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Home » Big Picture, Fitness and Sports Tech

Look Ma, No Gears – Living with NuVinci’s Revolutionary Bicycle Hub

Submitted by on October 22, 2012 – 7:56 pm3 Comments

 

cutaway view of NuVinci N360 CVP hub

There are no good figures for the number of Americans who ride bicycles.  Back in 2007 the National Sporting Goods Association generated this factoid:

“The number of Americans who ride bicycles is greater than all those who ski, golf, and play tennis combined.” 

We know the number is in the tens of millions, and we also know, based on bicycle sales that the number of bikers is increasing by double digits, as are the number of bicycle commuters.  Millions of Baby Boomers are among the cadre of avid cyclists.  Yet, as we age, our biking needs change.  Going up hills is more daunting.  And it turns out that even shifting gears has proven to be an impediment inhibiting Boomers and seniors from taking up the sport. But now there’s a revolutionary technology that allows you to adjust your bike’s ability to conquer almost any terrain without using real gears.  It’s called the NuVinci Continuously Variable Planetary Drive.  And yes, that’s a mouthful.  But it means that you can go from what traditionally would be a low gear to a high gear without having to move the chain from one gear to another.
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  • jonathan heller

    Very cool! It is a great move forward, but I wonder if they have any historic data on the performance of the fluid over time. In the electronics field, you look for ALT testing to tell you what happened, also, changes in temperature can affect viscosity, not that you plan to ride in 100+ or 30- temps.

    • http://www.intheboombox.tv/ Tom Hughes

      That’s a great question.

  • Scott

    I have had a Nuvinci 360 since July. I love it. I replaced my Shimano alfine 11 with it. It had 12Tkm and was on its death bed. The design is much more robust than a hub with internal gears. I have the impression there is more internal losses with my Nuvinci. Nuvinci won’t publish the efficiency numbers, so my guess they know it is less efficient, and don’t want to talk about it. My times to work got a little longer. If it were more efficient, they would be bragging about it.

    I would not take the Nuvinci on a long tour. It is heavier and less efficient than my traditional derailleur system on my treking bike. You are limited by the gear range. If I follow the guidelines on gearing (front to back ratio), I can’t get it as low as say a 27 speed treking bike. I would never think of touring with bags using it due to the poor low end ratios (if you follow their guidelines).

    It does have its niche, where it tops anything else, and that to me is the commuter market. There you want something robust and maintenance free. Shifting under load is easy and kind of fun when accelerating. You can slowly turn the grip shift as you accelerate keeping your cadence fairly constant all the time. You can also downshift about 3/4th of the range at lights too. There are no internal springs to pull the cable back, like on the Shimano hubs. It uses two cables. Whether you shift up or down there is always tension pulling on a cable. This means the system is insensitive to friction buildup in the cable housings.

    You are always in gear with the Nuvinci so there is no partial shifting or “gear-grinding” like with a poor shifting Shimano Alfine, when it has friction in the cable housing.

    It is very smooth and has a great feel during riding. I can highly recommend it for short distance, dirty applications, with relatively low slopes. There is a short 14% grade on my commute and I really have to huff and puff at a real slow cadence to get over it. I run a 28″ wheel with a 39T front chain ring and 22T on the back. On the top end I can peddle down hill max at 43 km/h and then I can peddle no faster. That is what you are limited to.

    Since I am not that large and heavy, I have though about exceeding their low end recommendation and run it with a front derailleur and other chain rings. I’ve really laid into the hub on steep hills and there was always traction and no slipping. I would guess the guideline is very conservative.

    From an engineering basis, the thing is so simple and will be hard to kill. Watch the videos on youtube for the Shimano Alfine 11, it is a mechanical engineer’s nightmare. It has lots and lots of small parts. The more parts in any machine the more that can go wrong. Since the Nuvinci is always in gear, there is no chance to generate chips and damage during “bad shifts” like with incremental gear systems.

    All in all it is a great product for the “short haul” market, but I would never take it on a multi-day tour, or with take it on a trip with saddle bags.