If sitting on a cruiser like a Heritage really annoys your tailbone any slightly forward riding position would keep the pressure off that. So really it's a matter of finding the correct seat to peg distance and then how much motor you want to apply to the equation.
Honestly the most comfortable of the 4 bikes I own and ride is my Speed Triple RS. The seat is the plushest of the bunch (sounds weird for a sport bike, but true as far as my lard butt can tell). I think it's due to how wide the seat is compared to my T-120, Thrux R, or Bobber (and the Bobber has a custom medical gel foam seat on it).
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