chapter 3

Gear.1.ts

class Gear {
  constructor(
    readonly chainring: number,
    readonly cog: number,
    readonly rim: number,
    readonly tire: number
  ) {}

  get ratio() {
    return this.chainring / this.cog;
  }

  get gearInches() {
    return this.ratio * new Wheel(this.rim, this.tire).diameter;
  }
}

class Wheel {
  constructor(readonly rim: number, readonly tire: number) {}

  get diameter() {
    return this.rim * (this.tire * 2);
  }
}