GPS (Global Positioning System) devices receive accurate location and time information from a network of satellites broadcasting their signals from space. The receiver is able to calculate its exact location using messages received from a minimum of four visible satellites, the times the messages were sent and the positions of the satellites corresponding to these times. Want to know more? Read our best cycling GPS buying guide.
Why do I need GPS?
Originally developed for defense purposes by the US government, today GPS has a host of civilian applications including as a navigation tool.
The latest GPS receivers pack their features into devices small and robust enough to be of great benefit to a variety of athletes and outdoor enthusiasts.
Lightweight, rugged and designed to cope with the elements, modern GPS systems have evolved into sophisticated tools for athletes to measure, map and analyse a wide variety of data to help in setting and achieving their goals for training and competition.
The latest generation of GPS navigational aids meanwhile are proving invaluable for runners, walkers, mountain bikers and road cyclists who can now pre-plan rides in unfamiliar areas, secure turn-by-turn directions for planned routes and record a multitude of ride, run or hike information that can later be shared online or via social media.
Which GPS should I get?
There are two basic types of GPS devices for runners, walkers and bikers etc to choose from.
The first and simpler type of device performs the functions of a cycle or sports computer, but using information transmitted by the GPS satellite system instead of wired or wireless bike sensors. This means they are simpler to set up, can be easily transferred from one bike to another, can be used by runners and walkers, and can also pack in additional features.
Such devices can provide accurate information on the location, time, speed and distance of runs or bike rides, with more advanced models also measuring heart rate (via a sensor worn on the chest), calories burned, cadence (number of rotations of the pedal), power output and more. Data from each individual workout can be stored for later analysis, building up into a complete picture of performance progression as well as a database of saved routes and rides. Athletes can also use training software, apps or online resources to use their data to prepare for an event or achieve a specific training target.
Some GPS devices also offer additional features such as an integrated compass and altimeter. Barometric altimeters track changes in pressure to pinpoint the device’s precise altitude, and can also track barometric pressure over time so the user can spot changing weather patterns.
More advanced GPS devices meanwhile begin to feature sophisticated mapping and navigation tools (similar to a car’s satnav unit), with colour screens to display maps on the device itself, audible signals for turns to be taken, as well as the capability to interface with online resources – downloading and uploading maps and routes to Smartphone apps and map sharing sites.
Why would I use a GPS instead of my phone?
Most Smartphones receive GPS data and there are multiple apps to enable them to be used as bike GPS devices.
Your Smartphone can also receive information from sensors on your bike either via Bluetooth or via a dongle for sensors using the ANT+ transmission protocol (ANT+ is an open-source wireless technology that enables information be exchanged between sensors and devices – e.g. so sensors on our bike can transmit data on cadence to your phone, computer or GPS device).
However the main disadvantage with using your phone is battery life, as having the screen permanently on (i.e. when using a map feature with phone affixed to handlebars) is a big drain on your battery’s life. GPS devices have longer-lasting batteries that work with optimised screens designed to be ‘always on’ – good to know when your hours out on an unfamiliar sportive route and getting a charge is out of the question!
The majority of bike GPS devices are mounted to the handlebars or stem so they are easily visible to the rider, with a 2.5-inch display and a microSD memory card slot for more memory or additional maps. As with bike computers, basic features such as speed, time of day and trip distance/time are standard.
After this, budget, mid-range and top-end devices will differ in the level of functionality they offer, with feature-packed units obviously being the more expensive.
Below is a roundup of the main features to look for on a bike GPS – the model you go for will depend to a large extent on your available budget:
• Maps: Not all GPS devices support navigable maps (like the ones in your car’s satnav). Mid- to upper-range models will come preloaded with one or more base maps, while you can download new or more detailed maps from multiple sources.
• Altimeter: Some GPS devices will feature a built-in barometric altimeter to display altitude information (this may also be available from GPS data but a built-in one is regarded as more accurate).
• Heart rate: The device is capable of receiving, displaying and storing data from a heart rate monitor (via Bluetooth, ANT+ or another protocol). Maintaining exertion within specific heart rate limits is an important factor in many training programmes.
• Cadence: Cadence – pedal revolutions per minute (RPM) is an important metric for your training programme. A cadence-display GPS device will communicate with sensors on your chainstay and crank arm to tell you how fast you are turning the pedals.
• Calories: Want to know how many calories you’ve burned in order to help with your recovery nutrition programme? Then look for a GPS with this display.
• Screen size and resolution: Your screen needs to be big enough to be easily readable, but not so big as to be unwieldy or prone to taking knocks. A screen size of 2.5 inches has emerged as standard for bike GPS units, while 160×240 pixels is the most common resolution. Mid- to high-end devices will also feature colour displays that can be easily read even in sunlight. Touch-screen devices make navigation a breeze, with bike GPS units designed to be used with gloved hands.
• Battery run time: Look for a GPS with rechargeable lithium-ion battery, similar to that used in your phone. Better GPS devices will offer a run time of around 15 hours.
• Weather and impact protection: Bike GPS devices – and especially those designed for mountain bikers- will need to be waterproof to protect against the elements, and sturdy enough to shrug off minor knocks and bumps from trail crashes.
Outdoor GPS units are typically available as watches which feature altimeter, barometer and compass functions, or as hand-held units which can display maps for navigation, with the ability to display and download high-quality maps as well as navigation-aiding features such as the storage of waypoints.
A handheld GPS of this type can be invaluable for anyone exploring the great outdoors and can aid navigation in poor weather or hampered visibility (although it should be used to support rather than replace traditional map-and-compass navigation skills). For shorter hikes on well-worn trails or road walks a Smartphone app may offer all the GPS functionality you need, but for proper backcountry work a dedicated GPS unit in either watch or handheld form will offer better satellite reception, more powerful navigation features, and better battery life – important considerations when civilisation may be many miles down the mountain.
Look for features including:
• Maps: As with bike GPS devices, some handheld units can display maps (with more available to download) but other low-end models don’t. Check before you buy
• 3D map view: High-end units may feature 3D topographical maps which offer an excellent indication of the lay of the land
• Compass: An accurate digital compass helps you navigate by bearing so you can stay travelling in a certain direction through unknown terrain
• Turn-by-turn directions: Like your car’s satnav, some handheld GPS units can guide you to your destination, every step of the way
• Screen size and type: Screens on handheld GPS units are large enough to read map detail but small enough to keep down the overall bulk of the unit
• Barometer: An outdoor GPS watch may display the current barometric pressure and temperature, enabling you to forecast weather changes
• Altimeter: Knowing your elevation is essential for mountaineers and backcountry skiers, while advanced GPS models feature extra data-crunching power such as the ability to lock elevation changes as a record of climbing progress
• Media card slots: To support microSD or other memory standards
• Channels: The number of channels determines the number of satellite signals the GPS is able to receive simultaneously. The more channels it can receive data from, the more accurate it can be. Lower-end GPS units are 12-channel, top-end devices can have up to 24 channels
• Waypoints: Waypoints are specific geographic locations – defined by latitude and longitude coordinates – that are recorded into the GPS device. Users can record waypoints as a means of returning to their point of origin, with better quality devices capable of storing more waypoints
Get your GPS system dialled in just the way you want it with our full range of spares for all major brands including replacement and aftermarket bike mounts, cadence sensors, heart monitor bands, chargers, carry cases and maps.
