Rollcage assessment tool — User manual

Introduction

The Rollcage assessment tool by Frog Racing lets you describe a roll cage once — its design, tubing, installation, welds and seats — and builds a live 3D model of it, rates it with the Frog Safety score, and checks it against the rules of your sanctioning body (ARA, NASA Rally Sport, CARS and others).

It is a pre-screening tool, not a certification: a scrutineer still inspects the car and issues the logbook. Use it to plan a build, check a kit before you buy it, or prepare for a logbook inspection.

What you need: a recent desktop or tablet browser (Chrome, Edge, Safari or Firefox). There is no account and nothing to install. Your work is stored in your browser on this device only — read Saving, exporting and importing before you put real work into it.

First visit: a short guided tour opens the first time. You can replay it any time with How it works at the top right; User manual opens this manual. The YouTube logo next to them plays the FIA Article 253 Rollcages Tutorial video.

The screen at a glance

At the very top, the YouTube logo plays the FIA Article 253 Rollcages Tutorial video, How it works replays the guided tour and User manual opens this manual. Below them, the top of the screen stays in view while you scroll: the rollcage's name, the part selector and the 3D model.

1. Rollcage name — type a name; it's the name the rollcage is saved under in the library.
2. Unsaved changes — appears as soon as anything changed since the last save. Click it to open the library, where Save is.
3. Rollcage library — your saved rollcages, the templates, and Save, Save as, PDF report and Export (see The Rollcage library).
4. 3D Model — shows or hides the model.
5. Part selector — the eight parts of the assessment, in order. Pick one to work on it.
6. 3D model — drag to turn it, scroll or pinch to zoom. Reset returns to the default view, Ghost bars shows the bars you could add in grey, Occupants shows the driver and codriver. Click a bar to jump to its question.
7. Frog Safety score — the cage's safety rating, updated as you answer (green when positive, red when negative). Part 8 explains how it's made.
8. Picture button (bottom right) — opens the rollcage pictures from Part 1.

Cards and colours. Each question is a card. A green bar on its left means it's answered and passes, red means it fails, and yellow means it still needs an answer or a check. Answered cards fold up to one line showing the answer; click a card to open it, and Collapse to fold it again.

The Rollcage library

The library is where every rollcage starts and where you save it. It opens by itself on your first visit; after that, open it with Rollcage library at the top right. Back to editing (or Close) returns to the rollcage you were working on.

At the top:

• Start a new rollcage — a blank rollcage.
• Import a rollcage from file — opens a .json file exported from this tool or from the Digital logbooks app.

The library has up to five sections, each in its own colour:

Each card shows a snapshot of the 3D model, the car's photo or the kit's product page, and its Frog Safety score in the top left corner (green when positive, red when negative).

Click a card to see what you can do with it. On a template, kit or sample, Start from template opens a copy as a new, unsaved rollcage — the template itself never changes. Its pictures and tags come with it.

On one of your saved rollcages the buttons are Load, PDF report, Export to file and Delete (see Saving, exporting and importing).

If the rollcage you're editing has unsaved changes when you load or start another one, the tool asks first: Save, Discard or Cancel.

Part 1

Vehicle & pictures

Part 1 records the car and documents its cage with photos. Nothing here is judged against the rules, but the photos are what a scrutineer will compare your answers with.

Vehicle description

Manufacturer, model, year, VIN and weight (kg or lb), plus the drive configuration and the occupants. Left- or right-hand drive mirrors the driver in the 3D model; the weight decides the tubing size some sanctioning bodies require.

Pictures

• Video overview — a link to a YouTube video of the cage, played inside the tool (Watch video, Change video, Remove).
• Video walk-around (beta) — record a slow walk-around of the car and cage and pick a file. The tool pulls the clear frames out of it: mark one 3/4 front and one 3/4 rear frame as the vehicle pictures; the frames you keep become rollcage pictures. It preselects about one frame per 5 seconds of video (12 for a one-minute walk-around), which you can change. The video itself never leaves your device.
• Vehicle pictures — one 3/4 front and one 3/4 rear photo of the car. The front one appears on the library card and both go in the PDF report.
• Rollcage pictures — photos of the cage, sorted into categories. Use Choose Files on a category to add photos to it, or Bulk upload with automatic AI sorting (beta) to upload up to 20 at once and let the tool suggest a category for each.

Tagging a picture

Each photo is a small card. The blue number in its corner is how many cage elements it's tagged with; hover it to see the tagged parts. Click the photo to open the card:

• Edit rollcage elements — turn the 3D model to match the photo, click each bar, gusset or foot you can see, and choose its design. Done saves the tags and a Selected parts snapshot of the model.
• AI analysis (beta) — suggests tags from the photo (needs an internet connection). Suggestions are never applied on their own: you accept or reject each one.
• Move to… — moves the photo to another category.
• Delete photo — asks for confirmation; it can't be undone.
• ▴ Less folds the card again; clicking an opened photo shows it full screen.

At the bottom of Part 1, two checks compare the photos with the design: Current design elements not documented in pictures lists the bars and gussets no photo shows yet, and Differences between pictures and current design lists tags that disagree with your answers in Parts 2–6.

Part 2

Rollcage design (bars & gussets)

Part 2 describes which bars, feet and gussets the cage has. Every choice redraws the 3D model at once, so start here when you design a cage.

Open a card to see the choices, each with a picture of that design. The FIA drawing number (253-x) is in the label.

Only the questions that apply are shown: a half rollcage, for example, hides the roof and door bars. Clicking a bar in the 3D model jumps to its card.

Part 3

Tubing sizes & materials

Part 3 records what the cage is made of and how big each piece is. These are the measurements a scrutineer checks with a caliper and a tape.

• Primary tubing — the material, outside diameter and wall thickness of the main structure: main rollbar, laterals, transverse members, backstays and the main rollbar diagonals. Usually 1.75".
• Secondary tubing — the same for the other bars: roof bars, door bars, sill bars, A-pillar reinforcement, harness bar and the optional bars. Usually 1.5".
• Tube specifications — says, bar by bar, whether each one uses the primary or the secondary spec. Clicking a bar in the 3D model jumps to its row.
• Mounting feet material and thickness, and Mounting plate size for each foot.
• Gusset material and thickness — one material for all gussets.

Each card enters inches or millimetres; the minimum sizes come from the sanctioning body picked in Part 7.

Part 4

Installation constraints (angles, distances...)

Part 4 checks how the cage sits in the car: clearances, angles, bends and how close each bar meets its junction. Angles you enter here also tilt the 3D model.

Two shortcuts save measuring every number: tables with many dimensions have a tick box to confirm them all compliant at once, and junction tables have one for all confirmed within 100 mm. In the 3D model, junctions within 100 mm show green, those over 100 mm show red and are drawn slid along the bar, and those not measured yet show as ghosts.

Part 5

Welds

Part 5 records, joint by joint, whether each weld is complete, and the size of each gusset. A cage must be welded all the way round every joint.

• Weld tables — one per group of joints, matching your design: transverse members, mounting feet, tube-to-foot, laterals and backstays to the main rollbar, diagonals, roof bars, sill bars, door bars, 253-15 supports and each optional bar. Mark each weld Yes (complete) or No.
• In the 3D model — double-click near a weld point of a highlighted bar (or a foot) to cycle it: green = complete, red = incomplete, ghost = not checked yet. A bar with several weld points is split into colours along its length, in the same order as its table rows.
• Gusset dimensions — for each gusset: length, corner cut-out radius (R < 1.5 D), hole diameter (H < D) and whether it's welded along its full length. The tube diameter D comes from Part 3.

Your weld answers also answer some sanctioning bodies' grandfathered checks for you, such as No bolt-together cage (Part 7).

Part 6

Seats, belts & routing

Part 6 covers the occupant equipment that attaches to the cage and the body: seat mounts, harness anchors and the lines that run through the cockpit.

• Seat mounting points — the driver's and codriver's seat mount type (stock mounts, or an FIA chassis-shell or crossmember mount with its plate sizes), and each seat's angle and location.
• Belt anchoring points — where each shoulder, lap and anti-submarine strap is anchored (harness bar, stock point, plate…), and how many points the belts have.
• Belt anchor distances and angles — the shoulder-strap distance and angles (FIA 253-61c and 253-61d), the lap belt angle and the 6-point spacing.
• Routing of lines — fuel, brake and electrical lines kept clear of the cage and protected.

The codriver rows only appear when Part 1 says Driver + Codriver.

Part 7

Sanctioning body compliance

Part 7 checks everything you answered against one sanctioning body's rules and gives a verdict. Pick the body you race with; your answers are kept when you switch, so you can compare bodies.

• Sanctioning body — grouped in the list:
  • No sanctioning body (the default): nothing is judged; only the Frog Safety score rates the design.
  • FIA 253 — full checklist: American Rally Association, NASA Rally Sport and CARS, checked item by item.
  • Documentation only: bodies with no automatic check yet.
  • Rollover protection rules (from PassTech), by discipline: only their rollover protection rule is checked — full cage, tubing size for the car's weight, welded plates — and the rest is listed for you to check by hand. Some ask for your class.
• Rules to check against — for bodies with grandfathering rules: New construction (a logbook issued now) or Existing logbook (the older rules for cages logbooked before a cut-off date). Many grandfathered items answer themselves from your design — for example the structure, welds, mounting feet, gussets, apertures and tubing; they show From the rollcage design with links to the answers they come from.
• Verdict — MEETS REQUIREMENTS (green), INCOMPLETE — needs verification (yellow) or NOT COMPLIANT (red), with the count of required items satisfied. Lists of failing and unanswered items follow; click one to jump to it.
• Construction route — FIA/ASN homologated (an exact, unmodified match to its homologation papers, exempt from the rest of the checklist) or FIA 253 Ch.8 custom build. A homologated cage can carry photos of its homologation papers.

Hide details folds Part 7 to its verdict and score.

Part 8

Frog Safety score

The Frog Safety score rates how protective the design is, whatever the rulebook. It's the number in the top left corner of the 3D model and on every library card; Part 8 shows how it adds up.

• Each line is one design choice, with its answer and its points. Stronger designs earn more: a full 253-3 structure earns +20, an X main rollbar diagonal +10, each door bar design and foot design +5.
• Unsafe choices cost points and show in red with an explanation — for example a missing foot or a bar meeting its junction too far away. A cage can score below zero: the Worst cage template shows every warning.
• The links at the top (drive configuration, occupants) take you to the Part 1 answers that change the score. Click any line to jump to its question.

The score only counts what you've answered, so it changes as you fill Parts 2–6.

Saving, exporting and importing

The tool does not save on its own. Your changes live only in the open page until you click Save in the Rollcage library — close the tab or the browser before that and they're gone. Whenever Unsaved changes shows next to the name, save.

Where your rollcages are kept

Saved rollcages and their photos stay in this browser, on this device — nothing is sent to a server. So:

• Another browser, another computer or a phone won't see them. Use Export to file to move one.
• Clearing the browser's history or site data deletes them, and a private or incognito window forgets them when it closes.
• Export the rollcages you care about from time to time: the file is your backup.

Save and Save as

1. Click Unsaved changes (or Rollcage library) at the top.
2. In Currently editing, click Save. It turns to Saved ✓, and the rollcage appears in Saved rollcages with a fresh 3D snapshot.
3. To keep the original and save your changes under another name, click Save as…, type the new name and click Save.

Your saved rollcages

Click a saved card for its actions:

Export to a file

Export to file downloads a .json file named after the rollcage (for example RS4 Rally car -- Froooog.json) into your Downloads folder. It holds everything: the answers, the tags, the vehicle and rollcage photos and the event log. Use it to back up, to move a rollcage to another browser or computer, or to send it to someone else.

• From Currently editing, the file includes any unsaved changes.
• From a saved card, it's the rollcage as last saved.

The file is plain text but large when it carries photos (several MB). Keep it as it is: don't edit it by hand.

Import a file

1. Open the Rollcage library and click Import a rollcage from file.
2. Pick a .json file exported from this tool — or from the Digital logbooks app, which uses the same format.
3. It's added to Saved rollcages as a new entry, with its photos, and selected; click Load to open it.

An import never replaces an existing rollcage, even one with the same name. If the file's sanctioning body isn't offered here, it's set to none and a message says so.

PDF report

PDF report (in Currently editing, or on a saved card) builds a Rollcage Assessment Report and downloads it: the vehicle and its photos, the 3D model from several angles, every answer part by part, the Part 7 verdict, the rollcage pictures with their tags and the Frog Safety score. It's the document to send to a builder or a scrutineer. The first report needs an internet connection to load the PDF maker.

Tips and troubleshooting

• Start from the closest template. A kit or sample with the same layout fills most of Parts 2–6; change what differs, then Save as your own name.
• Work in order. Part 2 decides which questions the later parts ask, so answer it first.
• Use the 3D model as an index. Click a bar to jump to its question in the part you're on.
• My rollcages are gone. They're kept per browser: check you're in the same browser and profile, not a private window. If the browser's data was cleared, import your last exported file.
• The model or a picture looks blank. Turn 3D Model off and on, or reload the page (Ctrl+F5) — save first.
• Something doesn't match my rulebook. The rules are encoded from each body's published documents, and the note at the bottom of the page says what each one covers. The scrutineer's call is final; tell Frog Racing at info@frogracing.us.