Early access: founding riders now
Indoor training for mountain bikers
DirtWatts rebuilds real trails from 1-meter lidar. Every pitch you see is the pitch your trainer pushes back with, on a bike and physics model built for dirt.
Free tier, no card. Runs in Chrome or Edge with a Bluetooth smart trainer.
Why DirtWatts
Road sims draw dirt as a texture on a smooth ribbon. DirtWatts starts from the ground itself: the real trail, the real grade, and a rider model tuned on mountain bike rides.
A watch's elevation drifts under tree cover and spikes on switchbacks, so GPS-built routes get fake 30% walls and lose the punchy pitches. DirtWatts lays each trail on the USGS 3D Elevation Program's bare-earth lidar, sampled every meter.
Speed comes from your watts through a model fitted to a real power-meter ride on mountain bike trails. It isn't a road model with the friction turned up.
Every scene is rebuilt from data about that exact place: land-cover maps choose the plants, aerial imagery finds the bare slickrock, and lidar puts individual trees where they stand.
The trail library
Each trail is ridden, cleaned up by hand and baked from lidar. We add trails every month, starting in Utah's mountains and desert.
Park City, Utah · alpine aspens
Park City, Utah · high desert
Moab, Utah · slickrock and sand
Free riders get two featured trails, rotated every month. Subscribers ride the whole library.
On the bike
Pairs over Bluetooth with FTMS and Tacx trainers. Resistance follows the grade under your wheel.
Power and heart rate zones, cadence, grade, minimap and the whole-route elevation profile.
Every climb is detected ahead of time. A banner shows its length, average grade and gain, then counts down what's left.
Follow, close follow or first person. Switch any time with a key or a gamepad button.
Download a FIT file after every ride and add it to Strava, Garmin Connect or intervals.icu.
Open it in Chrome or Edge and ride. Graphics scale from laptops up to an Ultra mode for gaming PCs.
Already on Zwift or Biketerra?
DirtWatts is the mountain bike piece your trainer setup is missing, priced to sit next to the app you already use.
What you need
Any trainer that speaks Bluetooth FTMS (most from the last several years) or a Tacx trainer.
Windows, macOS or ChromeOS. Safari and Firefox can't connect to Bluetooth trainers yet.
A Bluetooth chest strap adds heart rate zones to your HUD and your FIT file.
Switch cameras and run the menus from the bars with any standard controller.
Heads up: this browser can't pair a trainer. Open dirtwatts.com in Chrome or Edge on your computer to ride.
Pricing
No card needed.
$49.99 billed yearly, or $4.99 monthly.
Founding riders: $39.99 a year, locked for as long as you stay subscribed. Reserve now and pay nothing until paid plans open.
Compare plansQuestions
If your trainer pairs with apps over Bluetooth, almost certainly. DirtWatts controls trainers that use the Bluetooth FTMS standard (Wahoo, Elite, Saris, JetBlack, Zwift Hub and most others from recent years) and Tacx trainers. ANT+ isn't supported in the browser.
On a Mac, yes: use Chrome or Edge. Safari can't talk to Bluetooth trainers, and neither can any browser on iPhone or iPad. A desktop app is on the roadmap.
Yes. Your trainer sets resistance from the grade, and you shift your bike as you would outside. Virtual shifting for trainers is in development.
Every ride gives you a FIT file you can upload to Strava, Garmin Connect or intervals.icu in a few clicks. Automatic Strava upload is coming.
Early access
Join the list and we'll send your invite as spots open. Founding riders lock in $39.99 a year.
Make a free account in seconds. No card, no time limit.