NuVinci Harmony brings automatic shifting to e-bikes


August 9, 2011

The NuVinci Harmony continuously variable planetary e-bike transmission automatically maintains the rider's pedaling cadence

The NuVinci Harmony continuously variable planetary e-bike transmission automatically maintains the rider's pedaling cadence

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Fallbrook Technologies released the NuVinci Continuously Variable Planetary (CVP) N170 transmission for bicycles in 2007. The rear hub-based system does away with distinct, defined gears, it's sealed against dirt and other contaminants (unlike a derailleur), and it allows riders to change drive transmission ratios even when standing still. Last year, the company unveiled the NuVinci N360, which is smaller and lighter than the N170, yet has a wider range of ratios. Fallbrook has now announced yet another incarnation of the technology - the NuVinci Harmony - which is an auto-shifting version of the N360 aimed specifically at e-bikes.

The Harmony, which is intended for use with 12-48 volt e-bike systems, automatically adjusts the drive ratio in order to maintain the cyclist's preferred pedaling cadence. If you're going up a hill, for instance, it will shift into a lower ratio, so that it's no more difficult to turn the pedals than it was on the flats.

There are two handlebar-mounted controllers available for the system. The Base Controller simply allows riders to chose between three speeds of automatically-maintained cadence, with the push of a button. These will be preset by the e-bike manufacturer itself, as dictated by the gearing and other parameters of the bike. Typically, however, the cadence choices would consist of fast, medium and slow.

On the Advanced Controller, users can find the exact cadence that they prefer, then instruct the system to maintain it. Should they wish, they can also switch over to manual mode, and adjust the ratio themselves.

The hub interface itself weighs 250 grams (8.82 oz), and has a quick-release attachment for easy wheel removal.

Fallbrook Technologies' NuVinci Harmony CVP should start appearing on e-bikes in the EUR 2,000 (US$2,864) and up price range, starting early next year.

About the Author
Ben Coxworth An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away. All articles by Ben Coxworth

...not a poor man\'s bike by any stretch...


This is crock if ever there was one...

$2800 banana republic dollars for a hub with internal gears.....

Should be no more that $75 to $125.

Mr Stiffy

@ Mr Stiffy The prices mentioned were for the entire e-bike, not the transmission system. Still expensive though


Expensive ? That\'s a laugh ! Any complete bike at that price is still going to be shitty.

I just went biking 188 Km on the Eyjafjallajökull on a Sandman mountainbike. Climbing black ash ridges, across litterally-boiling rivers, on sharp obsidian-glass boulders and over ash-dusted glaciers... all at high-speed gales and in driving rain and sleet.

The bike ate it all - not even a flat tire ! Durability comes at a price, though.

I would have ridden a crank-mounted Pinnion gearbox-equipped Sandman Gobi (18 speed) if it had been ready.

It wasn\'t, so I had to choose between my wheel-mounted Rohloff gearbox-equipped Cannondale Prophet (14-speed) with 2,5\" Schwalbe Fat Albert tires and a derailleur-equipped Sandman on 3.8\" Surly tires.

The fattest tires were the obvious choice and did the trick admirably, but on these ashes (or on sandy beaches, for that matter) a sealed gearbox would have been much better than a derailleur, which needed constant attention.

The rain had one advantage : no dust blowing around...

Whether you need a bike to cruise the city streets or for extreme adventures : cheap models are only okay if you count on throwing them away after use.

I\'ve been driving my TWIKE electromobile for 13 years now. Not cheap, but still good as new...


If you live on your bike or perform extreme sports on your bike, then yeah...$2k isn\'t that big of a deal...but for 99.999% of the rest of us, the bike spends the vast majority of it\'s life hanging up in their garage...heck the tires on most bikes fail more from dry-rot than actual wear! No, a $200-$300 bike is more than enough for me...considering I haven\'t ridden my bike once in the past 2 years!


I am hoping that these are;

a) Strong;

b) Reliable;

c) Durable; and

d) The hub is available from the corner bike shop for about $80 a piece.

Mr Stiffy

wooo... sexy as hell! do want. great design work.

Chi Sup

A few thoughts:

If the gear unit is sealed, the it ought to have a very long life. If you are going for a rough tour then a derailleur is efficient and can be fixed if it goes wrong; but it can get dirty or jammed. If you commute, then a Stumey-Archer drive is sealed so it can run for many years and never give problems, apart from the cable drive, which is also the only way that grit can get into the hub; but if it goes wrong you are unlikely to be able to fix it at the roadside. I had wondered whether you could combine the Sturmey-Archer gears with a dynamo hub, and have an electrical switch to change gears, so fixing all the problems with the cable.

This new gadget in its present state seems closer to the Sturmey-Archer commuter model. You want something that can get you to work and back as reliably as possible without having to tinker with it and get your hands dirty; and you take it to a shop if it goes wrong. Absolute drive efficiency is not critical, but you would like not to get too sweaty if you are going in to work. With luck it may come down in price and migrate to non-electrical bikes.

Yay, science!

Richard Kirk

I ride an N170 and it\'s an absolute joy. Coincidentally I was talking just theother day to a colleague about how the hub would be the perfect base for an automatic transmission system, and here it is. It\'s awesome, and the auto version is the icing on the cake. I acn\'t wait to try it. And to all the haters I say \'Don\'t knock it \'til you\'ve tried it!\' I\'ve owned or ridden every transmission available from fixed to Dura Ace and Torpedo to Rohloff - and I can assure you, this is the future.

Facebook User

@ Richard Kirk.....

Could 2 Sturmey Archer hubs be lined up in tandem, to give a much broader gear range from a deeper low to a higher high.....

Like a sealed chain drive (in a case) to the hub in the frame, driving to a hub in a wheel...

Just a thought.

I like good gear (bicycle componentry and build quality) - at a realistic price, but I want practical commuter drives, not fiddly \"$5000 for 5 gram lighter gear sets\".

Mr Stiffy


\"No, a $200-$300 bike is more than enough for me...considering I haven\'t ridden my bike once in the past 2 years! \"

I too had a similar mountain bike stashed in my cellar for 10 years.....This last 3 years though I have a Bionx set up and I am now over 4,000kms already :)

E-biking ROCKS!!!!


great product !!, expand into electrical transmissions, adding spread (lower AND higher) to even still powerful torquey electrical motors, WITHOUT clutches.

Søren Algreen-ussing

What about a pneumatic hub with a regenerative braking setup that feeds air into a strengthened frame/air tank combined. Making the frame strong enough so that it can hold enough air to be useful might make it too heavy though. Any thoughts on that? You could also use the stored air to inflate the tyres if you get a puncture so you wouldnt have to carry a pump.


@aotror: Impressed but as with everything it would require a lot of work, calculations and sweat. Even getting a pneumatic hub running on a bike from a tank in the frame is difficult if at all possible (that is why no pneumatic car works despite time and again enthusiastic articles all around the web: it just simply cannot fit enough supply of compressed air in its tank to run on for more than perhaps ten minutes...with your concept...2 minutes may be it). Forget about regen braking or tire inflation before you have your concept working.

[I had my own idea regarding compressed air and bikes: a high pressure stiffened fairing you could easily deflate and stow away. This idea is for grab....(and of course I am not the first one who was toying with such imaginations...all attempts had been failure so far.)]

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