Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why did we wait so long for the bicycle?

rootsofprogress.org

Post reply on HN
Print view View original

301–310 of 515 posts

Re: Why did we wait so long for the bicycle?

#301

Post by trianglesphere »

nickbauman wrote: post #280
entee wrote: post #99

Earlier quoted context omitted.

As any cyclist who has been on cobblestones can tell you, the pavers used on Roman roads aren't friendly to bikes. This would be doubly true without a pneumatic tire. Amazing engineering but not suitable for a bicycle.

The Roman pavers you would ride on today are 2000 years old, remember. Back then they were in much better shape, right? https://en.wikipedia.org/wiki/Roman_roads#/media/File:Pompei...

I'm a little doubtful. It's hard to make a large pretty flat surface out of stone. That looks better than the french paves (which they still lay by hand in some places today), but still not fun without a modern bike.

Re: Why did we wait so long for the bicycle?

#302

Post by bookofjoe »

WalterBright wrote: post #236
Excel_Wizard wrote: post #29

>Yet it was a simple mechanical invention As a mechanical engineer, this statement baffled me. All manufactured technology exists in the context of the manufacturing capabilities available to the designer. The manufacturing tech had to be tremendously complicated before a decent bike could be made. Hollow steel tubes aren't simple. Ball bearings aren't simple. There is a reductionist viewpoint among "theory" people t…

The article also didn't mention weight. The lighter a bike is, the more effective it is. One made out of wood and iron would be simply too heavy. Imagine a cast iron wheel. Lots of people dismiss the Wright Bros as "bicycle mechanics". They kinda miss that lightweight bicycle technology, like chain drives and steel wire, were essential for their working airplane.

If ever you're in Washington, D.C., visit the Air & Space Museum, which has a room containing the ORIGINAL Wright Flyer. It is absolutely spectacular. To give context, the room contains one of their bicycles along with much context and background. Worth the trip every time I visit D.C.

Re: Why did we wait so long for the bicycle?

#303

Post by hyperpallium »

GlenTheMachine wrote: post #55

One possibly overlooked factor: the nature of travel has changed dramatically in the last 200 years. Right up until World War 1, my ancestors literally had no reason to ever go more than ten miles from home, and even that was rare. The entire extended family lived within a two mile radius. This was because they were all farmers, and farmers didn't need to travel often. Furthermore, if you did travel, well, you alread…

Yes, and like the edison light bulb and birdseye frozen fish, you need infrastructure: smooth roads. Horse and cart are more tolerant.

Re: Why did we wait so long for the bicycle?

#304

Post by dreamcompiler »

vageli wrote: post #248
Animats wrote: post #194

Earlier quoted context omitted.

"The precision of keeping all those threads perfectly spaced is one thing " Making the first precision screw requires a "screw originating machine".[1][2] This is a special-purpose device which can make a better screw than the ones used in building it. Then you can install the first precision screw in a lathe and make more screws in harder metals. This is how precision is bootstrapped. [1] https://chestofbooks.com/ho…

> "The precision of keeping all those threads perfectly spaced is one thing" > Making the first precision screw requires a "screw originating machine".[1][2] This is a special-purpose device which can make a better screw than the ones used in building it. I hadn't realized screws would be needed to create a screw-making machine. I love that we have machines that make better versions of their own components, something…

I spent many years building a database backend from scratch. Right from the beginning, you need a fast way to look up a file address given a simple key, and that mechanism needs to be persistent. Thus to build a database you first need ... a database. Bootstrapping this thing was tricky.

Re: Why did we wait so long for the bicycle?

#305

Post by dfeojm-zlib »

Excel_Wizard wrote: post #29

>Yet it was a simple mechanical invention As a mechanical engineer, this statement baffled me. All manufactured technology exists in the context of the manufacturing capabilities available to the designer. The manufacturing tech had to be tremendously complicated before a decent bike could be made. Hollow steel tubes aren't simple. Ball bearings aren't simple. There is a reductionist viewpoint among "theory" people t…

I swear Cannondale road bikes have more in common with aircraft than terrestrial vehicles. You gotta see the aluminum welds on insanely thin tubes.

Disclaimer: I lost my 20+-year-old baby-blue R800TT to frame damage that I bought while making $4.25/hour. #SadDayForMe

Re: Why did we wait so long for the bicycle?

#307

Post by stan_rogers »

derefr wrote: post #214
Excel_Wizard wrote: post #29

>Yet it was a simple mechanical invention As a mechanical engineer, this statement baffled me. All manufactured technology exists in the context of the manufacturing capabilities available to the designer. The manufacturing tech had to be tremendously complicated before a decent bike could be made. Hollow steel tubes aren't simple. Ball bearings aren't simple. There is a reductionist viewpoint among "theory" people t…

> Ball bearings Couldn't you just use anything sufficiently round and uniform and Mohs-hard, given a lubricant oil to protect it from wear? Glass marbles? Pearls? Rocks after a ridiculous amount of tumbling?

"Sufficiently round" is harder than it may seem. A roller or needle bearing would be immensely easier (cylindrical grinding between centres is a bit of a doddle compared to spherical accuracy)... and then you've still got the problem of making them sufficiently precisely that all of the rollers actually bear. Even today you make 'em in quantity first and sort them afterwards. A well-lapped plain bearing/bushing would work better than a bad roller.

(Yes, you can make something that looks like a ball or roller bearing even on a cheap 3D printer, and it may even have less friction than the thing that looks like a plain bearing/bushing you can make on the same machine, but it's not going to roll freely and take a load.)

Re: Why did we wait so long for the bicycle?

#308

Post by andrewflnr »

dredmorbius wrote: post #221
mveety wrote: post #183

Earlier quoted context omitted.

Why? That's akin to saying a mechanical engineer isn't worth their salt unless they know how to design and implement software. They're two different specialties that do different things. To be a good mechanical engineer you absolutely don't need to be good at making or even have tried to have make software.

Cross-discipline experience is invaluable, especially across several domains. One begins to appreciate commonalities, uniquenesses, and the infuriating significance of details only apparent on in-depth experimentation and iteration. As with usability testing, small-n samples, say three to five, go a long way. Do you have cross-domain expertise yourself?

That's all true, and almost entirely irrelevant to the (very strong!) claim "a software engineer who hasn't built some mechanism is not worthy of the title".

Re: Why did we wait so long for the bicycle?

#309

Post by pgreenwood »

Great article, but I would like to point out a common misconception regarding mechanical advantage that featured in the article. Mechanical advantage is not completely determined by the gear ratio. You also have to take into account crank length and the wheel size. Total mechanical advantage is determined by these three factors together. See https://sheldonbrown.com/gain.html

Re: Why did we wait so long for the bicycle?

#310

Post by mrob »

nickbauman wrote: post #280
entee wrote: post #99

Earlier quoted context omitted.

As any cyclist who has been on cobblestones can tell you, the pavers used on Roman roads aren't friendly to bikes. This would be doubly true without a pneumatic tire. Amazing engineering but not suitable for a bicycle.

The Roman pavers you would ride on today are 2000 years old, remember. Back then they were in much better shape, right? https://en.wikipedia.org/wiki/Roman_roads#/media/File:Pompei...

That still looks very uncomfortable without pneumatic tires.
Post reply on HN