LAMBDA Racing

ROAD BIKE GEOMETRY AERODYNAMICS SIMULATOR (switch to the german version)

Dipl-Ing. Jan Smekal © 2026
www.lambda-racing.de

Live Analysis

Saddle Drop
(Saddle minus Handlebar height)

-- cm

Reach (Saddle)
(Saddle center to Tops)

-- mm

Knee Angle

--°

Hip Angle

--°

Shoulder Angle

--°

Back Angle

--°

Knee-Pedal Distance

-- cm

Center of Gravity (F/R)

--% / --%

CdA (Drag)

Required Power

-- W

Quick Guide

The simulator works best on a PC/Laptop.

Step 1: Enter rider anatomy (at the bottom).

Step 2: Enter frame geometry or select a bike.

Step 3: Adjust settings and have fun.

Settings are saved when closed.

-------------

Guidelines

Knee angle (at 3 o'clock / 90°) = 110°-115°

Pay attention to the angle of your feet. It varies from person to person.

Guidelines & Proportions

Target Saddle Height (0.883 x Inseam)

-- cm

Reference Crank Length (0,195 x Inseam)

-- mm

Top Tube Length (effective)

-- mm

Stack-to-Reach (STR) Frame

Thigh / Shin Ratio

Inseam / Height Ratio

HANDLEBAR TYPE / GRIP POSITION

Ride Data & Resistance

Speed (for power calculation) 35 km/h

Road Gradient (careful, can be exhausting) 0 %

Altitude (meters) 0 m

Temperature (°C) 20°C

Tires

Surface

Air Density (Rho): 1.225

Crr Value: 0.0035

Riding Position

Crank Position 0° (Top)

Foot Angle 10°

Elbow Angle 130°

Only affects 'Tops' position

Handlebar Width (between hoods) 38 cm

Only affects power in 'Aero-Hoods' position

Adjustments

Spacers (plus 5cm for headset / stem) 2.0 cm

Saddle Setback (Offset) 0.0 cm

Stem Length 120 mm

Crank Length 170 mm

Bike Selection

Frame Type (Generic)

Lambda : Twin Force -- Road + Gravel

AVENGER : Everest -- Light Road

AVENGER : Gravel Speeder

AVENGER : Phantom II -- Track

Frame Geometry

Saddle Height (BB to Saddle) 73.1 cm

Seat Tube Angle 73.7°

Head Tube Angle 72°

Reach (Frame) 383 mm

Stack (Frame) 569 mm

Head Tube Length (visual only) 157 mm

Rider Anatomy

Body Height 180 cm

Scales all limbs proportionally.

Inseam 82.8 cm

Scales legs proportionally.

Shoe Size (EU) 44

L: -- cm

Weight (Rider) 75 kg

Thigh 47.2 cm

Shin 42.2 cm

Torso Length 59.4 cm

Arm Length 58.3 cm

Torso

Arm

Leg

Foot

Frame

Head Tube

Knee Plumb

Center of Gravity

Shadow

Link copied to clipboard. You can now save or share it.