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Yes, the mass of a bicycle (including its rider) affects the stopping distance if the bicycle's air speed is significant. In particular, more mass can affect the stopping distance noticeably when the bicyclist faces a strong headwind.

Let's look at some typical values for older road bikes:

  • Mass of bicycle plus rider = 90 kg
  • Best braking deceleration, on dry, level ground = 0.55 g = 5.4 m/s²
  • Rolling resistance at 12 mph = 35 W (proportional to speed)
  • Wind resistance at 12 mph air speed = 35 W (proportional to the cube of air speed)
  • 12 mph = 5.45 m/s

Without a headwind, at 12 mph, let's compare the wind resistance (in W) to the braking power (also in W). In this scenario, the wind resistance is negligible compared to the braking power:

  • Wind resistance = 35 W.
  • Braking power = 90 kg * 5.4 m/s² * 5.45 m/s = 2,650 W.

Without a headwind, at 30 mph, let's repeat the comparison. In this scenario, the effect of increased mass becomes barely measurable:

  • Wind resistance = 35 W * ((30 mph) / (12 mph))³ = 550 W
  • Braking power = 2,650 W * (30 mph) / (12 mph) = 6,620 W

With an 18 mph headwind, at 12 mph:

  • Wind resistance = 35 W * ((30 mph) / (12 mph))³ = 550 W
  • Braking power = 90 kg * 5.4 m/s² * 5.45 m/s = 2,650 W.

With an 18 mph headwind, at 30 mph:

  • Wind resistance = 35 W * ((48 mph) / (12 mph))³ = 2,240 W
  • Braking power = 2,650 W * (30 mph) / (12 mph) = 6,620 W

So with an 18 mph headwind, about 1/6 - 1/34 of the deceleration is the result of wind resistance. If Big Bob's bike/rider combination is twice as massive as Tiny Tim's bike/rider combination, I would expect Tiny Tim's stopping distance to be a few percent shorter than Big Bob's stopping distance when facing such headwinds. (It would be several percent shorter, but I expect that Big Bob has more cross-sectional area than Tiny Tim. Big Bob's greater wind resistance could offset about 3/5 - 2/3 of Tiny Tim's advantage from his lower mass.)

For further reading (and sources for most of the "typical values"), see Bicycling Science by Prof. David Gordon Wilson.

Yes, the mass of a bicycle (including its rider) affects the stopping distance if the bicycle's air speed is significant. In particular, more mass can affect the stopping distance noticeably when the bicyclist faces a strong headwind.

Let's look at some typical values for older road bikes:

  • Mass of bicycle plus rider = 90 kg
  • Best braking deceleration, on dry, level ground = 0.55 g = 5.4 m/s²
  • Rolling resistance at 12 mph = 35 W (proportional to speed)
  • Wind resistance at 12 mph air speed = 35 W (proportional to the cube of air speed)
  • 12 mph = 5.45 m/s

Without a headwind, at 12 mph, let's compare the wind resistance (in W) to the braking power (also in W). In this scenario, the wind resistance is negligible compared to the braking power:

  • Wind resistance = 35 W.
  • Braking power = 90 kg * 5.4 m/s² * 5.45 m/s = 2,650 W.

Without a headwind, at 30 mph, let's repeat the comparison. In this scenario, the effect of increased mass becomes barely measurable:

  • Wind resistance = 35 W * ((30 mph) / (12 mph))³ = 550 W
  • Braking power = 2,650 W * (30 mph) / (12 mph) = 6,620 W

With an 18 mph headwind, at 12 mph:

  • Wind resistance = 35 W * ((30 mph) / (12 mph))³ = 550 W
  • Braking power = 90 kg * 5.4 m/s² * 5.45 m/s = 2,650 W.

With an 18 mph headwind, at 30 mph:

  • Wind resistance = 35 W * ((48 mph) / (12 mph))³ = 2,240 W
  • Braking power = 2,650 W * (30 mph) / (12 mph) = 6,620 W

So with an 18 mph headwind, about 1/6 - 1/3 of the deceleration is the result of wind resistance. If Big Bob's bike/rider combination is twice as massive as Tiny Tim's bike/rider combination, I would expect Tiny Tim's stopping distance to be a few percent shorter than Big Bob's stopping distance when facing such headwinds. (It would be several percent shorter, but I expect that Big Bob has more cross-sectional area than Tiny Tim. Big Bob's greater wind resistance could offset about 3/5 - 2/3 of Tiny Tim's advantage from his lower mass.)

For further reading (and sources for most of the "typical values"), see Bicycling Science by Prof. David Gordon Wilson.

Yes, the mass of a bicycle (including its rider) affects the stopping distance if the bicycle's air speed is significant. In particular, more mass can affect the stopping distance noticeably when the bicyclist faces a strong headwind.

Let's look at some typical values for older road bikes:

  • Mass of bicycle plus rider = 90 kg
  • Best braking deceleration, on dry, level ground = 0.55 g = 5.4 m/s²
  • Rolling resistance at 12 mph = 35 W (proportional to speed)
  • Wind resistance at 12 mph air speed = 35 W (proportional to the cube of air speed)
  • 12 mph = 5.45 m/s

Without a headwind, at 12 mph, let's compare the wind resistance (in W) to the braking power (also in W). In this scenario, the wind resistance is negligible compared to the braking power:

  • Wind resistance = 35 W.
  • Braking power = 90 kg * 5.4 m/s² * 5.45 m/s = 2,650 W.

Without a headwind, at 30 mph, let's repeat the comparison. In this scenario, the effect of increased mass becomes barely measurable:

  • Wind resistance = 35 W * ((30 mph) / (12 mph))³ = 550 W
  • Braking power = 2,650 W * (30 mph) / (12 mph) = 6,620 W

With an 18 mph headwind, at 12 mph:

  • Wind resistance = 35 W * ((30 mph) / (12 mph))³ = 550 W
  • Braking power = 90 kg * 5.4 m/s² * 5.45 m/s = 2,650 W.

With an 18 mph headwind, at 30 mph:

  • Wind resistance = 35 W * ((48 mph) / (12 mph))³ = 2,240 W
  • Braking power = 2,650 W * (30 mph) / (12 mph) = 6,620 W

So with an 18 mph headwind, about 1/6 - 1/4 of the deceleration is the result of wind resistance. If Big Bob's bike/rider combination is twice as massive as Tiny Tim's bike/rider combination, I would expect Tiny Tim's stopping distance to be a few percent shorter than Big Bob's stopping distance when facing such headwinds. (It would be several percent shorter, but I expect that Big Bob has more cross-sectional area than Tiny Tim. Big Bob's greater wind resistance could offset about 3/5 - 2/3 of Tiny Tim's advantage from his lower mass.)

For further reading (and sources for most of the "typical values"), see Bicycling Science by Prof. David Gordon Wilson.

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Yes, the mass of a bicycle (including its rider) affects the stopping distance if the bicycle's air speed is significant. In particular, more mass can affect the stopping distance noticeably when the bicyclist faces a strong headwind.

Let's look at some typical values for older road bikes:

  • Mass of bicycle plus rider = 90 kg
  • Best braking deceleration, on dry, level ground = 0.55 g = 5.4 m/s²
  • Rolling resistance at 12 mph = 35 W (proportional to speed)
  • Wind resistance at 12 mph air speed = 35 W (proportional to the cube of air speed)
  • 12 mph = 5.45 m/s

Without a headwind, at 12 mph, let's compare the wind resistance (in W) to the braking power (also in W). In this scenario, the wind resistance is negligible compared to the braking power:

  • Wind resistance = 35 W.
  • Braking power = 90 kg * 5.4 m/s² * 5.45 m/s = 2,650 W.

Without a headwind, at 30 mph, let's repeat the comparison. In this scenario, the effect of increased mass becomes barely measurable:

  • Wind resistance = 35 W * ((30 mph) / (12 mph))³ = 550 W
  • Braking power = 2,650 W * (30 mph) / (12 mph) = 6,620 W

With an 18 mph headwind, at 12 mph:

  • Wind resistance = 35 W * ((30 mph) / (12 mph))³ = 550 W
  • Braking power = 90 kg * 5.4 m/s² * 5.45 m/s = 2,650 W.

With an 18 mph headwind, at 30 mph:

  • Wind resistance = 35 W * ((48 mph) / (12 mph))³ = 2,240 W
  • Braking power = 2,650 W * (30 mph) / (12 mph) = 6,620 W

So with an 18 mph headwind, about 1/6 - 1/3 of the deceleration is the result of wind resistance. If Big Bob's bike/rider combination is twice as massive as Tiny Tim's bike/rider combination, I would expect Tiny Tim's stopping distance to be a few percent shorter than Big Bob's stopping distance when facing such headwinds. (It would be several percent shorter, but I expect that Big Bob has more cross-sectional area than Tiny Tim. Big Bob's greater wind resistance could offset about 3/5 - 2/3 of Tiny Tim's advantage from his lower mass.)

For further reading (and sources for most of the "typical values"), see Bicycling Science by Prof. David Gordon Wilson.