NuVinci CVP Hub

Background
The NuVinci Continuously Variable Planetary (CVP) hub is the first and only bicycle drivetrain on the market that offers infinite gear-inch choices within an overall range of 350%. From NuVinci:

NuVinci CVP technology combines continuously variable ratios with the advantages of a conventional planetary gear set. A set of rotating spheres arranged around a central “sun” is used to transfer torque between two “rings.”

Tilting the spheres changes their contact diameters on the rings, permitting an infinite progression of speed ratios. The result is smooth, seamless and continuous transition to any ratio within its range, maximizing overall powertrain efficiency and ride quality.

For the past couple of weeks I’ve been riding a Surly Long Haul Tucker outfitted with a NuVinci CVP hub. The LHT was set-up by The Bicycle Business in Sacramento with upright bars, MTB levers, a single chainring, and the NuVinci hub/shifter combo.

Details & Impressions
The NuVinci hub is extremely smooth and quiet, much like a high quality internal gear hub. Its gear range is also similar to internal gear hubs such as the Shimano Alfine 8 and SRAM i-Motion 9 (see chart below). The amount of resistance created by the CVP is insignificant for its intended use on commuters, cruisers, and e- bikes, though subjectively I’d say it introduces slightly more drag than the Alfine or i-Motion.

Low, Medium, High — Infinitely Variable

The twist shifter’s “gear” indicator relates drive ratios to terrain: a flat line indicates level ground (high gear-inches) and a curved line indicates hills (low gear-inches). It takes 1.25 turns of the twist shifter to move through the entire range. The long throw on the shifter is good for fine tuning the ratio, but quick shifts from high to low are difficult to execute; somewhere under one full rotation of the twist grip would probably be better for most people.

Like internal gear and single speed hubs, the NuVinci CVP requires either horizontal dropouts, sliding dropouts, or a chain tensioner (our LHT used for the test was set-up with a chain tensioner). Removing the rear wheel is relatively simple and no more difficult than removing the rear wheel on bikes set up with internal gear hubs.

It took a while to get over the old habit of spinning up before making a shift, something that’s completely unnecessary with the NuVinci. With the CVP there’s no need to hesitate making adjustments because there are actually no “shifts”. In other words, each miniscule adjustment of the shifter results in a minuscule adjustment in gear-inches. Eventually I ended up using the twist shifter almost like a throttle, constantly changing the ratio to match cadence and pedal pressure depending upon the terrain and wind direction.

Conclusion
The NuVinci CVP’s main audience is likely to be newcomers who are intimidated by triple chainrings and derailleurs, or commuters who want a bullet-proof drivetrain with an industry-best 6-year warranty. It may also be a good fit for hybrid electric bikes where the hub’s substantial 8 lb. weight would be mitigated by e-assist. Unfortunately, having 8 lbs. concentrated at the rear axle on a lightweight bicycle is enough to alter the handling and may make it a tough sell on those bikes. Even so, I think CVP is a cool technology with a future, particularly if NuVinci can get the weight down into the 4-5 lb. range and hit a price point that is on par with competing products such as the Shimano and SRAM internal gear hubs.

Pros
User-friendly for novices
Quiet and smooth
Infinite “gear” ratios within a 350% range
Ability to change ratios while stopped, coasting, or under power
Weatherproof
Six-year warranty

Cons
Heavy (approximately 8 lbs.)
Relatively expensive (approximately $450)
Long throw on twist shifter

The LHT used for this review was provided by The Bicycle Business. Stop by their shop in Sacramento to test ride the NuVinci CVP.

The Bicycle Business
Fallbrook NuVinci

Disclosure: The Bicycle Business is a sponsor of this website.

17 Responses to “NuVinci CVP Hub”

  • John Umland says:

    Unfortunately, as a New Englander who likes to ride all winter, the owner’s manual recommends against exposure to road salt.
    Bummer.
    God is good
    jpu

  • clever-title says:

    I wonder if you could make an automatic transmission with this and a cyclocomputer, so that it lowers gear-inches when your cadence drops, and vice versa. Of course, the hardcore performance trainers wouldn’t want to deal with a heavy hub, so there’s probably no market for it.

    BTW – the hill indicator on the shifter is a really neat feature for newbies. I had a hard time explaining how to use a 3×7 to someone who had never ridden anything but a BMX.

  • Joel van Allen says:

    I’m not sure in what way a twist-shifter might be a pro, but they’ve always seemed counterintuitive to me because of how sensitive they can be when you shift your grip suddenly, or in particular, when you’re holding on for dear life on those poorly paved edges of the road between the blacktop and the gutter. I think about the number of times I’ve had to choose between swerving into traffic or taking on one of those inset drainage overflow grates (I imagine either the grate collapsing or my front tire being wedged in its grill, catapulting me off the bike); or worse, being wedged between the gutter and traffic and hitting those roadside dip-dee-doos created by years of shoddy repaving– hitting those at a good clip is a good way to swerve into traffic whether you like it or not. Those are the times when I not only want solid control of the bike, but I don’t want a grip that moves around, let alone shifts gears when it does.

    I watched the demo video for the CVP and was really impressed with the simplicity of the design, but a bit discouraged by the price and the weight. It would be awesome to see this kind of thing adapted to a carbon chain drive!

  • john Riley says:

    I don’t know why the word “planetary” would be associated with this hub. AFAIK there is nothing in it that bears any resemblance to what one thinks of as planetary gears (small gear cogs revolving like planets around a central gear cog).

  • CedarWood says:

    How durable is it? After reading their warranty and durability testing page, I noticed they give no details on how the testing was accomplished e.g. load weights, method of load application, amount of time load was applied, slip point, etc. Some numbers would inform the potential user much better, I think.

    I am shopping for an IGH for purchase next year. It will be subjected to regularly pulling a heavily loaded trailer up steep hills in all sorts of weather. Durability is therefore paramount in my mind. A Rohloff is regrettably out of the question due to financial limitations, but this hub is within reach.

  • Xtra says:

    I recently had a Nuvinci installed on my xtracyle and have been really enjoying it. To read a good short term and long term review that address the Nuvincis durability check out:

    http://bikehugger.com/2007/07/mondo-nuvinci-review.html
    http://longwalktogreen.blogspot.com/2009/11/nuvinci-longterm-follow-up.html#links

  • CedarWood says:

    @ Xtra

    Thanks. Those links are very informative.

    The NuVinci is now at the top of my list of contenders, though the manufacturer states a required gear ratio of 2:1. One of the above reviewers is using a 1.78:1 ratio with no ill effects, and I may need a smaller chainring for my application.

    Friction shifters are my personal choice, but the continuous twist shifter may have a similar feel. It looks like the shifter is not a full length grip, so I could cut down one of my cork grips and install the shifter in front of it.

  • Xtra says:

    Both reviewers are running less than 2:1. I’m running a 34t up front with a 22t in the back which is the same as the first reviewer.

  • Elliott @ Violet Crown Cycles says:

    CedarWood,
    Here in Austin, quite a few pedicabs use the NuVinci hub. I figure if they are strong enough for hauling a driver and 2-4 passengers everyday, they ought to work for you.

  • CedarWood says:

    @ Elliott

    Thanks. Based on what I have learned both here and on the web, I’ll be buying the NuVinci next year.

  • smalghan says:

    Except for the additional weight that caused a rougher ride on the back of my Giant MTB, I really liked using the NuVinci. The control box at the hub unit worried me a bit as well as I worried it would be shattered if the bike fell over. Luckily I never had to test it out in those conditions. Alan, did you have to learn to reduce pedal pressure when “shifting?” Turning the grip was much easier with a light foot, I ended up incrementally rotating the grip in the dead spots of my spin (no clips on the city beater bike it was on). My impressions are here: http://turanga.com/blog/?p=29

  • RI SWamp Yankee says:

    Not quite enough range for my liking. I live at the top of a ski-jump (sure seems like it when I ride up it on the way home), with a loooooooong downslope at the bottom, clear to downtown.

    I have an Electra Townie 24, which has a nice 34t “mega-range” freewheel in the back, and a bog-standard 44/32/22 triple up front. I spin out in the big ring on the way into work, and that 34t cog ain’t big enough, and the 22t chain ring ain’t little enough, to get up that killer hill at the end of the commute home without leaving me a sweating, panting wreck. If I had a choice, I’d want an IGH that has way more low-end than top end… I can always coast downhill, but I really don’t want to get off and walk halfway up a hill. Ideally I’d have both – but I really don’t need a gajillion intermediate gearing steps, either.

    The Rolhoff is nice, but it’s way too much money and has too many gears. Ideally, I’d like a three speed hub – up the ski-jump, down the hill, cruising on the flats – with a massive range between the extremes, and a reasonable beach-cruiser gear in the middle.

  • Bob says:

    RI SWamp Yankee if you use the NuVinci with a Rolhoff chain tensioner you can run a double chainring and a front derailleur. That will give you 131% more gearing.

  • kevin-somethingorother says:

    So, if I get a RANS Street with NuVinci hub and Q-rings up front… will I ever be able to shift on a hill (with the Q-rings eliminating the dead spots, I mean…) ? :-)

    But seriously, has anybody tried a RANS Crank-Forward bike with NuVinci hub? How was it? Any peculiarities of the combo to be aware of?

    I want to achieve a happy medium between letting the LBS guy do what he does best (build/prep a new bike for me) and doing a bit of pro-active thinking to avoid asking for stuff that’s only marginal together. I don’t know this LBS – it’s just that he’s the only RANS seller in 500 miles.

  • Bob says:

    @ Kevin
    We have not tried that particular combination, but from our experience it should not present any problems. You can shift a NuVinci under any load. If you are asking about shifting of a front derailleur that should work the same as if there was a traditional hub and derailleur in back.

  • inluvwithsara says:

    NuVinci has anounced a new model, the 360.
    30% lighter, external shift box eliminated, 17% smaller diameter, 50% less twist rotation to shift, and now a 360% “gear” ratio range.
    They said it should be available summer 2010

  • Kelvin says:

    I have a nuvinci set into a rans cruz, powered by both human and a cyclone 500watt motor inline with the chain (not a front hub). Shifting is smooth. Previously, I ran the same motor/bicycle but through a Sturmey Archer 8 speed. I think in ideal conditions (flat, no wind), the nuvinci can actually be more efficient since you can find an ideal cadence and will be less likely to use electric power to assist. However, in windy/hilly conditions where the electric assist is more often used, I find the nuvinci to be around 10% less efficient based on amps used measured on the batteries via “watts up” meters. Since this is a daily commute over the same route, the comparison is reasonably valid.

 
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