Bicycle GPS can provide you with your speed, distance, pace, elevation change, location, directions, and much more as you ride. There are more options than ever for using GPS technology while cycling, including dedicated cycling computers, and smartphone apps.
Two of the biggest advantages of a GPS cyclecomputer are the lack of wires, and quick interchangeability between multiple bikes. Unlike a typical cyclecomputer that needs a wired link to a magnet wheel sensor, a GPS cyclecomputer gets its location, distance, and speed information by pulling down GPS satellite signals. This capability also frees up your computer for switching between multiple road bikes or even mountain bikes without taking any time to change setup parameters to to install wires.
There are two categories of cycling GPS on the market: dedicated, handlebar-mounted computers, or smartphone apps. Each has its advantages and disadvantages.
Dedicated Handlebar-Mount Computers
The big advantages of dedicated GPS cyclecomputers over smartphone apps are waterproofness, durability, battery life, gloved-hand use, and on-the-road visibility of your stats.
Virtually every GPS cyclecomputer on the market is rated as waterproof or highly water resistant. This means, unlike a smartphone, you can leave it on your handlebar in the worst weather conditions, and remain confident that it will keep working, and still provide you with good data. Dedicated computers are also designed for the constant jarring, vibration, and in the case of mountain biking, the barrage of dust and dirt that would kill a smartphone in no time. GPS cyclecomputers also have a longer battery life than a smartphone. The Garmin Edge series of cyclecomputers, for example, has a battery life of 15 hours (an accurate spec, in my experience) while in active GPS tracking mode, compared with a typical 6 hours or less for a smartphone. GPS cyclecomputers are also designed to useable with a winter-gloved hand. This puts them one-up on smartphones, whose touchscreens generally cannot be operated without using a special type of glove. Last but not least, dedicated cyclecomputers are always there on your handlebar, providing you with the data that you want and need, while a smartphone is in your pocket. There are well-made, waterproof handlebar-mounts for smartphones, but to my eye, the are too large and ugly.
Smartphone Cycling GPS Apps
Given all of the advantages of a dedicated cyclecomputer, why even consider a smartphone app for your sport? The smartphone option has its strengths, too. Cost is a big one. If you already own an iPhone, Android operating system phone, or other smartphone, there are very good sports apps that are free - hard to beat that price. Even if you decide to go for a paid app, prices generally range from just $.99 to $9.99. In the Apple App Store alone, I counted more than 100 GPS apps that may be used for cycling. Also, many riders already carry their smartphones on rides for reasons of safety and just staying in touch, so it makes a lot of sense to have the phone to extra duty as your fitness GPS device.
Connectivity is another big smartphone advantage. With your phone connected to the internet via the cellular network, you can pull down fresh maps, routes shared by other riders, weather data, and much more while out on a ride. You may also take advantage of that connectivity to easily upload detailed training log and fitness data, route details, and shared routes and travel journals (including photos and videos) to a multitude of very well designed sports and travel sites.
I'm personally so hooked on the "pluses" of both dedicated and smartphone bicycle GPS, that I usually have both on my bike, and there is a lot to be said for that level of functionality for a dedicated cyclist. If you have to choose between them, though, these pros and cons should help you hone in on your best choice.