What is Wind Balance in Cycling and How to Read It

You finish a ride, upload it, and the numbers look worse than the legs felt. Or better. Wind is usually the reason, and until recently there was no clean way to put a figure on it. Wind Balance is that figure, a single number for how the wind treated you over a whole ride.

It runs from minus 100 to plus 100. Minus 100 means every pedal stroke was into a headwind. Plus 100 means the wind pushed you the entire way. Zero means it evened out.

Where the number comes from

Wind Balance is calculated by the MoguWind data field while you ride, and written into the FIT file of the activity. You see it afterwards in Garmin Connect, in the summary of the ride, next to the other metrics.

The important bit is that it measures what actually happened, not what a forecast predicted. The data field knows your heading from the GPS and the wind at your position, so every second it works out how much of that wind was hitting you head on, from behind, or across. Over a few hours those seconds add up into the balance figure.

That also means it does not need your route. You do not load anything, you do not tell it where you are going. It just reads the wind and your direction as you go.

Reading wind balance data on your bike computer

There is no universal good or bad score, it depends on the shape of the ride. A few reference points from real rides:

• Around zero. Typical of a loop. You went out into it and came back with it, which is what a circular route should give you. If a loop comes back at minus 40, the wind rotated on you during the ride, which happens more than people think.
• Strongly negative, minus 40 or below. You spent most of the ride working. Out and back rides into an afternoon sea breeze land here a lot.
• Strongly positive. Point to point rides with the wind behind, or a loop where you got the timing right.

Where it earns its keep is comparing rides. Two Saturdays, same route, same average power, twenty minutes apart. If one was minus 55 and the other plus 10, you have your explanation, and it is not your form.

Same route, same power, twenty minutes apart. The balance figure tells you it was the wind, not your legs.

What it does not tell you

Worth being clear, because a single number invites over-reading.

It says nothing about wind strength. A ride spent entirely in a gentle 8 km/h headwind and a ride spent entirely in a brutal 35 km/h headwind both score close to minus 100. The direction split is the same, the suffering is not.

That is why the balance sits alongside the other metrics rather than replacing them. In the same Garmin Connect summary you also get the average wind speed, the average and maximum headwind, the maximum tailwind and the share of time in head, tail and crosswind. Read together they tell the story. On their own, each is a fragment.

There are also five per second graphs recorded, wind speed, head and tail component, crosswind, wind direction and airspeed, if you want to scroll through the ride and find the section where it fell apart.

Setting up wind balance before you ride

Wind Balance is a verdict. It arrives when the ride is over. If what you want is to know beforehand, that is the web planner, and it works differently.

There you load a GPX or a Strava route, pick the day and the departure time, and it shows the wind kilometre by kilometre for the moment you will actually be at each point. Green where it helps, red where it hurts, grey for crosswind. It will also suggest a better hour to leave if there is one.

The two are worth using together, though for opposite reasons. The planner is where you decide which way round to ride the loop. The balance figure is where you find out, honestly, whether you got it right.

Wind balance in action: real ride example

Take a 90 km loop out of a coastal town on a summer Saturday. You leave at eight with barely any wind, head inland, and by midday the sea breeze has set in behind you for the run home. That ride might come back at plus 35. Nothing dramatic, but it explains why the second half felt suspiciously good.

Now run the same loop anticlockwise. Same distance, same climbing, same legs. You get the breeze in your face for the last 40 km and the figure lands somewhere around minus 30. Two rides, a 65 point swing, and the only decision that changed was which way round you left the car park.

That is the practical value of the number. Not the number itself, but the fact that it lets you check, afterwards and with evidence, whether the choice you made was the right one. Do that three or four times on the same loop and you stop guessing about direction.

Using wind balance without analysis paralysis

Most people start by checking it after every ride for a couple of weeks, and then it settles into something you glance at when a ride felt strange.

The habit that seems to stick is looking at it on rides you repeat. Your Tuesday loop, the climb you always do, the commute. Once you have five or six of the same route with different balance figures, you start to get a feel for how much wind is worth in minutes on that particular road. That is more useful than any single ride's number, and it is the sort of thing you cannot get from a weather app.

One caveat from experience. On very short rides the figure gets twitchy, because a couple of turns weigh heavily when there is not much else to average. Under about forty minutes I would not read too much into it.