I came to own the Timex Ironman through sloppiness. I left my biking magazine open to an ad for the (then new) Timex Time and Distance system on my dresser last November and Lee thought it was a subtle hint for a Christmas present. It actually wasn't. It was simply where I had left off reading. Anyway, Christmas morning there it was! I began using it.
The idea here is a single system that could replace a Pedometer, Odometer, and all the lap, pace and odometer functions on bike, and on foot. Being GPS based, in theory, it would require no calibration for stride or wheel circumference. This theory actually works, within some very stringent limitations.
The system consists of two components. A wristwatch, which functions as such, as well as the computer for determining speed, distance and all the permutations of calculating them. These include, an overall odometer (cumulative), speed (average, current, maximum), distance, pace, average pace, best pace, recall, timer, alarm, and other functions that I haven't even begun to use. The second component is a GPS satellite receiver, which transmits the information to the watch.
So, if you are here on the earth, and the GPS unit can see a couple of satellites and communicate with the watch, and your batteries are in good shape, you should get a really accurate readout of your performance! When everything is good, you do! The problem is that in the real world, things are seldom perfect!
The following are the flaws in the system! The manufacturer states that the GPS unit needs a clear view of the sky. Never have truer words been spoken! Oak Trees, too many overhead wires, buildings, solar winds and who knows what else all serve to defeat the receiver. So for that matter does too much bouncing around. For instance, hand holding the unit bounces the unit too much to allow it to "Lock on" to the signal. The GPS unit is supplied with an armband and a belt clip. On the bike, the armband works. But if you are running, you better wear it on the hip. Anywhere else bounces it around too much. It also sucks up batteries! I guess they designed the thing not to be too heavy, so they used AAA batteries to save weight. But, as a result, it only lasts for about three runs on either bike or foot (maybe about 6 hours). If you are like me, and you have limited time for playing this system is too high maintenance. Since it takes the GPS unit about 5 minutes to "lock onto" the satellites, you have two options. One, either disregard the first five minutes of your ride, or, two put the GPS unit outside when you wake up, then get ready so when you bolt out the door it has locked on and is ready to go!
My conclusion, again, when it works, it's GREAT! The problem is that it does not work reliably enough to be a good training aid. The theory is excellent. The idea is great. The accuracy is wonderful, when it works. But, unless you are going to run, bike, or whatever on the wide open plains of Illinois, save your money. Spend half as much on a good magnetic unit for the bike and a pedometer for running! Then spend some time to accurately calibrate them. In the mean time, until the satellites get stronger, or the receiver gets more sensitive, the frequency with which the Ironman fails to record your work makes it too much trouble to bother with!
Rating Over all 5
Accuracy: 9 When Working -- 0 When searching
Ease of Operation: 6.5
Battery Life: 4