loquin
Well-Known Member
is that we need lights as powerful as a motorcycle on our bikes at night. It's just not so. More light IS better at a given speed, but, remember that motorcycle lights are designed to provide enough light for the rider to see far enough ahead to stop, at freeway speeds. 70 MPH.
The issue is that the light energy density varies as the square of the distance. To double the distance that you can see, you need 4 times the lighting; to triple the distance, you need 9 times the lighting.
However, the distance you need to see ahead is roughly dependent upon the square of the speed that you're traveling (the amount of energy that has to be absorbed by the braking system is proportional to the square of the speed as well.)
Assuming that we are traveling at 1/2 of freeway speed (35 MPH) we would need 1/4 the distance to stop, all other factors being equal, as the motorcycle, and the lighting requirement for 1/4 the distance is 1/4th of 1/4th, or 1/16th the power of the motorcycle headlamp, if the same amount of light per watt is produced. So, a 50 watt headlamp on a motorcycle at 70 MPH could have a 3+ watt equivalent headlamp on a bicycle, and you would have objects being seen in time to stop.
Would it be nice to see an object as far away as you could with a motorcycle headlamp? Absolutely! But, it's not needed for safety.
The issue is that the light energy density varies as the square of the distance. To double the distance that you can see, you need 4 times the lighting; to triple the distance, you need 9 times the lighting.
However, the distance you need to see ahead is roughly dependent upon the square of the speed that you're traveling (the amount of energy that has to be absorbed by the braking system is proportional to the square of the speed as well.)
Assuming that we are traveling at 1/2 of freeway speed (35 MPH) we would need 1/4 the distance to stop, all other factors being equal, as the motorcycle, and the lighting requirement for 1/4 the distance is 1/4th of 1/4th, or 1/16th the power of the motorcycle headlamp, if the same amount of light per watt is produced. So, a 50 watt headlamp on a motorcycle at 70 MPH could have a 3+ watt equivalent headlamp on a bicycle, and you would have objects being seen in time to stop.
Would it be nice to see an object as far away as you could with a motorcycle headlamp? Absolutely! But, it's not needed for safety.
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