What you want is an old fashioned cavalry sabre taped lightly to the crossbar. Then you can wheel your steed around in such situations, draw your sword and charge. I'm assuming the R20 is stable enough to ride one handed. If not replace the nylon top bearing in the steering tube. That was put there to steady 'em up in the first place. It is possible that the sabre may be slightly long to be wielded from the saddle of Wasp, in which case a nice short navy cutlass may be more to your taste. I always think that terrorising ferrals and spilling their blood in the gutter is far more satisfying than a snide remark passed over your shoulder as one flees down the road.