Alt Bike Culture - Chinese man builds angled-wheeled bicycle

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82times
05-28-09, 12:02 PM
OK--what the heck is this? I usually hang out in the touring forums, but figured this a better fit for y'all. More photos of this at the url below.

http://www.china.org.cn/china/photos/2009-05/07/content_17738257.htm

http://img.skitch.com/20090528-1u7b92egc3kpew7xqnw8hqsgys.jpg

Is this just something whimsical, or is there some kind of purpose for the weird-angled wheels?

StephenH
05-28-09, 12:42 PM
It's a point-proving thing.

It's not obvious, but certain curves can be a constant width without being round. As those wheels roll, the centers of the wheels should move up and down some. But the bike is supported off the tops of the wheels, not off the centers, so the bike rides level.

One of my Martin Gardiner (Gardner?) books has a chapter on curves of constant width.

n8ked_rider
05-28-09, 02:06 PM
It's a point-proving thing.

It's not obvious, but certain curves can be a constant width without being round. As those wheels roll, the centers of the wheels should move up and down some. But the bike is supported off the tops of the wheels, not off the centers, so the bike rides level.

One of my Martin Gardiner (Gardner?) books has a chapter on curves of constant width.

Yeah that's exactly what I was going to say... :thumb:

jdmitch
05-28-09, 03:00 PM
It's a point-proving thing.

It's not obvious, but certain curves can be a constant width without being round. As those wheels roll, the centers of the wheels should move up and down some. But the bike is supported off the tops of the wheels, not off the centers, so the bike rides level.

One of my Martin Gardiner (Gardner?) books has a chapter on curves of constant width.

Er... what you talking 'bout wills?... there are very clearly axles in the center of those wheels...

*checks pics on site more*

http://images.china.cn/attachement/jpg/site1007/20090507/001109b42f980b6cb84f17.jpg

So, what' you're saying is that the hubs are actually on swinging arms, and the supports are actually on the rollers on the tops of the wheels? So, the hubs / swing arms are just there to keep the wheels aligned under said rollers?

If I'm understanding, that's pretty cool. If not, I'm still confused...

lz4005
05-28-09, 03:24 PM
So, what' you're saying is that the hubs are actually on swinging arms, and the supports are actually on the rollers on the tops of the wheels? So, the hubs / swing arms are just there to keep the wheels aligned under said rollers?

Yes, that exactly. So the swing arms and hubs go up and down a bit as the wheel turns, but the rollers on the horizontal members stay exactly the same height. (except for the fact that the tires are solid and the whole thing probably rides like hell)

rodar y rodar
05-31-09, 06:19 PM
Very cool. So the "diameter" is the same no matter where you cross the wheel even though the "center" isn`t always at the halfway point? I wish there were a video with it- it would probably be more better to watch than static pics.

Artkansas
06-03-09, 05:42 AM
OK--what the heck is this? I usually hang out in the touring forums, but figured this a better fit for y'all.

http://img.skitch.com/20090528-1u7b92egc3kpew7xqnw8hqsgys.jpg

Thanks for sharing. I finally figured out what the other posters were talking about, about this being to prove a mathmatical point. I think this is the most alt bike I've seen. :D

When word gets out about this fixie, it's going to be a must have for all the hipsters. ;)

dizzy101
06-04-09, 02:51 PM
So, what' you're saying is that the hubs are actually on swinging arms, and the supports are actually on the rollers on the tops of the wheels?

Yes, look at the top of the wheels. There are rails along which the wheels glide. The wheels have the shape of a constant-width curve, meaning the distance between the ground and where the wheels touch the frame is constant. Result: a bike that doesn't hobble but remains at the same height throughout the wheel's revolutions. Pretty clever design.