We run a 9610 with a 30 flex, a 9500 with a 25 foot flex, and a 2166 with a 30 foot flex. When we harvest wheat we run a 30 foot rigid on the 9500. We have ran the 30 foot flex on the 9500 and it handled it easily, but you must remember we only raise 33-45 bushel beans here. The only thing I wish is that the 2166 and 9500 had either duals or 30.5's just to make me feel better, the tires will squat when we have the heads on and the toppers full of corn. We run 8 row 30inch corn heads and they are heavier than the flexes. If you are in any beans that are better than 50 bushel you better get the 25 or 20 foot. One more thing, get one with a full finger auger and if you have contour master get a head with it, that big and unlevel ground will make a difference.