Nuvinci CVT hub

Mathurin

100 kW
Joined
May 24, 2006
Messages
1,166
Location
Quebec
Right, so there's a video of it here:
http://www.youtube.com/watch?v=2z9-NFxALXI

It's in german but the pictures give the idea...

I can see how a CVT would be pleasant in practise, on the other hand I have a 24speed DS bike with a 4:1 gearing range and it's fairly rare I actually use so many gears. By comparison, a similar weight/tire fixed gear bike yields me about 15% slower commutes. I don't know that there's really much to be gained going past 5 or so gears, it's more a question of the gearing's range. And then, given something like an 8 speed nexus is considerably cheaper and has about the same range as the nuvinci, but only about half the weight (nuvinci is a whopping 4 kilos), it's plain to see who's gonna be first to crest that hill... Of course this is first gen stuff so it's bound to improve, but I don't see it being advantageous compared to other currently available solutions. Only thing it's got is the novelty aspect. Am I missing something?
 
The times, they are a changin', and so is bicycling.

Chains are gearing-up to become relics, replaced by shafts or other zero maintenance alternatives; the gears replaced by CVTs like this. With light, ultra strong materials becoming cheaper, spokes are being replaced by mag wheels. Forgot where, but I just saw one on a top-flight racer's bike.

The nuvinci is just part of a long overdue big shift to stronger, lighter, lower maintenance personal transportation devices.
 
Dude, the nuvinci isn't lighter, it's about twice heavier then a comparable geared hub. As for being stronger and lower maintenance, where did you read that? I've not seen anything regarding it's maintenance requirements, and to my knowledge it's not been out long enough for it's reliability to be compared.
 
Dude, the nuvinci isn't lighter, it's about twice heavier then a comparable geared hub. As for being stronger and lower maintenance, where did you read that? I've not seen anything regarding it's maintenance requirements, and to my knowledge it's not been out long enough for it's reliability to be compared.

I was noting a general trend, not speaking specifically of the nuvinci...for all I know about it, this contraption may suck totally. If not now, at some point soon a viable non-gear torque/rpm converter will come to market as a complement for the chain-less drivetrains available.
 
Time will tell. The fact that carriage-trade bike maker, Ellsworth, is launching the NuVinci in their uber-$ The Ride bikes, means they've put their faith in the thing. It is surely more than a gimmick;
I expect it'll have much lower transmission losses than a geared hub.

Hard balls working against hard steel. Should last a long time,
and not suffer unexpected failure. If it wears out, it would be only slowly,
by spalling of the most-worked surfaces.

I don't think driveshaft bikes offer such efficiency as chain drive or belt drive;
the right-angle spur gears are relatively power-grubbing, and their alignment is very critical. Si?

----

User reports are not many at this stage.

Am shocked to learn it's that heavy, Mathurin. That's too bad.
 
On the Plus Side 8)

Imagine using this transmission for an ebike,
driving it by an electric motor of your choice, a la Currie style.

If the NuVinci were adaptable to have tandem freewheel sprockets;
why not hang a motor on the same side of the frame as the pedal chain?

Or just do the Cyclone-type drive?
It's all ready for that if one likes BB drive.

:?:
 
TREKKING LI NUVINCIâ„¢ WITH CVP DRIVE SPECS
PART NUMBER: IZ-NVTKLIMSM7-SB (SIZE S / M)
PART NUMBER: IZ-NVTKLIMML7-SB (SIZE M / L)
M.S.R.P.: $2,499.99 (S / M / L)

trekking_li_nuvinci.jpg



MOTOR
Exclusive Alloy Shell DC Brushless Geared Hub Motor

BATTERY
24V / 12.2AH Pack
(72) 3V Rechargeable Cells

CHARGE SYSTEM
UL Listed Li-on Currie High Power Smart Charger with LED status display

CONTROLLER
Exclusive Currie Electro Drive 24 Volt fully potted with Power Gauge function

TOP SPEED
Up to 18 mph / 29 kph (rider weight
contingent)

RANGE
Up to 30 - 40 Miles / 48 - 64 km with normal pedaling (rider weight contingent)

DRIVE
Exclusive Currie Geared Hub Motor, Fallbrook NuVinci â„¢ CVP Continuously Variable Planetary Drive

BRAKES
Tektro Alloy linear pull with Tektro Alloy Brake Levers

WHEELS
Veronique 700 x 25 A-Type double wall 6061 Alloy rims with stainless steel spokes and full fenders

TIRES
Currie Kenda E-Street 700 x 35

HANDLEBARS
Alloy Adjustable Rise Stem and Street Bars with Dual Density Grips

FORK
RST SMART T7, suspension

USER CONTROLS
Battery gauge, PowerOn/Off Switch and Easy Access charger port in down tube, Hella Lighting

SADDLE
GS Suspension Comfort and micro-adjust suspension post
FRAME
Exclusive Currie IQ Series 6061 Aluminum Alloy

CRANK AND PEDALS
Alloy 42T crankset w/PTS function; alloy
non-slip pedals, full chainguard

NET WEIGHT
44 lbs / 20 kg



http://www.izipusa.com/trekking_li_nuvinci.html


8)
 
8) :) 8) 8) :) 8)

________________________


edit:

OH
MOTOR
Exclusive Alloy Shell DC Brushless Geared Hub Motor
Dang!

The fools have put a Tongxin motor to the front hub.
They aren't exploiting the NuVinci for edrive at all.

:cry: :cry: :cry: :cry: :cry: :cry:


Imagine....you have a CVT in series with the drive motor, and an ammeter...and just tweak the drive ratio to obtain maximum motor efficiency for any given condition on the road.
Why, it could be done by servo, automatically.
 
Is the bicycle nuvinci stout enough to handle 500+W motor torque?
Well if not, the company has ones that surely are:
http://www.fallbrooktech.com/Market.asp

Though widespread adoption will take awhile, decades perhaps, the CVT seems superior to trannies in many ways. Eventually we'll all be driving/riding some kind of continuously variable torque/rpm converter whether automatic, or manual "shifting" like the nuvinci.
 
xyster said:
Is the bicycle nuvinci stout enough to handle 500+W motor torque?
Good question! I think it might well do-so. Here's why:
How much torque can a strong leg stomp into a pedal? (Lots more than the torque of a 500W motor, yes?)

Also, this first-gen NuVinci bike hub has a lot of money and reputation riding on it.
If these first units disappoint in any way, it'll be bad news for all concerned.
I figure that they've made this first bike hub tranny robust;
that'd account for the weight: lots of steel balls inside, lots of steel, period).

Well if not, the company has ones that surely are:
http://www.fallbrooktech.com/Market.asp

Though widespread adoption will take awhile, decades perhaps, the CVT seems superior to trannies in many ways. Eventually we'll all be driving/riding some kind of continuously variable torque/rpm converter whether automatic, or manual "shifting" like the nuvinci.
Thanks for your words and the pointer. Here, from their LEV page,



which beggars the question: why put the mass of the transmission (or motor, for that matter) into the wheel itself,
other than for space-saving or stylistic reasons?

If a hub motor is someday made with integral CVP transmission, cool!
But it'll be pretty heavy, eh? I don't see how they can not be heavy, what with the steel balls and the steel disks, and probably more steel than that,
owing to the need for great contact pressure of the rolling surfaces.
 
I don't see how they can not be heavy, what with the steel balls and the steel disks, and probably more steel than that,
owing to the need for great contact pressure of the rolling surfaces.

They could probably use a lighter metal instead, like titanium. Probably they're looking to keep the price down at first to spur adoption, coffer the capital, so they can manufacture lighter, higher-end units later.

I'm no metallurgist, so I'll ask: if price were no object, is steel or iron ever the best metal or material anywhere in a motorized vehicle?
I'd guess, no.

If yes, which vehicular parts are better off staying steel or iron for the foreseeable future?
 
In this case I'd wager my life, that only ball bearing-hard steel will do.

Titanium deflects too much, and it is notorious for galling.

Alas, steel is the only ideal material for high pressures and loads,
which this device does have to deal with; for the same reason that roller
and ball bearings, etc, are made of the finest grades of steel, properly hardened and toughened by heat treatment.

Note that they could reduce weight by using fewer balls.
But since the drive is by mechanical friction, the torque-bearing capacity slips, literally.

The lubricant/drive fluid...
must be a fluid with solid matter in suspension (d'oh, it says so at the site).
Amazingly high tech, in essence, I imagine the holy drive fluid
is nothing more at essence than oatmeal slurry in corn oil; something like that.




I wonder if Valvoline will pay me for my brains?
............................................................:roll:
 
In this case I'd wager my life, that only ball bearing-hard steel will do.

I'll take you up on that since I have put nothing on the table to lose. And instead of your life, if you lose I'll take your oath of fealty and a lifetime of slavery (don't worry, just household chores and stuff...nothing weird or too de-humanizing) :)

Need balls?
http://www.abbottball.com/

Some of these alternative materials, like carbon-steel, they say are being used in ball bearings too.

Then there's ceramic or titanium carbide w/steel coating
http://www.pacamor.com/
"Miniature & Instrument Ball Bearings: ...Miniature and instrument ball bearings are available with 440C stainless steel balls, or with ceramic balls or titanium carbide coated 440C stainless steel balls as hybrid options. "

ah ah, missed it the first time, one example of a non-steel ball bearing: ceramic.

I am prepared to now accept your oath of fealty and a lifetime of dutiful submission...PM me.
 
Nuvinci: 350% variation, ~4.2kg, max torque 130 Nm
Rohloff: 526% on 14 speeds, ~1.8kg, max torque 250 Nm edit: 100nm
Nexus8: 307% on 8 speeds, ~1.6kg, max torque ???

That Izip could have been about 2kgs lighter...
 
Mathurin said:
Nuvinci: 350% variation, ~4.2kg, max torque 130 Nm
Rohloff: 526% on 14 speeds, ~1.8kg, max torque 250 Nm
Nexus8: 307% on 8 speeds, ~1.6kg, max torque ???

That Izip could have been about 2kgs lighter...
You have a point. But we all know that just lately you've also gotten on a sort of shaving jag

(pardon my barb ha ha)

:idea:

Dear Mathurin,
I got a NuVinci on order, and would like to hire you for personal services.
Q: Do you shave balls?
 
Q: Do you shave balls?
I shall not let my fanbase ponder such questions anylonger.
The definite answer to all related questions may be seen here (NSFW!).

PS: Leave your dignity at the door all who dare find out,


PPS: The correct answer is: no.
 
PS: Leave your dignity at the door all who dare find out.
And how. It's not a Gman kind of place. In fact it's almost not a place at all.
There are many posters.
They are me and Mathurin and Mathurin and me, etc.


In order to grind the ball joke into the dirt,,,,
April 1, 2008
NuVinci Warranty Dept.

Dear Customer,

Our inspection of your returned transmission shows that the unit was abused by such overloading as is impossible to create by manual pedaling of a bicycle.

When we see this sort of overheating (evidenced by blue balls), we know we're dealing with another ebiker.

Your warranty claim is therefore denied.

Good day,

Francois Mathurin
NuVinci Customer Satisfaction Team Member
 
Reid, I'm still awaiting your submission for losing the bet. See last post, previous page, ceramic balls. Time is money! Interest is accruing! Hop to it, buddy or I'll dock your zero pay, making you an indentured servant yoked to debt for life!
Oh wait, if you're anything like most Americans, you're probably yoked to debt for life anyway.
See, this slavery arrangement won't be that different :)

-xyster
 
xyster said:
Reid, I'm still awaiting your submission for losing the bet. See last post, previous page, ceramic balls. Time is money! Interest is accruing! Hop to it, buddy or I'll dock your zero pay, making you an indentured servant yoked to debt for life!
Oh wait, if you're anything like most Americans, you're probably yoked to debt for life anyway.
See, this slavery arrangement won't be that different :)

-xyster
Look, Kinko :) I am not a metallurgist either, and I know nothing of specialty balls aside from those rolled in leather bars.
Here's my deductive logic for WHY there'd be ceramic bearing balls, ever: for the same reason that plastic ball bearings are also made: for survival immersed in corrosive fluids (see the robotic swim pool cleaning machines for plastic ball bearings).
But such bearings are for very light loads.
I suspicion that ceramic ball bearings are for use in low-load, high-temp, corrosive applications, fluid flooded or not.
But, low load and low speed, surely surly Shirley!

Bet lost, now it's your time to job hunt:


Looking for employment of a new and diff'rent course?
Introduce yourself to Mathurin and costume as a horse!

:twisted: pop pop pop! pussy punched ya!
 
But such bearings are for very light loads.

Crudcakes, looks like I'm doing the dishes again tonight. :cry:
 
To: info at fallbrooktech dot com

Subject: There is a pressing need for a tandem drive NuVinci hub

Date: Sun 03/04/07 06:10 AM


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Hello,

I am a member of the e-bike DIY community.

My Currie bike has singlespeed drive as shown in the stock-form picture.

What is wanted: a NuVinci with dual cogs: one for the pedal chain, one for the motor chain, both on the right side
so that the drive motor and pedaler both enjoy the advantages of variable gearing.


Question: Have you folks considered developing such a tandem drive? If so, I want one.

The CVP, as I reason it out, is the sole transmission type for this duty
because it won't torque-shock the motor, and vice versa.

In this proposal, the electric motor gains the needed gear ratio range without necessity for dedicated extra transmission.

If you could make even a one-off prototype, I would be intensely interested in purchasing it for evaluation and write-up on the ebike forums.
Or perhaps you've already thought of this idea; how great it would be,
how it would displace hub motors from higher-end ebikes
and put the Cyclone-type drive out of the picture entirely.

Elegance, minimalism, idealized performance for the electric drive,
and absolute form-follows-function...


Thanks for your thoughts,

I'm hopeful for your initial product's instant success, regardless whether you can supply or affirm toward my special request.


Reid Welch
Miami Florida

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Here come the Cyclone Yakuza... I did so enjoy the poems. Oh, well.


Of course, another alternative might be to draw-up a nice plug-n-play dual-freewheel. That might actually be patent worthy.

8)
 
TylerDurden said:
Here come the Cyclone Yakuza... I did so enjoy the poems. Oh, well.


Of course, another alternative might be to draw-up a nice plug-n-play dual-freewheel. That might actually be patent worthy.

8)
Ah, yeah,

Dear Yakuza,

Your Cyclone is a working, good thing, it really is


a total PITA to fit to some bikes, though.
The gearing is all out there in the open air on a noisome, nasty derailleur. I hear that it alters the pedal-feel of a bike, and requires a freewheeling chainring, in order to not make the pedaler's legs pogo sticks,
and facts are facts, and the NuVinci at this early stage, remains an unproven, pricey dream.
Whereas, your kit is only pricey and greasy.

Thank you Yakuza,

R.W.


__________
Dual freewheel cogs on (a perfected) NuVinci will blow away a cyclone. Plus, so much easier to hang any gearmotor you desire to the chainstays, instead of confined in the often space-limited bb area. No loss of ground clearance either.
So many esthetic and practical advantages....unrealized as yet.
 
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