How far do you really
lean?
Spoiler: your bubble level has no idea. Mid-corner it reads near zero — the physics guarantees it. TrueLean fuses gyro attitude with cornering forces to show the angle you’re actually carrying. On your phone, and nowhere else.
- On-device
- No accounts
- No tracking
- Free
Fig.01 — live cluster, sample ride
- Gauge range
- ±60°
- Data uploaded
- None
- Export formats
- GPX + CSV
- Requires
- iOS 17+
Fig.02 — the bubble-level problem
A level reads zero exactly when it matters.
In a steady corner, gravity and cornering force stack up and point straight down the bike’s own axis. To an accelerometer — or the bubble in a level — that looks exactly like sitting upright at a stoplight. So it shrugs and says zero, while you’re pinned at 43° hanging off the inside.
TrueLean does the trig instead. Gyro for attitude, GPS and turn-rate for the physics. The number stays honest through the whole corner — entry, apex, drive — not just when you’ve stopped.
lean = atan(v · ω ÷ g)
v = speed · ω = turn-rate · g = gravity
2°
same corner, mid-apex
43°
what you’re really doing
- g
- Gravity
- a
- Cornering
- R
- What a level feels
Fig.02a — forces on a bike at 35° of lean
Fig.03 — what’s on board
A full cluster. Then the whole ride to play back.
Everything runs on the phone in your mount: live instruments while you ride, a proper replay when you get home.
A live instrument cluster
Big lean gauge, zone colors, max-lean markers, and speed / lean / g tiles with a ride timer. Portrait or landscape, screen stays awake, OLED-dark so it won’t blind you at dusk.
Lean-colored route maps
Every ride plotted and painted by lean angle — straights cool, the spicy bits hot — with a marker on your deepest lean of the day.
Background recording
Screen off, phone in the tank bag — it keeps logging. Set it before you roll and forget it’s there.
0–60 & lateral g
0–60 mph / 0–100 km/h timing and cornering g, from the same fusion. For the bench-racing later.
Export everything
Your data, not mine. Any ride as GPX (with lean + speed) or CSV, straight from the share sheet.
Gloves-on start
“Start my TrueLean ride.” Action Button or Siri — eyes up, hands on the bars, nothing to tap.
All-day battery saver
On long hauls it eases off the screen and sensors to save juice — and never touches recording fidelity.
On-device lean model
A small Neural Engine model sharpens the estimate the more you ride. It learns on your phone and dies on your phone.
Your rides, on every device
iCloud sync keeps your ride history in your own private iCloud, so it survives a lost phone and shows up on the iPad when you get home. It’s yours alone — there is no TrueLean server to sync to. Off in one tap in Settings → iCloud Sync.
Save a ride to Apple Health
Finished rides can go to Health as a workout — start and end time, route, max lean and distance. Off by default, and write-only: TrueLean never asks to read your health data.
A lean ceiling you can hear
Set a ceiling and TrueLean tells you when you’re closing on it — audio cues through your helmet, so the warning lands without you ever looking down at the screen.
Tell it about your bike
Set up a profile for the bike you ride, so its details and settings live in one place instead of being re-entered. One bike for now — TrueLean doesn’t keep separate profiles for a garage yet.
Fig.04 — a ride, start to finish
Mount it. Forget it. Geek out later.
Three taps of setup, then TrueLean stays out of your way until you’re parked.
- 0100:00:00
Mount it & zero it
Clamp the phone to a rigid mount and tap once to zero. Any angle, any orientation — it calibrates to wherever your bars put it. No spirit-level fiddling.
- 0200:00:04
Roll on
Past the speed gate it starts logging lean, line, speed, and g — quietly, in the background, screen off if you want. Hands stay on the bars where they belong.
- 03+2:31:09
Park & replay
Back at the house: lean-painted maps, lean and speed traces, 0–60s, personal bests. Export it, or just bench-race it with your riding buddies.
Your rides never reach us. Ever.
Not your routes, not your lean angles, not a single ride record — because there’s no TrueLean server for them to go to. They live on your phone, and, while iCloud sync is on, in your own private iCloud, which only you can open. No account to make, no SDK phoning home, no cookie banner to swat away. The one thing you can send us is anonymous counts of how the app is used: off by default, asked once, and erasable in a tap.
Read the Privacy Policy →- Accounts
- None
- Servers
- None
- Trackers
- Zero
- Your rides
- Yours only
Fig.05 — before you ask
Straight answers.
Is it actually accurate?
It’s good. It’s not a $30k data logger bolted to a race bike. Everything is an estimate from a phone on a vibrating motorcycle — I say so loudly on the Safety page, and you should believe me.
Where does my ride data go?
Nowhere. There’s no account and no server, so there’s nothing to send it to. It lives on your phone until you delete it or export it yourself.
Can I watch it while I ride?
Please don’t. Set it before you roll and replay it after. TrueLean is built for the couch, not the corner.
Find out what you’re actually doing out there.
Free on the App Store. Bring a rigid mount and an iPhone with a gyro (iOS 17+). I read every email.
review your rides — don’t chase them · shiny side up