User-facing summary of what's changed, newest first.
What's next
Summary numbers now explain themselves. The cover names Good, Watch, Off target and No verdict without relying on hover, Neutral motion says what it estimates and that it is inferred from GPS/lean rather than throttle or brake sensors, and every cover figure links straight to its exact KPI definition. Evidence messages that quote a minimum or uncertainty now include the unit too.
The lead finding now shows you the corner, not just its number. Summary highlights the exact corner, says what the existing evidence found different and what to try next, and puts Coaching first for understanding; Inspect telemetry opens Analyze on the same reference lap and corner. Coaching shows the same location, and corner labels no longer force a T prefix.
Coaching is simply Coaching on road and circuit sessions. The navigation no longer adds a permanent “No road profile” warning on road runs; open Coaching and the workspace itself explains the current road limitation.
The lateral G figure now says it is a model — and shows you whether it holds up. Where the app works cornering load out from lean angle it is labelled modelled, not "derived", because it did not watch that happen: it calculated it. A new Lateral G check in Session data compares that calculation against the path your GPS actually recorded and reports how closely the two agree, along with what the comparison is based on. A value near 1.00 means they match. The one thing the model cannot see is your body position, so it reads low when you hang off — the check says that plainly, and says so instead of showing a number when your session has too few fast corners to tell.
Lateral G readings are lower, and closer to the truth. When the app works your cornering load out from lean angle, it now allows for the fact that a real tyre has width, so the contact patch moves to the inside of the corner as the bike rolls. The old calculation assumed a knife-edge tyre and read 9–25 % high against your GPS trajectory. Numbers in the cursor, the signal strip and the G-G diagram all drop accordingly; nothing about how you rode has changed.
Acceleration labels now match what you are seeing. Analyze switches its cursor, signal strip, controls and G-G diagram together between measured accelerometer channels and derived G.
Clearer evidence at first glance. The public homepage now leads with Analyze's satellite route and synchronized telemetry, while Compare's red/green gain-and-loss route stands out more clearly over the map without changing the measured delta.
Coaching now says what is different about the slow corner. Once a session pins repeatable time loss to one corner, the finding opens into what measurably differs there against your own best lap: where speed starts falling on the approach, how fast you are at the slowest point, your speed entering and leaving, how long the corner runs with no speed change the recording can resolve, and how far your path sits from the path your best lap took. Every line shows its size, its ± margin, and which channel it came from. It will not tell you that you braked too hard or should have opened the throttle earlier — your device records neither — and it compares you only to yourself, never to an ideal line. When several differences appear at once they are listed side by side, and the app says plainly that it cannot rank one of them as the cause. Differences it cannot separate from measurement noise keep their number and lose their sentence, with the reason shown. This needs a recording at 20 Hz or better; below that, which includes standard ~1 Hz exports, each comparison is named along with the frequency it would have needed rather than left blank.
A clearer first look. The public homepage now shows what Trackday Analyst can prove, then opens a real session in one click.
You can close a session — and the app stops pretending.Close session now sits in the Load session panel: it clears the open file and returns you to the welcome screen, while your saved Progress, notes, and preferences stay exactly where they were. Before you load anything, only Summary and Progress are offered, instead of workspace buttons that have nothing to show.
Every workspace opens where you meant to look. Jumping from Summary to Compare now lands at the top of the comparison — its heading, the delta at the flag, and the map — instead of dropping you mid-page. Coming back to a workspace you already visited returns you to where you left it.
A better session report on a phone. The map now arrives within the first screens: key figures compact into two columns, and the map spans the full width without hiding any detail. If your device asks for reduced motion, the app moves you instantly instead of scrolling.
Usable without relying on sight or a mouse. Time and distance sliders now announce the position, lap, and sector they are on; gains and losses are labelled in words and signs rather than only red and green; and the speed, lean, delta, and G-G charts carry readable text beside them.
Your files stay on your device — and history is recoverable. Every file picker now says processing stays in your browser. Removing a Progress record asks first and offers a short Undo window.
A calmer, clearer top bar. Five workspaces now read as normal navigation, while Help and Preferences keep secondary controls together. Load session stays prominent, and your appearance and analysis-default choices are still remembered on this device.
Coaching has its own tab. What the session shows about your riding now lives beside Summary, Analyze and Compare instead of being buried inside Analyze. Summary keeps the one finding that matters, with a button through to the rest. Inside the Coaching tab verdicts are shown as quiet outlines rather than filled markers — that screen is about evidence and its limits, not a scoreboard.
Your session report now says whether each number is good. Summary's key figures carry a green/amber/red marker against targets you can read by hovering — and where your data cannot support a verdict, you get a marker explaining why rather than a colour. Best lap stays unmarked on purpose. Typical pace is replaced by a lap-time consistency figure, which says the same thing without looking like the ideal gap repeated.
Records first, sources visible. Progress now opens with your personal best and improvement; Session data is a compact appendix that shows where every telemetry channel comes from.
Your session opens as a report. Summary now leads with the circuit, key lap figures, a map, and a lap ladder; the app starts in the light theme on a first visit.
A clearer corner to work on. When the data is strong enough, Summary now names the corner that repeatedly costs the most time versus your best lap, without guessing why.
More useful Summary. Best lap and ideal gap now sit beside typical pace and inferred neutral-motion share, while repeated coaching numbers are removed in favour of a focused next-session finding.
More honest neutral-motion comparison. Compare now labels the value as an inferred motion estimate, not brake or throttle use; it shows the factual difference between your two laps without a universal good/bad verdict.
Evidence-based coaching profiles in Analyze. Ranked opportunities use your own demonstrated sector times, with reference values, consistency context, and data-confidence limits visible. They do not claim brake, throttle, body-position, or other unrecorded evidence.
Prioritized coaching cards in Debrief. The most useful evidence is presented as a focused next-session experiment, with expandable values and honest empty states.
Quieter coaching. Analyze now keeps one coaching panel, with a focused recommendation first and supporting advice and evidence available when you need it.
Clearer Analyze layout. Telemetry, laps and sectors, and corners are now selected one at a time below the map.
Simpler navigation. Summary is now a normal workspace tab, while Racing is a quick Analyze control and Session data opens from its quality indicator.
Sharper visual hierarchy. Important session figures and coaching stand out more clearly, while detailed evidence stays quieter until needed.
A calmer, clearer visual system. Light and Dark now use distinct paper/sheet/plate materials, while lap times and telemetry line up in tabular figures.
A cumulative time-delta view on Compare's elapsed-time axis, so you can see where time moved against the clock as well as around the lap.
Longitudinal and lateral acceleration overlays in Compare, alongside the speed and lean traces.
Road segments you define yourself, instead of only the ones the app detects.
v0.8 — Sensor fusion for better accuracy and robustness
Roll-rate readings on RaceBox sessions are now noticeably more accurate and more robust, combining the gyroscope with the lean-derived value instead of relying on lean alone. Corner tables mark the improved source with a small gyro label in the column heading.
Session data shows the improved roll rate beside the older, noisier lean-derived one, with sample status and stated limitations, so you can see exactly what changed. Pick a complete lap to make the comparison easier to read.
Sessions without a gyroscope, including Diablo GPX, keep the existing lean-derived calculation and are otherwise unchanged.
The How it works page explains the method and its limits in full.
v0.7 — Map clarity, methodology page, polish
A new How it works link in the top bar (beside Guide) opens a public page explaining the engineering behind the analytics: how lean and lateral load are handled, how corners and braking zones are detected, how lap/sector timing and the cumulative time delta are built, and what the coaching does and does not claim. It is honest about its limits — the roughly 1 Hz sampling, the fixture-tuned thresholds, and why the raw accelerometer is set aside in favour of GPS- and lean-derived values.
The map is easier to read: S1 now shows in every view including Full session, numbered corner markers are violet circles clearly distinct from the slate-blue sector-gate labels, and Color by → Lean is far more vivid at moderate lean angles with a legend showing the real blue/silver/orange scale instead of a generic rainbow.
A Corners button in both Analyze and Compare shows or hides the numbered corner markers. It starts off, so the map stays uncluttered until you want them — and Analyze can now show them too, not just Compare.
Analyze is quieter: telemetry-outage warnings no longer repeat above the map, and the full threshold, classification, and outage details stay together in Session data. Derived-acceleration views show a compact ! that opens the full explanation there.
The Display menu now offers just Dark and Light. Your existing theme choice carries over automatically, and labels that used to be nearly unreadable in one theme are legible in both.
Demo sessions download only when you choose one, making the initial app load lighter. If a demo cannot load, you can retry without losing the session already open.
v0.6 — New identity, Analyze insights, theme simplification
Trackday Analyst has a new identity: a shared blue, silver, and orange chicane mark across the app top bar, welcome screen, and browser tab.
Circuit sessions now open with plain-language headlines about available lap potential, the sector that varies most, and lap-time consistency.
Corners is available in Analyze, not just Compare. Select a complete circuit lap to review entry, apex, exit, lean, and roll-rate data, and choose a row to jump the map cursor to that corner.
Analyze keeps the map in view on desktop with a single page scrollbar, acceleration labels that say what they measure, and compact telemetry controls you can open when you need them.
Telemetry-quality detail moved out of the way: an amber or red triangle appears on Session data when quality needs attention, with a short explanation on hover and the full details a click away.
The welcome screen now shows a real Compare example of where time is gained or lost, Export stays out of the way on phones, and corrupted saved settings or custom circuit entries can no longer stop the app loading.
v0.5 — Progress grouping, backup, user guide, mobile fit
A Guide link in the top bar opens the full user guide (and changelog) in a new tab, served directly from the app.
A new Local data panel in Progress explains that everything the app remembers is stored only in this browser, and lets you export it all as one JSON file and import it back — for example when moving to a new device.
Progress groups sessions by the app's recognized circuit identity rather than the file name, so RaceBox exports and misspelled files land with the right track, and mountain roads are named properly instead of appearing as "Road segment N". Older sessions get a one-time migration.
Session data gained a notebook for motorcycle, tyres, front/rear pressures, and a free-form note, remembering bike and tyre names locally as suggestions for later recordings.
Compare highlights the largest local gains and losses as navigation cards and focuses one matched corner at a time with synchronized speed, lean, and time-delta plots while the map marker follows. Recognized circuits show S2/S3 gate lines, and sector deltas pair signed times with proportional green/red bars.
The app now fits phone screens properly: workspace tabs stay above the content, Analyze and Compare controls wrap instead of widening the page sideways, and lap/telemetry controls start collapsed behind clear summaries.
v0.4 — Corners, circuit database, RaceBox CSV support
RaceBox support. Load a RaceBox (GPS + IMU trackday logger) session from its CSV export — laps, speed, lean angle, longitudinal and vertical G, and the track map all work exactly like a Diablo session, and a RaceBox recording is included as a bundled sample. Only the CSV export is supported, as it carries the richest data of the four; dropping an unsupported format now gives a clear error. RaceBox is not connected to the bike's electronics, so there is no throttle, brake, RPM, or gear data.
Circuit recognition and database. The app recognises known circuits automatically and loads their bundled defaults, and tells the Hockenheimring GP and IDM layouts apart from GPS track dimensions. A Settings → Track panel lets you edit sector gate positions, rename corners, reset to defaults, or save an unrecognised track as your own custom circuit, all stored locally.
Official turn numbers. On recognized circuits, corner markers, tables, and coaching summaries use the circuit's real turn numbers — with letter suffixes for split corners (Turn 3a, Turn 3b) and dashes for sweepers (Turn 3–4) — instead of arbitrary detected sequence numbers. Unrecognized tracks fall back to sequential numbering.
Theoretical ideal lap and run anywhere. Sector splits can now be derived by detecting gate crossings, so sessions without recorded splits still build an ideal lap and populate the Compare lap picker. Point-to-point road segments split into three distance-based sectors and get a theoretical ideal run for each direction, with the contributing runs shown.
Coaching by time lost, and honest G-G. Worst-corner coaching now ranks corners by the time you actually lost in seconds, not by speed drop. The corner table shows entry, minimum, exit, and speed-lost side by side with soft-edged braking bands, replacing falsely precise braking-distance claims that carried ±30–55 m of noise at 1 Hz. On a leaned-over motorcycle the G-G diagram defaults to the meaningful lean-derived friction circle, with footnotes explaining which source is active and why.
More accurate lap and sector times. Times now estimate the exact moment you crossed the line between the two nearest recorded points rather than using the next sample, so they are accurate to about a tenth of a second instead of a full second, and S1 + S2 + S3 sum exactly to the lap time. Your Compare lap selection is also remembered across reloads.
v0.3 — Redesigned workspaces, map modes, data-quality model
A persistent top bar and easier loading. The app name, the four workspace tabs, and a Load session button stay visible however far you scroll, and you can drop a .gpx file anywhere in the window rather than onto one drop zone. With no session loaded you get a friendly welcome screen showing the bundled samples as named cards.
Two-pane Analyze and Compare. At desktop widths (1200px or wider) both views split into a sticky left pane — track map, selectors, cursor inspector, replay controls, live readouts — and a scrolling right pane with the telemetry charts and detail tabs, so the map stays beside the data instead of scrolling away. The map re-frames itself when the window or panels resize; narrower screens fall back to a single map-first column.
Map modes and overlays. A satellite/schematic mode toggle on the map, direction-of-travel arrows along the track outline, a bright green start-finish gate marker, and a neutral track colour that stays distinct from the comparison line and heatmap layers.
Coaching diagnostics surfaced. Compare gained coasting-analysis cards and a corner apex diagnostics table comparing minimum speed, apex lean, and entry roll rate between both laps; click a corner row to jump the cursor straight to that apex. Analyze grouped its secondary panels into collapsible Insights sections with a compact Export toolbar.
Honest data quality. Recording gaps are classified as genuine outages, stationary stops, or suspended transit, so a normal break in the paddock no longer raises a warning, with a full gap breakdown in Session data. Lean angle reads as 38.2° R / 38.2° L instead of raw signs, and computed values carry a small derived badge so you know what the app calculated.
Visual polish. Calmer, standardized typography and headings, clean horizontal table gridlines instead of harsh grid outlines, fewer redundant boxes and borders, and top-bar and table layouts that hold together down to 360px without horizontal scrollbars.
G-G friction circle. Analyze gained a G-G diagram plotting lateral against longitudinal acceleration — resizable, with real numbers underneath (max lateral, longitudinal, and combined g), colourable by speed or sector, and clickable to jump the cursor to that exact sample. Compare overlays both laps on one circle with stats side by side. Where a single lap's raw accelerometer barely moves, the app says so explicitly rather than showing numbers that look meaningful but aren't.
Progress history and export. A Progress view tracks your best lap time over time per circuit using browser storage, and Export downloads a PNG snapshot of the track outline plus a CSV of derived lap statistics.
Automatic circuit recognition. The app recognises where you rode from the track shape itself, not just the file name, so differently named files group together in Progress, and Compare gives an honest check of whether two sessions are really the same circuit instead of silently lining them up regardless. It works entirely on your device from the GPS already in the files — no map lookup, nothing uploaded.
Coaching summary and map notes. Compare explains in plain language where time went: which sector cost the most, and which corner you carry less speed through and by how much, all built from numbers it already shows you. Analyze lets you drop short text notes pinned to a spot on the map, saved on your device and matched back to the same circuit in later sessions.
Lap consistency and multi-lap overlay. Every lap at a glance with the best complete lap in green and the unfinished in-lap clearly hatched, showing each lap's time lost to the best; click a bar to focus that lap everywhere. A separate overlay chart shows any number of complete laps' speed traces on one shared distance axis.
Named acceleration axes and clearer readouts. The raw X / Y / Z channels became Longitudinal (aX), Lateral (aY), and Vertical (aZ) everywhere they appear, with the honest note that the recorded longitudinal reading is a direction indicator rather than a real braking-G number — braking is still worked out from speed. Road sessions get run-based summaries instead of being described as having "0 laps", Compare can switch between distance and elapsed time, and repeated mountain-road traversals are recognized in both directions with separate uphill and downhill bests.
v0.1 — Track viewer: import, map, laps and sectors
Load a session and see your line. Open a Diablo GPX file to plot your ride on a satellite map, scrub through it with synchronized speed, lean, and acceleration charts, and read per-lap and per-sector times, plus a speed heatmap on the map.
Compare two laps. Pick two laps from the same session, or from two different session files, and see them overlaid on the map with a time-delta trace showing where you gained or lost time.
Delta map, ideal lap, and ghost replay. Colour lap B green/red to show exactly where you gained or lost time against lap A, combine your best sector times into a theoretical ideal lap to see how much time is on the table, and replay both laps as two markers moving around the map together with play/pause, scrub, and speed controls.
Braking and corner metrics. Compare detects individual corners and tables entry, minimum, and exit speed corner by corner between your two laps, with numbered corner markers on the map.
Mountain-road support. Point-to-point road and mountain rides are supported too, not just circuit track days: sessions with no laps are analyzed as uphill/downhill runs with their own comparison view.
Workspaces and usable charts. The app split into Analyze, Compare, and Session data, with a clearer Analyze layout (session header, laps list, map, fixed readout panel). Charts gained labeled axes, hover previews, click-to-pin, and keyboard navigation, and you can hide individual telemetry channels or zoom into part of the timeline without losing sync with the map.