I having been going over the whole 60 vs 70 series front tire for my SV and the speedo accuracy. We know that our speedos are reading about 10% fast with the 60 series front tires. I was looking for a calculator that could tell me the percentage difference in speedo reading between the 60 and 70 series tires. I came across this http://www.discounttire.com/dtcs/infoTireMath.dos tire calc that can handle motorcycle widths. The 70 series with will make you read about 4% slower than you're really going, for a total error of about 6% too high left over. Just thought Id share.