Yes, you could have a 525 or 520 set of sprockets, on the bike with a 530 chain.
I went out to where my 2002 gen.1 is parked, and tried to move the drive chain back and forth on the rear sprocket. it barely moved, side to side. This on a drive chain, with 20K miles on it. It is just about ready to be changed, as it is getting a tight spot, as I rotate the rear wheel. Can't complain about the mileage at 20K miles, however. I have numerous new chains to pick from, and of course, I have new sprockets, front/rear.
Just for reference, here are the sprocket numbers on the spare sprockets I have. Front is a JT front sprocket, JTF579-16RB, with 16 teeth. The RB denotes rubber on both sides of the sprocket, to deaden chain noise. Just like the o.e.m. front sprocket.
The rear is a Sunstar sprocket. 2-547445 are the numbers on it, with 45 teeth. As mentioned, I run a gen. 2 rear sprocket on both gen.1's, as it gives the bikes, a tiny bit more pop, in the corners. Slightly higher revs, but who cares. Both bikes run great.
Okay, I hope this helps you.
Best of luck to you.
Adios
P.S. you can obtain the same front sprocket I have from E-bay, for around 18 or 19 bucks, with free shipping. I get most of my parts, through E-bay. Being retired, and nothing better to do, i cruise the "bay" every day. Lol!
from side to side and it moves about a 1/8"