[ajdude]

I really hope you meant 40-50kph, because this feels incredibly fast on a bicycle. I try to avoid that if I can help it

[notesinthefield]

No, 40-50 mph happens often on a long decent. It's extremely exhilarating, dangerous and always takes a lot of focus.

[mauvehaus]

I've hit 45mph going down Tioga Pass towing a BOB trailer while touring[0]. Doing it on an unladen road bike would not be a big deal for a high level road cyclist on a good road surface.

[0] BOB's recommended top speed is 25 mph, for the record.

[mayormcmatt]

Damn, this is hardcore.

[mauvehaus]

It's also probably not the smartest thing I've ever done, but I survived.

[ubermonkey]

S/he does not. 50MPH is entirely plausible on even a relatively short alpine descent.

[323]

Check out this video, 100 kph descent in a competition:

https://youtu.be/I4aMTp6-WKU?t=23