I had to look up the "Hals conversion", I only knew it could possibly be a Buell race piece?
Typically a chain conversion is done with the proper sprockets and making the belt tensioner the adjustable part for chain slack, leaving the swingarm alone. Since the belt tensioner is placed specifically to make the axle centerline, transmission output centerline dimension constant through wheel travel, I don't know which way is better for a chain? Yes, I know when someone says Buell Race Team we get all giddy and assume it's perfect and designed in the hallowed grounds of Eriks cortex, but... you ever been near a real race team?! Simplicity outweighs longevity almost every time, haha.
Got pics? I've only seen one other like it. Rev-Moto has one on that SICK racer they made.
If you need any specific EBR wheel measurements let me know, I have an extra I can measure for ya:up: This may kick my butt into high gear to get this done on my Ss, but TBH the only thing stopping me is the chain conversion. I've done it on Buells before in the past and very much liked it. The throttle response is definitely more immediate, and even without any cush drive I never had problems with the wheel hub on any of them. BUT the Ss is my long distance steed so the benefits of a quiet, zero maintenance, and clean, belt outweigh the coolness of the chain and EBR wheels. Thats why I'm looking into the harder job of the bespoke belt sprocket.
TL;DR First one done wins! LOL.