FulGaz: How Virtual Cycling Speed is Calculated, Key Inputs, and Realistic Simulation

How does FulGaz calculate speed?

FulGaz calculates speed by integrating real-time power output from your smart trainer with a sophisticated physics engine that simulates rider weight, bike characteristics, gradient, aerodynamic drag, and rolling resistance to accurately replicate real-world cycling dynamics.

The Science Behind Virtual Cycling Speed

Virtual cycling platforms like FulGaz aim to replicate the sensation and challenge of outdoor riding within a controlled indoor environment. A critical component of this realism is the accurate calculation of speed, which directly influences the perceived effort, distance covered, and overall immersion. Unlike a simple speedometer that measures wheel rotation, FulGaz employs a complex model that considers multiple variables, mirroring the physics of real-world cycling.

Key Inputs for Speed Determination

FulGaz's sophisticated algorithms rely on a combination of rider-specific data, environmental simulations, and real-time power metrics to determine your virtual speed. Understanding these inputs is fundamental to appreciating the platform's accuracy.

• Smart Trainer Power Output (Watts): This is the most crucial input. Modern smart trainers accurately measure the mechanical power you are producing at the rear wheel. FulGaz takes this real-time power data and uses it as the primary force driving your virtual avatar forward. The higher your sustained power output, the greater your potential speed.
• Rider and Bike Weight: Your combined weight (rider + bike) is a significant factor in how power translates to speed, particularly on inclines and during accelerations. FulGaz requires you to input your accurate body weight and often estimates bike weight, or allows for its input, to correctly calculate the force required to move this mass against gravity and other resistances.
• Simulated Gradient: When riding a virtual route, FulGaz interprets the gradient data embedded in the video. Your smart trainer then adjusts its resistance to mimic the feel of climbing or descending. The physics engine uses this gradient, along with your power and weight, to determine your speed – you'll go slower uphill for the same power, and faster downhill.
• Aerodynamic Drag (CdA): Air resistance is the dominant force opposing a cyclist at higher speeds on flat terrain. FulGaz incorporates a simulated aerodynamic drag coefficient (CdA), which accounts for your frontal area and how aerodynamically "slippery" you are. While a precise individual CdA is difficult to measure without a wind tunnel, FulGaz uses an estimated value based on typical cycling postures and scenarios. As your speed increases, the effect of aerodynamic drag grows exponentially, requiring significantly more power to achieve even small speed increments.
• Rolling Resistance (Crr): This refers to the friction between your tires and the road surface. While less impactful than aerodynamic drag at high speeds, it's a constant force that must be overcome. FulGaz's physics engine includes a coefficient of rolling resistance (Crr) that simulates the drag from various virtual road surfaces.
• Mechanical Drivetrain Losses: A small percentage of your power is lost due to friction in your bike's drivetrain (chain, gears). While often a minor factor, a comprehensive physics model will account for these efficiency losses.

The FulGaz Physics Engine: Power-to-Speed Conversion

At its core, FulGaz employs a sophisticated physics engine that constantly solves equations of motion, similar to how engineers model real-world vehicle performance. It takes your instantaneous power output and subtracts the power required to overcome all opposing forces:

Power Output = Power to overcome Air Resistance + Power to overcome Rolling Resistance + Power to overcome Gravity (Gradient) + Power for Acceleration

By rearranging and solving these equations, the engine calculates the resulting speed. Here's a breakdown of how the major forces are integrated:

• Aerodynamic Drag: The power required to overcome air resistance is proportional to the cube of your speed (Power ~ Speed³). This means doubling your speed requires eight times the power just for air resistance. FulGaz's engine continuously calculates this force based on the simulated CdA and your current speed.
• Rolling Resistance: The power lost to rolling resistance is primarily proportional to your speed and the Crr. This is a more linear relationship compared to aerodynamic drag.
• Gravity (Gradient): When climbing, the power required to lift your combined weight against gravity is proportional to your speed, weight, and the sine of the gradient angle. Conversely, on descents, gravity assists your motion.
• Inertia and Acceleration: When you accelerate, power is used to increase your kinetic energy. The physics engine accounts for the inertia of your combined mass, meaning more power is needed to quickly increase speed, especially from a standstill or at lower speeds.

FulGaz's engine is designed to dynamically adjust these factors in real-time, providing a highly realistic simulation of how your power translates into speed on varied terrain and conditions.

Achieving Realism: Considerations for Accuracy

While FulGaz's calculations are highly advanced, several factors influence the practical accuracy and perceived realism:

• Accurate Rider Data Entry: Ensuring your correct weight is entered is paramount. An incorrect weight will significantly skew speed calculations, particularly on climbs.
• Trainer Calibration: Regular calibration (e.g., spindown test) of your smart trainer ensures its power meter is accurate and that the resistance it applies precisely matches the demands from FulGaz's physics engine.
• Estimated CdA and Crr: Since individual aerodynamic profiles and tire types vary widely, FulGaz uses generalized estimates for CdA and Crr. While these are generally good approximations, they may not perfectly match your specific real-world setup.
• Environmental Variables: While FulGaz simulates gradient and general wind resistance, it doesn't typically account for dynamic wind changes, road surface textures, or other nuanced environmental factors that affect speed outdoors.

Optimizing Your FulGaz Experience

To ensure the most accurate and immersive speed calculation experience on FulGaz:

• Verify Your Rider Profile: Double-check your weight in your FulGaz profile and ensure it's up to date.
• Calibrate Your Trainer Regularly: Follow your smart trainer manufacturer's recommendations for spindown or calibration.
• Understand Different Modes: Be aware that "ERG mode" (where the trainer maintains a set wattage regardless of your cadence) will feel different from "SIM mode" (where the trainer resistance changes with the terrain, and your speed is calculated dynamically). For a realistic speed experience, SIM mode is generally preferred.

By meticulously combining real-time power data with a comprehensive physics model, FulGaz delivers a highly engaging and scientifically grounded virtual cycling experience, translating your effort into a realistic on-screen speed.