I made that mistake last year. I set up some really cheap drag bars out of 3/4" galvanized pipe, but they limited the steering, and if I tried to turn too hard to the left my horn sounded
. I was still able to ride though. This time I made a bracket to rotate the bar clamps 90 deg so they stick off the front of the triple tree. This allows for full lock steering. You might try this with your supermoto. It would also lower the bars a little, and is very simple to make. just a piece of 2 inch angle, cut to fit and bolted to the tree.