NuVinci N360 Review

20 11 2010

 

Tom's rig...

Note: This isn’t my review.  Tom posted it to MTBR.com’s IGH Forum and I reposted it here with his permission since I figured some folks would be interested to hear what he has to say about this hub.

DISCLAIMER: I am not by any means an expert rider and I have not tried every piece of equipment out there or ridden every type of trail. The premise of this review is to provide observations of the real-world performance of the NuVinci N360 hub with as much detail as possible. It is not meant to be an endorsement or advertisement, just data for people to draw from, with a few of my personal opinions along with it. Yes, the hub is heavy. No, it’s not for everyone. Just don’t give me crap because I write way, way too much or have stupid opinions.

BACKGROUND: I’m 6’3″, 215 lbs and like to break things. My singletrack bike is a large Surly Karate Monkey with a Fisher Rig build kit and a Fox F29 80mm fork. It’s been set up mostly as single speed, but also ridden with a 1×9 setup for a while. As a SS it weighed in at just under 30 lbs. I built up the N360 hub to a Stan’s ZTR Flow rim with a way-fatter-than-2.35 Bontrager FR3 tire. The whole setup brought the complete bike weight up to 33.6 lbs. There really isn’t a single part of this bike chosen for weight reduction or speed, more for comfort and durability.

WHEEL BUILD: A friend at my LBS helped me string up the wheel. I’ll spare the details except for one anecdote: every time my friend lifted it out of the truing stand he kept thinking it was stuck, only to realize that it’s just way heavier than an average cassette hub. Listen to the NuVinci recommendations and lace 2x at most (for 36h), because the diameter of the flange is so large it will be even stronger than a 3x Alfine, in fact because you end up with shorter spokes it’s a lot like a 26″ wheel laced 3x-4x on a standard hub. Otherwise, it builds up really easily. I noticed that the wheel has a significant amount of extra drag on the truing stand compared to a basic freewheel hub, but it is not really noticeable on the bike and that resistance drops as the hub goes through it’s “break-in.”

BIKE SET-UP: Installing on the bike is straight-forward. Make sure the yellow marking on the hub are lined up, put the shifter mechanism in full overdrive, and line up the slots. There are manufacturer recommendations for the length of cable that needs to be showing out the end of the housing when the ends are installed (this is a two-cable set-up) with simple instructions that will get you in the ball park…follow those directions. Once everything is routed and (likely zip-tied) in place, shift the hub to full overdrive and check for cable slack, then do the same for full underdrive. Cable slack WILL screw up the shifter (more on that below).

TEST RIDE: After installation and cable tensioning, a quick trip around the parking lot is a good idea to make sure the shifter is working properly and you’re getting the full range of motion. I had some slack in both cables at first, which will cause the grip shifter to click and make noise and not behave properly. After adjusting the stops at the end of the cables, then tightening up the barrel adjusters on the shifter, all the clicks went away and everything works flawlessly. I recommend checking for cable slack after the first several rides, especially if you get any noise from the shifter, that will likely solve any problems.

FIRST RIDE: I took a loop that would involve about 10 miles of speed road riding, with about 2.5 miles of flowy singletrack in the middle at Lake Crabtree. Nothing crazy, just wanted to see how the gear range felt, and how it felt on the road and on the trail. Mine is set up with a 32T front ring and 18T cog, making for a total range equivalent to 32:36 up to 32:10. On downhills I could spin out the top gear, but never needed to go any faster than I was going, then on the trails I ride regularly there aren’t any climbs that I need a lower gear for. This is all the range I need for what I ride, but you can figure out if that’s enough range for you.

RIDE IMPRESSIONS: I’ll say this first: after letting about 10 other people tool around on my bike and play with it, the first two words without fail they use to describe it are “weird” and “smooth.” It’s very appropriate. First, shifting is as you would expect (except that twisting forward shifts to a lower gear), you twist and it shifts. There is no grinding, crunching, or clicking…you’re pedaling cadence just changes, making for a surreal feel over even the other IGHs. There is zero noise, no jerking forces on your legs, no missed shifts, no out-of-gear or ghost shifting sensation…it just shifts, is always in gear and works. My friend commented, “it’s weird riding with you and being able to hear you shift gears.”

The added resistance of the hub is barely noticeable, but it is there. The added weight is only majorly obvious when you pick the bike up (remember, that’s from my perspective, I’m not a weight weenie). During the first couple rides, the only odd feeling I noticed was when the bike was in full underdrive (32:36) and I was mashing up hill, I could “feel” the fluid in the hub. It wasn’t a grinding, more of a swishing feeling that has since faded, as I suspect it is some break-in related symptom (note: there is no malfunction or slippage in this condition, just and odd feeling at first). I did put markings on the tire and test for slippage by checking rotation ratio under no load by just rotating the cranks freely with the bike in a stand, then did the same with extreme torque, mashing scenario. RESULT: there is zero slippage in this hub. You may perceive something as slipping, but I assure you that is not the case. Inefficiency via drag, sure, but you will not make it slip.

This specific feature is one of the reasons I wanted to be an early adopter. It really is never out of gear, no jerking or sharp forces during shifting, you just pedal along so no matter what when you step on the pedal, you know what to expect. Already my knees feel better riding on this than they did on the 1×9. Of course, this is personal preference, so I’ll leave it at that.

So far, this bike has ridden like a SS. No drivetrain or chain tensioning issues, I can just spray it down after a ride if I want, no maintenance. I wail on wheels, not because I’m so skilled, but because I’m big and lack finesse. The point is, you’ll break something else before you ever break anything in this hub. The next test is to go outside the NuVinci recommended gearing range and put a 22T cog on the back and start piling on the torque on the steepest climbs I can find (they say it should be at least 1.8:1 chainwheel/cog ratio as a very generic guideline). From my testing so far I am fairly confident in saying the hub is plenty stout for any type of riding you would do.

SHIFTER: I’m putting a whole separate section for the shifter because in many ways it’s the most used and most critical part of this whole set up. If not set up properly as discussed earlier and cable slack is not eliminated from both cables, then you will have shifter issues. For argument’s sake, let’s say anyone that has this hub will know how to turn a barrel adjuster and it will be set up properly. What I was interested in was how it shifted in different riding conditions. The gear indicator with the little cartoon dude on the hill is pretty awesome if you’re goofy like me (I almost never look at it while actually riding anyways).

First, you can shift at a dead stop. This can be handy for obvious reasons and it’s very light pressure to shift, however if you are completely stopped then it will only shift through about half of its range before you’re met with a ton of resistance. NOTE: do not wrench on it to try to get it to shift the rest of the way through, you will just stretch the cables. If you just rotate the rear wheel at all (i.e.- start moving) then you can just as easily shift through the rest of the range. Not a performance issue, just something to be aware of. Where I find the shift-anytime feature most useful is when descending, knowing I’m about to hit a steep climb and I need to be a lower gear to maintain my momentum. I can be standing up, focusing on the descent, just twist the shifter a quarter turn, and when I start pedaling I’m already in that gear, period. Once I got used to doing this and how far to turn the shifter for an approximate gear change, it became super easy and comfortable (and it can bail you out of sloppy riding with immediate shift response).

Normal riding and shifting is extremely easy. There really isn’t a better word for it than “smooth.” It just works, try one and you’ll get it, instantly. Now, what people are more concerned about is shifting under load. The best way I can describe it is that there is a limit to how quickly you can shift under a really high load. If you’re loading the pedals to the maximum you will be met with a ton of shifter resistance, so you don’t want to be really cranking on the pedals and the shifter at the same time, but it will work. If you let off for even just the top/bottom of your pedal stroke for just a fraction of a second, the shifter will loosen up and change gears easily. I found that it’s easy to shift while climbing, particularly if shifting to a lower gear, but you do have to use more force on the shifter to get it to obey you. That will likely be another personal preference thing, because for me I’d trade a little extra wrist force for continuous, uninterrupted power transfer/gear change, instead having the crank slip a 1/8 turn while shifting or the sudden change jerking on my legs (again, this is a personal preference).

OVERALL OPINION: Yes, that says opinion, because this is how I feel about this hub:

If you have a chance to ride one, DO IT.

Chances are you won’t love it. It’s not meant for everyone, but it is totally cool. The majority of riders, particularly trail riders, aren’t even going to be able to get past the additional 3-4 lbs of weight. Obviously, it’s aimed at recreational riding, not performance/racing and as my riding buddy says, “you’d have to be nuts to think I’m adding weight to my race bike.” Granted, but that’s not the point of this hub from a mountain/trail bike perspective.

I love this hub because it’s: (A) easy to use (2) unbelievably predictable, (d) 100% reliable, and 4) I’m a big dude. I am the opposite of a weight weenie and am not a racer, so my bike is outfitted to be bullet-proof and fun, while allowing me to get a workout. Adding 2% to my total rider + bike weight? Not a problem to me. What I always hated was the way that derailers shift, the effect it has on your legs and pedal stroke, and the risk of damage to cages, chain slap, ghost shifting, adjustment and maintenance, etc. If you don’t have a problem with derailers and prefer race-ready components, you likely will not be a huge fan of this hub. If you hate derailers, you’ll probably fall in love with it instantly. Either way, it’s completely fun and totally different from any other gear system out there.

Hopefully the length of this post hasn’t deterred people from bothering, I tend to ramble, I just figured that someone out there might actually appreciate knowing some of this stuff if they can’t actually test one for themselves. If you’re in the Raleigh, NC area I tend to ride at Lake Crabtree during lunch whenever I can, I’m always happy to talk about bikes and let you check it out. Pictures of my bike are attached below.

-Tom


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5 responses

22 11 2010
Rob E.

I have the older 360, but everything Tom says rings true. The N360 is supposed to shift better under load, and the old model doesn’t have the issue where it will only shift through part of the range at a standstill, but that’s a pretty good trade off, if you ask me.

I especially agree with the wheel building issue. I built the wheel 3 times. Once because I thought my rims (700) were big enough to handle a 3X. Once because when went 2X, I didn’t read the instructions carefully enough to realize that at they recommended putting all the spoke heads on the same side of the rim. 1st wheel busted spokes at the nipple ; 2nd wheel at the hub. 3rd wheel has been solid.

I love my Nuvinci, and the only thing stopping me from upgrading to the N360 is that there doesn’t seem to be any way for me to break the current hub to justify the new purchase.

24 11 2010
diaryboybob

building two rigs with the 360 now…this “review” is making me wish all the bits were here and i could get the build finished and get riding…

26 06 2011
Todd Edelman

Dude, this is a brilliant review. Clear language, modest, and so on.

29 09 2011
Mike

Initial review of Nuvinci N360 on a recumbent tandem.
After one week/100 miles.

Bike ‘specs:
BikeE E2 recumbent tandem
rear shock
weighing in at 75 pounds with tools, waterbottles and lights
over 400 pounds of bike, riders and backpacks
(that’s over 180 kilos for you Unamericans)
set up as a daily commuter in the Berkeley, CA USA area
70-100 miles per week
Nuvinci N360 hub
20″ rear wheel, laced 1-cross
Install and wheelbuild by El Sobrante Cyclery, 94803
(thanks, Ken!)
32 tooth and 48t chainrings
18t rear cog
deraileur acting as a chain tensioner

Summary:
The Nuvinci N360 seems very well constructed, is viscerally pleasant to ride, idiot-proof and seamless to operate and can never miss a shift. It suffers the demerits of heavy weight (around 4 pounds), and relative inefficiency compared to a sprocket drive (I estimate 80% as efficient). I recommend it highly for low-maintenance cruiser/commuter use, non-competitive tandems, and especially, for recumbent tandems, but I don’t recommend it for going fast. If you ever see one on a bike, you’ve gotta try it.

Full story, with tangents:
Watching the drive train on our tandem wear away, daily, I knew it was soon headed for the great metal recycling bin in the sky. I like internal geared hubs (IGH) because of low maintenance and that they can downshift while stopped or stalled, which is a BIG deal on a recumbent (a ‘bent), where there’s no standing on the pedals to help regain forward movement again. I hoped the Nuvinci would also “solve” a tandem-specific issue of the Stoker and Captain coordinating getting off and on the power during shifts. With a standard IGH or sprocket drive, one has to ease up on the pedals in order to get a nice, quiet shift, and with a worn drivetrain, some pedal finesse is required to get certain shifts, such as down onto the granny ring. That all can be challenging for two people to coordinate, particularly on a hill or when a stall looms if choosing to obey a stop sign or avoid a sudden hazard (eg., from not obeying the stop sign). With the Nuvinci, however, the Captain can shift without notice and the ratio change will just happen seamlessly without upsetting anyone, since the drive is never disengaged.

On my tandems (yes, plural), I have the cranks set to be out-of-phase by 90 degrees between the Captain and Stoker. There is a chain that connects the two sets of cranks and one typically synchronises them in-phase so that both people’s feet move together, left/left,, right/right,, left/left,, etc, with essentially two big power pulses per rotation. However, the cranks can also be set out of phase: front left then rear left, front right then rear right, left, left, etc., to give four smaller power pulses per rotation. When I did this I noticed almost a gear cog-worth increase in power (we were climbing hills in the next higher gear than usual). This is on both the normal tandem and the ‘bent one, which has a rear shock that will compress a little with each power pulse. In addition to better performance, four little pulses should be easier on the drivetrain overall. On normal tandems one has to make sure both pedals are “up” on the inside of turns so that somebody doesn’t strike an inside pedal on the ground (catastrophy!). The pedals/cranks on the ‘bent tandem, however, are mounted so high that they can’t hit in a turn, so no worries no matter what their phase setup.

One issue I ran into when planning an internal geared hub was the amount of torque the hub can handle, which becomes an issue on a bike with two people torquing the drivetrain. Some manufacturers give input values for their hubs, either in an actual torque value or a chainring to sprocket ratio, eg., a 32t ring with a 16t cog gives a ratio of 2:1. Some hubs specify 2:1, Nuvinci says 1.8:1 and some don’t say at all, and I assume those ratios are for the strongest riders likely to use their hub. That minimum ratio and the reduction ratio of the lowest gear inside the hub is crucial as it says how steep a hill I can climb, and in Berkeley, we have hills! I figure that even though I’m not as strong as a pro rider, I may actually be able to spaz out the same peak torque once or twice, and with the stoker pedalling too (in phase), we could conceivably exceed pro torque in a moment of panic. But crank torque differs depending on whether one stands on the pedals or sits. Some back of the envelope calculations: just how much more torque does standing on the pedals impart than when sitting down and pedalling? Figure that if one is climbing a hill at the same speed then the power output is the same. Power is torque times rpm or pedalling cadence. Let’s say cadence while standing is 1/2 of sitting (say, 45 vs. 90). The cogs used for a standing climb are usually two to three higher (smaller) than sitting, for example a 24t down to a 16t. 16/24 is 2/3. 1/2 of 2/3 is 1/3. In other words, on the ‘bent where one can’t stand, a person may only be able to apply 1/3 of the torque as standing, and fudging a little more by assuming that one can push back into the seat a bit, maybe a person could put out 1/2 the torque. On the ‘bent tandem, both of us together sitting still won’t put out MORE torque than one person standing, and with an out-of-phase crank setup we’re putting out substantially less peak torque than one person standing. This also seems about right from how poorly we can climb hills compared with every normal bike we’ve ridden and with everyone who passes us up the hills… At any rate we’re running the 1.8:1 minimum input ratio (for a solo rider), to the Nuvinci, and can climb anything on our commute so the minimum is minimum enough for our needs.

One question I’ve read while researching the Nuvinci is, how much less efficient is it compared with a regular external sprocket drive? Nobody gives any numbers or data. Well, for over a week now we’ve climbed the hill to work in “full underdrive” of the N360 on the 32t ring, and it feels a bit easier than the 32/28 combo on the old drive. The gain ratio calculator on sheldonbrown.com says that 32/28 on our old setup with those wheels, etc, was a 1.6, while the N360 at full underdrive is at 1.2. Hmm, one is 75% of the other, which by my math gives a 25% loss as an “upper limit” for the hub. Up that hill with the N360 at full underdrive it is harder to pedal than the old 32/32, which has a gain ratio of 1.4, which when divided into 1.2 gives 86%, or a 14% loss as the “lower limit” for that hub. My guess is that the loss of the N360 is somewhere in the middle, around 20%, which is substantial; other internal geared hubs probably lose only half that. In other ratios the loss seems roughly the same or at least similar; the Nuvinci seems overall a tad slower than the old drive. Now, that said, after riding the N360 for a week, I don’t really care! Yes it feels slower, but the overall experience is WAY mellower than with the sprockets and deraileur. Look at the above numbers and realize we’ve left the realm of normal bikes and ride more of a human-powered land-yacht. It still takes about the same time to get to work, we don’t ever discuss the finer points of tandem communication while the chain skates around on the cassette, and we can power the pedals all the time instead of having these constant excuses to go slack, or struggling to avoid a shift. I can shift reactively instead of pro-actively; I don’t have to anticipate hills, stops or anything. Immediately it was obvious to both of us that this kind of drive on a non-racing tandem bike is the way to go. As Captain, I now constantly and almost subconsciously creep the ratio up or down to meet our immediate needs and to keep us working up a sweat (like a good DJ in a dance hall). With deraileur and cassette I was driving my Stoker nuts with all this compulsive shifting and the occasional ominous sound of the chain rattling, skipping and grinding from cog to cog, threatening a mis-shift, but with the Nuvinci nobody cares or really even notices the shifts. We just sit back, pedal away and enjoy the ride!

Would I recommend a N360? I sure wouldn’t get one for my solo bike: While I like the idea of an IGH, I have no problem shifting gears in a typical 3 or more-speed hub or cassette when I’m pedaling by myself. There would be no real advantage of the N360 and yet all the penalties of weight and drive inefficiency. I would recommend they try one, all those people who seem to use only one gear on their multi-speed bikes. We’ve all seen them – they ride around in one gear that has become so hook-worn that it probably couldn’t shift out if they wanted it to, while all the other cogs are pristine. These people seem to have an issue with shifting in general, maybe they fear the rattle of a perpetually out-of adjustment shifter or can’t quite get a clean shift with whatever arrangement and technique they suffer. The N360 is so fundamentally different to shift that they might really like it, and a N360 out of adjustment will still have a lot of range that’s easy to use. And I would unhesitatingly recommend that tandem riders, both normal and ‘bent, consider a Nuvinci. They/we have the problems that this particular IGH solves quite nicely.

So, Fallbrook, don’t miss out on marketing this hub to tandem users! Make whatever input ratio recommendations you need to insure the reliability of the hub for tandem use, specify out-of-phase cranks or whatever, but don’t miss this opportunity. This is a GREAT innovation for non-competitive tandem riders. I see you have this Harmony auto-shifter for the N360. If it is anything like the hub, I bet it has a huge, heavy battery, but works flawlessly. Get the Harmony to work on regular, non-electric-bikes and the two together would be awesome for tandems. There would be no arguing about the shifts, they would just happen! The ultimate maintenance-free bike? Put the N360 and Harmony on a shaft-drive comfort/commuter bike like the ones Dynamic sells, with a front generator hub to charge the Harmony battery and power lights, and run those thick, thorn-proof inner-tubes (that hold air for a month). It would be a bike almost as slow (and heavy) as a tortoise, but it would ride on forever and only need some air and a squirt of grease on the shaft every month/1000 miles! And I can’t wait for the next Nuvinci version.

If you’re in the Berkeley area and want to try the N360 on the land-yacht, give a shout to:
conboymike a t yahoo d o t com

Cheers,
Mike

25 10 2011
John

Thanks guys – interesting reading. I appreciate the clarity and depth. I’ll wait till these things are lighter and more efficient but I’ll try one next time I see one at a bike store.

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