自行车齿轮比计算器
计算自行车不同齿轮组合的传动比和速度。
齿轮比
2.94
Gear Ratio vs Front Chainring Teeth
公式
Bicycle Gear Ratios
The gear ratio determines how far the bike travels per pedal revolution and directly affects speed and effort.
Formula
Gear Ratio = Front Teeth / Rear Teeth
Development = Gear Ratio x Wheel Circumference
Speed = Development x Cadence x 60 / 1000
Higher ratios (big front, small rear) mean higher speed but more effort. Lower ratios (small front, big rear) are easier for climbing.
计算示例
50-tooth chainring, 17-tooth rear cog, 2.1 m wheel, 80 rpm cadence.
- 01Gear ratio = 50 / 17 = 2.94
- 02Development = 2.94 x 2.1 = 6.18 m per pedal turn
- 03Speed = 6.18 x 80 x 60 / 1000 = 29.6 km/h
常见问题
What gear ratio is good for climbing?
A ratio below 1.5 (like 34/28) is comfortable for steep hills. Mountain bikes may go as low as 0.85 (24/28) for extreme climbs.
What is gear inches?
Gear inches = Gear Ratio x Wheel Diameter (inches). This older system is still used by track cyclists and single-speed riders.
How does cadence affect speed?
In the same gear, higher cadence means higher speed. Most efficient cadence is 80-100 rpm. Elite cyclists may spin 100-120 rpm in races.
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