v02 · TOOT ENGINEERING

HORAI CLIMB

Climbing performance model · measure, then play, then choose the bike
Part one

The laboratory

Measure the rider and the machine, run one climb, and read the equation of motion term by term. Nothing here is a game — this part exists to produce the numbers everything below depends on. Get the mass, the CdA and the Crr honest here and the rest follows.

01RiderCdA —
Rider + kit + shoes + helmet
Bidons, food, tools
Threshold power, from a real test
Work above FTP — 15 to 30 kJ typical
Adjusts the height-derived CdA
02Bike & tyresCrr —
Complete, with pedals & components
Reference: bicyclerollingresistance.com, 100 psi / 6.9 bar, 42.5 kg load
Used only with tyre = CUSTOM
03Airρ —
Negative = tail wind
04The climb test
05Result
06Equation of motionP = v · (Fg + Fr + Fa) / η
Gravity Rolling Aerodynamic Drivetrain
TermExpressionForce (N)Power (W)Share
07Power demand vs speedstacked resistances
08Gearing & cadencedevelopment —
09What-if against baselineno baseline locked
ScenarioPowerSpeedTimeΔ vs baseline
10Sensitivity — one variable at a timefrom baseline
ChangeΔ time at constant powerΔ power at constant timeΔ speed at constant power
Lock a baseline in panel 04 to populate this table.
Part two

Now play

Pick a course or draw your own, then start taking things off the bike and see what happens. Half a kilo out of the frame. Better tyres. A lower position. The clock at the bottom is the only judge — and the honest answer is usually not the one people expect.

11Choose your courseloads into panel 12
Plan — schematic lengths true, shape invented
Profile — section true elevation
12The course
Held on climbs and flat
0 = pure coasting
Braking limit on descents
Below this the descent power applies
Sitting up, hands on the tops
Tuck on the drops
The rider shifts to keep it everywhere
Cassette taken from panel 08
#SegmentLength (km)Gradient (%)Δ alt
13Start taking things off−0 g
Lighter tubeset or layup — 100 to 1000 g
−100−250−500−750−1000
Cockpit, seatpost, saddle, bolts — 50 to 300 g
−50−100−200−300
Rims, spokes, tyres — 50 to 1000 g
−50−200−400−700−1000
Spare tube, second bidon, tool roll
On the climb testInitialOptimisedΔ
14Marginal gains ladderaerodynamics vs rolling resistance
AerodynamicsNew CdA (flat)Δ time — the climbΔ power — same climb timeΔ time — the whole course
Rolling resistanceNew CrrΔ time — the climbΔ power — same climb timeΔ time — the whole course
15The ridewhite = as it stands · orange = after your changes
SegmentGrad.CdAGear @ cadSpeed / time — initialSpeed / time — optimisedΔ
Part three

TOOT Engineering

No more abstract percentages. Here you pick a frame, a wheelset and a cockpit by name, and the numbers behind them are measured ones — weight on the scale, CdA from the tunnel, validated on two riders of deliberately different build. Three setups at a time, on the same course or on three different ones.

16Equipment databasestatus
17Three setups, one clock
SetupCourseFrameWheelsCockpitΔ kgΔ CdA %
SetupSystem massCdA (flat)Course timeAvg speedΔ vs fastest
HORAI CLIMB v02 · TOOT ENGINEERING · BIANCA ADVANCED INNOVATIONS