Jay,
If you want a lower sprocket ratio, you do have several choices. I was told CSC is going to sell rear sprockets in the range 42T-46T. Therefore, you could purchase a smaller, 42T sprocket from CSC to lower the sprocket ratio.
Also, the JTR473 sprocket is available in 40T, and it should be a perfect fit for the rear hub of the RX3.
You can buy this rear sprocket from Amazon for $21.37, with free shipping.
http://www.amazon.com/JT-Sprockets-J.../dp/B005DL7JLO
__________________
Spud
"Never argue with an idiot. He will drag you down to his level, and beat you with experience."
Mark Twain
2015 Zongshen ZS250GY-3 (RX3)
2006 Zongshen ZS200GY-2 (Sierra 200)
2005 Honda XR650L
2004 Honda CRF250X
1998 Kawasaki KDX220
Mods made to my Zongshen ZS200GY-2:
http://www.chinariders.net/showthread.php?t=6894