Measuring Pedaling Efficiency: Cycling Dynamics and Torque Efficiency Metrics

Introduction

Your power meter shows 250W, but is that 250W a “high-quality” 250W or a “low-efficiency” 250W? As dual-sided pedal-based power meters like the Garmin Vector and Favero Assioma have become popular in the Taiwanese market, Cycling Dynamics has given riders the first opportunity to see the details of their pedaling technique through numbers. This article will break down the meaning of each metric and how to use this data to improve your training.

Analysis of Core Cycling Dynamics Metrics

1. Left/Right Balance

The most intuitive metric: the power output ratio between your left and right legs. The ideal value is 50/50, but most riders have a 3–5% asymmetry.

• Asymmetry exceeding 6% requires attention, and may stem from: compensation for old injuries, leg length discrepancies, or saddle position offset
• Important note: Chasing 50/50 isn’t necessarily correct—minor asymmetry caused by skeletal structure is a normal physiological phenomenon

2. Effective Pedaling Arc (EPA)

Indicates the range of crank angles (in degrees) over which effective force is applied during one pedaling cycle.

3. Torque Effectiveness (TE)

Represents the proportion of effective tangential force relative to total force applied (%). The calculation formula is based on a comparison between positive force (propulsion) and negative force (resistance):

• High TE (>85%): Most of the force applied is in the effective propulsive direction
• Low TE (<75%): There is noticeable “back-pedaling” or dead force

4. Pedaling Smoothness (PS)

Measures the evenness of power output—the ideal pedal stroke should deliver power as evenly as possible throughout the entire cycle, rather than surging only at the “peak force angle.”

• The higher the PS (closer to 100%), the smaller the power fluctuation, resembling the smooth output of an electric motor
• In practice, a PS of 60–75% is already a fairly good level

Interpreting Data in Different Scenarios

Climbing vs. Riding on Flat Roads:
When climbing, due to high torque demands and low cadence, a general drop in pedaling smoothness is normal. Seeing your PS drop from 70% on flat roads to 55% on the Wuling climb in Taiwan is nothing to panic about.

Metric Changes During Fatigue:
In the latter stages of long-distance rides, EPA and TE typically both decline. If you observe these metrics deteriorating rapidly during training, it may be a sign of energy depletion, and you should consider refueling or reducing intensity.

Technical Improvement Training Plan

Base Phase (2 sessions per week, 15 minutes each):

• Single-Leg Pedaling Drill: 10 minutes per session, aimed at improving EPA and developing a feel for passing through the dead spots
• High-Cadence Training (100–110 RPM): 10 minutes, focusing on smooth pedaling, with a target PS of >70%

Advanced Phase:

• Segment-Specific Target Setting: On the trainer, set a “target TE >85%” and perform 20 minutes of steady-state pedaling
• Real-World Validation: Climb on the Yangmingshan routes in northern Taiwan (e.g., from Ge Wai Farm to Zhuzihu) and observe how the metrics change with gradient

Practical Recommendations

1. Record your average TE and PS for each training session to establish a personal baseline, then track trends on a weekly basis
2. Don’t chase all metrics at once—it’s recommended to focus on improving just one metric per training cycle
3. Cross-reference historical data in Garmin Connect or TrainingPeaks to more easily spot technical progress
4. Note: Different power meter brands calculate Cycling Dynamics slightly differently, so avoid direct cross-device comparisons
5. Technical training during the off-season rest period is more suitable for extensive drill practice than during the racing season

Conclusion

Cycling Dynamics has given pedaling technique a quantifiable language for the first time. No longer do you have to rely on feel and say “my pedaling feels rough”—you can now precisely state, “My effective pedaling arc is only 85 degrees, and I need to improve my technique through the top dead center.” Data-driven training is now standard equipment for the modern competitive rider.

Related Reading

• Road Bike Pedal Efficiency Analysis: How to Improve Your Pedaling Technique
• Quantifying Pedaling Smoothness: A Study of New Analytical Metrics for Power Meters
• Quantifying Cycling Efficiency (GE/PE): How to Become a More Economical Rider
• Pedaling Smoothness Training: Advanced Technical Workouts to Improve Pedaling Efficiency