NuVinci N360

edited March 2013 in Rover
Before ordering my Rover, I did a lot of reading in the forum in order to better informed. I was considering ordering a single speed Rover. then get a NuVinci hub and have a local shop install it for me. I was able to find a shop that had experience installing the NuVinci and he cautioned me about the hub. According to him, if you are cruising along in 8th gear and make an emergency stop you should shift no further down than 4th gear or the cable would be pulled out of the hub. Has anyone had this experience?i

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  • edited March 2013
    Rcjone19 wrote:
    Before ordering my Rover, I did a lot of reading in the forum in order to better informed. I was considering ordering a single speed Rover. then get a NuVinci hub and have a local shop install it for me. I was able to find a shop that had experience installing the NuVinci and he cautioned me about the hub. According to him, if you are cruising along in 8th gear and make an emergency stop you should shift no further down than 4th gear or the cable would be pulled out of the hub. Has anyone had this experience?i


    I never heard of that problem of the cable being pulled out of the hub. Makes no sense at all, frankly. They apparently had a problem with an earlier version with it locking up if you applied power while rolling backwards, but that was supposed to be fixed last summer by a redesign.

    On another note, the big issue for me, when replacing a hub, would be the person that is going to build the wheel around the new hub. Some mechanics are excellent at wheel building, and other's don't have a clue. I just read a couple of posts about a very well known shop that built a couple of wheels around an internal hub and almost immediately, the customer had loose spokes and a wheel going out of true. The person that built this wheel obviously didn't know what he was doing. I have had wheels built over the years, that I never had to touch in thousands of miles, because the person that built the wheels for me was an expert. I have also had wheels that needed constant truing and even broken spokes, because the wheel wasn't built correctly. If a wheel is built and tensioned properly, it should be pretty sturdy, especially on a 20" rim.

    I have had really good luck with my SA-8 and have a bit over 12,000 miles on it with zero problems. I had thought about replacing it with a Nuvinci, if and when it dies, but it operates like it did on the first ride, so it seems like it will last forever. I attribute this to three things:

    1. Keep checking the adjustment, as outlined in the owners manual. If the adjustment isn't correct, you can cause damage to the hub , because it is like having a manual transmission car, and not shifting it all the way into gear, when shifting. I check the adjustment about once a month, and 96% of the time I don't have to touch it. If you can't see the yellow mark, use a Q-tip with some alcohol to clean it.
    2. Do not shift when pedal pressure is applied. I grew up on a SA 3 speed hub which I got on my first English Racer bike in 1953. All I ever did to that hub was adjust the chain, and oil it periodically and check the adjustment. I never shifted it while pedaling. That hub had thousands and thousands of miles on it, and never malfunctioned.
    3. Don't over torque the hub. I have read about lowering the size of the front crank, which of course puts much more strain on the hub body and internal gears. Some internal hubs won't even warranty their hub if you overtorque it, in fact I think that applies to the Nuvinci. I spoke to a bike mechanic in Europe last summer, and he has been repairing internal hubs for years, since they are very popular in Europe. He told me that most internal hubs like the SA are designed to utilize a low gear of around 25", which is about what the stock Rover SA8 has as a low gear. He said if you go much below that, you are probably going to over torque the hub, and eventually might have problems with it. I also use a torque wrench when I remove and reinstall the rear wheel for a tire change, which has nothing to do with operating torque on the hub, but keeps the threads on the axle from being damaged or the wheel slipping in the drop-outs.

    I think most of the SA-8 failures are because the above three items are not checked or ignored.

    Now the one thing that gives me pause on changing to the Nuvinci hub is this, I like the gearing on the Rover SA-8. I mostly ride Rails to Trails like the Silver Comet in Atlanta, and a couple of park Trails, which are not too hilly. The steepest grade on the park next to my home is around 10% and I can climb that in first gear at around 5 mph. What I like most about the SA8 is the high gear of 79". On the Silver Comet, there are long grades both up and down, and the 7th and 8th gear on the SA8 lets me ride along in 7th gear, at a comfortable cadence doing around 15 mph. When the grade starts a downhill, I can shift up to 8th gear and at 90 rpm I am doing around 22mph. The 24" low gear is able to handle all the hills that I encounter on my rides. The Nuvinci, with the 32T crank, has a range of 18" for a low, which is great for climbing steeper hills, but the high gear of 68" is just a bit higher than my present 7th gear on the SA-8. This means that on my normal rides, I will be spinning out on some of the downhills that I could still be pedaling on with the SA-8. The only way I could remedy that would be to replace the front crank with a larger crank, to get a higher gear inch, and of course that would sacrifice the 18" low gear. Replacing the front crank with a 36T would result in a low of 21" and a high of 76" which is almost the same as the SA8 range, with a little better low gear for climbing. The cost of course would be around $700 with the hub and crank.

    The only other option is the Nexus Hub, which I rejected right from the start, due to it's very poor high gear of 62". 90 RPM cadence would result in only 16.2 mph, and sustaining 90 rpm is not something that I like. My days of spinning at that rpm for miles are over.

    Sorry I got long winded on this topic, but it has been something that I have been interested in for decades, bike gearing. I see many times, that gear inches are totally ignored when people discuss possible gearing combinations on bikes and trikes, and to me, that is the gold standard of understanding how any particular setup will react when riding it. If I know that the gear inch combination is say 20"-90", without even riding the bike or trike, I can tell if I will be comfortable with that gearing setup on the routes that I normally ride. Then all I have to do is figure out how to get that range, using the hub-gear-tires size combinations that will get me there, and remember. the final drive gear is the tire you have on your ride.
  • I appreciate the info, and it makes me feel better about my decision of going with the standard SA-8. My wife and I are in our mid 60's and haven't done much biking in recent years. I'm hoping that will change with the new Rover tandem. We had a standard tandem bicycle but discovered very quickly that we started peddling with different feet, a put down opposite feet when stopping. Not a pretty site when two seniors go sprawling on the ground. The trike should prevent that once I learn how fast (or slow) to take tight curves.
    Thanks again. I'm open to any and all sound advice
  • edited March 2013
    Rcjone19 wrote:
    I appreciate the info, and it makes me feel better about my decision of going with the standard SA-8. My wife and I are in our mid 60's and haven't done much biking in recent years. I'm hoping that will change with the new Rover tandem. We had a standard tandem bicycle but discovered very quickly that we started peddling with different feet, a put down opposite feet when stopping. Not a pretty site when two seniors go sprawling on the ground. The trike should prevent that once I learn how fast (or slow) to take tight curves.
    Thanks again. I'm open to any and all sound advice

    A tandem bike is a whole different animal as you discovered, and riding a tandem trike, is quite a bit easier especially starting and stopping. I think the two choices I would consider on a Rover for a hub are the SA-8 and the Nuvinci. If I lived in a mountainous area , or expected to be riding in one, I would lean heavily towards the Nuvinci, because of the lower gearing. Then just finding a way to make the high gear a bit higher, like a front derailleur or the Paterson would be something I would have to consider. The only negative issue regarding the Nuvinci, that I have read about, is the efficiency of the hub, which apparently Nuvinci does not want to make public. I have read posts by several people in the last year questioning that issue, and I also read a post on this forum by someone that got the Nuvinci, duplicated rides that he had done with his SA8, and found the Nuvinci resulted in a slower average speed. He then removed the Nuvinci, and went back to the SA8. That would concern me, if I found that I was losing say 10-15% of my pedaling effort and speed, due to losses in the hub. On the other hand, it seems that the Nuvinci is pretty bullet proof, since reported problems with it seem to be very rare. The idea of being able to fine tune the gear you want, rather than selecting pre-set gears, is a big plus in my opinion. Sometimes you are in a gear that seems a bit low, and you shift up and the next gear is a bit high. With the Nuvinci, if your favorite cadence is 76 RPM, you could dial the controller to keep that exact cadence, regardless of the terrain.

    Getting back to the SA8, I have read quite a few posts where people are complaining that learning to stop pedaling while shifting the SA8 is too difficult, so they don't like the hub, or shift under power anyway. To me that makes absolutely no sense at all. When I first got my Rover, it took me about 5 minutes of riding around a parking lot and shifting to get used to shifting while not pedaling. That would be like someone driving a standard transmission car and saying it is too bothersome to have to push in on the clutch when going from one gear to the other. While some IGHs claim you can shift under load, I think most good mechanics who have worked on IGH's would tell you that your hub will last alot longer if you don't shift under power. When you change from one gear to the other, why do it under a load? Now the design of the Nuvinci is different, because there are no individual gears, so shifting while pedaling apparently is not putting the hub under any kind of strain. Another complaint I read is the loss of momentum on a climb because one has to stop pedaling for the 2 seconds it takes to go from one gear to the next. If you lose that much momentum in 2 seconds, you must be climbing up the side of a building, in my opinion.

    This summer my Rover will be 3 years old. So far the SA8 is working perfectly after 12,000 miles. If and when it dies, I will have to decide whether to just get another SA8, or spend a few hundred more dollars and get a Nuvinci. I do think the SA8 is alot more reliable than people think, and the reason I feel that way is a Google Search of failures of the SA8 doesn't turn up many at all. Most of the failures are of an older version of the current SA8, and the pawl design was changed after that. A couple of leaky seal hubs, but that could be the over-torquing problem as a major factor.
    Even Nuvinci has had a rash of leaking hubs, more frequent than reported with SA. This is just one of several posts about leaking Nuvinci Hubs from their forum http://nuvinci.informe.com/forum/bicycl ... html#p2321 ( I read today that Nuvinci is closing their forum the week of March 5, 2013, so I am going to copy and paste just one of the posts on seal leaks below)
    Re: What is inside an N360?
    by Oran on Mon Apr 09, 2012 6:03 pm

    I’m very interested to learn that I’m not the only one who has had more than one leaking hub. 5 hubs ! I am currently waiting on my third hub. Both have leaked on the drive side so that the freewheel fills up with traction fluid. The first one started leaking at about 300miles (500km). The second one at about the same mileage but the leak is not bad so I am still using it and have now done 700miles (1100km). From what I was told and can see without taking it apart the second hub has different supposedly better seals which is probably why the leak isn’t too bad.

    I was hoping my next hub, which should be a 2012 model, has had this issue fixed but it doesn’t sound like it. Surely Fallbrook haven’t made a mistake and blamed the seal for the leak rather than doing a proper investigation and found the real fault. Clearly something needs to be done about the leaking issue and the wear that is occurring whether it is the course of the leak or not. I’ve been thinking about how I would fix the wear issue and it is quite a difficult problem to solve without using expensive bearing. If the O-rings were hard enough to prevent contact they will probably be too hard and wear out instead.

    As for shifting under load the N360 may be designed to shift under load and does shift under load but doing so seems to be damaging the hub. As can be seen in the photos in my previous post most of the wear has occurred on the left of the top slot and right of the bottom. This would suggest that it is happening under load as these are the sides the ball axles will be pushed against. There has to be a change in the position of the ball axles or change in ratio for any wear to occur. So the wear must be occurring while shifting under load.



    Here is another of several leaky Nuvinci hub posts http://nuvinci.informe.com/forum/bicycl ... -t989.html

    Other than that, for a hub that is used all over the world, and is used on many Terratrikes as their standard 8-speed, I am not seeing very many complaints Sturmey Archer comlaints on the latest 8 speed model, and if you have something that is failure prone, the first place that this is seen is on the web.
  • I have two Rovers, one with SA8 and one with NuVinci. Also have 5 bikes with IGH. The NuVinci is the best of the lot by far. I would never consider an SA8 for a tandem. With a NuVinci on a tandem you wouldn't ever have to coordinate a shift; just naturally adjust the shifter to maintain your cadence with your comfort level of effort.

    If I ever buy another trike it will have a NuVinci hub.

    Wes
  • itchyfoot wrote:
    I have two Rovers, one with SA8 and one with NuVinci. Also have 5 bikes with IGH. The NuVinci is the best of the lot by far. I would never consider an SA8 for a tandem. With a NuVinci on a tandem you wouldn't ever have to coordinate a shift; just naturally adjust the shifter to maintain your cadence with your comfort level of effort.

    If I ever buy another trike it will have a NuVinci hub.

    Wes

    Good point about the Tandem shifting, hadn't thought about that. Curious, What is your high gear in gear inches on the Nuvinci Rover and what crank wheel are you using? My concern after reading about the Nuvinci for a couple of years in many articles is the reported efficiency of around 80%. That is alot of energy to lose for a cyclist, in the hub.
  • CaptainBob,
    I have a 20 cog on the NuVinci. It's paired with a Patterson on the front, and BA 215's all round. It's geared about right for hill riding, but I've found it a bit low for SW Florida's flat land. Low range (25 tooth chainring) on the Patterson spins out for me at about 10 mph. I ride 12-14 and thus lose use of the Patterson low range, which I have found to be noticably more efficient. Low range is direct gearing and the high range (45 tooth equivalent) is achieved with an overdrive mechanism. I'll probably get a 18, or even a 16 cog for the NuVinci, and the tools to swap it out as necessary so I can use the Patterson direct gearing most of the time when I'm in Florida, and use the 20 when I'm traveling.

    I would have changed my wife's SA8 to a NuVinci, but a RideKick was a better upgrade for her.

    Wes
  • itchyfoot wrote:
    CaptainBob,
    I have a 20 cog on the NuVinci. It's paired with a Patterson on the front, and BA 215's all round. It's geared about right for hill riding, but I've found it a bit low for SW Florida's flat land. Low range (25 tooth chainring) on the Patterson spins out for me at about 10 mph. I ride 12-14 and thus lose use of the Patterson low range, which I have found to be noticably more efficient. Low range is direct gearing and the high range (45 tooth equivalent) is achieved with an overdrive mechanism. I'll probably get a 18, or even a 16 cog for the NuVinci, and the tools to swap it out as necessary so I can use the Patterson direct gearing most of the time when I'm in Florida, and use the 20 when I'm traveling.

    I would have changed my wife's SA8 to a NuVinci, but a RideKick was a better upgrade for her.

    Wes

    If you are still using the stock 20" wheel that would mean your gear range in low would be 8.5 to 30" . I believe 30" is equivalent to 2nd gear in the SA8 Rover. You should be able to climb up Mt Everest with that, although not go very fast. You high range is 21-75" which is more like the standard Rover SA8, although a bit lower than the SA-8s 24-79". Your high range would probably be the only range I would find usable , about 98% of the time since I don't ride in mountainous areas.

    By the way, if someone wants to get a Nuvinci to replace an SA-8, and likes the gearing of the SA8, the perfect replacement would be the Nuvinci with the 20T sprocket coupled with a new crank at 46T, which I have seen on the web for around $70. That would result in a low gear of 21.5" which is about 3" lower than the SA8 low, and a high of 77.3 which is about 1 1/2 inches away from the SA* high, which should be almost undetectable. This would make this new setup a bit easier to climb, with the same top speeds as the SA8 Rover. In my opinion this would be a much better choioce than the Nexus 8 speed which has only a 62" top gear, which to me, is unacceptable.
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