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Anothe new internal hub

Sir_Crackien

Turbo Monkey
Feb 7, 2004
2,052
0
alex. va. usa.
don't think that thing will be even remotely inexpenise if it is to work right. the thing is working under a ton of pressure (actually probibly more). i can see this thing slipping under high loads of sprinting.

cool idea though
 

Inclag

Turbo Monkey
Sep 9, 2001
2,357
76
MA
Check out the video at Fallbrook Technologies. That is some beautiful machine work!
 

zedro

Turbo Monkey
Sep 14, 2001
4,160
0
at the end of the longest line
Nately27 said:
very nice...
they buit a wicked cool lookin prototype: (dl the movie)
http://www.fallbrooktech.com/02_Demo.asp

interestingly enough, I saw this very CVT a few weeks ago in a paper on Variable speed wind turbines on NREL.gov. go figure
its mentioned on their site that one of the applications would be used for wind turbines. I'm kinda with the Sir on this though, i'm a bit skeptical on its ability to provide the "torque density" required (as they put it) for a more aggressive application. It's too bad they dont provide any data, if it works as stated it could be the holy grail.

Vicious rumor dept: didnt DW mention he was persuing a new tranny technology to be applied in a g-box format?
 

Nately27

Monkey
Jul 29, 2003
121
0
zedro said:
its mentioned on their site that one of the applications would be used for wind turbines. I'm kinda with the Sir on this though, i'm a bit skeptical on its ability to provide the "torque density" required (as they put it) for a more aggressive application. It's too bad they dont provide any data, if it works as stated it could be the holy grail.

Vicious rumor dept: didnt DW mention he was persuing a new tranny technology to be applied in a g-box format?
Yeah, I dont think they have the data to extrapolate up to wind turbine sized applications. I say that because in that NREL paper, they simply assume that it could take the torque loading and would only add 20,000 to the cost of the gearboxes already used. In some ways its not a stretch though, becuase they do state they can add more of the planetary balls to increase capacity, up to 12.
 

zahgurim

Underwater monkey
Mar 9, 2005
1,101
12
lolAsia
Wow, if it actually works, this is a cool step forward.
I'd love to get my hands on one for testing.

Any pictures of the shifter?
 

kinghami3

Future Turbo Monkey
Jun 1, 2004
2,240
0
Ballard 4 life.
Awesome idea! I didn't think it would work until I saw that there was a horizontal axle going through each ball. I can see grip shift working better than any other method, but I hate the way it feels.
 

davod

Chimp
Jun 13, 2004
32
0
I think it's funny that this is called the 'NuVinci', and another cvt hub posted earlier was called the nupace of something.......
 

zedro

Turbo Monkey
Sep 14, 2001
4,160
0
at the end of the longest line
kinghami3 said:
I can see grip shift working better than any other method, but I hate the way it feels.
being an indexless system i could see a bunch of different solutions, even electronic shifting (see how they shifted by rotating that handle? replace with a small DC servo).
 

zahgurim

Underwater monkey
Mar 9, 2005
1,101
12
lolAsia
I could see electronic shifting being pretty cool...two thumb buttons, one to move your ratio up, and one to move down.
Or, just an old-school non-indexed friction shifter.

I'd stay away from gripshift style if I was designing it myself, as they are indexed and have a pretty heavy activation pressure to move them, as you don't want to jostle your ratio while riding something bumpy. I'd want to keep a light, non-indexed action on the shifter, so it would be easy to find your ideal ratio.
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,944
0
MV
Toroidal CVTs are nothing new, first patented in 1886, they are widely used in heavy industries. Typically the units are very heavy due to the massive forces involved, and have decent efficicency (80-92%). It will be interesting to see if this technology can successfully be used for bicycles. I am watching. It's a considerable engineering challenge to get the efficiency up to match a chain system. Should be fun to watch!

Zedro, yes, I am still working and filing for patents, but I am taking it one step at a time. No need to rush it. If what I am working on does in fact work, it will be very good I think. If not, no harm done, it has been fun so far!

dw
 

Red Bull

Turbo Monkey
Oct 22, 2004
1,773
0
970
zedro said:
being an indexless system i could see a bunch of different solutions, even electronic shifting (see how they shifted by rotating that handle? replace with a small DC servo).
ZEDRO! The mindless herds of Newbs on MTBR need you!