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Comment by bluefirebrand | Hacker News Reader

I'm betting there are people who can barely go 27.8 mph on a bike at their top speed

That's unbelievable to imagine honestly, someone on a bike going as fast as they can and this guy sprinting past them

But it's reality

When I was in my 20s, I was in great shape, riding thousands of miles a year (distance riding, not racing). On a flat, straight track in still air, I'm pretty sure my top speed was around 32mph. And while pro cyclists would scoff at my personal best there, most people aren't even coming close to that.

I was going to say only 32? Then realized it was miles per hour.

Flat land 32mph? That's pretty good! I can barely get over 30.

I would say the _majority_ of people would not reach that speed on a bike in normal situations

A downhill where a road bike can reach that speed is pretty normal. I reach those nearly every day on my to work commute and I live in Iowa - there is a reason we are known for being flat so if I can find a hill to reach those speed surely anyone else can too. Of course I am riding a road bike, kids and mountain bikes may have limitations (tires?) that slow them down.

Reaching those speeds on level ground doesn't seem possible for a normal human, but level ground is rare.

I can hit 45 mph going down hill on my 1980 road bike... but that's just balance, carrying enough potential energy, being too stupid to slow down to a reasonable speed, and having hills that I have to walk the bike up most of the time. There's some skill and physical conditioning there, but not a whole lot; at that speed, there's a lot of instant feedback on form, which helps encourage one to get low and tight.

I think if we're talking about how fast you can get your bike to go, flat land, still air is implied. I don't have a lot of those conditions to try, but I'm happy to cruise around 15, and maybe push it to 20 if I don't need to save my energy for a nearby hill.

I'm not sure what you might mean by a "normal human".

I used to be a back-of-the-front-of-the-pack triathlete, with a previous history as an ultramarathon and touring cyclist. In my best shape (probably aged around 46), I was training on a flat loop course with some younger very strong but not professional cyclists where we would generally pull the group at 28mph for about between 20-60 seconds at a time.

I appreciate that there's a distance between that sort of thing and an "average person", but it's not a whole lot larger than the distance between the people who were in the group and, say, professional tour cyclists.

Most people won't be able to even reach 27.8 mph on a bike, you need a decent road bike and some training.

I suspect that "most people" even includes the guy who sprinted at 27.8 mph. The crank lengths and gearing are all wrong on a bike for an explosive sprint, preventing all the right muscles from being recruited to the job. No matter the speed and gear, your feet are constrained into spinning around the same smallish circle. And wile you can use your whole body in order to sprinting on a bike, it's not the same like when a running sprinter uses their entire body.

Mmmhh, not sure about that. Most people, even if not reaching high speeds, can still go substantially faster on a bike than running. Even grandmas, it's all relative.

People like Bolt should be compared with bike sprinters, who top out at around 45mph.

You can look at Tadej Pogačar’s recent rides on Strava.

It’s awe inspiring. His times are just so fast, and over hilly terrain in the heat, for day after day.

apples to oranges. Look up this meatball https://en.wikipedia.org/wiki/Robert_F%C3%B6rstemann

“His thighs were measured with a circumference of 73 centimetres (29 in). A circumference of 86 centimetres (34 in) has also been recorded, and the size of his quad muscles has led to him being called "Quadzilla" by some in his sport.”

Top level competitive flying 200's are sub 10s. That's an average speed over the timed distance of 72km/h or 44.75 mph with a peak around 75-77km/h.

https://en.wikipedia.org/wiki/World_record_progression_track...

edit to add the Tokyo Olympics qualifiers all under 10 seconds: https://en.wikipedia.org/wiki/Cycling_at_the_2020_Summer_Oly...

That's definitely not true. You can sprint explosively on a bike, you just have to get up and push your legs down on the ground. Since your leg is at 90 degrees you can exert maximum power. I've done 50kph on the flats on a bike, it's not that hard; far easier than on foot!

Or just go downhill.

A class 3 ebike (the kind legal on most streets but illegal on most rec paths due to their speed) has a top speed of 28mph, so I would say so. Barring a steep decline of course.

I wouldn't go near that speed on a bike wearing a tour de france outfit. Crashing at those speeds will be very, very painful.

A friend of mine had a low speed crash on his bike, and knocked his front teeth out. After that, both he and I bought full face helmets.

When I ride dirt bikes, I wear a full set of armor. I look like a storm trooper. But I've crashed many times, and was unhurt. The armor is worth every penny. (The only way to learn how to ride a dirt bike is by crashing it.)

checkout japanese keirin racing armor.

also low speed crashes can be worse than high speed because it's worse to hit and stick vs hit and slide.

On indoor tracks, bikes do something like 45mph

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