Thompson Speedway road course · Kawasaki ZX-4RR · 31 Aug 2026 · 7 sessions · 29 clean-pace laps · GPS + IMU + OBD

Thompson by the book: your framework, run on one rider's day.

Eric — this sorts Thompson's eleven corners with your rule (roll speed / drive / entrance) from measured track geometry and the bike's threshold-of-traction speed, puts the lines Igor actually rode beside each corner's prescription, and asks whether the prescribed line paid in exit speed on this day. Speeds in mph, distances in feet. Everything is measured; the thresholds we had to choose are stated.

The rule, as applied

Roll speed when the corner's minimum speed is above VTOT — full throttle at full lean cannot spin the rear, so momentum lost is not recoverable — or when the corner is a connecting turn the rider neither brakes for nor drives out of. Drive when the minimum is below VTOT and the exit feeds a long straight. Entrance when a braking entry is followed by a short or no straight. VTOT for the ZX-4RR is set at 50 mph (your 400-class figure); the second map shows 43 mph, the value the app fits from the bike's own wide-open-throttle curve at Palmer.

Our measurements of your words: "long straight" = at least 5 s on the median speed profile from the exit to the next corner the rider brakes for; "brakes for" = the profile dips at least 7 mph before the next slowest point; "carried" (the exit still paying through the next corner) = a dip under 3 mph; "connecting turn" = reached without braking and left with under 12 mph of rise before the next corner — the 12 is set by your own call that T2 is a roll corner (it rises 8 mph out toward T3). Two numbered halves of one corner (T5/T6, 0 mph between them) are judged as one, at T6's exit. Track limits come from aerial imagery and lidar; every lap is placed on the road between them, lean-corrected to the contact patch, so "apex" below means the point where the line runs closest to the inside edge and "centre" means the middle of the arc.

The circuit, sorted

roll speeddriveentrance

Book vs ridden, corner by corner

"Ridden" is the median of the 29 clean-pace laps. Apex = where the line is closest to the inside edge, against the arc's centre (− early, + late). Vmin = the slowest point against that apex (− before, + after). GOBU re-add = share of laps where lean was added back after the throttle was cracked — a gas-on-bike-up violation. ✓ = the ridden shape is the one the book prescribes. A corner entered without braking (T2, T6, T9, T10) has its slowest point at or before its turn-in, so it reads far before the apex.

Each corner

Strip: median line per session through the corner, inside edge at the bottom, outside at the top; the tinted band is tarmac, warm ticks are kerbs, the dashed vertical is the arc's centre. First session dashed, last session bold.

Did the prescription pay?

For each target the book sets for a corner's strategy: laps that met it versus laps that didn't, exit speed relative to the session median, pooled across corners as the median difference; "helps" / "hurts" count corners where the difference is at least 0.6 mph. Only targets with at least three laps on each side count.

What the day said

Read with

Built from the same data and code as the pre-ride plan (2025, Tiger Sport 660) and Palmer. Questions and corrections welcome.