Kinetic energy doesn't kill cyclists in the usual circumstances.

You need very little kinetic energy to make a cyclist topple and fall. The fall itself can lead to injury and death, lying on a street in the midst of all the traffic is even more dangerous.

Any touching of car and cyclist is very, very dangerous. That's why I brought up the example of cyclists passing cars with practically no space between them. They feel it's safe, but it's incredibly dangerous.

Which "normal circumstances" are you referring to? Suggesting that a fall itself might kill a cyclist is pretty far fetched.

Lying on a street - yes. Because cars might roll over you, cause of the kinetic energy.

Getting squished between cars - yes. Because of the huge mass of the car.

Banging your head against an opening car door - yes. This time it is because of your own kinetic energy that hits a small surface area which is immobile cause of the mass of the car.

So it is quite dangerous to get near to cars, yes. But almost always because of the huge mass of the cars, especially if they are moving. That was the point of ggp.

Total kinetic enegy has little to do with it, a car can kill someone at 1MPH by running them over. At 30+MPH a cyclist can easily kill themselves by hitting something head first even with a helmet. Simple truth is only an idiot goes 30MPH in a bike lane where they can easily hit someone.

30+ mph! Thats tour de france velocity with a lot of kinetic energy (albeit still less than a car at 10mph I think).

Sprinting at 30mph expecally down a hill is vastly easer than mainting that for the long term.

Many of these people where not going all that fast. https://en.wikipedia.org/wiki/List_of_cyclists_with_a_cyclin...

Well, an 80 kg cyclist+bicycle system at 30mph has about 7 000 joules of kinetic energy.

A 1 ton car at 10 mph has 9 000 joules of kinetic energy, so about 30% more.

My point was that the car's mass at the point of impact doesn't matter, because the cyclist doesn't die of an immediate trauma from the collision. He could be tipped over by a pedestrian, or bad street conditions.

He dies – as you put correctly – because of all the cars around him. Of course kinetic energy is relevant there, but it doesn't matter to the argument, because the claim was that being touched by a car is much more dangerous than being touched by a cyclist. And that's wrong.

As soon as the cyclist falls he's in mortal danger.