inside the nuvinci hub

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Vinci

New Member
Aug 18, 2010
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Austin, Tx
I do understand the warranty thing. I did design my drive train so the hub should never *see* more than about 80 ft lb of torque, but your comment about *spikes* got me thinking. I don't have room for an isolator unless I use a belt in the primary reduction. I wanted to do that anyway, so you've given me another reason to machine up some special sheaves. ; )

Denny
Take a look at adapting a Gates Carbon Drive.

WRT to the spikes, most people don't understand that the torque rating of any IC engine is an average number. The actual torque coming from the engine looks something like the EKG trace of a human heart, with a big, short, sharp spike in torque just after TDC. That is what kills transmissions unless you have an isolator of some sort. All automotive drivetrains have them, and most scooter/motorcycle drivetrains have them as well.
 

Vinci

New Member
Aug 18, 2010
14
0
0
Austin, Tx
Vinci is N.V. gonna make a hub in the future for our motor bikes? Thanks again for getting in touch with us! Your knowledge and incite is very valuable to us!!

I see the developers kit now. Wish I would have knew more and bought that:( Well not so much for the shifter but stronger guts
Fallbrook Technologies

How about getting this thing left side drive? A good design would be to shave weight , do away with the power robbing J Shafts and gear box's. Well for or tiny motors.. anyway!:)

Since getting my clutch to behave this hub has been very nice lately!
Not much market demand for a left side drive, though we did make a 1-off for a Honda 70 that we showed in some European shows. It used a Dev Kit with the auto shifting function. You just leave the Honda trans in 2nd and off you go!

The Dev Kit shifter opens up all kinds of options for you. You can program a shift map to do whatever you like. Most of the pedelecs that we have fitted a kit to are set up to maintain a constant pedal cadence, no matter what the bike speed is. They are a real revelation to ride!
 

Vinci

New Member
Aug 18, 2010
14
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0
Austin, Tx
Heck of a proving ground eh? laff

I just wanted to thank ya for your participation & interest Vinci, good ta have ya here w/o a doubt (^)
You're welcome! Glad we could offer a bit of help. I should note that I won't have time to lurk here with regularity, but if anyone has a question on NuVinci, they can always PM me and I should see that pop up in my e-mail.
 
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camlifter

Active Member
May 4, 2009
1,033
16
36
acme labs marion ohio
i've been doing some research on traction fluid since i want to try a different fluid in the hub, i came across rotrex superchargers which use the same type of ball drive as the nuvinci, they spin at a much higher rpm and create much more heat. it uses a special traction fluid called rotrex sx100, i bought a liter of it and will try it out. the rotrex has a service life of 50k miles for the oil. heres a link i found of people talking about traction fluids.Info on SX100 Traction Fluid - Bimmerforums - The Ultimate BMW Forum
 

Vinci

New Member
Aug 18, 2010
14
0
0
Austin, Tx
i've been doing some research on traction fluid since i want to try a different fluid in the hub, i came across rotrex superchargers which use the same type of ball drive as the nuvinci, they spin at a much higher rpm and create much more heat. it uses a special traction fluid called rotrex sx100, i bought a liter of it and will try it out. the rotrex has a service life of 50k miles for the oil. heres a link i found of people talking about traction fluids.Info on SX100 Traction Fluid - Bimmerforums - The Ultimate BMW Forum
Unless they've changed their fluid recently, it will not perform as well nor last as long as the Invaritorc 638 will. The Invaritorc is a synthetic. Theirs is a lesser fluid, and they may in fact have changed to a version of Invaritorc by now.

Traction fluids in general are very unique among lubricants. The performance is measured by "coefficient of traction", or Ct for short. All fluids have some Ct, with Mobil 1 and other similar synthetic oils being the worst. Put that in your NuVinci and it will slip REALLY smoothly! You won't go anywhere, but the pedals feel really smooth! :-||

Typical oils will have a Ct somewhere in the 0.005-0.01 range. Traction fluids have hook-shaped molecules, that when passed through a rolling contact between two hard pieces of metal, stack on top of one another and hook together ever so briefly. Analogies ranging from stacked firewood to velcro have been used by researchers to describe this "elastohydrodynamic lubrication", or EHL for short, over the years. This gives traction fluids Cts in the range of 0.04-0.10, depending on fluid and the specific conditions, so 4x-10x better than anything else you can buy off the shelf.

Furthermore, traction fluids also have an extremely high bulk modulus, which is a fancy way of saying that they don't give when you squeeze them. This is a huge aid to the durability of any traction drive, whether its ours or the Rotrex fixed ratio planetary they are talking about on the bimmer forum. This can make a 10x or more improvement in durability.

So, all that to say, just call NuVinci Customer Service and ask nicely for a bottle of Invaritorc if you need it. A LOT of stuff was looked at before Invaritorc was settled on, and you can bet your life that there is a very good reason both Fallbrook and Rotrex use these very expensive fluids. NONE of the characteristics above are going to show up in the lube analysis that the bimmer forum guys are wasting money on.

PS - Feel free to cut and paste the fun facts above onto that bimmer forum if you like - show them where the real geargeads reside! brnot
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Vinci is N.V. gonna make a hub in the future for our motor bikes? Thanks again for getting in touch with us! Your knowledge and incite is very valuable to us!!

I see the developers kit now. Wish I would have knew more and bought that:( Well not so much for the shifter but stronger guts
Fallbrook Technologies

How about getting this thing left side drive? A good design would be to shave weight , do away with the power robbing J Shafts and gear box's. Well for or tiny motors.. anyway!:)

Since getting my clutch to behave this hub has been very nice lately!
Don't you just love the Forum Search?
That is how I finally found what I was looking for in this least likely forum area before just starting a new topic about the DevKit in the main.

I e-mailed Fallbrook this morning with my questions but the mail came back with this...
---
Recipient: <[email protected]>
Reason: 5.1.1 <[email protected]>: Recipient address rejected: User unknown in relay recipient table
---

No biggie, this is recent and related to what I started researching when 'one of those dreams' that wakes you up at 2 am you have to get started on right then and there happened this morning.

In short, just a basic geared Jackshaft for our left side 2-stroke kits to get rid of that second chain to a no geared bike.

Chances are there just isn't enough demand for a left side drive hub so as usual it is innovation time.

In my course of searching the net for enclosed geared bike hubs I came upon FallBrookTech and their Developers Kit.

It is nearly noon my time so I only have 8 hours into it, most of it spent reading the Dev Kit Manual to understand this apparently new offering, and being a computer guy by trade just couldn't stop until I had a pretty good grasp of it.

I will go ahead and get this posted now to kick this topic back up while I compose my ideas, it will be awhile, but read that Dev Kit Manual .pdf to see what this computer programmable automatic or manual NuVinci hub can do now. It blew me away, and that is unusual for me.

We are talking a completely programmable shifting system based on your build with a laptop and USB cable to on the fly guys to get it dialed in before you set it... This is major guys.

I am off to to compose the details now ;-}
*poof*
 
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KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Where to start…

Let’s agree (or at least agree to disagree) that a second chain stinks, and so does not having any gears, especially on a low HP ‘legal’ motor like a 48cc in my town.

Let us also agree (or at least agree to disagree) that for this mod it won’t be a budget ride, but may be about the most rider friendly way to accomplish a myriad of improvements with the widest variety of build options.

Before you even start trying to understand this and asking question, please, read the whole NuVinci Developers Kit Installation Manual.
You will be lost if you don’t.

Regarding the Hub Electronics:

It requires at least a 12V power source to operate. That may be a problem for most.
But what the electronics that power the 32 bit processor and sensors plus the actual changer that moves the gear ratio shaft in and out in ~900 useable positions needs power.

That was not a typo.
The servo that drives the ratio position of the changing shaft on the hub goes from 0 to 1000 rendering a 0.5 (underdrive) to 1.75 (overdrive) gear ratio range.

The thing is, you can program the thing via some really cool computer tools to program it to operate in the exact RPM power band spot you want at any speed you happen to be wanting itself.

*** If you don’t understand computers, micro-controllers, and follow the manual you are not out of luck there are defaults, but for me this is Really Cool! ***

The most you can realistically expect is a 64 speed automatic, but a dozen ranges should be enough to keep the RPM’s in the sweet range.

Jackshaft NuVinci Combo?

Seems to me a slight established Jackshaft configuration mod could put the NV as part of it so it didn’t matter what your pedal side was like.
All it needs is an extra idler gear to reverse the direction on each side to turn it around and still function stock.

Personally I would like nothing better than to get ride of all the chains in a Jackshaft until the one that drives the pedal side freewheel but considering motor drive chain/clutch area that won’t work, so how about something this?

A planetary gear system in the motor drive sprocket at the jackshaft to the auto-shift hub as the transfer shaft to reverse direction on the left for any hub, and another on the output to get it to the wheel going the right way on the right?

It would have to be one pretty special sprocket to do it, but isn’t that what freewheel cranks are?

If you have no gears now you do with no actual bike hub change and only 1 chain, if you do you never know what could be possible.

Best I can do for now, it is well after 3PM here without even a bite to eat but now you have the basics, just reverse the direction on each end of whatever geared Jackshaft hub you use in the thing itself.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
Their making a smaller hub now. Guessing the heavier duty hub like I got will soon be obsolete?:( These motorized bicycles are going to be a rapidly growing market...

Manually shifting my hub is working out good for me!
 
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Vinci

New Member
Aug 18, 2010
14
0
0
Austin, Tx
I e-mailed Fallbrook this morning with my questions but the mail came back with this...
---
Recipient: <[email protected]>
Reason: 5.1.1 <[email protected]>: Recipient address rejected: User unknown in relay recipient table
---
Glad to hear you are interested KC. May I ask where you found that e-mail address? It does not appear to be a listed FTI address, as your bounce indicated. If it's floating around on the company website somewhere, it needs to be killed off.

Otherwise, I'll help as I can on any questions you might have.
 

spad4me

New Member
Jan 20, 2008
472
0
0
Arizona Bullhead
Cam lifter what size of engine are you using.

I just bought a Nu Vinci hub from Staton He is dumping the old models for $229
NuVinci CVP Model N171B Gear ratio 350%: Staton Inc

His warranty for engine power is only 30 days.

Staton changed the warranty after this post to his new policy of NO warranty for any motorized bicycle use.Feb 16 2011

Pedal power is three years .
I can not even assemble the parts in 30 days .LOL so pedal for me
I plan on using my tried and true pedal power to ensure a proper break in then eventually after I am sure it is good to go .
Maybe in ayear or two A gp 460
 
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camlifter

Active Member
May 4, 2009
1,033
16
36
acme labs marion ohio
i'm using the morini s6s, a 10 hp 2 stroke, it's way to much power for the nuvinci, goat herder is using the 5 hp morini with some luck. there are a few people on this forum who are using the 66cc kit motors with the nuvinci and having good success with it. if you keep it under 5 hp you should be alright.
 

spad4me

New Member
Jan 20, 2008
472
0
0
Arizona Bullhead
Nice to know an inexpensive gp460 outputs 4.2 hp stock.
With a chamber about 5.5 @ 13000 rpm
I use a scooterguy type setup with a sick bike parts freewheel chainring.
This will be my first nuvinci setup .
Not my first cvt setup.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
Spad mine is still working strong. It took awhile for me to rule the clutch out of the equation. You posting that link did not help things. I darn near ordered a spare.

I will report on Q to every one if it breaks. You are going to love shifting gears on the fly with that thing.

I really gave a hard run at breaking mine! I put some documentation at http://motorbicycling.com/f47/coil-spring-test-video-21494.html
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Glad to hear you are interested KC. May I ask where you found that e-mail address? It does not appear to be a listed FTI address, as your bounce indicated. If it's floating around on the company website somewhere, it needs to be killed off.

Otherwise, I'll help as I can on any questions you might have.
Thanks, but I scoured every page on your web site for hours and just don't recall, but best guess would be in the .pdf developers papers or Install papers.

In short if you don't see it as a link on your web site, it was in a .pdf file.

So Vinci, lets talk ;-}

We can do it here so others can share, or you can certainly contact me e-mail.

If you read my first post you get jest.

If you can make a counter-clockwise version, be it for a second drive or in a Jackshaft, you may have a winner.

I am a pretty technical guy, I know all about manually adjusting the hard drive head seek mechs on 12" 1MB old main frame computers with a scope for minute movement.

How you are applying it to your hub for a programmable gear ratio to match the bike just blows me away!
As mentioned I poured through all of your tech manuals and understand how it works, very clever actually, Kudos to you ;-}

I have a myriad of questions but I'll start with just the basics.

On a typical 3-speed manual hub the slightest variation in the shifter mech on the axel makes a huge difference, as does the cable, how do you compensate for that when it so much more critical with what, like 64 unsealable position movements in an inch?

Is 64 the right number for a max or would say 21 speed to make it easier to program make a big difference too?

As for programing the hub (I love saying that) I studied the tools so what is the best way for Joe Blow motorized bike builder like me to use it to actually test? strap a laptop to the handlebars and go for a ride?

I seen you are working on a "handle bar" control panel too, I mentioned my idea's about that too.
Any of them sound doable?

I'll leave it at that for now.
It's late and I'm hungry and that is plenty to chew on for one day.

Thanks again Vincie, nothing pleases me more than a designer wanting to directly participate with those that have a genuine interest in possible improvement/mod ideas.

I take that back...
Nothing BUSINESS related does ;-}
 
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Vinci

New Member
Aug 18, 2010
14
0
0
Austin, Tx
KC,
See my responses below in bold italics:

Thanks, but I scoured every page on your web site for hours and just don't recall, but best guess would be in the .pdf developers papers or Install papers.

In short if you don't see it as a link on your web site, it was in a .pdf file.

Thanks, I'll dig around for it

So Vinci, lets talk ;-}

We can do it here so others can share, or you can certainly contact me e-mail.

For a discussion like this, let's have it here so others can learn, if that's OK with you

If you read my first post you get jest.

If you can make a counter-clockwise version, be it for a second drive or in a Jackshaft, you may have a winner.

I wish we could justify it, but we can't. There's just not enough volume. WRT to the jackshaft, perhaps there is something out there off the shelf or very close to it that will work?

I am a pretty technical guy, I know all about manually adjusting the hard drive head seek mechs on 12" 1MB old main frame computers with a scope for minute movement.

Yikes! I bet you were good with punch card mechanisms too! What's the over/under on how many readers of this thread are even close to old enough to know what we are talking about? ;-D

How you are applying it to your hub for a programmable gear ratio to match the bike just blows me away!
As mentioned I poured through all of your tech manuals and understand how it works, very clever actually, Kudos to you ;-}

I have a myriad of questions but I'll start with just the basics.

On a typical 3-speed manual hub the slightest variation in the shifter mech on the axel makes a huge difference, as does the cable, how do you compensate for that when it so much more critical with what, like 64 unsealable position movements in an inch?

If I get your question correctly, the answer is that the 3 speed is a discrete, opportunistic shifting device. The NV is neither opportunistic (command a shift, and it will shift right now, the 3 speed wants to wait until it is unloaded) nor discrete (if the cables are stretched, the system will just take of the slack and shift anyway, though the exact points you shift to may not be repeatable, they won't be off by much either.)

Is 64 the right number for a max or would say 21 speed to make it easier to program make a big difference too?

The more speeds the merrier. The fewer you use, the greater the perception will be that the NV is shifting. When you use the max number of points, the shifts become imperceptible and the whole system feels very fluid. OTOH, doesn't hurt to start simple and learn.

As for programing the hub (I love saying that) I studied the tools so what is the best way for Joe Blow motorized bike builder like me to use it to actually test? strap a laptop to the handlebars and go for a ride?

No need to be so sophisticated. More importantly, look at the road, not your instrumentation! There is probably a path to something like an iPhone app to take data on the bike if you really want to go that far. Let me give you an extreme example that you can scale back from: If you were an automaker, you would plot brake specific fuel consumption of the engine in "island" form with x and y axes being engine speed and torque, respectively. Then, you would overlay lines of constant power. For every power level commanded by the rider, there will be a corresponding finite set of torque/speed points that provides the lowest possible fuel consumption OR you can choose to pick a spot that gives the power commanded while operating the engine at the lowest possible torque - this gives you lots of reserve for acceleration. You create your shift maps from this sort of logic.

Complicated, right? I'll guess that there is not a publicly available BSFC map for most small engines, though it might be worth your time to dig around on government websites like the EPA's to see if anyone did such a map in the process of evaluating weedwhacker pollution or something like that.

OK, now that you understand the hard way to do it, what can you do as just one guy with a motorized bike and some spare time? Well, you can try collecting straightline performance data for various shiftmaps that you're trying out for one. I don't know if an iPhone app intended for cars like Dynolicious is sensitive enough to give you 0-30 or 5-20 acceleration data on a motorized bike, but it might be. I have no connection to or experience with those programs, but you want one that does NOT require connection to the car's OBD II port to work. If they work for this, you're golden, if not, you're out $9.99 or whatever they charge these days.

Structure your experiments carefully and consistently, and remember that what feels best to the seat of the pants does not always produce the best performance numbers!


I seen you are working on a "handle bar" control panel too, I mentioned my idea's about that too.
Any of them sound doable?

I'll have to look back in the thread. Regardless, it sounds like you have more than adequate computer skilz to brew up your own system!

I'll leave it at that for now.
It's late and I'm hungry and that is plenty to chew on for one day.

Thanks again Vincie, nothing pleases me more than a designer wanting to directly participate with those that have a genuine interest in possible improvement/mod ideas.

You're welcome, but I don't know that I would characterize myself as a designer! More like a very knowledgeable enthusiast who knows the company well!

I take that back...
Nothing BUSINESS related does ;-}
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Outstanding response Vinci, thanks bud ;-}

I am just so intrigued with this whole programmable drive train I can't even stand myself.
Talk about right up my alley!

This of course is for higher end bikes, but those are my favorite kind to build anyway.
To heck with the left side drive, lets talk jackshaft and a new hub.

''use an iPhone app..' hehehe, naw, I don't buy into those gadgets other than my TV remote.
I have E-mail and a land line with my own answering machine, no IM, and that suites me just fine.
'Too instant' contact wise I found years ago with one of those Motorola 'Brick' phones was not a good thing for me ;-}
 

camlifter

Active Member
May 4, 2009
1,033
16
36
acme labs marion ohio
ok a little up date on my hub, i have it back together and working in the normal rhd direction. i've learned alot about this hub in the last few weeks.
i hoped to make it work lhd, but i see now that it can't using the parts that come in it. the 2 sprag drive units i thought could be swaped to reverse the drive but it dosen't matter which one is on which side since there both the same, swaping them it still works in the rhd direction.
as for the oil it dosen't seem to do a lot, i ran mine with no oil in it. only the residual oil left in it after draining it and it still work fine, i wouldn't run it that way but it did still work.
as for making it work lhd it can be done but will need to have new drive units made with the ramps cut in the opposite direction and the wire bail spring wound the other way around the drum.

in this pic you can see which way the ramps are cut into the driver, they need to be cut the other direction to work lhd.
maybe we can get fallbrook to offer them as a separate part for those of us who want to mod are hubs to left hand drive.