What is a Gear Ratio?

A gear ratio is the ratio between the number of teeth on the front chainring and the rear cog, determining how many times the rear wheel rotates for each pedal revolution.

Imagine you're riding a bike. You push the pedals, the chain drives the rear wheel, and the bike moves forward, right? The bicycle gear ratio, simply put, is a proportional relationship between the front chainring (the large gear you pedal) and the rear cog (the small gear on the rear wheel). This ratio determines how many times your rear wheel will rotate when you complete one pedal revolution. It's like an "agreement" between you and your rear wheel. If the agreement is that one pedal stroke makes the rear wheel spin many times, you'll initially feel it's "heavy" and requires more effort, but once you get going, the speed will be fast. If the agreement is that one pedal stroke makes the rear wheel rotate just a little, you'll feel it's "light" and effortless, but the speed will be relatively slow.

How Does Gear Ratio Affect Cycling?

Simply put, the bicycle gear ratio is the "chief conductor" of your cycling experience, directly determining how your power and speed are converted. The core impact is reflected in the following points:

Determines Pedaling Effort

High gear ratio: Pedaling feels heavy, requiring more force, like pushing a heavy barbell in the gym. Low gear ratio: Pedaling feels light and very effortless, like easily climbing a gentle staircase.

Determines Cycling Speed

High gear ratio: One pedal stroke makes the rear wheel rotate many times, so your speed potential is higher, suitable for pursuing speed on flat roads and descents. Low gear ratio: One pedal stroke makes the rear wheel rotate fewer times, speed is slower, but allows you to keep moving on steep slopes.

Affects Cycling Efficiency and Endurance

Proper use of gear ratios allows you to maintain a steady and efficient pedaling frequency (like 80-90 RPM per minute). This prevents premature muscle fatigue, saves energy, and lets you ride farther and longer. Put your effort where it counts!

Protects Your Body

When starting or climbing, forcing high gear ratios (heavy gears) puts enormous pressure on your knees, which can lead to sports injuries over time. Using appropriate low gear ratios can effectively protect your joints.

In summary, gear ratios are like a car's transmission. A smart rider constantly adjusts gear ratios to adapt to different road conditions, with the ultimate goal not to be "faster" or "slower," but to keep their body in the most comfortable and efficient output state.

Gear Ratio Calculation

Gear Ratio = Front Chainring Teeth ÷ Rear Cog Teeth

For example: 50-tooth chainring with 11-tooth cog, Gear Ratio = 50 ÷ 11 = 4.55 What does this number 4.55 mean? It represents that when you complete one pedal revolution, the rear wheel will rotate exactly 4.55 times.

How to Choose the Right Gear Ratio

🚴‍♂️ When starting from a stop:

Strategy: Use low gear ratios.

Reason: Just like a car starting in first gear, low gear ratios allow you to start moving effortlessly with minimal force, while also protecting your knees.

🛣️ When cruising on flat roads:

Strategy: Use medium to high gear ratios.

Reason: Find a gear ratio that feels "just right," where your pedaling frequency (cadence) is neither fast nor slow, and your speed can remain stable. This is the most efficient and comfortable state!

🚵‍♀️ When tackling uphill:

Strategy: Switch to low gear ratios.

Reason: This is the most important application of gear ratios! Switch to a low gear ratio that feels easy before you reach the hill. Remember, the goal is to maintain steady breathing and pedaling rhythm, not to "fight hard" with the mountain.

🌄 When flying down from a hillside:

Strategy: Switch to high gear ratios.

Reason: At this time your speed is very fast, using high gear ratios allows you to continue pedaling and accelerating when needed, rather than letting your feet spin freely.