In a few short years cycling GPS units have opened up a huge range of possibilities in the ways we plan, record and compare our rides. Let’s take a look at what they can do for you and which ones perform best.
GPS stands for Global Positioning System, which if we’re being pedantic refers to the USA’s network of 24 satellites that originally became operational in 1995. This is just one of several positioning systems in which a receiver uses satellite signals to determine its location on the earth’s surface. However, like hoover and aspirin, it’s become the generic term for its category.
GPS satellites broadcast very high-precision time signals, generated by the atomic clocks they have on board, along with information about their orbits. From the data in the signals from at least four satellites a GPS receiver can calculate its position and determine your latitude, longitude and altitude.
That piece of raw data opens up a huge range of possibilities. A GPS unit can calculate your speed without needing to measure how fast your wheels are turning; it can measure the distance you’ve travelled, and record a series of location points so you can review your route on a map after the ride or in real time if the unit has a map display.
Given a map with the right additional data such as road and junction layouts, a GPS receiver can also help you navigate, and this is the function that’s really driven the proliferation of GPS devices. I can’t imagine trying to drive without one. The ancient AA road atlas that’s in the car ‘just in case’ is really there to roll up and fend off anyone who tries to take my car GPS away from me.
Early GPS receivers were slow to get a positional fix and struggled to pick up the signals from satellites if there was anything in the way, like tree cover or buildings. Advances in electronics have improved performance dramatically. Modern GPS units can get a fix indoors, and some use the Russian GLONASS system as well as the American satellites, improving speed and accuracy.
And where GPS receivers were once wallet-clenchingly expensive, you can now get a non-mapping unit for under £90, thanks to Moore’s Law and economies of scale.
If you have multiple bikes, a big advantage of GPS computers is that you can swap them from one to another without faffing changing set-up.
Bryton has a big range with a total of 11 units from the simple, non-mapping Rider 20+ to the full-featured Rider 60 and the new Rider 530 — and variations in the included accessories mean the complete range is huge.
Cycling accessories maker Cateye has long included computers in its range, and has several models with GPS capability.
Cateye’s Stealth models have built-in GPS, but most of its GPS computers use the GPS receiver in your iPhone or Android phoneto determine your location. That makes the £50 Strada Smart one of the cheapest ways of displaying GPS data on your handlebars
Garmin dominates the cycling GPS scene by dint of having got in early with the Edge 205 and 305 in 2005. The US/Taiwanese company has refined and improved its range and now offers nine models, from the simple, non-mapping Edge 20 which you can find for as little as £80 to the all-singing, all-dancing Edge 1000 which starts from about £300. Garmin recently introduced two new models, the Edge 820 and Edge Explore 820.
Known for lights and other accessories, Lezyne jumped into the GPS arena in 2016 and now has with a range of five units, the Micro GPS, Micro C GPS, Mini GPS, Macro GPS, and Super GPS. All five are non-mapping devices for riders who just want their ride data. They'll all work with Bluetooth Smart sensors and the Micro, Micro C and Super work with ANT+ too.
All Lezyne's GPS units connect to the Lezyne GPS Ally smartphone app app which allows for on-the-fly email, text and phone call notifications, and they provide live tracking that displays your current location and metrics to specified email recipients.
You might know Taiwanese electronics maker Mio better as the manufacturer of Navman satnav systems for cars. Mio is another brand of parent corporation Mitac.
Mio makes three ranges of GPS units, all with map displays: the wifi-enabled Cyclo 50x series; the Cyclo 31x series, which are virtually identical but without wi-fi; and the large-screen but reasonably-priced Cyclo 20x units.
Polar is best known as a pioneer of heart rate monitors, and has developed probably the most extensive and advanced range of training features in that category. Its two cycling GPS units, the V450 and V650 have a wide range of training-orientated features including fitness tests and assessments of training effect and training load.
The V450 is a non-mapping device while the V650 can download and display 450x450km segments from Open Street Map to guide you on your way. You can find the V650 for as little as £136.50, which is very cheap for a mapping GPS.
Fitness electronics maker Wahoo Fitness started out with sensors that transmit cycling data to your phone, then expanded with two models of GPS-enabled computers. The Elemnt is a full-featured mapping GPS unit, while the Rflkt uses the GPS receiver in your Apple or Android smartphone to determine your location.
Other brands pop up from time to time. For example, you’ll find GPS units on Amazon from Holux, Canmore, i-gotU, Memory Map and others, and cycle computer maker Sigma Sport has one GPS unit in its range, but the ones listed above are brands you’re most likely to find in bike outlets.
GPS types and functions
There are two main types of GPS: mapping and non-mapping. The larger display needed for a mapping GPS requires a larger battery, and that all increases the cost. For the extra money you get navigation and routing functions that can be extremely useful when riding in unfamiliar areas.
Many riders don’t need a map. If you just want to record data like your route, heart rate and power output (if you have a power meter), a non-mapping unit is all you need.
The massive array of functions offered by even relatively basic GPS units can be daunting, but manufacturers have generally done a good job of designing user interfaces that make it easy to find your way around them.
Let’s take a look at some of the functions you’ll find.
Standard computer functions. Like any conventional non-GPS computer, a GPS unit will tell you your current speed, distance, ride distance, average speed, maximum speed and so on.
Since there’s a fairly powerful little processor sitting in most GPS units, designers tend to include just about every speed/distance/time function you can think of.
For example, some of Garmin’s GPS units have a feature called ‘virtual training partner’ which pits you against an electronic competitor who’s doing a set average speed, or against yourself the last time you rode a course.
Heart rate functions. Many GPS units come with a heart rate strap, or will work with one, usually using the ANT+ protocol (see below).
Power functions. If you have a power meter, many GPS units will work with it to record your power data along with your ride and heart rate data, and display a range of measurements and averages so you can confirm that the reason you feel like you’re working your arse off is that you’re working your arse off.
Training functions. With a programmed workout sequence, many GPS units can do the brain work of counting intervals or timing efforts for you, feeing you up to concentrate on the effort itself. Some also have in-built fitness tests or can monitor your training effort and load so you don’t overdo it.
Geographical functions. These include both navigation and route recording, functions that are unique to GPS units. If you simply want to get somewhere, almost all mapping GPS units let you put in a destination as a postcode, name of a village or point of interest and will then give you directions to it, usually with turn-by-turn warnings as you approach junctions. However, even when you use a setting like ‘avoid major roads’ GPS map data often doesn’t differentiate between a quiet minor road and a dual carriageway A road, which can lead to some interesting route choices.
A better idea is to plan your route in advance using either the GPS maker’s own tools, such as Garmin Connect, or one of the many route-planning websites out there. Transfer the route to your GPS and you can then follow it exactly.
Recording a route lets you follow it exactly on a future ride — handy if you’re being guided — and has opened the door to competing against friends and strangers online through Strava.
If you’re following a planned route, then the unit can tell you how far it is to your destination or to the next landmark. It can usually also work out how long you’ll take to get there based on your speed so far.
If you’re happy to really roll the dice on where your ride takes you, some GPS units can generate a random route of a specified length, an entertaining gimmick that can be useful for exploring new areas.
Many non-mapping units will still give you turn-by-turn directions so you can follow a pre-loaded route. The display in these situations is usually a line showing you the upcoming turn.
Time functions. As well as the obvious — time of day, ride time, stopwatch and so on — GPS units often have extra time functions that depend on satellite data. These include sunset and sunrise times and automatic lap time functions based on detecting the spot where you started.
Altitude functions. GPS units can work out your altitude from satellite data, but this doesn’t tend to be very accurate. Altitude data usually comes from a barometric altimeter, which uses atmospheric pressure to determine your height above sea level.
Barometric altimeters are susceptible to errors caused by changes in the weather, but if you upload your ride data to a ride-sharing site you will often be able to correct the elevation readings.
Having an altimeter lets you see extra information like how fast you’re climbing and the gradient so you can confirm that killer hill really is insanely steep.
Wireless communication functions. It’s common for GPS units to have the ability to communicate wirelessly with other devices or sensors, using low-power wireless communication protocols such as Bluetooth and ANT+. This is usually how GPS units communicate with cadence sensors, heart rate monitor straps, power meters, phones and even other GPS units. Some GPS units are able to use your home wi-fi to upload your ride, and will do so automatically for you.
Eight of the best GPS units
There’s probably no more controversial product category in cycling than GPS units. They all have flaws, but their feature sets are often so large a flaw that’s a deal-breaker for one rider may go unnoticed by another, or at least be tolerable weighed against other features. Here's a selection of our favourites
Because it's been replaced by the 105, this compact GPS-enabled computer is available from various sources for £50 or less. It has a monochrome screen with customisable display, allows you to download a record of your ride, and will work with an optional heart rate monitor for a full record of your ride.
The Lezyne Mini GPS computer is an easy-to-use option that gives you basic ride information on your handlebar along with the ability to upload, store and analyse your rides on Lezyne's GPS Root website. It works with Bluetooth sensors and with the Ally app can give you turn-by-turn directions.
If you're a bit of a technophobe or you just aren't interested in masses of ride measurements, the Lezyne Mini GPS might be a good choice for you because it's very simple to use.
We liked the original Mini GPS, and we expect the 2017 version with mapping to be just as good.
The Edge 25 is Garmin's smallest ever GPS computer, and along with its diminutive size, Garmin has nailed the user interface, which is a dream to use.
If you don't need route mapping and navigation and just want to track all the important metrics like speed, distance and elevation, the Edge 25 does everything you need.
It's light, just 25g, and takes up very little space on the stem using the supplied quarter-turn mount that Garmin has been using for years. The 128x160 pixel display is small and grayscale, but it's pin sharp and the new lighter font makes it easy to see at a glance how fast you're riding.
Polar’s V650 is extremely reasonably priced for a mapping GPS with a heart rate monitor strap included in the box. It’s an easy-to-use GPS bike computer with some neat features, including a large colour touchscreen and a small white front LED for visibility if you get caught out after dark.
In keeping with Polar’s fitness orientation, there are several fitness tests and training load functions here that you’d need training software to replicate with other GPS units.
However, the V650 can use only Bluetooth Smart to communicate with sensors, not ANT+, so the range of accessories you can use with it is limited, and the only power meters that will work with the V650 are those made by Look, PowerTap, Stages and the Wahoo Kickr.
Peculiarly, the V650 doesn't work with the cheapest power meter we're aware of, the £350 4iii Precision, but its cheaper kid brother, the M450 (£114.08 with a heart rate strap) does. That means the cost of entry of training with power is now under £500.
A mapping, touchscreen-equipped GPS for about the same price as Garmin’s non-mapping 520, the Cyclo 315 HC is well-liked by people who own one. We haven’t tested it, but we’ve liked other Mio units we’ve used.
The Wahoo Elemnt Bolt is a compact and aero GPS bike computer that offers a vast amount of useable information, navigational capability and an excellent battery life at a reasonable price.
Garmin brought its Edge rage into the Strava Age with the 520, which automatically updates its internal database of segments in your area and warns you as you approach them.
It’s one very impressive piece of kit. It works smoothly, with a nicely redesigned control interface and display, and is bang up to date with all the features (barring full mapping) you could want from a cutting edge performance monitoring tool. The Strava Live Segments work well during 'non-course' rides, and provide that little bit of optional motivation should you want it (subject to subscribing to Strava Premium).
Garmin Edge 810 — £NA
Remember what we said above about GPS units and controversy? The Garmin Edge 810 has it in spades. Some people love their 810s for their ease of use and ability to, for example, automatically upload a ride via your phone or let loved ones track where you are if you’re out on your own.
Others however, find the routing algorithms inconsistent and are driven to distraction by some units' tendency to crash randomly, corrupting your ride data in the process.
With the Edge 820 now on sale, the Edge 810 has just about vanished from the channel and we only mention it here in case you stumble across a good deal on one or are considering picking one up second hand. Dave Atkinson’s extensive review of the Edge 810, linked below, should help you decide if you can live with its limitations.
The Garmin Edge 820 is a features-packed, compact and neat cycle computer that is a decent update to the popular 810. Perhaps the screen could be a little more responsive and the GroupTrack could be more accessible, but overall it's an impressive piece of kit.
All in, it is probably the best performance and navigation computer I have used and that Garmin has been able to pack it all into such a small unit is astounding.
The Edge 1000 is Garmin’s beefiest GPS, and a big improvement over its predecessors. The screen is big and easier to read, the base mapping and routing are much improved and the connectivity with other devices makes keeping track of your data a simple job. The resistive touch screen, hardware buttons and simple interface mean it's easy to use in poor conditions and when wearing gloves.
Our official grumpy Northerner, John has been riding bikes for over 30 years since discovering as an uncoordinated teen that a sport could be fun if it didn't require you to catch a ball or get in the way of a hulking prop forward.
Road touring was followed by mountain biking and a career racing in the mud that was as brief as it was unsuccessful.
Somewhere along the line came the discovery that he could string a few words together, followed by the even more remarkable discovery that people were mug enough to pay for this rather than expecting him to do an honest day's work. He's pretty certain he's worked for even more bike publications than Mat Brett.
The inevitable 30-something MAMIL transition saw him shift to skinny tyres and these days he lives in Cambridge where the lack of hills is more than made up for by the headwinds.