My daughter misplaced my rear spring, the shorter spring and I got one off a Gen1/2. There was no difference I could tell, other than age, but I do hear a slight ting sound and I believe it's coming from the rear brake spring. I can take the foot peg and pull it up, let it drop and can hear it slightly hitting something.
Just my experience, I plan to take it off and put a buffer around it. I had found the original spring, but prob threw it away.