NuVinci bike hub anyone?

[gyre]

I found something saying the ratio has only changed 10%.

[Tiahaar]

Oh! curses gyre!! now you've done it The new 11-speed Shimano internal gear hub was successfully staying off my radar...you had to remind me.

My old NuVinci has a 350% ratio, the new model is yes 360%, the 11Shimano is 409% and the Rholoff is 526%.

The NuVinci does smoothly change ratios and does so flawlessly. You do have to ease up just a bit to help rotate the shifter.

I just like the clunk of specific ratios. Ride a NuVinci, you'll either love it or find it disconcerting. I'm constantly fiddling with the shifter and wish it had 'click-points' you could either have on or off (like some of the old road bikes had).

BUT...dangit...the 11Shimano is only a bit more than a NuVinci360...must...choose...

[gyre]

The rohloff is supposed to have internal shift points.
Very positive.

What do you think of the hybrids?

[Tiahaar]

hmm you mean the hybrids that have both internal hub and external cassette gears? never ridden one, would like to try, like one of the Sachs/SRAM 3 x 7, 3 x 8 or 3 x 9 hubs.

edit to add ebay has a Shimano Alfine 11 kit for $575 right now...resisting...
http://cgi.ebay.com/Shimano-Alfine-11-H ... 4cf7499fad

[gyre]

Yes, I like the sachs.
I need an internal for my electric though.

I thought I found the 11 speed much cheaper than that, closer to $350.
I wasn't looking too closely though.
It isn't a huge step up from the 8 speed though, unless you're on a mountain.
The 8 speed is supposed to be much more efficient than the 7 speed shimano.

[Zhust]

Funny that 4 years ago I was posting against the NuVinci. Since then, I guess, I've read Bicycling Science so I have a different view of the need for shifting.

Anyway, I'm working on a project (as mentioned here on ePlaya) and have ordered a NuVinci for it. I was looking for maximum ratio change, at least 7 gears, and lowest cost and settled on the NuVinci because of it. I could probably have gone with a cheaper option, but I think it was the widest range-per-dollar.

We'll see how it goes ...

[Elliot]

A few months ago I bought an old style NuVinci (called the N171) from the factory for $150. This was the close-out price. Maybe they still have some -- you should be able to contact them thru their web site.

The old one is larger and stronger than the new one. They figured out that the N171 was stronger than necessary for bicycles -- more like motorcycle strength. (In other words, they entered the market on the cautious side -- no customer failures allowed. Kudos to them!)

I'm using two NuVinci N171s in series on one of my big Kinetic Sculpture Racing trikes, and I'm cheating on the input ratio on the first one also. And this vehicle weighs something like 2-300 pounds, and I climb sand dunes with it, "bench pressing" the pedals (recumbent riding position). Yet no failure.

There is a bit of friction in the NuVinci, though. In a rudimentary sense, it can be thought of as an overtightened ball bearing.

[gyre]

Great deal, Elliot.
I wish I had some money now.

I think it's a beautiful design.
I am more concerned about weight, but think it might be worth it on an electric.
The better gearhubs aren't all that light either, though lighter.

[Elliot]

Finally found a photo of the above-mentioned tricycle. NuVinci hubs visible below my leg. (The second hub more visible than the first.)

[gyre]

Very cool

[Zhust]

I'm using two NuVinci N171s in series on one of my big Kinetic Sculpture Racing trikes, and I'm cheating on the input ratio on the first one also. And this vehicle weighs something like 2-300 pounds, and I climb sand dunes with it, "bench pressing" the pedals (recumbent riding position). Yet no failure.

Well that's promising. As it stands, my project will gear-up for a higher-RPM jackshaft so I'm not so worried about the NuVinci failing.

On another note, I'm having two maker-useful adapters being manufactured. One is a Sturmey-Archer-style sprocket adapter (the sprockets have 3 dimples that mate with 3 grooves and stays in place with a snap ring) that bolts on to a 6-bolt disc brake mount. The other is a plate that has holes for the 6-bolt disc brake, McMaster-Carr's SH-style "quick disconnect" hub, and 5-hole patterns for 94mm, 110mm, and 130mm chainrings. I'm also building a less-conventional adapter for the 125mm spoke ring on the NuVinci to a 130mm chainring.

This will let me run from the hub to a standard sprocket available all over the place. Admittedly the cost puts it outside the range of the junk-repurposing hobbyist, but it does offer gear ratio flexibility.

[Elliot]

Good going, Jay.

Initially, in a bench test, I used a jack shaft with tremendous up-gearing between the two hubs in order to lower the torque on the second one. That should work, you'd think, but the high speed resulted in so much friction that I could barely turn the assembly.

I'm taking the output off the brake mounts on both mine. Note in the above picture that they are offset so the chains line up.

[Zhust]

That should work, you'd think, but the high speed resulted in so much friction that I could barely turn the assembly.

I only have one which will be driven directly by the pedals at a higher-than-necessary ratio ... unless you're right and the friction is gets to me. I'm adding a high/low transmission/jackshaft after it with ball bearings. My untested plans are to have the high/low set to be just above the maximum gearing of the NuVinci, slightly better than dual-NuVinci's with a range from 4.9 gear-inches to 78 gear-inches (dual-NuVinci's would be 360%*360% = 1300% whereas the gap between low-and-high on mine yields a 1600% range from low-gear, lowest NuVinci to high-gear, highest NuVinci). [Ratios subject to change without notice.]

(For those who don't know, "gear-inches" is a horribly named unit that refers to the equivalent wheel diameter of a pennyfarthing which is a big-front-wheel old-timey bike with direct drive. So the gear ratios make it as if the pedals were attached to a unicycle-type wheel with a diameter in inches of that many gear-inches. So on mine, imagine pedaling a wheel that's the diameter of a CD [slow but powerful] all the way to a wheel 6 1/2 feet tall [fast but no power].)

I'm taking the output off the brake mounts on both mine. Note in the above picture that they are offset so the chains line up.

Oh yeah ... the contrast isn't ideal, but I can see the sprocket on the front NuVinci on the disc-brake side. Sweet.

[Elliot]

May the ghost of Sheldon Brown bless you for understanding Gear Inches! An archaic unit of measure, but still Oh so useful.

And you have good eyes to see that sprocket. My overall gearing is too high, so that sprocket is scheduled to become smaller. Then I will have what I need for the Kinetic Races. Last I spoke with the engineer at the factory, he gave his blessing to shrink that sprocket. Said he'll replace the rear unit if I manage to break it.

Of course, anything can be broken. A friend in Oregon has managed to break his, but from what I understand he put some awwwwful load on it.

[Zhust]

May the ghost of Sheldon Brown bless you

This will need to be incorporated into something I do. In lieu of bumpers, how about "top-tube stickers"?

[Elliot]

Good and well, but I have the perfect bumper sticker for home-built vehicles right here:



(WARNING: Thread drift in progress. WARNING: Thread drift....)

[Canoe]

I'm building a cargo bike with a mid-mounted N360.
The triple chainring drives a 15T on a jackpost, which drives the N360 with 22T to 18T. This means the 22T meets the 1.8 N360 drive ratio.

22T chainring providing 14 to 51 gear inches
32T chainring providing 20 to 74 gear inches
42T chainring providing 28 to 102 gear inches

I don't see myself ever using the 42, but it's already there.

The bike has 26" rims with Surly tires giving an effective 29" wheel diameter. I'm assuming 14 gear inches will provide for hill climbing or pulling a trailer around at Burning Man?

To get the final gear inches I want, I need to get a 12T driven off of the disc mount to drive the rear wheel's 1/8" 22T.
Is there anything out there than can easily be adapted to get a 12T spaced out from the disc mount to give clearance for the chain?

Thanks,

[gyre]

Sounds like a great playa bike.

[Elliot]

14 will be plenty low.

As for your final drive, this sounds to me like a part that must be fabricated. This may be easier if you change these sprockets to larger ones (while keeping the ratio).

But it is difficult for me to give good advice from here. Best of luck!

[Canoe]

14 will be plenty low. ... This may be easier if you change these sprockets to larger ones (while keeping the ratio)...

Thanks!

The largest gear I've been able to find for the rear hub is a Surly 22T, so I'm kinda stuck there.

I found a bicycle recycle place in town that was open today, even with it being a holiday here. I played through parts and it appears that I can used a Freehub 16T gear as a flange to drill and bolt to the disc mount, with the gear welded to a cut down Freehub spline shaft (not AL, nor mild steel, but a hardened steel of some sort), which in turn can take a 12T gear as usual, only with one tab enlarged to allow it to be installed in reverse due to the left-hand drive of the rear hub. Parts obtained for $5.

I will ask my machinist tomorrow if they can weld & machine the 16T to the cut-down spline shaft. Hoping this is a go.

I'm predicting that the only thing on this build that will get to be standard will be the bell...

[Mr.Coffee]

I'll be bringing a prototype nuvinci-equipped bike to the playa this year for torture-testing, so if you guys have any questions or gripes, feel free to run them by me. This is a current 360% hub, while earlier models were 180% and perhaps a 350% as well. I've found the initial drive ratio really helps tune the range of the bike, as it's low range gets silly-low, at the lowest range it needs more teeth on the crank.

[Canoe]

BM is one of the main reasons I chose the N360.

... to the playa this year for torture-testing... any questions ... feel free to run them by me...

Please!
Where to find you?

... I've found the initial drive ratio really helps tune the range of the bike, as it's low range gets silly-low, at the lowest range it needs more teeth on the crank.

Someone at Surly has one and has tried driving it below the 1.8 minimum. He reports that the lower you go, there's an increasing noticeable resistance you're pedaling against. So, I've geared to have my 22T drive at the 1.8. Actually, it's 1.79, rounding to 1.8 for the warranty. Problem?

The 32T chainring drives the N360 at 2.61.
The 42T chainring drives the N360 at 3.42.

See any issues?

Thanks,

p.s. probably not material, but my earlier "42T chainring providing 28 to 102 gear inches" was actually a 44T chainring. The 42T chainring yields 27 to 97 inch gears.

[Mr.Coffee]

I'm not quite sure where I'll be camping, but I was thinking 5:30 and j, or over in the eights or nines.

I'll be on GMRS channel 5, subchannel 7 if you'd like to try that. I'll be in a 30' monkey hut (hrm, pretty common, huh?)

It'll be covered with IR-cryo insulation (bright, BRIGHT silver) guess that's still pretty ubiquitous, huh?

there will be a white chevy astro van parked next to it (heh, not helping either).

I'll post a message in center camp when I settle down under this handle.

Also, I plan to check out terminal city,so if I like the fellas there enough that they remember me, they might be able to tell you as well.

[Canoe]

I'm not quite sure where I'll be camping, ...

I'm trying for 4 to 5 L. Not sure what I'll be sleeping in yet. No rush, there's two weeks left.

If it's done in time, I'll be on an (nearly) 8' Wooden Cargo Fat Bike with the N360 mid-mounted with left rear drive, towing a white camping cooler with a blue flag like last year if I get around to adding a flag pole to this years version. Actually, the bike should just break 8 feet if I get the squirrel done, but I'm running out of time.
Don't know what the bike will look like - a friend's painting it...
It's the wooden geometry-test mock-up made ride-able. Hope the 12" steerer tube arrives in time.
Have to add brakes.

[Mr.Coffee]

Nice, that sounds like a sweet project! I hope you get it wrapped up in time, I'd like to get a look at it.

If I make 5:30 and j I'll be close enough that I might be able to find you, we'll see how that works out.

[Canoe]

... I might be able to find you ...

If it's done in time, I expect to be out and about a lot.

Hope the guy storing my paddles shows up. I'd hate to be caught in a flood...

[Zhust]

I will ask my machinist tomorrow if they can weld & machine the 16T to the cut-down spline shaft. Hoping this is a go.

I'm predicting that the only thing on this build that will get to be standard will be the bell...

I had to abandon plans to finish a trike this year for Burning Man, but I did get some extra parts made that mate up well with the NuVinci:



The spoke holes are adapted with a 3-part ring that has #3 screw holes (about 2.5mm diameter) and 5 10mm holes in a 130mm ring which mate with a chainring of that diameter. It takes 5 washers to space the ring out far enough to fit a chainring nut on, and then a 10mm washer spaces the chainring away from the adapter so the chain will fit.

The disc brake adapter has 6 holes in a ring that accept flat-head screws and provide a Sturmey-Archer style 3-point sprocket. You have to remove the dust shield to get it to fit on because the ID hole is 1 inch. I just broke mine off, although I could have removed the nuts at the risk of not tightening them to the right tension.

130mm chainrings run from about 38 teeth to 50 if you can find them although 42T is more typical. Sturmey-Archer rings are typically 18T although I found sources for 13T to 25T (except 24T for some reason).