gear-ratio

A cyclist shifts to a lower gear-ratio to climb a steep hill.

Definition

1. Noun:
   • Mechanical engineering: "gear-ratio" refers to the ratio of the rotational speeds of two or more interlocking gears in a mechanical system. It is typically expressed as the number of rotations of the driving gear relative to the driven gear.
   • Transmission context: In vehicles, "gear-ratio" describes the relationship between the engine's crankshaft speed and the wheels' speed, affecting torque and acceleration.

Usage Examples

• (The relationship between the front chainring and rear sprocket affects effort.)
• (A smaller number of driven gear rotations per driving gear rotation.)
• (The ratio of engine speed to wheel speed was changed.)

Advanced Usage

• "to have a high gear-ratio": to have a configuration where the driven gear rotates many times per rotation of the driving gear, often used for high speed.

  • Race cars typically have a high gear-ratio for maximum speed on straightaways. (The driven gear spins faster relative to the driving gear.)

• "to match the gear-ratio": to align the gear sizes so that the system operates efficiently.

  • The engineer matched the gear-ratio to the motor's power output. (The ratio was calculated for optimal performance.)

Variants and Related Words

• Gear (n): a toothed wheel that meshes with another to transmit motion or change speed.

  • The gear in the watch is tiny but precise. (A small toothed wheel.)

• Ratio (n): the quantitative relation between two amounts, showing the number of times one value contains or is contained within the other.

  • The ratio of students to teachers is 20:1. (Proportional relationship.)

Synonyms

• Transmission ratio: a synonym often used in automotive contexts.
• Speed ratio: a synonym emphasizing the rotational speed relationship.
• Drive ratio: a synonym used in mechanical systems.

Related Idioms

• "Shift gears": to change one's approach or strategy, derived from changing gear-ratios in a vehicle.

  • The company decided to shift gears and focus on online sales. (To change direction or method.)

• "In high gear": operating at maximum speed or efficiency, related to a high gear-ratio.

  • The project team is working in high gear to meet the deadline. (Working at full capacity.)

Phrasal Verbs

• "gear up": to prepare for a specific activity, often by adjusting or setting a gear-ratio.

  • The team geared up for the championship match. (Prepared intensively.)

• "gear down": to reduce speed or effort, analogous to selecting a lower gear-ratio.

  • The driver geared down before the sharp turn. (Shifted to a lower gear.)