It does sound as if the noise does indeed come from the clutch. It couldn't hurt to engage and dis-engage the mechanism (engine turning) in neutral a couple of times, before your initial roll out. Been my experience that noises such as you described are indicative of wear taking place or worse. You should schedule a inspection when you have time. Don't forget to have a new gasket on hand, Triumph installs the gaskets dry, with 3 or 4 spots of adhesive on the inboard side, just enough glue, that the sucker won't likely survive a teardown and re-use.
