Gyrochronology, an empirical relation between rotation and age, is potentially among the most precise methods of stellar age determination for lower main sequence stars. In this poster we describe a project to test competing gyrochronology models using wide noninteracting binaries. Such pairs span a broad range in age and metallicity and, most importantly, components of a given pair should yield the same rotation age. Kepler and TESS are ideal instruments to measure stellar rotation via modulation of light curves as active regions (spots) rotate in and out of view. The archives of these contain many thousands of wide pairs. Our sample selection, project methodology and some preliminary results will be presented. Support for this project from NSF grant AST-1910396 is gratefully acknowledged.