My Strada Cadence cyclocomputer odo is about 2-3% off. I know it's not a big difference, but i would like it to be dead on accurate. I just changed tires the other day and it was dead on before i changed. I have it set for a 700x35c tire, which are the new tires. I'm going farther than what the computer is saying. I know that i could change the tire setting, but how do i make it more accurate? Would i set it for a bigger tire or smaller tire?