GPX TO TRAINER · BUILT FOR MOUNTAIN BIKERS
Ride any trail. On your trainer.
Turn a GPX into a ride on your smart trainer. The trail’s real climbs push back, through a 3D world built from the route. Ride one of ours, or upload your own.
IN THE BETAMT TAMTAHOE FLUMELEADVILLEBENDDINO FLOWSEDONAKINGDOM TRAILSCRESTED BUTTE+ ROAD: SA CALOBRA · BIG SUR
WHY SADDLEOUT
Built for mountain bikers.
01A real elevation profileYour smart trainer follows the trail’s actual gradient, so a climb you know pushes back the way it does outside, and descents ease off.
02A level built for your rideUpload a GPX or FIT of the trail you want and we generate the level on demand: the terrain, the trail and the plants that belong there, from that area’s map data.
03Not just pedallingOn the way down the trainer eases off, so you can coast and rest, or hold a squat over the bike to stay in it. Like on the trail, you don’t pedal the whole time.
The GoPro bounces on the handlebars; in the game your view stays steady.
Also rides road.Mountain biking is our focus, but road climbs and coast highways ride just as well. Pick road when you upload one.
What it isn’t.It’s not a survey-grade replica, and a stationary trainer can’t reproduce outdoor line choice, braking or traction. The climbing and the place are real; the handling is a trainer’s handling.
STARTER PACK · 8 ROUTES
A few classics to start.
Real trails, built from GPS rides into places you can ride through, and polished by us. More arrive as downloads.
FEATURED · POLISHED BY SADDLEOUT
MORE ROUTES · MOUNTAIN BIKE
MORE ROUTES · ROAD
CREATE A ROUTE · BETA
Ride your own trail.
Upload a GPX or FIT of a ride you want to try, anywhere in the lower 48 US states. It joins the build queue, and when it’s built it shows up in the game under My routes, ready to ride.
First comes the terrain and your trail or road, usually 15–30 minutes after it starts building. Then the plants and scenery that grow there, another 10–20. We email you at each step. Beta testers get to try it as it opens up.
CREATE A ROUTEONE SPOT ON BACKBONE TRAIL · FIRST VERSION, THEN WITH PLANTS AND SCENERY
THE BETA
Open beta. Early build.
Anyone who wants to try it can. Confirm your email, pick your device, and you get the install link straight away. This is an early build: visuals, routes and compatibility are all still in progress, and what you tell us decides what we fix first.
What you get
+Early access to real-route riding on your own setup.
+A direct line to the team. What you report decides what we fix first.
+Your own trails, built from a GPX, as route creation opens up.
What we ask
01Test the game on one of our supported devices.
02Test your trainer and equipment.
03Test our route generator: upload a GPX, it joins the queue, then ride it.
04Give us feedback.
Suggested setupWhat we’ve ridden ourselves, so we know the experience is good.
✓A Windows 11 PC. Ours is a high-end desktop a few years old (RTX 3080, 32 GB of memory), with a Wahoo KICKR CORE 2 with a Zwift Click for shifting. Ridden start to finish. Much more modest PCs should be fine, and the list on the right is where we want that confirmed.
Minimum testedThe lowest-end devices we’ve run the game on. It runs; we’ve not yet ridden full sessions on them.·Galaxy S21 (Android)
·iPhone 14
Need testers on…Common setups we haven’t tried. On a PC the graphics card decides the experience, so that’s how we list it. Own one? Tell us in the setup and you’ll help most.
PC GRAPHICS
?Modest desktop cards: GTX 1660, RTX 2060, RTX 3050 or 4060, Radeon RX 6600 (we aim for 30 fps on a GTX 1660 or RTX 3050 with 6 GB, and nobody has confirmed it)
?Gaming laptops with an RTX 3050 or better
?Laptops with no separate graphics card (Intel Iris Xe, Radeon 780M)
PHONES AND TABLETS
?Phones older than the S21 or iPhone 14: Galaxy S10 and S20, iPhone 11 and 12
?Newer phones: Galaxy S23, S24 and S25, Pixel 7 and newer, iPhone 15 and newer
?iPad (any recent model)
TRAINER OR BIKE
?Tacx NEO 3M, Flux and Flow Smart
?Zwift Hub and Zwift Ride
?Elite Direto, Suito and Justo
?Wahoo KICKR (2020 and newer) and KICKR MOVE
?Wattbike Atom and Saris H3
?A basic trainer or spin bike with a Bluetooth power meter
FAQ
Straight answers.
What is this?
A trainer app for mountain bikers. Your smart trainer follows the real elevation profile of a trail while you ride through a 3D level built from the route. Choose one of ours, or upload a GPX and we generate the level for the ride you want.
Who’s building this, and why?
I've been riding a long time, but started doing some XC racing in the last 2 years. I've now done the Downieville Classic in Northern California twice, but I live in Southern California (Long Beach), so getting up there to pre-ride the climb wasn't much of an option ahead of the race. I figured I might be able to use a smart trainer to at least simulate the climb.I got a fairly rudimentary version of it working from the GPX file of the route ahead of the race this year, and used it to test my fitness level and estimate how I was doing towards my goals. The climb in the game came within ~5 mins of my actual ~1.5 hour climb, so I was stoked to see it was a solid way of testing. It helped me train for the race, and I beat my last time by 9 minutes.Tuning it against real ridesSince then I've been working to nail down the resistance and physics, and to get the graphics, look and feel to a spot that feels more like the real place.The way I've been tuning it is pretty simple: ride a real route with a power meter and a GoPro, then ride the same route in the game and compare. On a recent ride at Los Mares I recorded power, speed, cadence and heart rate, and even called out my gears out loud so I could line everything up with the video afterwards. Then I ran that ride back through the game's physics and adjusted things like rolling resistance and wind drag until the speeds matched what I actually did. The first pass had me climbing about 13% slower in the game than in real life; after tuning it's within about 3%.The goal is to give you as accurate a representation of the real effort as possible, and a bit of the vibe of the real place.SEDONA, REAL · THE SAME SPOT IN THE GAME · SLICKROCK AT HOME · MOAB IN THE GAMEJeff · SaddleOut founder
How do I get in?
Confirm your email, then pick the device you’ll ride on. You get the install link right there: TestFlight on iPhone and iPad, Google Play testing on Android, or a download for Windows PC. Then open the game and link it to your account. There’s no test of skill or fitness.
Does SaddleOut work with my bike?
SaddleOut talks to your equipment over Bluetooth, not ANT+. So far it has been ridden on a Wahoo KICKR; everything marked “should work” below comes from each maker’s published specs.
SMART TRAINERS AND SMART BIKESThe full experience. SaddleOut sets the resistance for every hill, so climbs push back and descents ease off. Shift with your bike’s gears, or use virtual gears with a Zwift Click or the on-screen buttons.
KNOB BIKESSupported, with you in control of resistance. SaddleOut reads your power and cadence and turns them into speed on the real hill, but it can’t change a knob bike’s resistance. Before each climb it tells you how steep and how long it is (“Climb ahead: 8% for 2.0 mi”), so you can turn the knob up. More knob means more power, and more power means more speed. The difficulty setting only applies to smart trainers.
POWER METER ONLYRides like a knob bike. Speed comes from your power and the hill. Shift your real gears as you would outside, and you’ll get the same climb tips. Your power meter needs Bluetooth, since phones and tablets rarely support ANT+. Most modern pedal, crank and hub power meters have both.
PELOTONA standard Peloton doesn’t broadcast its data to other apps, so you need an add-on Bluetooth power module. The Bike+’s automatic resistance only works inside Peloton’s own app, so in SaddleOut you’ll use the knob.
WHICH MODELSSMART TRAINERS AND SMART BIKES · THE HILLS SET YOUR RESISTANCE
- Tested: Wahoo KICKR CORE 2
- Should work (recent firmware): Wahoo KICKR, KICKR CORE, KICKR MOVE, KICKR ROLLR, KICKR Bike
- Should work: Tacx NEO 3M, NEO Bike Plus, Flux S / Flux 2, Flow Smart
- Should work: Zwift Hub Classic / Hub One, Zwift Ride (use a Zwift Click to shift)
- Should work: Elite Direto, Suito, Justo, Avanti, Zumo, Tuo
- Should work: Saris H3, JetBlack Victory / Volt, Magene T600, Stages SB20, Wattbike Atom and Proton, Van Rysel D100 / D500
KNOB BIKES · YOU TURN THE RESISTANCE
- In testing: Schwinn IC4 / Bowflex C6
- Should work: Peloton Bike or Bike+ with an add-on Bluetooth power module (such as FitSwitch)
- Should work: similar spin bikes that send standard Bluetooth power
POWER METER ONLY · YOUR OWN BIKE, YOUR OWN GEARS
- Should work: any Bluetooth power meter on your bike, on rollers or a basic trainer
NOT SURE YET · HELP US TEST THESE
- Tacx NEO, NEO 2, NEO 2T
- Wahoo KICKR SNAP, Tacx Vortex Smart, first-generation Wattbike Atom, Thinkrider
NOT SUPPORTED YET
Not sure, or not listed? Join anyway. Put the exact model in the trainer box when you do the setup. Those are the setups we most want tested.- Keiser M3i / M3i+ (they use Keiser’s own Bluetooth format)
- Peloton Bike or Bike+ without a power module
- Echelon and NordicTrack / iFit bikes
- Trainers that only speak ANT+
Which platforms can I play on?
Windows PC, Android phones and tablets, iPhone and iPad, and Apple-silicon Macs (M1 or newer; the Mac runs the iPad app through TestFlight). Tell us your device when you sign up and we’ll send the right build.
How do I get the build?
We email instructions for the device you picked when that build is ready: TestFlight on iPhone and iPad, a Play testing track on Android, and a versioned download link on PC. Then open the game and link it at saddleout.com/link.
Can I ride my own route?
Yes. Upload a GPX or FIT file of the ride and we build it into a route you can ride in the game.
What device data do you collect?
Your signup answers only, until you say otherwise. Before the app sends any diagnostics, it asks first and explains what’s recorded: device model and OS, app version, performance, crashes and stalls, and trainer or controller connection events. Diagnostics never include your FIT files or GPS tracks. You can switch them off or withdraw at any time.