Which data fields should you display on your head unit during a bike race?

Garmin head unit on a ride in Lane Cove National Park showing the data fields you should display on your head unit during a cycling race

Today’s cycling computers can give cyclists insight into all kinds of data. Customisable screens on head units like the Garmin Edge 520 and the Wahoo Element Bolt allow users to choose what information they want to view about their ride, and when they want to view it.

With the Edge 520, for example, you can view up to ten different data fields at a time. With 138 different data fields available at time of writing, that’s over 535 trillion possible combinations of data fields on any one screen – with that many choices, even if you changed your screen configuration every single second, you’d have enough different configurations to last over 16 million years! That doesn’t even consider the fact that with the press of a button, you can scroll up and down to view even more data fields. The Wahoo Element has similar functionality.

Some of the available data fields are basic: current speed, time of day, distance travelled. Others have a niche appeal: calories to go in your workout, pedal smoothness, checking the battery level on your Garmin lights. Still others are obscure to the point of being useless – have you ever needed to know your 30-second average vertical speed?

Bike computers may not be essential for racing (at least, not according to my guide on how to start racing), but they are pretty much ubiquitous. So with so many options available, how should you set up your data screens for a bike race? Allow me to explain what works for me.

Basic set-up

Before we get into the data fields themselves, a few general words about setting up your head unit for a race.

One screen only

Firstly, I only enable one data screen. During a race, I don’t have the time to fiddle around with my head unit. I certainly don’t want to be pressing buttons to switch to different data screens. I need to be able to view all the relevant metrics at a glance, keeping my hands on the bars.

Auto-lap

Secondly, I usually enable the Auto-Lap setting. This automatically starts a new lap when the GPS detects that I’m passing my starting point, or any other location at which I’ve manually pressed the ‘Lap’ button. This has limited usefulness during the race itself, but it’s helpful for analysing the data afterwards. I can see, lap by lap, whether the pace was quick or slow, whether my power was high or low, etc. It’s also a helpful metric for my race commentary videos.

Separate Activity Profile

I’ve incorporated these settings into a separate ‘Activity Profile’ on my Garmin. I have separate Activity Profiles for indoor training, outdoor interval training, commuting and racing – each with their own unique data screen configurations. You can customise your Activity Profiles through in the ‘Settings’ menu on your Garmin. Wahoo computers allow you to customise your fields through the accompanying phone app.

With that in mind, here’s, in my opinion, the data fields you should display during a race.

Data fields to display during a race

1. Elapsed Time

‘Elapsed Time’ shows how much time has passed since the race began. I prefer this over ‘Time’ and ‘Moving Time’ because the clock doesn’t stop if you stop for a crash or mechanical issue. This metric is essential during a criterium, where the race distance is equal to a predetermined number of minutes plus a predetermined number of laps. Only with Elapsed Time can you accurately keep track of how much time there is until the finish.

2. Distance

Just as Elapsed Time does during criteriums, ‘Distance’ tells you how far you are into a road race, and how far you are from the finish. On point-to-point courses and featureless routes such as West Head, where each section of road is visually indistinguishable from the next, Distance helps you keep track of where you are. In multi-lap races, as long as you know the length of one lap, Distance allows you to calculate how many laps you’ve raced, even if you’ve lost count in your head.

3. Time of day

‘Time of Day’ is a basic clock, showing you what the time is. While not necessary during the race itself, I find this metric absolutely essential during warm-up. It ensures that I don’t lose track of time and miss my race start.

4. Speed

Knowing your current movement speed helps you gauge whether or not it’s a good time to attack. Often, I’ll be sitting comfortably in the bunch, feeling fresh and ready to launch off the front – but I’ll look down at my head unit and see that we’re flying downhill at 55km/h. At speeds that high, if you were to stick your nose into the wind with an attack, you’d be unlikely to last long. On the other hand, if I’m feeling fresh and see that the speed is just 30km/h, I can tell that the pace has slowed. If the group has hesitated, it could be time to make a move.

5. Heart Rate

Watching my heart rate, measured in beats per minute, helps me gauge my effort. When I’ve been reeled back into the peloton after an attack, the heart rate metric lets me see whether or not I’ve recovered. If my heart rate has stayed high since being caught, I’ll think twice before attacking just yet. If it’s has dropped to a more sustainable level, I’ll know that I’m ready to launch another one.

Some people use heart rate to determine whether or not they’re on a good day. For them, a low heart rate means their body is fatigued and unable to put out their maximum effort. This tells them to manage their energy reserves more conservatively during the race. This might be helpful for some, but for me, I rarely train hard enough to be fatigued on race day.

6. Power – 3 second Average

‘Power 3s Avg.’ shows the average watts you’ve put out over the last three seconds. Of course, you’ll need a power meter to view this metric. Similarly to Speed, Power allows you to gauge how hard the bunch is riding, and whether it’s a realistic moment to attack. The advantage is that Power is independent of terrain, whereas Speed will vary if you’re riding uphill or downhill or into a headwind or tailwind. I know that if my Power is consistently high while sitting in the bunch, I won’t be strong enough to get away at that moment.

Some riders argue that Power is a useless metric in a race. They argue that you either have the strength to stay at the front of the race, or you don’t – it doesn’t matter how many watts you’re delivering. That might be true if your aim is simply to stay with the bunch, but if you aim to get into a breakaway, Power is a helpful tool for pacing your effort . If you know your power zones, you can ensure you ride at the maximum power level you can sustain for the remainder of the race without blowing up. If you can see the bunch gaining on you even while you’re pushing out your maximum wattage, you can think about saving your legs for later.

Riding to power in a race might mean you spend a lot of time staring at your head unit. But hey, if it works for Chris Froome, who are we to argue?

7. Cadence

‘Cadence’ shows the current rate at which you are spinning the crankset, measured in revolutions per minute. Usually, I can approximate my cadence by feel. However, under the pressure of a race situation, it helps to be able to verify that feeling with hard data. Cadence is important during longer races, where you should be aiming to spin at a higher cadence (say, 90-100rpm) early into the race, saving your leg strength for harder efforts later on. Displaying cadence on my head unit reminds me to stay in an easier gear and spin the legs as much as possible.

Final words

Ultimately, you decide what data to view during a race. If you don’t have a heart rate monitor, power meter or cadence sensor, obviously you won’t be able to view those respective metrics. For me, however, these seven data fields help me most during a race. With these displayed, I’m comfortable that I’m not missing out on any vital information.

There’s another side to it, too: data is fun! Watching how fast you’re going, how much power you’re putting out, how your heart rate is trending – it can be fascinating. And if all you get out of your bike computer is a little more enjoyment while racing, I think that’s an excellent way to use it.

What data do you display during a race? Let us know in the comments!

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