NuVinci Hub

kennyb

Member
Could someone give me a short lesson on what the Nuvinci Hub does for a bike. I'm trying to wrap my head around the idea.

Thanks,

Kenny B
 
A NuVinci hub allows the bike rider to have an infinitely variable transmission inside the rear hub. Other kinds of internally geared hubs have some sort of twist or click shifting with a certain number of fixed gear ratios. With the NuVinci you turn or twist a shift unit on the handlebars but there's no fixed gears, no clicks; just a constant variation of gearing that you can dial in as you ride or at a stand still to create a comfortable pedaling experience. This way you can have the gearing feel exactly the way you want it to. They use a set of spherical planetary gears inside the hub with a pair of alignment rings that adjust the planetary spheres and that translates into a gear ratio but it's stepless and very smooth.

There are several models of the NuVinci system with the most recent including an automatic shifting system, the Harmony H/Sync, all run from your bike's computer console. Now if you want a little more control then there's the Harmony, but that's still automatic. For a manual, stepless system there's the Nfinity N330/380/380S. In many cases you have access to a wider gear ratio range than a typical set of cogs. These can be retrofitted to most bikes and there's a belt drive option, too.

NuVinci has a couple of good videos explaining the technology that can provide a visual understanding.
 
A NuVinci hub allows the bike rider to have an infinitely variable transmission inside the rear hub. Other kinds of internally geared hubs have some sort of twist or click shifting with a certain number of fixed gear ratios. With the NuVinci you turn or twist a shift unit on the handlebars but there's no fixed gears, no clicks; just a constant variation of gearing that you can dial in as you ride or at a stand still to create a comfortable pedaling experience. This way you can have the gearing feel exactly the way you want it to. They use a set of spherical planetary gears inside the hub with a pair of alignment rings that adjust the planetary spheres and that translates into a gear ratio but it's stepless and very smooth.

There are several models of the NuVinci system with the most recent including an automatic shifting system, the Harmony H/Sync, all run from your bike's computer console. Now if you want a little more control then there's the Harmony, but that's still automatic. For a manual, stepless system there's the Nfinity N330/380/380S. In many cases you have access to a wider gear ratio range than a typical set of cogs. These can be retrofitted to most bikes and there's a belt drive option, too.

NuVinci has a couple of good videos explaining the technology that can provide a visual understanding.
 
Ann:

Thanks for the explanation. Between your explanation and the videos I now have a much better understanding of a Nuvinci Hub. I may opt for a Riese and Muller Tinker ebike in order to enjoy that technology.

Kenny B
 
I'm trying to wrap my head around the idea.
You're in for an interesting experience. I have one observation and a minor complaint about the N360. When you ride a NuVinci installed hub you have to re calibrate your thinking about setting a "gear" for each riding circumstance....because there aren't any reproducible gear ratios, only approximations. I got fairly good at setting the gearing with time, but it's imprecise. Most noticeable when you want a certain gearing for grades which you know will work. Not a deal breaker, but something you have to get accustom to. The one complaint I have is drag. The NuVinci hub does tend to have a noticeable drag that is more noticeable in higher gear ratios. I still enjoy riding the NuVinci outfitted bike, but for commuting I prefer a bike with defined gear ratios.

Court J.
 
For me, the best feature about the Nuvinci N360 is that you can shift it up or down while standing still, without having to pedal. If you forget to shift down before coming to a stop, you don't have to start back up in a high gear.
 
For me, the best feature about the Nuvinci N360 is that you can shift it up or down while standing still
Yes, that is a plus. Handling power is a possible issue. Mine is on a 500W 36V mid-drive and so far it has worked flawlessly, but I would probably not put it in a 750W 48V system.

Court J.
 
Ann:

Thanks for the explanation. Between your explanation and the videos I now have a much better understanding of a Nuvinci Hub. I may opt for a Riese and Muller Tinker ebike in order to enjoy that technology.

Kenny B


Ive been curious about the Nuvinci hub as well ... happen to have those vids stored in my bike info library ... would like to test ride one to see what operation fells like.
Are these available on speed pedelecs perhaps ? maybe with a 350w mid drive ...
 
I have very limited experience with the Nuvinci N380 (since my R&M is brand new (100 miles ridden)) but so far I am very pleased. It is so smooth and in my opinion brings a whole new (positive) dimension to biking. My area is relatively flat and being able to dial-in the gearing because it is a CVT is really nice. When cruising on flat terrain where there are just gradual grade shifts sometimes a slight gear change is a lot more efficient than shifting a complete gear as I do with the Alfine 8 on my human powered bike. Also shifting at a stop is a plus as pointed out (this applies I think to all IGHs).

On the flipside (don't want to say negative): a couple of times on a flat straight-away in Tour mode I hit the end of the gear range. I'm not sure if that is the technically correct way to say that but I mean I wanted to make it more difficult to pedal to increase my speed but I couldn't - I didn't have any range left. I imagine that could happen at the other end too but I don't have any big hills around here to test it on. At that point, since I couldn't pedal much harder I had to go from Tour mode to Sport thus increasing the cadence. No big deal but I felt like I could have maximized my battery usage if I had more gear range and could have done more with human power.

I've also experience this on my regular bike with my Alfine 8. My Spot is a pretty fast urban style bike. I was once gaining on a road biker on a straight-away but I ran out of gear range and couldn't quite catch him. There have been a couple of times with that bike that I regretted not getting the Alfine 11.
 
over50 ,

tks ... I have the Alfine 11 so more than likely I would have a similar experience.
do they recommend oil service intervals or is it sealed for life ?

B.
 
over50 ,

tks ... I have the Alfine 11 so more than likely I would have a similar experience.
do they recommend oil service intervals or is it sealed for life ?

B.
Sorry you've got me on that one. I bet Chris Nolte or someone more knowledgeable can chime in and answer that. In the near future I definitely intend to get into the manuals and online materials a bit more.
 
Yes, there is some occasional servicing needed but only for the internal freewheel mechanism in the NuVinci hubs. The N360 and Harmony systems use a special formula lubricant that is permanently sealed inside the cvp unit and does not need maintenance. Check out the Owner's Manual for the Harmony system for more details.

@flymeaway, the Harmony & Harmony H/Sync let you preset some of those gear ratios; this addresses the issue you mention about dialing in that perfect gearing for specific riding conditions. Not knowing when the N360 system you have was made, the original version came out about 6 or 7 years ago and had a substantially different design than now, so I'd bet there is less drag with the freewheel system now. The N360 has been a popular rebuild kit for any rider wanting to get away from conventional gearing.
 
I have very limited experience with the Nuvinci N380 (since my R&M is brand new (100 miles ridden)) but so far I am very pleased. It is so smooth and in my opinion brings a whole new (positive) dimension to biking. My area is relatively flat and being able to dial-in the gearing because it is a CVT is really nice. When cruising on flat terrain where there are just gradual grade shifts sometimes a slight gear change is a lot more efficient than shifting a complete gear as I do with the Alfine 8 on my human powered bike. Also shifting at a stop is a plus as pointed out (this applies I think to all IGHs).

On the flipside (don't want to say negative): a couple of times on a flat straight-away in Tour mode I hit the end of the gear range. I'm not sure if that is the technically correct way to say that but I mean I wanted to make it more difficult to pedal to increase my speed but I couldn't - I didn't have any range left. I imagine that could happen at the other end too but I don't have any big hills around here to test it on. At that point, since I couldn't pedal much harder I had to go from Tour mode to Sport thus increasing the cadence. No big deal but I felt like I could have maximized my battery usage if I had more gear range and could have done more with human power.

I've also experience this on my regular bike with my Alfine 8. My Spot is a pretty fast urban style bike. I was once gaining on a road biker on a straight-away but I ran out of gear range and couldn't quite catch him. There have been a couple of times with that bike that I regretted not getting the Alfine 11.
Over50,
Thanks for posting your observations of the Nuvinci N380 CVT high-low ratio range
Your feedback on the R&M Charger is very useful and appreciated as I have included the 25km/hr Charger Nuvinci on my short list
Based on my current road bike gearing which allows me to comfortably cruise at 30-35km/hr, I have concerns if the N380 will give me enough high ratio range to cruise at similar speeds without having a too higher cadence
I am looking at gear ratio change out options if I was to buy a bike with the Nuvinci N380 hub and thought this might be helpful to you as well
Using the Gates Carbon Drive Calculator http://www.gatescarbondrive.com/Apps/DriveCalculator/index.html it appears as you may have a few options to change your current front and rear pinions to get higher gear ratios whilst optimizing your current 111t belt
This is providing you have enough adjustment at the dropouts to vary the chain stay lengths to accommodate the new pinions accordingly
I have assumed your bike has the below pinions and belt size which were taken from the R&M site listed for the Charger HS Nuvinci
Motor pinion 22t
Rear hub pinion 24t
Chain stay length 485
Belt 111t
Gear ratio 0.917

If so then the below options are available

New ratio option #1
Motor pinion 24t
Rear hub pinion 22t
Chain stay length 483.99
Belt 111t
Gear ratio 1.091

New ratio option #2
Motor pinion 26t
Rear hub pinion 22t
Chain stay length 478.45
Belt 111t
Gear ratio 1.182

Not sure what the cost would be to purchase new front & rear pinions from Gates, but it may be worth pursuing
 
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Harmony & Harmony H/Sync

Can this system be purchased as an add on to existing installations? My research led me to believe this product was only available to OEM's. I can't say how old the 3 units I bought are there's no manufacturing date on the box or the unit. The one I haven't installed in a wheel is serial N250984.

Court J.
 
From the data inside the manual I posted yesterday, it might be doable Court J. I'd take a minute and call Fallbrook Technologies in Cedar Park TX, the NuVinci creators and talk with one of their techs that handles the ebike systems. The company is really moving forward on CVT systems for bigger, vehicles like cars/trucks. Big plus is better fuel efficiency with the infinite gearing. If this does work, please post about it.

Contact info:
Telephone (USA): +1 888-NuVinci (688-4624)
Fax: +1 (512) 267-0159
Email (USA): [email protected]
 
Can this system be purchased as an add on to existing installations? My research led me to believe this product was only available to OEM's. I can't say how old the 3 units I bought are there's no manufacturing date on the box or the unit. The one I haven't installed in a wheel is serial N250984.

Court J.
This can be purchased aftermarket by qualified dealers. We have worked with H-Sync on a bike we were helping to develop. It's a little finnicky to get setup, but when it works it's great. I think this concept is great and I hope development continues to take place here.

This can't be retrofitted to Bosch powered bikes though. It requires different firmware. We're trying to encourage the possibility of this sort of upgrade, but I'm not sure if it's going to happen.
 
With respect to using the N380 and Gates belt drive system combination (new Tinker), I've noticed an annoying vibration/thrumming feeling suggestive of excess friction, usually at higher pedaling rates. Wondering: does this disappear as the system "breaks in"?
 
I have a Delight with the 11 speed derailleur and I also get that annoying vibration/thrumming feeling.
I have a theory that this is possibly caused by the fact that the chain wheel is small and rotates at 2.5 times the pedaling cadence.
This vibration seems to occur mainly at higher cadences in the higher gears (i.e. the smaller gears on the cassette).
My theory is that this sets up a resonance that results in the vibration/thrumming effect.
Does anyone else notice this effect?
 
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