The Oregon Senate passed a bill updating laws around electric bicycles on Monday. It's named for a Bend teen killed in a collision while riding an e-bike last summer.
I did way more than 1000km/month on my bicycle back in my time. I know what happens when you are stupid enough to break with the front wheels only. Even with disk brakes on both wheels you don’t have enough contact with the ground to ride at such speeds in a traffic-safe way. That’s why I object to the idea that a bike with 28mph would be safe, and would definitely require insurance for such a vehicle.
The brake reaction time normally used in design, therefore, is 2.5 seconds.
Stopping distance in a car is therefore 140.22 ft.
Do you think that you can’t do equal or better on a bike?
Any situation that you believe a car can do safely, there’s no reason to believe a bike couldn’t either. FFS we have these wonderful things called motorcycles. Much less contact with the ground [than a car], much higher speeds. Works just fine.
If you agree that humans can control a car going 75mph, then a bike going 28 isn’t an issue.
Yes, but a car has actually appropriate brakes for the speed they are going at. With bikes, even good brakes are not really up to such speeds.
Go ride a bike… Grab the left brake as hard as you can. You will change your mind.
I did way more than 1000km/month on my bicycle back in my time. I know what happens when you are stupid enough to break with the front wheels only. Even with disk brakes on both wheels you don’t have enough contact with the ground to ride at such speeds in a traffic-safe way. That’s why I object to the idea that a bike with 28mph would be safe, and would definitely require insurance for such a vehicle.
https://www.omnicalculator.com/physics/stopping-distance
https://www.webpages.uidaho.edu/niatt_labmanual/chapters/geometricdesign/theoryandconcepts/BrakeReactionTime.htm
Stopping distance in a car is therefore 140.22 ft.
Do you think that you can’t do equal or better on a bike?
Any situation that you believe a car can do safely, there’s no reason to believe a bike couldn’t either. FFS we have these wonderful things called motorcycles. Much less contact with the ground [than a car], much higher speeds. Works just fine.
If you look at that page carefully, it gives the full formula for the brake distance. And assumes a factor of f=0.7 for an average car.
The AASHTO gives a factor of f=0.25 for a bike. Which means: Yes, there is a difference.
The f for a motorcycle is somewhere in between, but nearer to the .7 than the .25.