard and does void warranties.
-Performance is affected. Turn in is affected in 2 ways. By the larger tire size and the lengthening of the wheelbase. The larger tire also adds additional unsprung mass.