The conversion from belt drive to chain drive on the Savage/S40 isn't that hard to to.  The pulleys just need to be replaced with the front and rear sprockets of your choice and the appropiate 520 drive chain.

As to why; well it's like a lot of things connected to motorcycles and life in general I guess.  It's a matter of choice and pereferance.  If you're happy with the style of the Savage/S40 and the belt drive that's great. I, on the other hand didn't like the style of the bike (cruiser), nor the belt drive.  I knew that the bike had a lot of potential to be made into something more to the style of my liking/choice.  The bike has great "bones", but isn't the style of bike that I like.  Folks can like/appreciate a bike, but still change it to suit themselves.

As for the 520 chain conversion questions/issues that I had I'm happy to say that all my issues have been resolved.  I have gone from a 17/45 sprocket combo to a 18/47 combo and the chain rubbing on the front of the swingarm problem is solved. The chain doesn't rub on the swingarm any more.  Another thing that I've found is that there is plenty of case clearance with the 18t front sprocket and the 520 chain (11mm at the tightest point).

Thanks to everyone who chimed in with suggestions and solutions to my questions!!  Carry on!!  wiguzziman