In the pursuit of optimizing road cycling performance, discussions often revolve around weight, aerodynamics, and rolling resistance. However, what about the efficiency of the rider's pedal movement? Pedal efficiency is frequently overlooked, despite its significant potential to enhance overall performance in road cycling.
With the Bike Fitting Pro, Vélobsessive offers a solution to measure, analyse, and improve pedal efficiency.
What is Pedal Efficiency?
In an ideal world, every ounce of force applied to the pedals would translate directly into forward propulsion for the road bike. Unfortunately, this is not the case in practice. When one leg exerts maximum propulsive force on the crank, the other leg simultaneously counters this movement, creating resistance against the generated propulsion. Additional factors, such as lateral swaying or inadequate synchronization of force application with the crank position, can also impact pedal efficiency. If the rider sways laterally or applies pressure at the wrong moment, it results in inefficient propulsion.
Pedal efficiency is expressed as a percentage, indicating the portion of the total force that is effectively converted into forward propulsion.
There is enormous potential for improvement in pedal efficiency. An average hobbyist rider typically achieves a pedal efficiency of 30-40%, while a professional can reach approximately 60%. These figures highlight the realistic possibility of doubling efficiency.
Measurement and Analysis of Pedal Efficiency
During a Vélobsessive Bike Fitting Pro session, pedal efficiency is precisely measured and analysed. The measurement takes place on the Bike Fitting Simulator over a defined period, incorporating three-dimensional stress. This includes not only vertical force applied to the pedal but also lateral swaying movements and force distribution in relation to the crank position.
Following the measurement, a detailed report is generated, evaluating the following parameters separately for the left and right sides:
1. Total 3D Effective Force Ratio
This value represents the overall pedal efficiency, for example, at 30% (34% left, 26% right).
2. Left/Right Distribution
The percentage distribution of force between the left and right legs, such as 45% right and 55% left.
3. Force Vectors in the Entire 360° Movement
Blue and red arrows represent force vectors concerning the crank position. Red arrows indicate forces hindering propulsion, while blue arrows represent forces contributing to propulsion. The ideal direction for vectors is at 0° forward, at 90° downward, at 180° backward, and at 270° upward. Improving pedal efficiency involves minimising the red arrows and directing the blue arrows optimally.
4. Lateral Deviation of Force
From a rear view, the lateral deviation of force vectors is evident. In this example, the rider applies slight inward pressure, possibly due to a short pedal axle or anatomical reasons.
5. Crank Angle at Maximum Force Development
DThis image summarises the point of maximum force development concerning the crank position. In the example, it's evident that force development in the right leg occurs slightly late (red line) at a crank angle of 119°, ideally happening between 90-110°. The blue line in the line chart should closely align with the respective foot generating propulsion, revealing that the right foot is braking more than the left.
The final image in the report summarises the braking effect of the rear foot and the lateral distribution of force on the pedal. The force impact on the pedal should be centred, and the distribution should be as narrow as possible.
Improvement Measures
After evaluating and analysing pedal analysis data, it's crucial to take appropriate measures for improvement. During the Bike Fitting, testing various crank lengths can assess their impact on pedal efficiency. For instance, shorter crank lengths may lead to a smoother pedal movement and increased efficiency. In cases of lateral swaying, an extended pedal axle might provide a solution.
However, pedal efficiency is generally most improved through targeted and long-term training. After such a focused training phase, it's advisable to conduct a follow-up check and re-measure pedal efficiency.
Conclusion
In summary, pedal efficiency in road cycling is an often-overlooked element in optimising overall performance. Vélobsessive's Bike Fitting Pro provides a solution for precise measurement and analysis of pedal efficiency. The measurement report offers detailed insights, enabling targeted measures for improvement, such as adjusting crank lengths or implementing a focused training programme.