Stupid noob question (yes, another..)

[FarHorizon]

Does anyone make a 'bent with the Shimano Nexus 8 hub? It would seem that such a drivetrain would be LOTS simpler and lighter than a gear/derailleur system.

[gattm99]

Nope heavier and more complicated,

[2manybikes]

Nope heavier and more complicated,

Don't forget less efficent.

[ppc]

Does anyone make a 'bent with the Shimano Nexus 8 hub? It would seem that such a drivetrain would be LOTS simpler and lighter than a gear/derailleur system.

FarHorizon, whether the bike is a bent or not, geared hubs have pros/cons. Here they are:

Pros:
- Low maintenance
- Weather-proof
- No derailleur to bash against sidewalks or stones (for DH or XC)
- Ability to shift without moving
- Simpler chainline that's always straight and easy to enclose (i.e. longer chain life)
- On some bents (ex. BikeE), ability to replace chain tubes with a pair of chainguards on each side of the single chainwheel to guide the chain (impossible with a front derailleur)

Cons:

- Heavier than derailleurs
- Costlier than derailleurs (but one may argue that the cost can be recouped by the lower maintenance costs if you ride a lot)
- Not as efficient as a clean, well maintained chain drive, although to be honest, since no chain drive is always clean all the time in real life, it's not really an issue and this point can be safely ignored unless you're some kind of purist racer
- Impossible to maintain on the road or find readily available parts to fix it at a LBS during a tour

As far as bents are concerned, unless you choose the very expensive 14-gear Rohloff with its wide range, I don't think geared hubs are very good, because on a bent you can't get off the saddle and compensate for the lack of range most of these hubs offer compared to a cassette. Unless you live in a flat country like Holland of course.

[FarHorizon]

...Unless you live in a flat country like Holland of course.

Thanks for the synopsis! For me, the pros outweigh the cons. I'd like to try one. I live in a state similar to Holland in more ways than one, so the range (once set with the proper size chainwheel) should be fine.

Now for the fun question - who makes an easy-to-assemble 'bent frame that I can adapt to the hub I want?

[ppc]

Thanks for the synopsis! For me, the pros outweigh the cons. I'd like to try one. I live in a state similar to Holland in more ways than one, so the range (once set with the proper size chainwheel) should be fine. Now for the fun question - who makes an easy-to-assemble 'bent frame that I can adapt to the hub I want?

Most, if not all geared hubs can be fitted with a torque arm that you tie to the chainstay with a collar. It's not as slick-looking as a hub installed in a specially-designed dropout but it works just as well. Simply ask for the torque arm with the hub when you order it. The width of the hub is standard 135mm with a regular QR skewer. The hub flanges usually have a larger diameter than a regular hub's, so you'll need shorter spokes to build the wheel. For common wheelsizes, the hub manufacturer can usually supply a bag of spokes, otherwise you'll have to crack out the spoke length calculator program and get custom spokes made (or make them yourself). Of course, if you have an extra $30 to waste, just get a LBS to order the hub, the rim, and let him build the wheel (wheelbuilding is one of the rare things worth paying a LBS to do, assuming he knows how to do it properly: if you don't know how to build a wheel, it'll save you a headache and painful fingers after 2 hours of truing).

Anyway, the idea is that, unless you specifically want to build your very own custom bent with a particular hub, you can use any bike, build a wheel with the hub of your choice, install the wheel as a drop-in replacement, attach the torque arm to the chainstay, install the shifter onto the handlebar, route the shifter cable(s), adjust the cable run, and off you go.

Just a note on the shifter: most hubs come with their own special shifters. Most of these special shifters are of the twist-grip type, and may not be ideal with a USS handlebar. Many USS bents use Dura-ace bar-end shifters or equivalents, for bar/hip clearance reasons. So beware if you want to install a geared hub on such a bike: you should try to simulate twisting the shifter while in your seat, and see if your hand doesn't bang on your leg, before ordering anything.

Have fun with your project, let us know how it goes :-)

[FarHorizon]

...Have fun with your project, let us know how it goes :-)

Thanks again, ppc - great info. I've always wanted to try wheelbuilding, so I guess I'll buy a hub and get ready. Should I e-Bay for a used 'bent or try other sources?

[ppc]

Thanks again, ppc - great info. I've always wanted to try wheelbuilding, so I guess I'll buy a hub and get ready. Should I e-Bay for a used 'bent or try other sources?

Unless you already know what specific bent you're after, I suggest you start by determining what bike you like. It's not easy as it sounds, all bents are different, the recumbent family is much more diverse than the world of uprights, and so you need to find a bent that works for you. Not all will suit you, and you shouldn't get any old bike that looks nice because chances are you won't like it and you'll regret the purchase.

Check this post here to get an idea of how to choose your bike: http://www.bikeforums.net/showpost.php?p=1543661&postcount=5. The most important thing is to try the bike before buying. Once you've determined what you want, eBay, classifieds, or even buying new are all fine. Just remember this: good bikes tend to stay with their owners, so if you see a lot of bents of the same make/model, beware: either the particular model isn't good, or the manufacturer is going/gone out of business and people are dumping their bikes.

[FarHorizon]

Got it. Based on your info, I think I'm looking at a LWB, under-seat steering, rear suspension model. Suggestions as to models? (or where to go online to see what's available?)

[ppc]

Got it. Based on your info, I think I'm looking at a LWB, under-seat steering, rear suspension model. Suggestions as to models? (or where to go online to see what's available?)

Sorry, I can't help you there, I don't have much experience with LWB bikes. I suggest you check the buyer's guide on BROL (http://www.bentrideronline.com/Buyer's%20Guide/2002%20Guide%20Welcome.htm), read this here forum as well as BROL, and google a lot, to root out reviews, testimonies and horror stories from people who have already bought the bike(s) you might be interested in. Ask on the forum as well, I'm sure members will be happy to share their experiences.

[Brian]

A bent with only eight gears sounds like a compromise. I suggest riding a recumbent first, but only using one chainring, to see what it's like with limited gearing.

[ppc]

A bent with only eight gears sounds like a compromise. I suggest riding a recumbent first, but only using one chainring, to see what it's like with limited gearing.

The comparison isn't very apt: it's more a matter of range than number of gears: the Nexus-8's lowest ratio is 0.527, and the highest is 1.615, making a range of 306%. This would be roughly equivalent to a bike with one chainwheel and a 34-11 cassette, which really isn't that bad considering it's a geared hub. I can almost picture myself riding most of my favorite routes on my bent with a Nexus-8 and a 38T chainwheel, if I developed crazy leg muscles for tough hills and coasted on the way down. A sure way to kill my knees going uphill, and less than ideal for downhill speed, but usable.

But yes I totally agree with you, it is a compromise. Essentially what FarHorizon will get is a heavier, more expensive bike with a poorer range and wider gaps between gears than a regular derailleur-equipped bike. At least with derailleurs, you can trade-off range for small gaps in gears and vice-versa, and fine-tune gears to your liking. I reckon geared hubs are a bad idea on anything but all-weather city bikes and work bikes, with the exception of the DualDrive which is an okay compromise, and the fantastic Rohloff Speedhub.

But hey, that's what FarHorizon wants and he says the pros of a Nexus-8 outweigh the cons for him, so... :-)

[FarHorizon]

...what FarHorizon will get is a heavier, more expensive bike with a poorer range and wider gaps between gears than a regular derailleur-equipped bike...

Yes, but --- What I'll also get is a simplified chain line, weather-resistant drive gears that won't have to be cleaned after every ride, more than enough range for flat-land riding (all I'll ever do), no hassles with derailleur adjustments (or index stops, or cable slop, or sticking pivots, or chain suck, or missed shifts, or being stuck at a stop in too high a gear, or having the chain fall off the rings, or worrying about the derailleur being out of adjustment and swinging into the spokes, or...).

If this were a "hill country" or "mountains" bike, the traditional options would make sense. For my use, durability, simplicity, and low maintenance top all other considerations. Thanks for the feedback, though - I appreciate your opinions and will give them additional consideration before I begin spending. :)

[ppc]

Yes, but --- What I'll also get is a simplified chain line

Yes


weather-resistant drive gears that won't have to be cleaned after every ride

Yes, although if you don't clean the chain regularly, you won't get much mileage out of it and you'll ruin the sprocket, which is a special 3-spline sprocket for geared hubs I might add (i.e. more $$$ to replace, and you'll have to order it, as it probably won't be readily available at your LBS)


more than enough range for flat-land riding (all I'll ever do)

Are you sure? Many people think they like this or that type of riding, and their tastes evolve and they get into other things. It's nice not to limit yourself from the start. Unless you are really REALLY sure you'll never want to tackle big hills someday :-)


no hassles with derailleur adjustments (or index stops, or cable slop, or sticking pivots or chain suck, or missed shifts, or being stuck at a stop in too high a gear, or having the chain fall off the rings, or worrying about the derailleur being out of adjustment and swinging into the spokes, or...).

I have a feeling that some incompetent LBS adjusted one of your bikes like a pig once, and you have a bad opinion of derailleurs ever since :-)

A well-installed and well-adjusted derailleur will never do any of the things you mention. That includes routing the cables correctly and using teflon coated cables and sleeves (that ensures correct indexing and never a shift missed), using a decent derailleur with a return spring worth its salt (no cable slop at the bottom of the cassette), settings the stop screws correctly (no derailleur swinging into the spokes or chain falling off the ring), setting the derailleur's distance to the sprocket (snappy shifting) and doing a little maintenance regularly (never have to worry about anything going out of adjustment). Once I set derailleurs, they're good for years and I never touch them again, unless I crash so bad it whacks the rear derailleur, but that never happened to me on a bent, only on a DH bike. It takes no more than 30 minutes to set derailleurs correctly, and you can almost forget them afterward, save for a little initial cable stretch corrected by adding a couple of stops in the shifter once.

Also, be aware that geared hubs can be finicky to adjust too: in the case of the Nexus-8 you're looking at, it shifts across 8 gears with little cable pull, so setting the indexing can be dicey. It's trouble-free when it's set up right, but it's no more or less work than adjusting a derailleur.

I'll grant you that you can get stuck in high gear if you have to crash-stop, but it just takes lifting the rear wheel and giving a couple of turns of the pedals to get going again. The rest of the time, you just have to make "preventive downshifting" second nature.

As for chainsuck, it has nothing to do with the front derailleur: this happens when your chain is so stretched its pitch doesn't match that of the chainwheel anymore. This is a problem due to you failing to change your chain in time: when chainsuck starts to happen (usually on the granny ring, especially when it's dirty), you can bet you've ruined your cassette and small rings with your stretched chain. The only reason chainsuck doesn't happen with a direct chainline is because the chain has no slack, so bad links are effectively yanked out of the teeth forcibly by the return run, but you're still trashing your chainwheel and cog, just silently.


If this were a "hill country" or "mountains" bike, the traditional options would make sense. For my use, durability, simplicity, and low maintenance top all other considerations. Thanks for the feedback, though - I appreciate your opinions and will give them additional consideration before I begin spending. :)

Derailleurs are nice on the flat too: they give you small gear steps and allow you to always find the right rythm for your legs. If you live in a place where it really rains a lot, I might understand why you want a geared hub so bad, but otherwise I think you're missing a great opportunity to learn how to set derailleurs right and experience how snappy and trouble-free they can be :-)

This said, whatever makes your clock tick. I personally like derailleurs, because they're cheap and flexible, but I freely admit I want to get me a Rohloff, for no other reason than having that baby on my bike and enjoying a great piece of German engineering. So if you want a Nexus-8, go for it. If you end up getting bored with it, you can always sell it and go back to derailleurs.

[FarHorizon]

Thanks again for the thoughtful feedback, ppc! You're basically correct about well-adjusted derailleurs. I've currently got two that work fine on different bikes. I've just got a jones for something different... The riding I do (and within 150 miles in any direction of my home) is flat as a pancake. If I wanted to take a bike with me somewhere else to go riding, it probably wouldn't be the 'bent. My current bikes have 16 and 20 gears available, and I use all of three or four on each!

Another cause of chain suck (just as valid as the wear you mentioned) is that my 10-speed chain doesn't like wider chain rings. If I use common chain rings on that bike (rings that were not meant for 10-speeds), and don't clean the drive train to hospital standards, I get chain suck. Just an aside...

I'm unfamiliar with the Rolhoff. I'll Google it & see. I'm willing to spend the $$ if the unit is worth the money. Thanks again for your patient responses! They're much appreciated!

[Brian]

I don't see the simplified chain line part. You'll still need pulleys and tensioners, along with tubing to run portions of the chain through. Only now you'll have to deal with keeping proper tension on what, a 10 foot long chain? And I don't know anyone that cleans and lubes their chain after every ride. But I mostly mountain bike, so maybe it's different for those on the road. But your chain will still be exposed with a Nexus hub.

Have you ridden a recumbent? Because you won't be using the same muscles you use on your other bikes. You may be in for quite a surprise when you find out that your widely-spaced wide range of gears is not enough.

But keep us updated. At least this project will have had some thought put into it.

[ppc]

I don't see the simplified chain line part

1 ring + 1 sprocket + 1 wide hefty chain vs. 2 or 3 rings + 7, 8, 9 or 10 sprockets + 1 narrow chain + 2 derailleurs? :-)

On a bent, the chain is so long that crossing is almost never an issue. But there are other advantages to having a single sprocket and a single ring, such as the ability to run a fixed tensioner (i.e. without spring, leaving a bit of slack on the return run of the chain, ensuring the chain can never derail), and the ability to hack together a total chain enclosure with nylon tubing, a full chaincase sawed in half and clever glueing and bolting to the bike. I've seen it once on a friend's bent and it's brilliant: he oils his chain twice a year, rain or shine, and it lasts forever. I must say, just for not having to deal with dirty chains, geared hubs are pretty damn tempting...

[Brian]

I don't think you have much experience with very long chains and chain tensioners. With your heavier chain and enclosure, you'll need a lot of tension to keep it from sagging and causing friction within the enclosure. But you seem dead set on avoiding 5 or 10 minutes of maintenance once a month, in order to avoid replacing a $20 part. Why not just go shaft drive, and eliminate the chain altogether?

[ppc]

I don't think you have much experience with very long chains and chain tensioners. With your heavier chain and enclosure, you'll need a lot of tension to keep it from sagging and causing friction within the enclosure

As I stated above, the enclosure in question consists of 2 halves of a normal chaincase attached to the bike, one at the chainwheel, one at the sprocket, nylon chain tubes in between, and glue/duct tape to close off all the remaining holes.

There are no friction issues between a chain and nylon tubes as long as the top tube isn't set to force the section of chain under tension out of its route. That's what nylon tubes are for. On the return run, the chain has no tension and a nylon tube can guide it just fine. My Optima Condor has a chain tube to make the chain arc above the front fork, in lieu of a pulley, and the system works just fine without any friction, abrasion or noise.


But you seem dead set on avoiding 5 or 10 minutes of maintenance once a month, in order to avoid replacing a $20 part. Why not just go shaft drive, and eliminate the chain altogether?

I'm not dead-set on avoiding maintenance on the chain. If I was, I wouldn't be trying to convince FarHorizon that derailleurs work better for cheaper :-) I clean my chain regularly like a good boy, but that doesn't prevent me from being envious of my friend who never cleans his and oils it once in a blue moon...

[MapleTrail]

I was getting ready to purchase a trike (Hase) with the Nexus 8 Hub when I stumbled upon this very informative thread. I am 60+ and have had very poor luck maintaining derailleurs, despite ppc's positive attitude. He must do this alot!

My main interest in bikes is RIDING them rather than optimizing them. Mostly trails and shopping trips with mild hills, where fun & exercise are the main incentives. But I would like to take on more challenging hills in the future. I'm not interested in racing but want to receive the bike ready to go from the dealer, who is not nearby. Some comments above make me wonder if 8 gears are enough, even with the wider spacing. On my present CycleGenius 3.0 (20" drivewheel, 21 to 94 gear inches maybe), I find the gears repetitious or overlapping, and often find myself in the highest gear on the level.

The 14 speed Rohloff will cost CONSIDERABLY more on this bike so I'm wondering if it is really worth it? I considered the Schumlp Speed Drive at the front, but this would add complexity and some overlapping ratios again. One top shelf dealer advised that friction would be a problem with this combination? So perhaps this money could get more return applied to the Rohloff.

One thing I didn't see mentioned was the appealing SIMPLICITY of gear selection with these Hub Drives - no complicated deraileur combinations to fiddle with!

Could ppc or others comment on the pros & cons of these two hubs for my riding style? BTW, I have no aversion to pushing my bike up a hill because this is also good exercise and sometimes just as fast. But how would one push/steer/pull one of these UnderSeatSteering delta trikes (Hase Kettwiesel/Lepus, etc) up a steep hill? I posed this question on another forum but no answers yet.

[Brian]

At your age, if you've not had luck maintaining derailleurs, don't worry about them. Spoil yourself and get the Rohloff. You didn't spend all your life working to start skimping now. :D

[ppc]

I am 60+ and have had very poor luck maintaining derailleurs, despite ppc's positive attitude. He must do this alot!

Not really, I just follow the procedure step by step, so I never have to do it twice. If you understand how a derailleur works (which really isn't that hard) then it becomes obvious how it has to be set up. As for being 60, that's no excuse :)


I'm not interested in racing but want to receive the bike ready to go from the dealer, who is not nearby.

I know you don't want to tinker, but if you really want to enjoy your bike, you should learn how to do the basics, otherwise you'll end up having to wait for the LBS to do it and wishing you could go ride instead, when it could be nothing more than a 2 minute adjustment of something or other. Honestly it's not that hard, there are great resources out there on the net to get you started without sweat.


Some comments above make me wonder if 8 gears are enough, even with the wider spacing.

I tend to prefer big range over finer gear spacing, but that's just me. Many riders prefer to sacrifice range and have more options to find their ideal pedalling rythm all the time.


On my present CycleGenius 3.0 (20" drivewheel, 21 to 94 gear inches maybe), I find the gears repetitious or overlapping, and often find myself in the highest gear on the level.

Then your bike isn't geared right for you. It takes some time to find your preferred chainrings and cassette if you've never done it. No two bikes are alike, they're matched to their owners. It sounds like yours isn't.


The 14 speed Rohloff will cost CONSIDERABLY more on this bike so I'm wondering if it is really worth it?

If you really value peace of mind, and you ride many miles, the speedhub is a sound investment. It's reported to last many tens of thousands of miles without needing anything more than an oil change twice a year. But you have to clock these miles for the savings over derailleurs/cassettes/rings to become apparent.


I considered the Schumlp Speed Drive at the front, but this would add complexity and some overlapping ratios again. One top shelf dealer advised that friction would be a problem with this combination? So perhaps this money could get more return applied to the Rohloff.

I think speed drives and mountain drives are very expensive for what they provide. What's more, I don't much care for the torque they introduce in the bottom bracket shell. If you're looking for many gears in a gear hub, I suspect you're indeed better off with the Rohloff.


One thing I didn't see mentioned was the appealing SIMPLICITY of gear selection with these Hub Drives - no complicated deraileur combinations to fiddle with!

Well, I reckon riding with derailleurs is like driving with a stick shift: after a while, you don't think about your shifting, about what your foot does with the clutch and when, and how your hand shifts... It just becomes automatic. It's the same with derailleurs: there's a time where you just don't think about any of this, you just ride. Gear hubs are great for ease of maintenance, and also for shifting at rest (great to restart after a crash-stop) but otherwise, it's a solution to a problem that takes care of itself in 2 or 3 weeks anyway.


Could ppc or others comment on the pros & cons of these two hubs for my riding style?

Only you knows your riding style :) First, I suggest you go to a LBS to help you re-gear your bike right for you, and have him explain to you how derailleurs work and how to set them. Give this solution a try for several weeks, and see if riding your bike becomes more pleasurable. If you feel there's improvement, you may end up changing your rings or cassette a second time, to fine-tune your gearing, but at any rate it'll be cheaper than getting a speedhub, and if you do end up getting a geared hub eventually, you'll have a much clearer idea of your gearing needs to help you choose. As for mixing two hub gears, I say forget it: it'll be heavy and not a very elegant solution.

[Mars]

FarHorizon,
It seems to me that you are really into the idea of the multigeared hub. If that is what you are passionate about, then I say go for it. ppc and others have pointed out some possible drawbacks, so now you are in a position to make an informed decision. If it still tickles your fancy, build your wheel. Sounds like a fun project to me. I ride my bent in Vermont and upstate New York. It is pretty rare for me to need to leave the middle chainring. I do, of course, but I don't NEED to. I could easily cope with the onw chainring. Also, remember that for many years, people rode massively heavy steel bikes with a singel gear or, for the deluxe models, a 3 speed hub. Many people here still rie bikes like that....

[FarHorizon]

New game plan - Semi-low-racer with Shimano Nexus 8 and FRONT WHEEL DRIVE. Minimum chain, probably a moving BB with the front wheel. Simple, elegant, efficient. Happy New Year!

[bentcruiser]

Does anyone make a 'bent with the Shimano Nexus 8 hub? It would seem that such a drivetrain would be LOTS simpler and lighter than a gear/derailleur system.

Most bents with geared hubs use SRAM 3x7, 3x8 or 3x9 internally geared hubs. It is because the theory goes that the actuation ratio on the SRAM stuff has a better pull for longer reaching cables like on recumbents.

Other systems used is Schlumpf Innovations' mountain or speed drives (http://www.schlumpf.ch/) or even Rohloff Hubs (http://www.rohloffusa.com/frame.htm).

Do not discard the ideas of these hubs. They can be extremely useful. I had one on a recumbent that my wife now rides. They may have a slight drag but they are very reliable. If I had to choose, however, I would like to try a Schlumpf Drive. Hostel Shoppe sells them (http://www.hostelshoppe.com/cgi-bin/readitem.pl?Accessory=1026422445).