-Featured Product
Know your real payload number before the trail does. Rig-Locker runs Static Stability Factor, center of gravity, and axle-by-axle GAWR against your exact build. Stability comes back as degrees of safe side slope, not a color. Built by an engineer with 33 years in aerospace composites, not an app company.
▪ OEM-published specs for every vehicle in the database. Center of gravity from NHTSA NCAP measured data where it exists, labeled as an estimate where it does not.
▪ One rollover scale for every rig: the NHTSA rollover-star break points. Vehicles over 10,000 lb GVWR are flagged, since NHTSA does not rate that class.
▪ 30-day money back on Pro. Ask for a refund, get one.
See it on a real rig: Jeep Wrangler Rubicon payload — what you can actually carry. Related reading: Best Overlanding Apps and Overland Packing List.
Rig-Locker Lite — Free. Start here.
Check your loaded weight against GVWR and each axle, see your Static Stability Factor and safe side slope, plan fuel range, pick gear from the built-in item catalog, and run a pre-trip health check. Free, permanently. No card, no account, no email. Opens in your browser and works offline.
Rig-Locker Pro — $129 one-time
Everything in Lite, plus you place every item on a 3-D view of your rig, so axle split, left/right balance and center of gravity come from where the weight actually sits. Adds lift and tire CG, tilt limits, loaded tire pressure, towing and GCWR, a 12V amp-hour audit with a 7-day projection, route legs with fuel stops and tilt checks, an OEM baseline that shows what your build cost you in payload and slope, packing templates, budget, trip history and a maintenance log. Optional CAT-scale calibration so the numbers match your ticket, not an estimate.
Founding price: $129 one-time, regularly $179. First 150 rigs. Pay once, own it forever. 30-day money back.
Know Your Rollover Numbers Before You Roll Out
Real output from a loaded 2025 4Runner Trailhunter build (2 people, 5 days, 125 lb rooftop tent). PRO calculates all of it from the exact spots you place your gear — before every trip.
- Front axle: 3,083 / 3,100 lb GAWR — 99%, 17 lb spare. A GVWR-only check never shows you this.
- Payload: 469 of 655 lb used — 72%
- Loaded SSF: 1.08 — ELEV on the NHTSA rollover-star scale
- Static tilt limit: 47° · safe side slope ≈ 24° (half the tip-over angle, our safety margin)
- Loaded CG height: 31.1 in (stock 30 in, estimated)
- Roof load: 125 / 150 lb
SSF rollover risk calculated with the NHTSA formula. Stock CG for this model is an estimate. Estimates for planning only — confirm axle weights at a certified scale before departure.
The Dashboard for the same rig — payload, each axle against its GAWR, and safe side slope, all from where the gear sits.
Weigh It Once. Trust Every Number After That.
Every payload app on the market is guessing. It takes your gear list, adds up the weights you typed in, and hands you a number.
Rig-Locker Pro doesn’t have to guess. Take your loaded rig across a CAT scale, enter the steer and drive axle weights off the ticket, and the app corrects itself — permanently. From that moment on, every axle load, every GVWR and GAWR margin, every alert, every tire pressure recommendation and towing calculation is anchored to what the scale actually said, not to what the model assumed.
The correction is per-rig. Calibrate the Tacoma, and the Tacoma is calibrated — your other vehicles are untouched. Change your loadout enough to drift from the ticket, and the app tells you it’s time to re-weigh.
A scale ticket costs about twelve dollars. It’s the cheapest accuracy you will ever buy.
Look for the CALIBRATED tag on your Payload Calculator — that’s the app telling you it’s running on real numbers. (Pro only.)
It Lives on Your Home Screen. It Works Where There’s No Signal.
Rig-Locker isn’t something you download and install like a program, and it isn’t a website you have to keep logging into. Open it once, enter your key, and add it to your home screen — it becomes an app icon like any other. Full screen. No browser bars. No address bar eating the top of your display.
And it works with no signal at all. Activation needs internet exactly once. After that, the app runs entirely on your device — out at the trailhead, in the canyon, wherever you actually need it. Your rig data never leaves your phone.
1. Open the app. Go to ax-mfg.com/app/pro in your browser. Nothing to download.
2. Enter your key. Your license key arrives by email. Paste it in, tap Activate.
3. Add to home screen. iPhone: Share → Add to Home Screen. Android: ⋮ → Install app.
-Lite vs Pro
What's
Included
Rig-Locker by AX-Mfg
& gear management
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