GearWatts
Every watt, every pulse
GearWatts is a web app that analyses your rides from the files your cycling computer records. Gears, power, climbs, maps and your whole season, in one place and only visible to you. Free during the beta.
What you get
Six areas, all built from the same files you already have. If a file does not carry a signal, GearWatts simply does not show that part.
Every chainring × cog
If your groupset is electronic, GearWatts reads every shift that Di2 or AXS wrote into the FIT file. For each chainring and cog combination you get time, power, cadence and speed. You see the development in metres per pedal revolution and which gear you really ride at each gradient. Your shifting habits are there too, cross-chaining included. Rides with a mechanical groupset still work for everything else. Only FIT files carry shifting data.
Curve, zones and form
Your power curve set against your own history, so you see whether this month beat the last one. Time in zones, left/right balance, and fitness, fatigue and form week by week. A monthly FTP estimate shows the trend without a test day. All of it needs a power meter on the bike. The numbers are recalculated from your profile, so if you change your FTP, the past rides follow.
Your climbs, found for you
GearWatts detects every climb in your rides and gives it a category and a profile by sections. No segments to create, no list to maintain. The climbs you repeat are grouped: you see all your times on them, your best one and how you have improved. Open a climb on the 2D map or in 3D, with the route drawn over the terrain. Stretches in a car and stretches you did not pedal are left out.
The route in 2D and 3D
The route coloured by speed, power, heart rate or altitude, so you read the ride at a glance. Switch to 3D and the ride replays over the terrain. Satellite imagery is available in Spain. One more map gathers all your rides, so you can see where you have actually been. Indoor rides and virtual worlds have no real GPS track, so they stay off the map. The page tells you how many were left out.
Year after year
Kilometres per week, this year against last year and against your best year, up to today. Your streaks of weeks riding, and your records by distance and by climbing. The home page puts this week next to last week at the same point, so you know if you are ahead. Highlights show your best 20 minutes and your hardest climb of the last 90 days. A season is easier to read when it is not a list of files.
Upload or connect
Drag in .fit, .tcx or .gpx files, several at once or a whole folder. Or connect Garmin, Polar or Hammerhead and your rides arrive on their own. Compare two rides side by side whenever you want. Keep several bikes in your garage: each ride goes to the right one by name, sensors or dates. Your bike can even become pixel art, drawn from a photo in your browser. Dark and light theme, in four languages.
How it works
- 01
Upload or connect
Sign in with an e-mail link, create nothing else. Drop your files or connect Garmin, Polar or Hammerhead.
- 02
We read the file
The file is parsed in your browser. Gears, power, climbs and maps are worked out from what it records.
- 03
Explore
Open a ride, compare it with another, or step back and look at the season. Everything stays in your account.
Why gears and watts together
A power number tells you how hard you pushed. It does not tell you how. The same 250 W on a 7 % climb can be a smooth 85 rpm in a light gear or a grind at 60 rpm in a heavy one. Your legs know the difference. Most dashboards do not.
An electronic groupset records every shift, and your head unit records the rest. Put them side by side and some honest questions get answers. Which gear do you actually use on a 7 % climb? Do you spend half the ride in two or three combinations and never touch the rest? Is your cassette a good fit for the roads you ride, or is there a gap exactly where your terrain sits?
The same goes for power. Knowing your best 20 minutes is useful. Knowing how your watts are spread across chainring and cog combinations is different: it shows where you are efficient and where you only get by. Add the development in metres per pedal revolution and you can compare a 50×34 setup and a 48×31 one with real numbers from your own rides, not with a chart from a catalogue.
GearWatts exists for that. It is not trying to be a social network or a training plan. It reads what your computer recorded, gives each signal context, and leaves the conclusions to you. If your groupset is mechanical, you still get power, climbs, maps and season. The gear analysis is the part that needs Di2 or AXS data in a FIT file.
From the guides
Short, practical reads on gears, power and climbs, written for people who ride.
Gear development: metres per pedal revolution
How to calculate gear development in metres per pedal revolution, compare 50/34, 52/36 and 48/35 setups and pick chainrings and a cassette for your terrain.
What electronic shifting records in your ride files
What Shimano Di2 and SRAM AXS write into a FIT file and what the shift events reveal: time and power per gear, shifting habits, cross-chaining, cassette choice.
FTP and power zones: estimate, train, avoid traps
What FTP is, how to estimate it from ordinary rides as 95 % of your best 20 minutes, how to read the power curve and seven zones, and when estimates mislead.
Normalized Power, TSS and the fitness–fatigue chart
How Normalized Power, Intensity Factor and TSS are calculated, and how to read CTL, ATL and TSB to plan a build or a taper, with worked numbers and the limits.
How climbs are detected and categorised from a ride
How software finds climbs in an altitude profile, why distance times gradient gives categories 4 to HC, how races differ, and how to compare your VAM.
Why your ride altitude lies, and how to clean it
Barometric jumps after a stop, GPS altitude that invents 25 % ramps, and why two apps report different total ascent. Causes, fixes and how to get cleaner data.
FIT, TCX or GPX: which file to export, and how to get it
What FIT, TCX and GPX files keep (and lose), how to get your original files from a device, Garmin, Strava or Polar, which sync options exist, and a privacy tip.
Questions, answered
Is GearWatts free?
During the beta, yes: uploading files, connecting your device account and the analyses described on this page are free, within a limit on registrations and analyses that has not been set yet. In the future some features may become paid. The site shows ads to cover its costs; the privacy pages explain how it handles cookies.
Which devices and files does it work with?
It reads .fit, .tcx and .gpx files, so any cycling computer or app that exports one of them works. You can upload several at once or a whole folder. FIT is the richest format and the only one that carries shifting and pedalling data. If you upload two files of the same ride, GearWatts keeps the most complete.
Do I need Di2 or AXS?
Only for the gear analysis. Shimano Di2 and SRAM AXS write each shift into the FIT file when they are paired with your cycling computer. Without them you still get power, climbs, maps and your season. Each ride in your list shows which signals it contains, so you know what to expect.
Can I use it without a power meter?
Yes. Maps, climbs, speed, heart rate, your season and comparisons work with any ride. Gear time and development also work if you have electronic shifting. What needs a power meter is the power part: the curve, zones, balance, fitness and fatigue, FTP and power per gear combination.
Where is my data stored and who can see it?
Only you can see it. Each account reads and writes its own data and nothing else. There are no public profiles or sharing features. The analysis runs in your browser. We keep a summary and the data of each ride, plus the original file so rides can be recalculated. You can delete rides at any time.
How do Garmin, Polar and Hammerhead work?
Garmin uses your personal API key from its Personal API programme, and brings your whole cycling history. Hammerhead and Polar ask you to authorise GearWatts on their website. Hammerhead gives your full history. Polar only allows new sessions, up to the last 30 days, so older ones come in by exporting FIT files and uploading them.
Does it connect to Strava?
Not yet. Strava does not give shifting data or the original FIT file through its API, which is exactly what GearWatts needs. What you can do today is take the original FIT files from your Strava data export and upload them. Those files carry everything the analysis needs.
Which languages and units does it use?
The app and this site are available in English, Spanish, French and German, with a dark and a light theme. Units are metric: kilometres, metres, kilograms and watts. There is no switch to miles or feet at the moment.
Every watt, every pulse
Drop in a ride and see what your cycling computer has been recording. It takes a minute, and it is free during the beta.
Open GearWatts