Has anyone ever tried this for 'special applications'? Or do they sell knobby-er wheels for the belt/gear drives? I can't get over how well my money-pit S21ESN sticks to even a vertical ditch. I actually look forward to mowing my ditches now! They're just 1 5/8 inch drywall screws, sticking out about 3/4 inch, but it made all the difference! The only trouble it gives me now is fuel starvation if the mower runs too long on too steep of a incline.