Bought a 2007 Kawasaki 900 Vulcan and it has been converted from a Belt to Chain drive. I got no problem with that except I'm needing to replace the Rear Sprocket and I don't have a clue what kind it is to even began. All the variables that goes into it all I can determine is the chain is a 525 the existing one has 48 teeth and I'm wanting to drop to 46. It's a 5 bolt pattern and worn out. I know I need a steal and this one is aluminum. How do I determine the correct size to fit?