Frank is Grover's cousin in the book Two Wheels for Grover. When Grover comes to the country to visit Frank and Rosie for two weeks, it is Frank who discovers that Grover has never learned to ride a bike.

Telling his cousin not to cry, Frank teaches Grover how to ride a bike on his little old bike, promising to catch him if he falls. Soon Grover is zooming around and steady on his new wheels.