To fit Triumph they would need to make one with the cable pull built in, and the universal one's won't work, as they depend on the Japanese technique of using a separate throttle tube. I don't know if one of the Harley models would be persuaded to fit, but I think their standard is similar to Triumph, that the cable pull is part of the grip. Harley uses fat bars, but if any are necked down to our size at the grip end it might be worth some experimentation to get some for that type, and try them.