Choose a time interval while the system seems to be moving at a constant speed. During this interval, make measurements and determine the following for the larger front chain ring gear: The period of rotation of the gear
The average angular speed of the gear
The radius of the path the chain takes as it travels around the gear
The average tangential speed of the chain links as they travel around this gear
Also notice that there are colored dots painted on the chain and gears that you can use to make measurements.