I think the way it works is that until it hits a certain rpm, the front pully doesn't close up enough to make the belt tight. Effectively the same as a clutch. That's my theory. I'm not gonna take it apart to see what's inside 'til it breaks.
thats nice too. great wheels , and that looks like a recliner for the seat . i like how used all the bike frames come together , almost needs a great dane pulling it