Do You Need a Bike Computer?
It's called a computer, but it's really just a fancy speedometer/odometer with a few added features — or a lot of them if you want to pay the price. A bike computer adequate for your purposes will cost about $25. A typical model hooks by wire to your bike's front wheel. Mounted on the handle bars, the computer provides useful information once you get started such as the amount of time you have been riding, your speed, the distance traveled, and the current revolutions per minute. When the ride is over, the computer will tell you your average speed and how far you went.
All of this information is important because as you enter the date in your logbook, you will be able to tell if you are improving or regressing. Knowing your revolutions per minute (rpm), or cadence, is important because you normally want to stay at about 90, but some drills will call for you to go faster. With your bike computer, you will meet the target goal but not exceed it. Your workouts will be better.
Bells and Whistles
As you might imagine, bike computers can do a lot more than the basics. Some are wireless, and some provide altitude, barometric pressure, temperature, or even GPS information. In fact, there are GPS devices designed for the bicycle that can convert to run mode for triathlon training. Hop off the bike, push a button on the GPS device on your wrist, and start running. What could be simpler? You can also find bike computers that will monitor your heart rate and count the calories burned.
Even a basic computer will keep track of total miles to help you know when your bike needs some maintenance. After 5,000 to 6,000 miles, the gears on your bike will have worn down, and you will need to replace them. The information you need is always right there on your bike computer.
Do I really need a computer for bike training?
Without a bike computer, your workouts will be time based. That's okay for nonserious competitors, but if you don't know how far you have ridden week to week, you won't know if you are improving or going in the opposite direction.