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another gearbox bike - two expandable gears.

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bikenweed

Turbo Monkey
Oct 21, 2004
2,435
0
Los Osos
Assuming that (Rock Shox?) fork is flex free, they won't have any problems with front wheel clearance on the drive train there. Sketchy!
 

ÆX

Turbo Monkey
Sep 8, 2001
4,920
0
amarillo
well after the chain goes from the bb to the first jackshaft it goes to a "chainring that goes from a effective size of like 30T to 44T. so does the other one. make a invariantly variable;e ratio.

easy.
 

kinghami3

Future Turbo Monkey
Jun 1, 2004
2,240
0
Ballard 4 life.
Ok, I think I know what's going on. As rotation speeds up, one gear expands and the other shrinks, keeping the chain tight but changing the ratio. I think I see how they change size, but I'm not quite sure. No shifting required, but it's friggin huge. I hope that's a prototype.

edit: I got ninja posted!
 

patineto

The RM Mad Scientist
Feb 19, 2002
935
0
berkeley, ca
bcd said:
well after the chain goes from the bb to the first jackshaft it goes to a "chainring that goes from a effective size of like 30T to 44T. so does the other one. make a invariantly variable;e ratio.

easy.
Alex i'm so glad you found that picture on my photo gallery (I got it from some interbike gallery) anyway you are the perfect guy to see the possibilities as oppose to only see the shortcomings.

Be well,,,oh i see you posting on the frame forums,,,good for you, more than a Inventor and a overall smart fellow you are a kissA66 rider
 

S.K.C.

Turbo Monkey
Feb 28, 2005
4,104
25
Pa. / North Jersey
...on the frame it says "Auto-G X"....

I don't see any shifter either, so I'm assuming what we are looking at here is a kind of automatic gearbox that works off of pressure sensitive clutch-plates of some sort???

These are activated by pedaling input, such as the amount of torque being introduced to the system????

:think:
 

thaflyinfatman

Turbo Monkey
Jul 20, 2002
1,578
0
Victoria
S.K.C. said:
...on the frame it says "Auto-G X"....

I don't see any shifter either, so I'm assuming what we are looking at here is a kind of automatic gearbox that works off of pressure sensitive clutch-plates of some sort???

These are activated by pedaling input, such as the amount of torque being introduced to the system????

:think:
Centrifugal force and rolling speed I would guess (and run the freewheel on the gears not the wheel or something).

How does the second chain avoid slipping? I can see how the sizes would expand and whatnot, but tooth count is directly proportional to diameter, how do you have an increasing number of teeth?
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,944
0
MV
saw it/ held it/ talked with the inventors at interbike, its a CVT, no shifting, lots and lots of parts. It was not too light either. Pretty cool though. It sounds like a thousand clocks ticking together when its working to shift.
 

thaflyinfatman

Turbo Monkey
Jul 20, 2002
1,578
0
Victoria
So how does it actually transmit power from the rotating plates (and the half a dozen little sprockets) to the chain? Can the sprockets spin freely or not?
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,944
0
MV
thaflyinfatman said:
So how does it actually transmit power from the rotating plates (and the half a dozen little sprockets) to the chain? Can the sprockets spin freely or not?
the little sprockets have gears attached to them and the little gears ride on radial gear racks. The power is transmited through the sprockets into the gears, and into the gear racks. The available torque determines if the sprockets can ride up the gear racks more (changing the ratio) or if the whole assembly should turn.

Dave
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,944
0
MV
bcd said:


each one is a little freewheel.
Alex, on this particular design, all the sprockets are attached to the inner side plates by gears. There are no freewheels.

Dave
 

peter6061

Turbo Monkey
Nov 19, 2001
1,577
0
Kenmore, WA
That's very similar to something I was working on a while back. I still someday hope to have it in the works, but have too many other projects going currently. I'd love to see it work.

Mine was not an 'automatic' system though. It used a friction/indexed shifter to set gear between a specific desired range.

Nice to see people thinking in this direction though.
 

TheInedibleHulk

Turbo Monkey
May 26, 2004
1,890
0
Colorado
It's the exact same concept as a CVT, however it looks entirely useless on that bike. If they could make it about half that size and encase it in a DH bike they might have something.
 
May 12, 2005
977
0
roanoke va
TheInedibleHulk said:
It's the exact same concept as a CVT, however it looks entirely useless on that bike. If they could make it about half that size and encase it in a DH bike they might have something.
you would also have to be able to not only fine tune but adjust, while riding, how much torque is requried to alter the ratio. that would require a shifter and thus negate half of the positives of the system. i'm still happy with my 2x9 drive train.
 

mandown

Poopdeck Repost
Jun 1, 2004
15,481
2,714
Transylvania 90210
downhilldemon said:
your going to hit those gears on so many thing it doesnt even look like it would be worth it!
looks like the lower wheel hangs down past the bash guard :nuts:

well, at least you would never have to worry about buying a go-ride down tube protector.
 

skinny mike

Turbo Monkey
Jan 24, 2005
6,416
0
i dont get why people are complaining about it being a hardtail. its a prototype internal drivetrain, why waste time developing it at first around suspension? dw, as a bike designer and engineer, what are your thoughts about drivetrain technology moving in this direction?
 

thaflyinfatman

Turbo Monkey
Jul 20, 2002
1,578
0
Victoria
dw said:
the little sprockets have gears attached to them and the little gears ride on radial gear racks. The power is transmited through the sprockets into the gears, and into the gear racks. The available torque determines if the sprockets can ride up the gear racks more (changing the ratio) or if the whole assembly should turn.

Dave
Ahh ok... that would require some pretty precise calculations/machining wouldn't it, to ensure that the sprockets rotate at the right rate as they move up the rack?
 

w00dy

In heaven there is no beer
Jun 18, 2004
3,415
33
that's why we drink it here
Sorry to resurrect such an old thread, this is just cool.

It looks to me as though two of the little cogs are fixed and the others spin freely to line up with the chain.

It is big and clunky now, but definitely has potential. Very neat concept.
 

Percy

Monkey
May 2, 2005
426
0
Christchurch NZ
OMG!!

That is very clever, but what a nightmare to keep running smoothly, especially on a MTB, also $$$$$$$$$$$$$$$$$$$$$$ caaaa-chinggg!!!!
And another thing, its bound to be heavy, look at the number of plates there, 4 in each "unit" that I can see, plus the chainring doofers, that all weighs something, even if made of alloy or Ti.
 

Hailight

Chimp
Mar 5, 2006
63
0
it's a prototype of some automatic gearsystem.... have read an article in some magazine

quite a while ago, can't really remember, but I think the idea was to have no gears, just a constantly changing ratio without any steps that you would have on a system based on gears