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Velocipedia

gianlucagimini.it

11–20 of 110 posts

Re: Velocipedia

#11
Though being biased by this article, I do think I could have drawn one correctly. It's fun to ask peers though, surprising things go wrong. I even saw the double-chained one, surprised by that! (Chain attached to both front and back.)

Re: Velocipedia

#12
post #9
post #4

Earlier quoted context omitted.

No frame between rear wheel and front chainring. No strength.

But the front wheel is also missing that beam on a correct bicycle. Edit: implying: if the front wheel doesn't need it, why would the rear wheel?

Turning would be quite difficult on a bike with one. ;)

Re: Velocipedia

#13
post #2

What is wrong with the topmost bike?

Just to expand on what others said, the tubes that the frame is missing are called chainstays.

Is it really impossible to build such a bike? Given a strong enough material it would be possible. I have not idea about the structural analysis in this case. Does such a material exist?

Re: Velocipedia

#14
post #8
post #6

Earlier quoted context omitted.

The frame is missing the tube between the rear wheel hub and where the pedals connect - it would presumably splay out if you sat on it.

If you're really lucky, then the chain would provide some strength. Pedaling would be really hard with such a tight chain, though.

...and anyway, the frame would flex a lot, likely dropping the chain.

Re: Velocipedia

#15
post #9
post #4

Earlier quoted context omitted.

No frame between rear wheel and front chainring. No strength.

But the front wheel is also missing that beam on a correct bicycle. Edit: implying: if the front wheel doesn't need it, why would the rear wheel?

Distribution of weight is not equal.

Re: Velocipedia

#18
post #13

Earlier quoted context omitted.

Just to expand on what others said, the tubes that the frame is missing are called chainstays.

Is it really impossible to build such a bike? Given a strong enough material it would be possible. I have not idea about the structural analysis in this case. Does such a material exist?

I can't see what the advantage would be though - if you do have a wonder material better to go with a more standard frame design and increase stiffness and/or reduce weight.

NB ~20 years ago I did have an "elevated stay" frame which was neat in some ways - no chain slap and the chain didn't go through the frame. However, the frame failed catastrophically while I was at traffic lights....

Re: Velocipedia

#19
post #13

Earlier quoted context omitted.

Just to expand on what others said, the tubes that the frame is missing are called chainstays.

Is it really impossible to build such a bike? Given a strong enough material it would be possible. I have not idea about the structural analysis in this case. Does such a material exist?

"I have not idea about the structural analysis in this case."

There's your problem. The chainstays are there for Good Reasons. http://www.mece.ualberta.ca/tutorials/ansys/BT/Bike/Bike.htm... If you take them out, now most forces on the bike effect one point in the frame, right beneath the saddle. Making the frame stronger requires more material (=weight) or better material (=price), whereas a rhombus of two triangles solves the problem efficiently.

In other words, you are proposing a problem to which the current bike design is the solution.

Re: Velocipedia

#20
bicycles facing left: 75 %

bicycles facing right: 25 %

That's unexpected. For some reason I'd think more would be facing right than left, and if I were to draw one it would probably be facing right too. I don't know why but it seems to feel more "natural". I just Googled images for "bicycle" and 32 out of the first 40 were facing right.

I noticed all the renders were facing right as well, even if the original drawing wasn't.

I wonder if the dominance of right-hand-traffic countries is related.

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