08 July, 2011
What Road Bicycle Gear Ratio Should I Use in the Hills?
When climbing hills with a bicycle, it can be difficult to maintain an adequate amount of power, speed and cycling cadence. However, using the correct bicycle gear – commonly referred to as the gear ratio – can improve cadence and power transfer, which will increase your ability to climb the hills. The gear ratios you use in the hills are dependent on numerous factors, such as fitness level, grade of the hill and desired cadence.
Power transfer while climbing hills is a combination of the specific gear ratio and cadence – commonly called revolutions per minute (rpm). Overall speed for climbing a hill is dependent on the amount of power produced, which is directly influenced by the gear ratio. For example, strong, experienced cyclists can use a high gear ratio while maintaining a good cadence to produce more than 200 watts of power, while beginning or inexperienced riders reduce the gear ratio to produce about 100 to 200 watts.
Revolutions per Minute
Cadence and rpm are an important consideration for selecting gear ratios while climbing hills. According to Levi Bloom, professional cycling coach, choosing the correct gear ratio for hills is a personal preference relating to the ability to maintain an optimal cadence. For example, Lance Armstrong prefers a high cadence using a lower gear, while other professional cyclists choose a higher gear ratio and reduced cadence. A general rule considers an optimal cadence between 75 and 90 rpm, with some coaches allowing 60 rpm while riding steep or difficult hills. By staying within this cadence range, the gear ratio allows for efficient power transfer.
The available equipment and crankset also affect the gear ratio for hills. Changing the components may be necessary if you are consistently riding hilly terrain. Travis Woodruff, an elite cycling coach, recommends all riders, regardless of ability level, use a compact crankset combined with an 11-23 cassette. This crankset combination allows you to switch to a smaller gear ratio for long, steep hills.
Simple calculations can be used to predict your recommended gear ratio based on your body weight, cadence, power output and percent grade of the hill. Using those factors, you can calculate the length of the gear ratio along with the speed potential for that hill. For example, a cyclist weighing 175 lbs. with a cadence of 70 rpm pushing 200 watts on a 10 percent grade needs a 26-inch gear set to maintain 5.5 mph on the hill.
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