Utility Cycling - Nuvinci question

I know we've got a couple of Nuvinci users on utility bikes, so I thought I'd ask here.

Got my hub yesterday. I was prepared for it to big and heavy, but was still surprised to see how big and heavy it was. So, okay, maybe I wasn't that prepared.

But what is surprising is how much resistance I feel when trying to turn the hub on it's axle. I'd like someone to assure me that that's normal before I build a wheel up around this thing. I set the hub up on my truing stand and gave it a spin. It rotates when I push it, but not easily, and the internal friction causes it to stop immediately when I let go.

Is that what it should be like? Are my coasting days over? Or will the addition of a tire give it a little more rotational mass to keep it going? Or, and I should maybe hook up the shifter to test this, could it be in a high gear as it is, and maybe it'll move a little more freely when I downshift?

I'm just wondering what your all experiences were. I'm excited to build this thing up, but not so excited that I want to do it if the hub ain't right.

I have a NuVinci installed on a Peugeot porteur. It shifts very easily and since a utility bike is not meant go fast, I can live with the weight of the hub. Its a CVT transmission, so its quite a different experience from conventional IGHs. Even with its drawback, I still recommend it.

Thanks. I've already been sold on the Nuvinci. It's waiting to be built into a wheel as we type. I'm just wondering if it's normal to have a fair amount of resistance to spinning? I expected a big, heavy hub. I'm just surprised at the amount of force it takes to spin it. Maybe on a wheel it won't be so bad.

You won't feel it in relation to the bike. The NuVinci inchworm shifter is easy enough to click through to find the desired speed to match the terrain. When the display shows a flat line, it takes considerable force to pedal but as you dial it up into a curve, riding the bike becomes progressively easier. Then its a matter of fine-tuning the setting in which you want to pedal on a given terrain.

Rob: I've been riding one on a daily basis for almost a year, and, yes, it will be fairly stiff to start. It will loosen up somewhat as you ride it, as some of the resistance comes from the external seals, which will break in. It will always be stiffer than, say, a track hub or even the average cassette hub (though some of those can be pretty stiff, too), but it will never stop you from coasting, and you would be very hard pressed to even notice it when riding. I think anyone who has a serious problem with it on the road will probably want to check carefully for peas beneath their matress before they go to sleep, too. Seriously, it is not a racing hub, but it will change the way you ride, and I will be extremely surprised if you aren't grinning hugely for at least the first week (or more).

Rob: I've been riding one on a daily basis for almost a year, and, yes, it will be fairly stiff to start. It will loosen up somewhat as you ride it, as some of the resistance comes from the external seals, which will break in. It will always be stiffer than, say, a track hub or even the average cassette hub (though some of those can be pretty stiff, too), but it will never stop you from coasting, and you would be very hard pressed to even notice it when riding. I think anyone who has a serious problem with it on the road will probably want to check carefully for peas beneath their matress before they go to sleep, too. Seriously, it is not a racing hub, but it will change the way you ride, and I will be extremely surprised if you aren't grinning hugely for at least the first week (or more).

Same.

I think anyone who has a serious problem with it on the road will probably want to check carefully for peas beneath their matress before they go to sleep, too. Seriously, it is not a racing hub, but it will change the way you ride, and I will be extremely surprised if you aren't grinning hugely for at least the first week (or more).

That's what I wanted to hear. Thanks y'all. I was just a little concerned at the amount of force I needed to apply to turn it. Good to know that it's not unusual. I'm hoping this wheel will be built up the weekend and hopefully the huge grins will shortly follow.

Well, y'all were right, of course. The hub felt less stiff once it was built into a wheel and even less stiff on the bike. The bike finally hit the road this weekend and there was no noticeable stiffness at all. It rides like a dream. Thanks to all the folks whose brains I picked while getting this set up. There's still some issues to resolve, so probably the brain picking isn't over, but I put almost 50 miles on the Nuvinci Long Haul Trucker build this weekend, and it's been great.

http://farm4.static.flickr.com/3438/3377690928_f7aa8d3735.jpg (http://www.flickr.com/photos/mr_e/3377690928/)

Nice job. I am curious now though - what chain tensioner did you use and what front derailleur are you using?

Nice job. I am curious now though - what chain tensioner did you use and what front derailleur are you using?

I used the Paul Melvin Chain Tensioner http://www.paulcomp.com/melvin.html.

There's no front derailleur yet, although I chose the Melvin specifically because it's double pulley system pulls enough chain to allow for two front rings. I actually have two front rings, just no way to shift between them, so I'm currently in the small ring. It has enough range for 90% of my riding. Sometimes I wish I could go a little lower on the hills, but that is mostly laziness, and there's not much to be done about it since my gear ratio is as low as recommended. At the high end I wish I could push a little more on long flats and descents, but most of my flats and descents are not that long, so I cope just fine for now, but I will be looking for a front derailleur that can work with my set up.

Another issue I've seen with the Melvin/Nuvinci combo is that the Melvin bolt interferes with the Nuvinci shifter housing. I've seen people work around this by carving some of the shifter housing away and/or by zip tying the shifter housing into place rather than relying on the lock tabs to hold it. I managed to sidestep this by digging around the drawers in the bike co-op until I found a derailleur hanger bolt that was a little shorter than the one supplied with the Melvin. With the spacer, it doesn't seat as deeply in the derailleur hanger as the original, but it gets far enough, and, since the shifter housing very nearly touches it, it is not coming out.

Also the drive side, no-turn washer from the vertical dropout kit did not mesh with the derailleur hanger bolt. But the dropouts on the Long Haul Trucker were narrow enough that the axle only goes in one way and cannot turn. Nuvinci support agreed that as long as the axle couldn't turn, and so long as I had the non-drive side, no-turn washer in place, the drive-side washer was not essential. I just used the washer supplied for horizontal dropouts for spacing purposes and put the tab on the outside of the dropouts.

It was fiddly to set up, especially finding a bolt that worked with the Melvin but didn't interfere with the shifter, but I'm very happy with it. I've got between 70 and 100 miles on it so far, and I love how it works. I have some issues with the cables to sort out, but probably not until I replace my handlebars, and I want to figure out the front derailleur situation, but so far I'm very happy with it.

Aha! That's interesting, thanks. I am starting to see merits to a two chainring setup with a Nuvinci.

I think I had some struggles getting the No turn washer on the drive side in too, but it worked out in the end.

If you look here: http://tinyurl.com/das6m7 you will see several chain tensioners that I have made which work with the NuVinci shift box. The most recent one uses a Shimano Tourney (TX-31) rear dearilleur, which include a very short bolt for attachment to the dropout. A bit of derailleur destruction, a bit of fabrication, and Robert is your parent's sibling (as they say). I'm still waiting to see what NuVinci comes up with.

That's great. I was thinking I might have to go the DIY route before I got the Melvin to work. It looks to me like yours have the advantage of getting great chain wrap at the cog. On the LHT, the Melvin sits almost directly beneath the cog, so you get maybe a tooth or two less engagement then what you'd get with horizontal dropouts. You look like you've dealt with that issue and then some.

I'm curious to see what Nuvinci comes out with, too, especially since they show their gear range using a theoretical two chainring system but neither endorse any chain tensioner, nor do they offer their own, yet. At least I don't think they do. There's mention of one being available with a release date of sometime last spring, I think, but I haven't actually seen it.

So far, in my research, the Melvin is the only one that matches the Nuvinci's chainline, but has compatibility issues with the shifter. I was lucky enough to find a non-destructive solution, but a few people have had to do some crazy hacks, and I can't imagine Nuvinci would endorse that, so it'd be great if they offered their own solution. Knowing that the Melvin can match the chainline and pull a lot of chain, they could even go so cheap as to offer a "Nuvinci-sized" chain tensioner bolt that's compatible with the Melvin.

Rob: It's a bit hard to see in the picture, but the U-bolt on the Tourney version allows about 15mm of chainline adjustment, which is nice. We'll see what NuVinci comes up with; so far, they haven't shown anything or asked for any advice. I'm looking forward to seeing how your projest goes.

So far, in my research, the Melvin is the only one that matches the Nuvinci's chainline, but has compatibility issues with the shifter. I was lucky enough to find a non-destructive solution, but a few people have had to do some crazy hacks, and I can't imagine Nuvinci would endorse that, so it'd be great if they offered their own solution. Knowing that the Melvin can match the chainline and pull a lot of chain, they could even go so cheap as to offer a "Nuvinci-sized" chain tensioner bolt that's compatible with the Melvin.

Actually I've posted here before that the DMR STS Chain Tensioner matches the Nuvinci chainline and doesn't interfere with the shifter at all. This picture demonstrates that

http://farm4.static.flickr.com/3127/3233158511_17cd2ba22a.jpg

Actually I've posted here before that the DMR STS Chain Tensioner matches the Nuvinci chainline and doesn't interfere with the shifter at all. This picture demonstrates that


Yeah, sorry, I didn't mean that no other tensioners would work. I think there are a few options. I just meant that if you're wanting to run a double up front, I haven't found any other options.

Yeah, sorry, I didn't mean that no other tensioners would work. I think there are a few options. I just meant that if you're wanting to run a double up front, I haven't found any other options.

That's a fair point. I think with a bit of hacking it could be made work with a double up front. There is room for the pulley to move from left to right a bit, enough for a double I would think. hmm this definitely has me thinking.

That's a fair point. I think with a bit of hacking it could be made work with a double up front. There is room for the pulley to move from left to right a bit, enough for a double I would think. hmm this definitely has me thinking.

Side-to-side play may not be the most important factor. I think the issue with single-pulley tensioners is how much chain slack they can take up. You have to pull enough chain to account for the tooth difference between front rings. And with a single-pulley, the smaller the chain ring, the less chain wrap you get around the rear cog (or, if you're pushing the chain up instead of down, the closer you get to the top chain). I don't know that those issues will make it not work, but they are definitely things to keep an eye on if you try it. And they are the reasons why I went with the Melvin.

I just got mine running with the NuVinci chain tensioner. It is a single wheel tensioner without spring loading of the arm. It looks similar to the DMR STS unit so far as I can judge from the picture. The tensioning wheel has enough side float to accomodate about 5mm of chain line variation.

Can you show us this picture? I've never seen one before. How much do they cost?

Actually I've posted here before that the DMR STS Chain Tensioner matches the Nuvinci chainline and doesn't interfere with the shifter at all. This picture demonstrates that

http://farm4.static.flickr.com/3127/3233158511_17cd2ba22a.jpg

Do you have a problem with chain slap without running a spring tensioner? When I ran an xtracycle with a mtn bike with horizontal dropout w/o tensioner, I had issues with either chain slap or too taunt a chain. I wonder how it is with the big dummy.

I'm using a Rohloff tensioner with my NuVinci on the Xtra.


Can you show us this picture? I've never seen one before. How much do they cost?

http://homepage.mac.com/awcg/.Pictures/Bike/CP1.jpg
This is the On-One Doofer on my commuter.

http://fixie-king.dk/oscommerce2/catalog/images/singulator.jpg
I'd give a link to it on the On-One site but their site is now a Flash® mess.
Surly also sells a singulator.

Thanks for the images but I was referring the Nuvinci designed tensioner.

Ah. I thought you were referring to a single wheel tensioner.

Thanks for the images but I was referring the Nuvinci designed tensioner.

Lousy about taking pictures but it is shown in the NuVinci Parts Catalog downloadable from the below page on their web site. Shown on page 6 of the PDF. Cheap too as a Google search found it listed for $22.50 or so.

http://www.fallbrooktech.com/08_bike_specs.asp

And there it is. Good to know. But it seems like neither the Nuvinci nor the STS tensioner would work for a double front chainring. Since neither has a spring, they can't run with a double unless you reset the tensioner every time you switch chainrings.

Rob;

Right you are. Normally you would want a spring loaded double idler wheel tensioner for a NuVinci or IGH hub that is to be used with two or three chainrings and a front derailleur. The NuVinci shifter assembly that fits on the hub is large enough, and close enough to the rear derailleur hanger mounting hole though, so there can be clearance issues with most tensioners which mount there.

I am not sure what standard design two pulley tensioner would fit with the NuVinci hub for your application.

Well, the only part of the Melvin that's non-standard is the bolt I used to attach it. That said, there may still be some clearance issues. I've had the shifter mechanism pop off twice now, leaving me wondering why my shifting was not having any effect. The good thing is that once I realize it, it pops right back on and away I go. Still, I'm going to have to look at that and see if I can prevent it in the future.

But, just to be clear, because I don't want to mislead anyone, AFAIK, any of the tensioners mentioned in this thread will work if you want to run a single chainring up front, but if you want to run a front derailleur you will need a spring-loaded tensioner. The other tensioners being mentioned, the Nuvinci and STS, won't work with a front derailleur because they will not take up or give up slack on the fly. If they can pull enough chain, you might be able to use them with a double up front, but you would have to reset the tensioner each time you changed front rings, so there's no point in putting front derailleur on. You might as well move the chain manually when you're resetting the tension.

If you're going with a small enough difference in front chainrings, you might get away with a single-pulley, spring-tensioned chain tensioner. I don't know if that's true, but it seems like it might work. It also seems like it wouldn't be worth anyone's time because tooth difference in your front chainrings might not be large enough to merit bothering with multiple chainrings. It all depends on how many teeth worth of chain a single pulley tensioner can handle. I think the Rohloff tensioner and Surly's fit into this category. They might work fine running one front chainring, but to run a double, they'd have to be able to pull a couple of teeth worth of chain at least.

If you really want to run a double (or maybe a triple) up front with a front derailleur, you most likely need a two-pulley tensioner to handle the differences in chain lengths caused by different-sized chainrings. Val has done some awesome work making tensioners from rear derailleur parts. Alternatively there are a couple of commercial, two-pulley tensioners that I know of: the Paul Melvin and one from Shimano. Shimano's offering is made to go with their Alfine hubs and, according to its specs, does not work within the Nuvinci's chain line. I don't know if they can be modified to work or not, but unless you already have one to play it, it's probably not a safe way to go.

While I have not yet tried to install a derailleur on my bike, I believe front derailleurs have been installed using Val's creations and using the Melvin. If other Nuvinci/front derailleur combinations have been successful, I haven't found mention of them.

Sorry for the recap, but it was getting confusing. Some of my posts seemed to be talking about tensioners in general, when I really meant "tensioners used with a front derailleur." And some of the other posts read like they might be talking about "tensioners used with a front derailleur," when I think they really meant tensioners in general.

Just to confirm; yes, indeed, one of the intended purposes of the tensioners I have made is to allow the use of a front derailleur with a relatively wide range between chainrings. On my bike, I have a 46/34 combination, and on the Bike Hugger's Bettie ( http://tinyurl.com/9jfmcj ) I believe we used 36/24. Makes for nice wide range ratios.

Another issue I've seen with the Melvin/Nuvinci combo is that the Melvin bolt interferes with the Nuvinci shifter housing. I've seen people work around this by carving some of the shifter housing away and/or by zip tying the shifter housing into place rather than relying on the lock tabs to hold it. I managed to sidestep this by digging around the drawers in the bike co-op until I found a derailleur hanger bolt that was a little shorter than the one supplied with the Melvin. With the spacer, it doesn't seat as deeply in the derailleur hanger as the original, but it gets far enough, and, since the shifter housing very nearly touches it, it is not coming out.
...
It was fiddly to set up, especially finding a bolt that worked with the Melvin but didn't interfere with the shifter...

I just wanted to add an update in case anyone tries the same thing. I have had the shifter mechanism pop off the axle a few times since I started using this set up. I determined that it was, in part, because my chain tensioner bolt was still interfering with the shifter seating properly even though the bolt was shorter than the one that came with the Melvin. Last night I carved away a little of the shifter mechanism's housing to accommodate the bolt, and hopefully that will do the trick, although I'm not sure that I took away quite enough of the casing, so we'll see. The shifter mechanism is housed in fairly thick plastic, so I was able to remove a small chunk out without actually breaking through the housing, which is good, but I think if I have to take any more away, it will break through. Then I'll have to figure out if I want to leave everything open to the elements or find some way to close it up. I'm thinking perhaps a piece of inner tube (or a patch) and some rubber cement might seal it up enough if I break through.