If it is your tailbone (typical on cruisers) then risers or taller/pulled back bars will only make it worse. My SM had risers that pulled them back. It felt very much like the BA riding position but narrower bars. It killed my tailbone. Moving the bars back foward was instantly more comfortable.
While I have done some long rides on my SM I am still in the market for a touring bike, though I am looking for more of a sport tourer or an adventure bike, not an 800lb bahemouth. Waiting to test ride the new tiger.