Controlling RPM of two wheels with one encoder?

[asteb27]

We are using two cim motors hooked up to each wheel. In our prototype testing we found the RPMs to be within 5% of each other. Because we all we're doing with the encoder is ensuring that both wheels are within a certain tolerance of RPM, I don't think we need two. When wheel 1 is traveling at the ideal RPM (as determined by the encoder), we can offset the PWM value sent to wheel 2 to ensure it will also be at (or very close to) that ideal RPM. We are not changing the speed of the wheel based on distance, or anything fancy like that, so a second encoder is extraneous.

--The Friend