[Lio]

> Biking at 45-48 MPH is rare, dangerous,

Not sure where you get that from. Amateur road cyclists can pretty easily reach 50MPH given a long enough hill and do so pretty uneventfully.

That's dressed in just shorts, jersey, helmet and fingerless gloves.

A professional racing cyclist could easily break 60MPH on closed roads and even 80MPH on occasion.

For someone like Tom Pidcock who knows[1]. In the linked video he's topping out at about 100kph (60mph) but it's worth noting that that's without being allowed to sit on the top tube of this bike. They banned that (even though it wasn't linked to any crashes).

The bike manufactures will eventually just add dropper posts to all pro road bikes and those speeds will go up again.

https://www.youtube.com/watch?v=3f4Pp4oYh28

[Retric]

Rare as in what percentage of the time is someone on a bike going 45+ MPH?

I’d be surprised if it’s more than 1% for more than a handful of people. An ultra elite athlete on a normal bike can hit that on level ground in an absolute sprint, but you can’t sprint for very long. Going downhill requires time spent going up the hill.

The women’s 1 hour speed record is 30.6MPH, the men’s is 35.3 MPH. So sure downhill, rolling start, or motor-paced people can reach extreme speeds but they really aren’t doing so for hours a day. Streamlined recumbent bicycle can do it far more easily but that’s niche territory.

[pixl97]

The amount of time that standard cars reach 100MPH is rare, and it is dangerous. Professional racing drivers have cars that reach 200MPH+, it is insanely dangerous and all kinds of specialized equipment is in place to keep the driver from dying.

You seem to be conflating that if someone reaches a particular speed it is safe which the whole 'velocity squared' doesn't give two damns about. The energy you have to safely dissipate increases very quickly.

[Lio]

No, I don’t think I am conflating that at all.

I’m not a professional rider. Nothing special about me.

Yet on a small hill near my house, with a maximum gradient of maybe 8%, I regularly hit 40mph.

When I need to I’m able to safely decelerate uneventfully.

It’s really not that rare. It happens every ride. I get to the bottom and I just go on with my day.

You won’t suddenly loose control if go past a arbitrary speed. Just read the road conditions and act accordingly.

This is not something only professionals do whilst wearing body armour. That’s an obviously silly suggestion to anyone that regularly rides a bike.

If you must make a car analogy then a better one would be crashing at 80mph on a motorway. If you do it will be life changing.

The same thing applies on a bike going 40mph but I happily do both when I think it’s appropriate to the conditions.