Originally Posted by RChung

If you're new to road biking then cadence has essentially no importance: it simply tells you how fast your feet are turning the cranks, in rpm, and if you're new to road biking you don't yet have enough experience to put that into context and to know how to evaluate it. OTOH, if you're experienced at road biking then cadence also has essentially no importance. It's shown on bike computers because it's easy to measure. People like to think if it's easy to measure it must be good for something. It's not. Some people will tell you to pedal at some magic cadence number, like 80 or above. Cadence depends on your terrain, your gearing, and especially your physical condition so if random guys on the internet who don't know you or your terrain or your bike prescribe a particular cadence range (and they will) you should ignore 'em. Cadence is a red herring. Just find the right combination of cadence and gearing that lets you ride comfortably. If you feel like you're bogging down, change gears; if you feel like you're spinning too fast, change gears.