Mike
I'm not the R's.... but go to this site and read and then click on the computer spread sheet and you will answer all of your questions...
It's a article published by Circle Track mag and is perfect and the spread sheet allows you to fill in the variables and change sizes of things and it computes the front to rear Ratio's....
If you have any questions let me know ...it's good to know what you are doing before you do it...
http://dsr.racer.net/brake_bias.htm
Morris