The ball tip or beef rump very rarely needs trimming. Just pat it dry with a paper towel. Now apply an even layer of salt on all sides. Then add a (liberal) amount of rub all over the meat. Let it rest overnight in the fridge. It pays off to give it time, so the rub has time to settle in and work the meat.
Fire up your grill, prepare it for indirect grilling. Have it running at 265° F. We want to do a low ‘n slow so the smoke has time to flavor the meat. But at the same time we don’t need to go too low, as this cut of beef doesn’t need tenderizing. Use the snake method if you’re using a kettle grill, or even better, a Slow ‘N Sear. Place the meat on the indirect side and close the lid. Add 1-2 wood chunks for smoking on the glowing embers. I use cherry, but oak, pecan and apple works just as well.
Leave the beef on the grill for roughly 1.5 hours. It is ready when the internal temp hits 55° C (130° F). Remove it from the grill and let it rest 10-20 minutes. Now slice it and enjoy! Leftovers are kept in the fridge and enjoyed the next few days as cold cuts.