Nuvinci CVT hub

[Reid Welch]

The more I dream about this setup, the fonder it grows.


Imagine, you want to start fast, run fast, but with reasonable battery economy?

Just full throttle the bike from the stop, starting off in lowest gear, and
feed up the gear ratio as the bike gains speed;
you're running the motor at its sweetest spot for economy OR go for power; either way, you're gonna get up to speed a lot faster than if single ratio'd.

and do this whilst holding down the current instead, to a level of your choosing, whilst still having max power or max economy, watch your ammeter or make an audio (tone generator) ammeter, even.

It would be oodles more fun, this CV system, than shiftless biking, or jump-ratio gearing;
it gives you something to do that you can -feel-.
And it'll be without lurch,shock, noise or jumping chains, etc.
Wait... it'll have major jump off the line, like a Cyclone, but... faster because no lost shift time. No sklatter noise of jumping chain...

Just a bare swooshing sound, I imagine...

 

[xyster]

I'm excited about these small CVT's too. Maybe within 5 years, perhaps by 20, I think CVT's will replace geared trannies (transmissions, not transsexuals or transvestites -- though probably those trannies will find interesting, "alternative" uses for CVT's too )*.

*Disclaimer: this statement not intended to offend, only to poke healthy fun at a more visible element of the human condition.

 

[fechter]

My Honda has a CVT. 60,000 miles and no problems. It's interesting to see the rpms just slowly rise when I'm climbing a hill on the freeway. The technology is certainly doable, but scaling it down to bicycle size is challenging.

 

[Reid Welch]

apropos of possible future shock,

eh, this is not what you think by the link:


http://www.rohloffspeedhub.com/



now, to look more..

:wink:

be wary, it's not so great...I don't suppose...the former USA Rohloff guy is p.o.'d at them all:


http://nupace.com/product.htm

dissection:

http://www.bikeforums.net/archive/index.php/t-156965.html


awagner

After staring at their CAD rendering and also a couple of the pictures from their patent for a few minutes, I understand how their mechanism works. I will try to describe it to you.

The relevent US patent is 05971877.

Explaining the mechanism from the axle outwards, and neglecting literaly hundreds of bearings, we have:

1. A fixed axle and associated torque arm. They don't clearly show the torque arm in their diagram, but it must be there and it wouldn't be very interesting if it was. The axle is eccentric in the middle section, standard in the portion that joins with the frame. The axle only moves when your torque arm rattles loose and beats the hell out of your rear triangle.

2. One Eccentric sleeve with engages the axle in the portion where it is itself eccentric. This is reminiscent of an eccentric bottom bracket. By turing this sleve relative to the axle (By having the stop for a boden cable on the torque arm and the cable clamp on the sleeve), the amount of eccentricity of the outer diameter of the sleeve can be changed relative to the axis of the axle. The sleeve only moves when you shift "gears", and it does so continuously rather than being indexed.

3. Four pawl holders, which are concentric about the outer diameter of the larger eccentric sleeves from (2). They do not engage with anything except the pawls they are holding. Each pawl hoder has two sets of pawls oriented in opposite directions.

4. Pawls. Each pawl is held in by a spring mechanism, rotates about the end in the pawl holder, and has teeth on the outside, which engage with (from chain side to drive side):

5. An outer toothed ring that is fixed to the rear cog.

6. Three more toothed rings. Each toothed ring engages with two sets of pawls, one from each pawl holder. The two sets of pawls associated with each toothed ring are oriented in opposite directions.

(Parts 3 - 6 are all moving whenever you are pedaling.)

7. The hub shell, which engages a single set pawls, i.e. the leftmost set. This set of pawls freewheels when you are coasting. The hub shell rotates axially about the center of the axle.

To understand how the pawls work, imagine a very flexible person standing on skis that are parallel, one slightly forward. Now assume said person passes out. Gravity pushes said flexible person down and he/she does the splits, pushing one ski forward and one back.
Analogy:
Gravity <--> Eccentric sleeves acting as a cam relative to the hub shell / toothed rings.
Skier <--> Pawl Holder
Pawls <--> Legs
Skis <--> Two adjacent toothed rings

So on one side, say the front, of the hub you have pawls engaged with teeth and expanding, and on the other side, say the back, you have pawls contracting and engagine with new teeth. The more eccentric the outer diameter of the outer sleeve, the farther down the pawls "squish" during each cycle.

The design does have some elegant properties:
- You don't have to change the dimensions of any of the parts relative to each other to change the gearing range of the hub. This is in contrast to the much seemingly difficult to design and dimension gears in a traditional gear hub.
- While there is a rediculous number of parts, there are not really very many types of parts.
- It may not be as difficult to service as it seems; It seems like each pawl holder and associated two sets of pawls stays together when you pull the mechanism apart.
- I could imagine it being very smooth when in good working order and at lower speeds. I imagine the pawls whining a bit at higher speed, i.e. not when they are engaging, but when they are slipping to new teeth.
- It is, IMHO, easier to understand than a rohlhoff.
- Does not rely on friction like many other continuous gearboxes.

So no, they don't seem to be a hoax, yes, it seems that have a workable mechanism, and no, I wouldn't recommend buying one until they bring the price down by a factor of ten or so and hire a competent marketing department.

I think I'll pass.

edit: Even the former Canadian importer of Rohloff
http://www.freeridehubs.com/Contact_freeridehubs.html
is down on Rohloff,
yet he is very UP on shilling NuPace hubs.

Oh boy, what a business! Only $995!

-----

All this goes to show what a class act Fallbrook is running so far with their years and millions invested in the NuVinci patent development process.

I remain hopeful for the NV CVT . Yah, it's frictional. Seems to be part and parcel in the parts business,
that makers and vendors and users
rub and wear badly against each other.


-----

edit: red herring, or not?

http://www.bentrideronline.com/messageboard/showthread.php?s=3458391e665110bec924c442fe176276&p=93650&page=2

Originally Posted by AndyTiedye
If CVTs are so inefficient, why do they use them on hybrid cars?

Because electric motors are much more sensitive to operating at their "optimum speed" then gas motors, so Optimum ratio is their goal.

 

[Krow]

I have the NuVinci hub on order right now. I plan to replace the Shimano Nexus 4 on my Giant Lite. Since the Lite is crank driven, the wider gear range and easier shifting should be a double benefit. I'll be interested to see how the Panasonic controller does with the NuVinci. I've heard of others swapping in a Nexus-8 to good effect.

I'll check in with a full report when I have it up and running - probably in a couple weeks.

cheers,

keith.

 

[Reid Welch]

I have the NuVinci hub on order right now. I plan to replace the Shimano Nexus 4 on my Giant Lite. Since the Lite is crank driven, the wider gear range and easier shifting should be a double benefit. I'll be interested to see how the Panasonic controller does with the NuVinci. I've heard of others swapping in a Nexus-8 to good effect.

I'll check in with a full report when I have it up and running - probably in a couple weeks.

cheers,

keith.

Oh, this is great news. Finally we'll hear a report.
NuVinci has a discussion forum. It's dead as a doornail.
Admin monitors the panel and reads everything.
I did get one PM exchange from them when I asked permission to read the closed panel for user reports. Denied.

But you are going to be a user, Keith. Perhaps they'll let you read their closed panel?

For the rest of us----well, see how my thread went at the NuVinci friendly happy helpful place (not)

http://www.atcnuvinci.com/support_forum.php

 

[xyster]

Ah yes, the classic progression of frustration. We've all been there, eh?

http://atcnuvinci.informe.com/introduction-of-an-endless-sphere-lev-forum-member-dt9.html

"My name is Reid Welch.
I participate at the Endless-Sphere ebike / LEV discussion forum.
....
I'd like to learn more about the NuVinci hub,
and I'd like to promote the product.
....
Here's my highly modified Currie cruiser e-bike
....
I need guidance here. Is either proposal practical?
Thanks for any thoughts,
....
Until there's some more active participation here,
...
I hope Staff will supervise that thread and prevent myth/rumor promulgation.
...
You all are more than welcome to join in at Endless-Sphere.
...
Please answer here, read there, join there, answer there, and let's keep the balls rolling.
...
Read Paul, read of Paul, see Paul work, and see his potential, his integrity, his popular appeal.
...
There seems to be no point in this forum.
Why have it be public ?
...
What manner of support and promotion and welcome is this?
...
= me, for ever asking "

:lol: :lol: :lol:

I'm not laughing at you, and I'm really not laughing with you either since this common frustration ain't really funny, I'm laughing at....uhmmm...something else I'm sure!

 

[Reid Welch]

The person or persons there at ATC/NuVinci's help forum
must agonize over what to say
how much to say
and how to utter the...

Fallbrookian Truth

The prospect of pink slips after mis-speaks
muzzles the mouth holes of techs flacks and geeks.




______________________


I suppose that now
I'm out of special favor :wink:
for preferential treatment

as a reviewer of NuVinci product.

I may as well be helpful
as I can surely be.

Here's an iconic logo for their firm
the famous you-know-what:

http://img355.imageshack.us/img355/8717/nuvincisphinxiconri9.jpg

 

[Lowell]

Well at least it seems to be a more real product than those 2 stroke hub motors...

 

[Reid Welch]

It's a real product. It's a real company with clout.
It's going to be good, this hub.

However, their public relations
suck rusty steel balls.

____________________
_________________________

Here's Tony Ellsworth's "The Ride" at its first showing



He favors very wide rims for balloon tires.
I agree with him on that point, esp. for a rear wheel.


I like the way the NuVinci looks in all-black. IMO
his stylish spendybike would look even better with Big Hank slicks.

http://www.ellsworthbikes.com/default.aspx

 

[Lowell]

I like the way the rear fender is integrated into the frame and is load bearing.

 

[Mathurin]

I don't like the way the fenders are too short to protect the rider from road crud.
May as well just save the weight...

Fleabay Nuvinci thingie 400usd

 

[Reid Welch]

I agree with you both. Hey, the fenders are not all that fenderful.
Yet, isn't that interesting how he did make the integral rear fender
part of the frame, to bear load.

The bike is pricey by our standards, aimed at the carriage trade/collector/biker market.

Gotta say, it's esthetically beautiful, stem to stern.
It's truly industrial art. Art is not always all ways utilitarian.

_________________
___________

Now, where do we begin "improving" The Ride (their model's name) with our duct tape additions, Milwaukee drill packs,
and at least six halogen headlight bulbs in series?

And for me: I gotta have a ding-dong bell---and the bulk of a Unite motor hung off one side....

_______________

...We'd ruin Tony's nerves in one hour or less

if he ever came here for a look...

Poor guy



No, smart and active guy.

because he makes market.

______________

What have we done today to make market appeal of our e-bikes?

Do we ride beauties or beasts?

_______

In my unwanted opinion, if we can afford two ebikes---make one a test sled ugly as hell, OK, because we're inventors and prototypers endlessly modding;

ah, but, maybe have one other bike so creamy looking
it makes people quiver, "that's so cool!" Deecanio, Stevil, and others here we know.

I have only one e-bike, so I do best to try to keep it pretty clean,
and try to promote e-biking by looks, not just function, because

the way to sell steak is to sell the sizzle.

 

[Toorbough ULL-Zeveigh]

I like the way the NuVinci looks in all-black.

http://www.ellsworthbikes.com/default.aspx

Just don't tell these guys.


Trade Dress

Trade Dress allows WaveCrest to exclude others from copying the look of its products. An example of WaveCrest trade dress is the wheel with a black hub motor.



http://www.wavecrestlabs.com/technology/ip.html


I'm hoping that large diameter hubs of every kind become more commonplace. When the cops begin to catch on & BOLF electric hub motors they won't be able to automatically assume a bike is powered. Hub driven ebikes will blend in more in a larger population of big hub non-powered bikes, helping out with the stealth.

 

[Lowell]

I don't like the way the fenders are too short to protect the rider from road crud.
May as well just save the weight...

Fleabay Nuvinci thingie 400usd

How many guys are actually going to ride that bike in the rain though? That bike is all style and show.

Does anyone know what the wheelbase is on the Ride? If their website is to scale, it looks to be longer than the 46-47" Rogue. That's exactly the kind of frame I'm looking for, but at maybe 1/10 the price. Lots of room inside the frame for 100's of A123 cells, long wheelbase and most importantly, designed for road going use without 8" travel suspensions.

 

[Toorbough ULL-Zeveigh]

It's the structual fender that's functioning as the ersatz seatpost which opens all that juicy space inside the frame.

As well, what's missing in the posted picture that they show on their website is that a tail light is suposed to be integrated into the end of the fender which is why it ends where it does. Again for style. Wonder if they removed the light to make the bike more affordable? :lol:

 

[Reid Welch]

...Wonder if they removed the light to make the bike more affordable? :lol:

Surely not. That photo shows the prototype The Ride at a trade show some time ago.
The production bikes are not yet delivered--they may not yet be physical reality--hence the artwork representations at the Ellsworth site.


It's clear the light will be integrated into the rear fender tip.


And as for (lol) our resident SmartyPintoPants with his "fleabay" joke,

Mathurin, you've surely just lead us to the present, actual builder of these very first Nuvinci hubs:
Staton-Inc in Oklahoma. They are the eBay seller of these first five hubs on eBay
and they note that the NuVinci hubs are made in Oklahoma City.


From their website, see:

(excerpt:


ü The Staton Inc. custom rear hub, your pick of the 28, 32, 36 and 48 hole sizes. They are made in Oklahoma City, Oklahoma to exacting standards in our modern manufacturing facility. Each hub contains four high speed double sealed 12 mm ball bearings mounted to a 10 mm x 1.0 x 7.875â€￾ long axle. Each axle, all ball bearings and every component that we manufacture, are made to our exacting specifications.

ü For the left hand side of the hub, we use a left hand threaded 16 tooth freewheel sprocket, for the engine to drive from. The advantage of using left hand thread, to screw the freewheel sprocket onto the hub, is that you drive from all the spokes, and the sprocket remains perfectly centered, at all times. Unlike other kits they "bolt" a sprocket or pulley to 5 to 12 spokes. They are not centered, they pull break and bend spokes then your wheel falls apart. Belts break - hard to change.

ü A perfectly centered sprocket increases performance throughout the entire rpm range as well as reducing noise, vibration and harshness.

ü For the right side of the hub we use standard right hand threads with standard type screw on type freewheel sprockets. Our screw on type freewheels are available in single speed, five, six seven and eight speed varieties. Please note: we do not include a right hand freewheel in our kit. Take your old freewheel off and re use it or you may want buy a new one.

 

[Krow]

The Nuvinci hub came this week. I bought it built into a Rhyno Lite wheel. A local bike shop was drooling to hook it all up for me.

They finished the project this afternoon and I now have the only (??) Giant Lite electric with Nuvinci hub (woo hoo). This replaces the Shimano Nexus-4 hub that came with the bike.

The key features of the Nuvinci are:

1. wide gear range - 350%. According to my calculations, I'm now riding from 25 up to 88 gear inches.
2. "infinite gear control" - the CVT system allows very fine control of the gearing anywhere within that range.
3. self-contained unit - low maintenance internal hub
4. easy shifting - can change gear ratio at any time, including at rest
5. weight - 4.8 kgs

Since I already had an internal hub on the bike, I didn't gain much on points 3 or 4. The added weight is a disadvantage, but not that noticeable on a 60 lb commuter e-bike (ask me again when the battery dies on a long hill).

The Shimano Nexus-4 has a total range of 180% and I was turning from 41 to 73 gear inches. The greatly expanded range of the nuvinci is very nice - especially on long hills up to my house. I tried my daily nemesis - a half mile long climb at 8% grade. The Shimano hub with the Panasonic motor had managed this but with a lot of additional effort at a slow cadence. With the lower gear ratio, this hill is a lot more manageable. I spin the gears more, but still make 5-6 mph.

So, the wider gear range is definitely helpful, but I could have replaced the Shimano 4 with a Shimano 8 for a similar effect. The Shimano 8 has approximately the same total range and it's lowest gear is almost as low as the Nuvinci.

The big difference is the CVT effect. The twist shift doesn't click, it just smoothly twists. The total travel of the twist shift is surprising. It takes almost a full 360 rotation to run through the whole range. I guess that gives you pretty fine resolution, but it means taking your hand off the shifter 2-3 times to go through the whole range. It will shift under load, but it's a lot easier to take the load off the pedals for an instant during the shift - just like other gearing systems.

I'm still learning about the interaction of the Giant Lite's Panasonic motor and controller with this gearing. As you may know, the Panasonic motor is crank-driven and is torque-sensitive. The motor is additive to the rider's input and drives through the gearing. Very helpful when going up hills with this modestly powered (240-350W) motor. The controller reduces it's assistance when the torque on the pedals is very light or very heavy.

The fine resolution on the gearing allows me to play a lot more with how much the motor contributes. If I spin the gears with light pressure at a high cadence, the motor doesn't contribute. As I increase the gearing, I can find a point where the motor starts to kick in intermittently through the pedaling cycle. Further increase will bring the motor on throughout the rotation.

I'm still thinking about the best approach to using this increased gearing control. I think it will allow me to find a better balance between riding and motor assist during the longer flatter stretches of my commute, but still provide more assist when needed. I'll have to do some longer runs to see how this impacts total range. My commute just got 4 miles longer this week, so I've started carrying my charger with me. Maybe I'll get enough additional range to leave it at home.

Not bad for a first day! I'll continue when I've had more experience on the new beast.

cheers,

keith.

 

[Matt Gruber]

thanks for the report!
now we need somebody to try an etek on it 8)

 

[TylerDurden]

Great review!

 

[Reid Welch]

Very nice report. And later if you can offer more review concerning its behavior as a purely pedal operated transmission; its feel and such, as compared to the Shimano. Does it feel as free-rolling as the other?

It's not possible with your bike, it being a pedelec, but another point of curiosity here is to learn how the Nuvinci would slide through its range while under e-power only, and how (by ammeter) the best (lowest current consumption) is to dial in.

This latter point is of the greatest interest to myself: how the Nuvinci might provide the most ideal gearing for any particular motor-powered road speed/grade load.

Thanks for a wonderful review. More to come? We're all ears.

cheers,
Reid

 

[Toorbough ULL-Zeveigh]

It doesn't look like this review has been linked to yet.

http://tech.groups.yahoo.com/group/power-assist/message/62978




Hi Folks,

We have been testing out a new NuVinci hub, on our trike, with the 500
watt cyclone, and it's a blast!

We like it. This product was designed for electric vehicles,being their
larger system can be used on golf carts. It has been overbuilt.

The best part of this system, is the ability to shift at a stop. I
really like being able to down shift into a nice low range to take off with.
I can not detect any slippage, on a steep hill, with my hard pedaling,
and a full 800 watt blast of assist. You do have to lighten up the load
to shift, like with any trany, be it a bike, motor bike, or car, so it
is to be expected. But the 350 % range is sweet, because we have been
restricted to a single chainring up front, with our freewheeling crank
set up. So now we actually have a lower low gear, a higher high gear,
and all of the choices in between! Plus, the ability to shift at a stop,
makes it a must have now. Nice stuff!

If anyone would like to try one, please feel free to stop by our shop,
and take a test ride for yourself...
I will try to post a picture of the set up on our page here on the
power-assist yahoo site.
We will be up in Maine at the vello spring gathering, with the
electrathon racing, on May fifth. Beech ridge raceway...

Happy trails, Josh K.
http://www.electric-cycle.com

If he's right & that it's been overbuilt intended for electric golf carts, then that alleviates any qualm I had over it's robustitude.

 

[Krow]

Thanks for your interest, Reid.

I've completed a full week of commuting and riding with the new hub for a total of about 120 miles. This hub is making a big difference to my riding experience.

The Giant Lite is crank driven and the controller responds to the pressure on the pedals. I find it very easy to adjust the "gearing" to ride just over the point where the motor assist kicks in. The Nuvinci shift control is exactly as advertised - "like having a dimmer switch on your bike". I find that I can move the gearing ratio to meet conditions so easily that I don't ever hesitate to change as i ride along. And, even small changes have an impact on how much the motor kicks in.

I also believe that I can find a more efficient gear ratio for climbing. The added gearing range means I can drop lower than before. Since it's pretty easy to shift, even going up hill, I can fiddle with the ratio while going up the hill to find the right combination of work from the motor and from me.

The overall effect is to amplify the already great Giant Lite experience. It really does feel like a bicycle that amplifies your effort when needed rather than an electric scooter with pedals.

I'm riding with a lot less assist now during my regular commute. The motor kicks in mostly on starts to make me snappier off the blocks and then again up the big killer hills we have around here.

This has had a big impact on battery range. I ride the 15 mile round trip to work and use about 20-30% of the charge. With the Shimano Nexus-4 I was using about 50-60% of the charge. Sorry that I don't have ammeters and other tools to get a more precise measurement.

For me, this has been a very successful experiment. The combination of crank drive, pedal-sensing controller and fine resolution shifting makes my e-bike experience more efficient and more fun!

cheers,

keith.

 

[TylerDurden]

Great review!

It takes balls to test a NuVinci...

Keep your eyes on the pic's "viewed" counter, there is a bit of interest in this gizmo.

 

[Matt Gruber]

reminds me of cars' power steering.
people want just the right amount of effort to feel as if they are actually muscling it around a corner. but not enough to get sore muscles. of course in most cars it is just an illusion,
here u are doing real work.
.
anyway, gentle testing is nice, but i'd like to see an etek on it.