NuVinci Bicycle CVT

[mikefish]

it has balls:

[youtube]kVPjhmTThPo[/youtube]

i would love to see this on an Ebike

 

[dumbass]

I put one on one of my my ebikes earlier this summer. It works great with very smoot shifting. I am running it with a small Cyclone 360w motor that drives through the crank sprocket chaining. The one thing I don't like is you can't shift when crank is under load. You need to back off on the crank pressure to shift. But the ratio is always perfect for any situation and you can shift standing still. I used the stock hub sprocket that came with the Nuvinci hub so my top gearing is a lot lower then it was originally. I used to hit 28 MPH with hard peddling. But now I top out at about 23 MPH. Not a major problem because I only trail ride now and I'm better off with the lower end gearing improvement.

 

[Ypedal]

http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=9342&start=150

8)

 

[Reid Welch]

I put one on one of my my ebikes earlier this summer. It works great with very smoot shifting. I am running it with a small Cyclone 360w motor that drives through the crank sprocket chaining. The one thing I don't like is you can't shift when crank is under load. You need to back off on the crank pressure to shift. But the ratio is always perfect for any situation and you can shift standing still. I used the stock hub sprocket that came with the Nuvinci hub so my top gearing is a lot lower then it was originally. I used to hit 28 MPH with hard peddling. But now I top out at about 23 MPH. Not a major problem because I only trail ride now and I'm better off with the lower end gearing improvement.

I just bolded in blue a key sticking point against the NuVinci, that I was not aware of before.

I hear that it's fairly heavy; must be. It is a "geared" transmission, but the "gears" are simply and properly, hard balls. The power transmission comes, if I recall, from their proprietary drive fluid, which makes the balls and raceways "grip".

HAVE at this moment of writing, a LIME rear wheel (two, one bent and one OEM new, but the Hank is mounted.
Need to weigh the assembly, but it is LIGHT, even with the hank in place. The wheel is based on the old, simple NEXUS basic three speed.
A Nexus Inter Eight would weight about the same, and can be shifted under full power.

But, as we long ago discussed/asked rhetorically, will such a transmission stand up to the HARD pressure of a fast-spinning Cyclone-type of motor
during the shifts?

IF "yes", then the Nuvinci has little to offer over the Nexus Inter Eight, or the very costly Rolloph (spelled wrong),

these geared transmissions must have a higher internal loss than the NuVinci. Not able to do a full search at this time,

Q: what is the power transmission efficiency of a good internal geared transmission, v. the Nuvinci, v. a derailleur in good order?

I think/expect that the typical derailleur suffers considerable power wastage due to its running the chain in other than a straight line.
And too, for off-road work, that derailleur chain tensioner and the exposed cogs are all dirt and junk grabbers.

So, in summary: I like a straight chainline or..what will be the next step: the cogged belt drives just now coming to marked for internal geared hubs.

And WEIGHT: Nuvinci is necessarily heavy, isn't it? Like about ten pounds?
WILL WEIGH both LIME wheels, one without the tire, the other has the Hank tire (about 800 grams, that).

Weight counts there because it is essentially unsprung weight unless we are running soft, fat tires (most don't).

Many choices, not a one is perfect, not yet, not even 110 years since the introduction of the shaft-drive (chainless drive) bike of one, two, three or more "speeds": those are lossy as hell with their bevel gearing and the flexure of frames under strains, making the bevel gear drive even less efficient.

Best of all, no question, if efficiency is wanted and lightness is paramount, and if NO gear changing is needed: the fixed gear coaster type hub, or the fixie.

But how many of you with Cyclone drives can make do with a fixed gear? A: none, I would guess, unless you live in Kansas, flat.

Just musing. Need to find the gram scale. Will report back with weight-numbers of the Shimano wheel with its Inter Three hub, with tire and without tire in place.
________________
addendum, per usual, I go off on tangents. Thread starter makes notes about HIS Cyclone/NuVinci and how well it works.
We remember backwards about three years ago when this all first came up: that would be the dream combo.
Thread starter has it! Great! So what if the rear wheel is five or seven pounds heavier that a derailleur type of rear hub?
You have a double wall, wide rim and soft tires, maybe: that wheel is gonna be curb and bullet-proof.

I try to not digress, but I always fail: Thread started notes one little, annoying, problem: he has to back off of his e-power in order to shift the
CVT Nuvinci. THAT can be a major objection to =some= riders, but really, it's just and 'extra step' that must be mentally calculated.

IDEAL: a CVT that works like the NuVinci, but will "shift" under fullest power, automatically, by electronic brain and servo motor, to keep the Cyclone-type motor running at its most efficient (max torque per what ) range at all times. That'd be heaven, ten pound rear wheel or not.
Just the inherent extra chain and complexity of the Cyclone type system.

For me, flatland, easy rider who likes to jump curbs at speed: the single speed Stealth Cruiser project bike with front eZee wheel is perfect,
but only because I'm a twenty-per-rider and this is flat land. No clicks of ratchets, no tire tread noise. Coasting is SILENT. Power? Slight e-drive sound
from the eZee: you can hear it but pedestrians cannot hear the bike under power. Ding bell required to alert dog walkers. Simple is as simple does.

Now if I could only apply my =mechanical ideal principles= to my prose rambles that never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never never END
:lol: :lol: :lol: :x :x :x :x :|

 

[Miles]

Q: what is the power transmission efficiency of a good internal geared transmission, v. the Nuvinci, v. a derailleur in good order?

Generally, in order of efficiency (most efficient first):

Derailleur

Hub gear

Hub gear with belt drive

Nu Vinci

 

[EVnewbie]

I have a Nexus 7 speed internal hub, it is OK and I didn't break it yet.
Did some research on internal hubs with durability, longevity and spare parts availability etc. There are two internally geared hubs that are rated for tandem use, the SRAM P5 Cargo and Rohloff 500/14 hub. My brother wants an Armageddon bike, something that will ride through anything, (snow and mud) won't break and be simple to fix. Surly Pugsley with those 3.7 inch wide tires, 65mm wide rims to hold the tires, no suspension and both wheels have 135mm axles. Since the front and back wheels are swappable, it will run SRAM P5 cargo 5 speed hubs with coaster brakes. The front coaster brake will be connected to a motorcycle brake lever with a cable pulling a bike chain piece to activate the coaster. A Schlumpf Mountain Drive internally geared two speed crank finishes off the build since you shift it by kicking a lever to "shift" the two ratios. One brake lever, one thumb shifter and two interchangable hub wheels will allow the thing to crash all day and not need parts.
Internally geared hubs really get a workout in Europe so I read reports on their longevity. The Rohloffs last many years but the cost is very high. The SRAM (used to be Sachs) hubs last at least 50 to 100,000 KM for their 3-5-7 speed hubs. They have diagrams online how to maintain them and you can get parts. The Nexus hubs have not done so well, the bearings get contaminated and they trash the race which is part of the hub shell. (Nexus 7 speed, not sure of the others but they are of the same design) You can't get parts for the Shimano hubs so it is trashed. My Nexus 7 had a problem and I brought it to a bike shop to get parts, they are not available. No drawings and the owner said he has tried to get parts for them but no dice. He pointed out you need special tools to take the hub apart but he can't get those either. Replace the wheel... I know my Nexus NEEDS to be taken apart and relubed but I can't take it apart. Guess I'll ride it until the bearings destroy the seat or until the dried out grease destroys the gears.
It will be replaced with a SRAM P5 Cargo or their new i9 hub. The i9 has even spacing between the 9-speeds, it can be taken apart for lubrication, parts drawings are available, parts are available and no special tools are required to take it apart. I used a Sachs 3x7 hub about 10 years ago and would take it apart every winter to clean and lube the planetary gears. Never had a problem with the hub. Now I have a proprietary Shimano hub that is disposable. Yeah, sign me up for another Shimano disposable and let me put a motor drive to it to accelerate the destruction. I think I'll pass.
The NuVinci looks to be the perfect hub for a motor though. It is rated for 5 KW input, easy to "shift" from minimum to max and can be shifted to higher speeds under load. You can't downshift it under load but that makes sense mechanically. They even have a two sprocket hub with a 16 to 22T freewheel and a 44T sprocket for motor drives. I like the dual chain setup and that high sprocket count will make motor drives easier to gear down. Now that Ypedal has built up an ebike with one, I am excited to see how it performs when beating the hell out of it.

 

[Reid Welch]

Q: what is the power transmission efficiency of a good internal geared transmission, v. the Nuvinci, v. a derailleur in good order?

Generally, in order of efficiency (most efficient first):

Derailleur

Hub gear

Hub gear with belt drive

Nu Vinci

Thank, you, Miles. You are always so concise and such a gentleman,
to even put up with my carps and annoyingly long postings.

_______________

EVnewbie, above this post, input superb, practical info.
All my former questions answered. For my manual ride LIME, the Shimano three speed will do it OK,
but now I know I will never e-power through that hub, even if it, a three speed, may be more robust than a seven or eight Nexus.
Besides, I =want= to be able to get into rear hub for routine cleanout of the wear products. My Stealth Cruiser's coaster hub is
single speed, super simple, and very strongly made. I can grease it from the outside (a small hole) by injection, and force out any water
or dirt or whatever that the friction shoes inside rub off of themselves and the inside of the hub shell. That hub will last forever,
but I got a spare wheel and hub assembly for fifty bucks, just in case.
thanks!

 

[Miles]

Q: where can I best find these "figures", not that I doubt at all;
only that, in theory, at least, a derailler running it highest gear would be, (correct me if mistaken?): biggest chainwheel to smallest cluster cog=
chain line way from straight = tangental pull = a loss of power transmission efficiency.

There are several references, I'll see what I can find.

Yes, highest gear on a derailleur is usually least efficient - mostly due to the losses on the small sprocket (deflection angle under load for each link plus chordal action) - the losses due to chain mis-alignment and deviation through the jockey pulleys are less significant.

 

[Miles]

Have read, probably at Sheldon's site: that a straight line drive of a single, fixed gear, coaster or not, is, with a good new chain and good new cogs:
about 98% efficient. 2% gets lost as heat.

The "new" cogged belts will reduce that 2% to probably, about one percent (there's still rubber flexure and cord flexure of the belt construction.

Even the new 11mm pitch Gates Carbon belts will be less efficient than a chain (at pedal drive speeds), I think.

 

[Miles]

References:

http://www.bhpc.org.uk/Data/Sites/1/Uploads/humanpower/PDF/hp52-2001.pdf

 

[dumbass]

I put one on one of my my ebikes earlier this summer. It works great with very smoot shifting. I am running it with a small Cyclone 360w motor that drives through the crank sprocket chaining. The one thing I don't like is you can't shift when crank is under load. You need to back off on the crank pressure to shift. But the ratio is always perfect for any situation and you can shift standing still. I used the stock hub sprocket that came with the Nuvinci hub so my top gearing is a lot lower then it was originally. I used to hit 28 MPH with hard peddling. But now I top out at about 23 MPH. Not a major problem because I only trail ride now and I'm better off with the lower end gearing improvement.

A lot of people seem to be worried or at least talking about the added weight of the Nuvinci hub and it's efficiency (or lack there of). Let me be the first to tell you it's heavy and from what I've read the efficiency is only exceptable not great. I'll also tell you that once you get used to it you will think it's the greatest thing since the invention of the wheel. The smoothness of it can not be imagined. And don't over state the problem I mentioned about shifting under load. It's not that big a deal and I was told will improve with use.

In my opinion what efficiency is lost to the mechanics of the hub is gained back in your ability to exactly match your desired ratio for the situation of the moment. I don't care how internal or external gears you never have exactly what you want or need unless you have the Nuvinci. As for the added weight........ my bike originally weighed in at 40# and with the Nuvinci installed it weighs in at 44.5#s. WOW...4.5#s!! Trust me it's no big deal and well worth it. Consider the fact that most people mount their batteries over the rear wheel and that's a lot more then 4.5#s.

I am considering buying another Nuvinci for my other cheap bike (Ezip). But I will relocate the Ezip motor to drive the Nuvinci from the right side of the bike so it is actually using the Nuvinci gearing.

 

[Reid Welch]

Miles,

Thanks for your hours of work to get the data for me.
Thanks for that hard work; I've been sidetracked today or would have googled and read and read...
and still not know what you have found. Will study your data and citations tonight, probably.

Again, much obliged for your help, sir.

r.

 

[Reid Welch]

I put one on one of my my ebikes earlier this summer....(snip)

Great "real results" reporting; thanks!

Say, if you can someday post pictures and or videos, that'd be wonderful.
I'm into pictures, as you know.

Thanks again, and best of ebiking to ya',

r.

 

[MitchJi]

Hi,

Good comparison of different geared hubs here (Rohloff, Nuvinci, Nexus 8 and SRAM 9):
http://www.velovision.com/mag/issue29/vv29hubgears.pdf

IDEAL: a CVT that works like the NuVinci, but will "shift" under fullest power, automatically, by electronic brain and servo motor, to keep the Cyclone-type motor running at its most efficient (max torque per what ) range at all times. That'd be heaven, ten pound rear wheel or not.

The new Nuvinci Kit has those features (auto-shifting and shifting under power, with customizable shift maps):
http://www.fallbrooktech.com/05_PressReleases_DevKit.asp

Press Release March 16, 2009

NuVinci® CVP Developer Kit Now Available from Fallbrook Technologies Inc.

– Provides vehicle designers with easy, low-cost way to implement NuVinci continuously variable planetary (CVP) drivetrain technology –

(San Diego, Calif., March 16, 2009) – Fallbrook Technologies Inc. (Fallbrook), announced today that its NuVinci CVP Developer Kit is now available for purchase directly from the company.

The NuVinci CVP Developer Kit will be on display – along with examples of how it can be used – at the Taipei International Cycle Show in Taipei, Taiwan March 17-20, 2009. The Fallbrook Technologies booth number is L919a.

The NuVinci CVP Developer Kit helps builders of electric-, gas-, human-powered and hybrid vehicles integrate the NuVinci drivetrain into their designs. The kit includes NuVinci CVP, shift actuator, programmable controller, wiring and mounting hardware. Software tools, design instructions and technical documentation are also included.

The base price of the kit is US$595, plus shipping and handling. To obtain more detailed information and register to receive purchasing instructions, go to http://www.fallbrooktech.com/developerkit.

http://www.fallbrooktech.com/09_lev_kit.asp

The kit includes:
NuVinci Continuously Variable Planetary (CVP) Transmission (silver color with 36 spoke holes) Speed Sensor and Integrated Wiring Harness

Electronic Shift Controller with 32-bit Microprocessor (operates on 12-48VDC) NuVinci Desktopâ„¢ Application and USB Connection Cable

Electronic Shift Actuator with integrated Position Encoder

Configuration and Shift Tables can be edited with a general text editor program (such as Notepad)

I have a Nexus 7 speed internal hub, it is OK and I didn't break it yet.

He pointed out you need special tools to take the hub apart but he can't get those either. Replace the wheel... I know my Nexus NEEDS to be taken apart and relubed but I can't take it apart. Guess I'll ride it until the bearings destroy the seat or until the dried out grease destroys the gears.

Doesn't sound like servicing is a problem (Shimano Alfine 8 speed):
http://endless-sphere.com/forums/viewtopic.php?f=28&t=7468&p=113229&hilit=+rohloff#p113434

The Shimano Alfine is better than most (bang for buck). The benefits outweigh the weight disadvantages in my view. Stronger wheel, protected from the elements, reliable shifting and wide ratio gearing are a few. The downside is more unsprung weight but in my experience handling isn't affected much on the road. I used a Rohloff rear wheel in MTB Downhill competition and there was a difference in handling for sure. I have a non-suspension cargo bike we developed for postal delivery with a the Shimano Nexus hub and the handling difference is undetectable, and we tried very hard to detect it. They're extremely reliable and after about 6 months the trick is to open it up, pull out the mechanism and wash all the grease out then dunk it in light gear oil, sit to allow the excess to oil run off and then re-install. It's a 10 minute job and you won't believe the performance after that. Repeat every 6 months. Another downside is that it is a bit of a pain to change a tire.

More info here:
http://hubstripping.wordpress.com/hub-stripping-tips/

 

[amberwolf]

Just remember for all of you that want to use the NuVinci on an ebike and have it be part of the motorized drivetrain--you'll void the warranty on the hub, if the motor causes damage to it. Since you have no way of proving if it did or did not do the damage, and must take the word of Fallbrook, you'd be stuck even if you knew it was not that if they did choose to not repair it under warranty.

Also remember that it must be used as the rear wheel hub of a bike, and can't be used as a non-wheel transmission somewhere, or again the warranty is void.

I wanted to point these two things out in case any of you wished to use one as I had wanted to, since my CrazyBike2 uses the regular drivetrain to shift gears for the motor to give me a more efficiently-operating and wider torque range on the motor, as well as the pedals. I'd wanted to replace the entire rear gearshifting setup with the NuVinci, but not in the wheel itself, rather in the body of the bike (partly so that even if someone managed to steal the rear wheel they would not get the NuVinci, but mostly so I could keep all the drivetrain parts I could in one place, and keep the wheel light and quick/easy to replace with another whole wheel in case of failures, especially on long trips).

Either of the things I wanted to do would have voided the warranty, even though NuVinci actually contacted *me* about using their hub in my project, via my project blog at http://electricle.blogspot.com
After I read the warranty info, I asked them about that, and eventually they answered that unfortunately that's the way it is, but that they might someday consider changing it.

If they don't change it, they are excluding a whole lot of potential customers, including all of the ones for the custom-made bikes and trikes I wanted to start making once I have a working range of designs (that aren't made of recycled junk ).

I love the concept, and I would love to have one, but unless I can find one used that wouldn't have been warranty-covered anyway, it'll never happen until they change that warranty.

 

[Reid Welch]

amberwolf cuts the meat to the bone for me, above.


here is my "dream" set-up, then, that I will never make happen because,
simple is as simple does and you just try taking a bowden cabled bike for repeated swims, anyone?
Or...

OK, a "dream for me" if I were not going into deep water or riding routinely in the rain:

Nuvinci rear with a Big Hank at 25PSI, max.

Front hub geared or non geared emotor, with DISK brake, mechanical, on the front only.

A one-wheeled-braked bike, only. Flatland here. A twenty five mph bike. Disk brake fits, for instance, to an eZee hub, no problem.


A hardtail cruiser bike. One brake lever, for that front brake on the left (am left handed). One thumb throttle (from Justin's firm) on the right.

Gear the Nuvinci so that it can allow me to give my 150W of meek output, at a comfortable cadence at say, 25mph: as fast as I care to go.

Front hub and rear hub painted black and black rims and Big Hanks.

Front Big Hank will require at least 25PSI, because it will be the BRAKING tire, and so, I cannot run it at the present bike's mere 10PSI:
sidewall wrinkles if a front Big Hank is run soft and braking is heavy.

LOST: the super-cushy ride of a 10PSI front tire. Retained: it's still a cushy, curb-proof tire and wheel combo. Crash proof,
nearly as strong as a Surly Pugsley, but still looks like a regular bike, except for the two, strangely large hubs front and rear.

edrive front, and conventional Nuvinci manual assist for the rear. Would have the NuVinci twist shifter in the usual place, I think that's at the right grip?

Thumb throttle for the eZee? On the right or left bar, not sure which side, offhand thinking, but YES, only one brake, and it would be a front brake.

I hate, hate, hate, cables and lashed-on wires and giant or small disconnects.
With the eZee kit, I could, essentially, just install a Nuvinci to my existing Stealth Cruiser.

I won't be doing any of this, because my present bike is =all that I need= for my purposes, really....I only wish I'd gotten a 48V PING 20AH.
The Nuvinci would be extra icing, and be used within its limits.

Rhetorical: my Stealth Cruiser IS cable of running through hub-deep water or even under water. I doubt that a Nuvinci is so waterproof as this:
the bike must be able to withstand full submersion without real damage, or I can't call it "the world's only" sub-capable ebike/eBOAT (pontoons and going a half mile-per across Biscayne Bay.

Wash the salt off the present bike when I get home, dry it in a fan's blast of air, pump fresh grease into the old school bottom bracket as a P.M. (preventive maintenance) action; drain and refill the eZee of its Reid-installed couple of ounces of ATF (prevents water ingress and so far, has not affected eZee action.)

Summary, what I have, is really good enough for me: rear wheel coaster brake only and fat, STICKY, soft Big Hanks,
we have no thorns nor broken glass here. I have yet to get a gash or slice of my Hanks.

But there are, we now know, SO MANY good ways to make an ebike to serve OUR particular wants.

I need not edrive through a Nuvinci. I need not punish a Shram (sp) with edrive. Front drive works well enough for me.
It does not snow in Miami, but four months of the year, boy, does it rain. Fenders are fitted for this reason.
And the bike looks like a simple NOTHING "can't fence this for shite", bike to a bike thief.

To each his own way. We all just do this: KWYADAWYADI.

What a great thread. I'm out now. Thanks for this thread, all who have made it so useful.
Hard choices? Not for me. But for others: they HAVE to have a front brake. I do not need a front brake,
and so, will not have one.

Wunderbar all 'round.

We all THINK

 

[dumbass]

Just remember for all of you that want to use the NuVinci on an ebike and have it be part of the motorized drivetrain--you'll void the warranty on the hub, if the motor causes damage to it. Since you have no way of proving if it did or did not do the damage, and must take the word of Fallbrook, you'd be stuck even if you knew it was not that if they did choose to not repair it under warranty.

Also remember that it must be used as the rear wheel hub of a bike, and can't be used as a non-wheel transmission somewhere, or again the warranty is void.

I love the concept, and I would love to have one, but unless I can find one used that wouldn't have been warranty-covered anyway, it'll never happen until they change that warranty.

Like anything else if it's not used as designed intended you risk voiding the warranty. However, let me tell you what happened to me. I had a problem with my shifter and called service on the phone and told them my problem. They sent me a new set of pre-made shifter cables (this does not come with the original kit) plus a set of tools for the future should I need to remove the freewheel. It was all sent to me no charge including shipping. They didn't even question my purchase date even after I told them I have the "08 model. And lets face it how would they know how you had it mounted on the bike if you didn't tell them?

One last point on the warranty........Before I installed it with my Cyclone motor kit I emailed them to confirm in would not effect the warranty. They replied in writting it would not. However, I would recommend that everyone do the same thing as the issue will change depending on your selected horse power. But as I have read they are being used with gas powered motors as well that are a lot biigger then I plain on using.

 

[dumbass]

I put one on one of my my ebikes earlier this summer....(snip)

Great "real results" reporting; thanks!

Say, if you can someday post pictures and or videos, that'd be wonderful.
I'm into pictures, as you know.

Thanks again, and best of ebiking to ya',

r.

I'll try to get some pics for ya but my laptop crased so I need to reload photo software to reduce the pic size so I can download it and I don't have it on this PC. So as soon as I can get the software loaded I get you some pics. If you are in a hurry send me a personal message with your email address and I can email you the standard "big" pics.

 

[John in CR]

How hot does a NuVinci get when it's motor driven up a long hill, so a lower gearing is used? I was under the impression that they lost about 10% at the top end of gearing, but much more in low gear. If people are putting 2kw into them, then if they're as inefficient as I've been lead to believe, a lot of heat would show up on long hills. If they never get hot, then my interest is heightened.

John

 

[amberwolf]

Like anything else if it's not used as designed intended you risk voiding the warranty.

Sure, but they knew what I was doing and how I was doing it and what the NuVinci would be doing, and they themselves suggested that I use it, implying that they know it would take it.

However, let me tell you what happened to me. I had a problem with my shifter and called service on the phone and told them my problem. They sent me a new set of pre-made shifter cables (this does not come with the original kit) plus a set of tools for the future should I need to remove the freewheel. It was all sent to me no charge including shipping. They didn't even question my purchase date even after I told them I have the "08 model. And lets face it how would they know how you had it mounted on the bike if you didn't tell them?

Since they know where my project blog is (they posted on it!) they would certainly be able to see how it was used since I'd have that up on that blog, even if I didn't tell them. My project isn't exactly unique but it is different enough to stand out too much to "hide in the crowd", so to speak.

I do think that they likely bend over backwards for a lot of things they don't need to, and that most companies would not (especially these days). But since I can't *expect* that to happen, only *hope* that it would, I couldn't afford to invest that much money in what would be a key integral part of the bike without the assurance of a warranty that would fix it if it did fail.

One last point on the warranty........Before I installed it with my Cyclone motor kit I emailed them to confirm in would not effect the warranty. They replied in writting it would not. However, I would recommend that everyone do the same thing as the issue will change depending on your selected horse power. But as I have read they are being used with gas powered motors as well that are a lot biigger then I plain on using.

Yeah, I've read of a lot of uses for them that aren't covered by warranty if the use breaks it. It's fine if the person has that kind of money to throw away in the event of uncovered failure, but that's nearly a month's pay for me. Half a month if I went with one of the shady-seeming deals I see on web searches now and then. There is a good reason I am building this project out of recycled parts, other than the 'green" factor and the challenge of it (which is a lot of fun, usually).

That's why *I* asked them about that warranty, and when they replied that they *would* hold to the terms of the warranty and not cover those failures, then I decided I'd have to just wait and not bother saving up for one.

The thing is, that even if I had money for all this, I still couldn't use their product, because I intend someday to build a cargo trike for people that don't want or can't afford or don't really need a car for most of their travels and trips. That's going to need a transmission, and I would like to have one that could be controlled by it's computer so that the user never has to shift, that all they do is ride it like a bike but without having to really pedal much because the motor/etc does most of the work for them. Automatic transmissions are popular for good reason, even though they're usually less efficient.

Doing it with gears or chain/sprocket is possible, but not as smooth and not as efficient as a CVT, and using a pulley/belt CVT is going to take more space and have more maintenance issues than the NuVinci should.

So I want to use one in the trikes I'd like to sell, but no one would buy it if I had to tell them that if the transmission fails, it's not covered by warranty, so tough luck on that part. I certainly couldn't ever absorb the cost of them failing if they did. I wouldn't be selling these things for huge profit margins, because the idea is to get them to people that can't afford that much (like me), so I would have very little to fall back on should major parts like that fail.

Short and long of it is that while it's awesomely useful, they shouldn't be encouraging people (which they are) to use it for purposes which they know they won't cover if it does break because of it. And it isn't useful for any commercial venture where it is in the motor's drivetrain, for that reason.

 

[amberwolf]

I'll try to get some pics for ya but my laptop crased so I need to reload photo software to reduce the pic size so I can download it and I don't have it on this PC.

If using Windows, it has Paint that will let you reduce the size, though it isn't as "easy" as some other software.

Open the image, press Ctrl-W, then type in the same percent reduction you want in both of the top two boxes. Ignore the other two. Press Enter, then use SaveAs and a new name to make a new smaller version of the file (so you don't save over the old one).

 

[dumbass]

I'll try to get some pics for ya but my laptop crased so I need to reload photo software to reduce the pic size so I can download it and I don't have it on this PC.

If using Windows, it has Paint that will let you reduce the size, though it isn't as "easy" as some other software.

Open the image, press Ctrl-W, then type in the same percent reduction you want in both of the top two boxes. Ignore the other two. Press Enter, then use SaveAs and a new name to make a new smaller version of the file (so you don't save over the old one).

Thanks for the info. I didn't know (never really looked) paint could do photo reduction. thanks again.

 

[dumbass]

Like anything else if it's not used as designed intended you risk voiding the warranty.

Sure, but they knew what I was doing and how I was doing it and what the NuVinci would be doing, and they themselves suggested that I use it, implying that they know it would take it.

The thing is, that even if I had money for all this, I still couldn't use their product, because I intend someday to build a cargo trike for people that don't want or can't afford or don't really need a car for most of their travels and trips. That's going to need a transmission, and I would like to have one that could be controlled by it's computer so that the user never has to shift, that all they do is ride it like a bike but without having to really pedal much because the motor/etc does most of the work for them. Automatic transmissions are popular for good reason, even though they're usually less efficient.

Doing it with gears or chain/sprocket is possible, but not as smooth and not as efficient as a CVT, and using a pulley/belt CVT is going to take more space and have more maintenance issues than the NuVinci should.

So I want to use one in the trikes I'd like to sell, but no one would buy it if I had to tell them that if the transmission fails, it's not covered by warranty, so tough luck on that part. I certainly couldn't ever absorb the cost of them failing if they did. I wouldn't be selling these things for huge profit margins, because the idea is to get them to people that can't afford that much (like me), so I would have very little to fall back on should major parts like that fail.

Short and long of it is that while it's awesomely useful, they shouldn't be encouraging people (which they are) to use it for purposes which they know they won't cover if it does break because of it. And it isn't useful for any commercial venture where it is in the motor's drivetrain, for that reason.

OK, you may already have thought of this or may think it's stupid but have you considered the belt and pully system? I have a 250cc motor scoter and the transmition is a set of automatic variable pullies. As the motor speeds up the clutch engages and the faster you go the more the racio changes to add speed. Of course you wouldn't need a clutch but the pully ratio could be controled by load and speed sensors. Just a thought..............

 

[dumbass]

How hot does a NuVinci get when it's motor driven up a long hill, so a lower gearing is used? I was under the impression that they lost about 10% at the top end of gearing, but much more in low gear. If people are putting 2kw into them, then if they're as inefficient as I've been lead to believe, a lot of heat would show up on long hills. If they never get hot, then my interest is heightened.

John

OPPs......I went for a ride this morning with my wife and we came upon a down hill run in the forest preserve that she refused to try because it was so steep there was a sign stating to walk your bike down the hill. It was a nice paved section so I thought want the hell I'll give it a go. As it turned out I had to ride the brakes pretty hard all the way down the winding 1/4 mile long road. That was the fun part........then I had to peddle back up again. I was able to get a xlight head start (maybe 50 to 75 feet) before starting back up it. I ran in my lowest range with full power and peddling my tush as hard as I could. I made it back up with no major problem but I wouldn't want to do that for much longer then the 1/4 mile. It would have been interesting to check the Nuvinci and the motor at that time. I would think if they were going to heat up that would have done it.

 

[John in CR]

OPPs......I went for a ride this morning with my wife and we came upon a down hill run in the forest preserve that she refused to try because it was so steep there was a sign stating to walk your bike down the hill. It was a nice paved section so I thought want the hell I'll give it a go. As it turned out I had to ride the brakes pretty hard all the way down the winding 1/4 mile long road. That was the fun part........then I had to peddle back up again. I was able to get a xlight head start (maybe 50 to 75 feet) before starting back up it. I ran in my lowest range with full power and peddling my tush as hard as I could. I made it back up with no major problem but I wouldn't want to do that for much longer then the 1/4 mile. It would have been interesting to check the Nuvinci and the motor at that time. I would think if they were going to heat up that would have done it.

Yes, it would be interesting, but not under human power. I'm talking about at least a kilowatt or 2 of EV power, not a hundred watts or 2 or even 3 or 4. Even at a 20% loss, human power alone couldn't heat it up much. Sorry I misunderstood and you're pedal power only.

John