bragi

I've been toying with the idea of putting an IGH on my touring bike for the winter. I've always had derailleurs on my bikes for my entire life, but I've noticed that bad weather is hell on the drivetrains, and I've been reading that IGHs are better in rough climates. I'm also getting a little tired of dealing with gears that are always a bit touchy even in the best of conditions, and that require almost constant maintenance. I dream of gears that work smoothly and simply, never skipping a gear or making annoying noises for months at a time, with little or no maintenance. I do have a few concerns, though:

1. How much weight do IGHs add? A little extra weight is okay, since my bike's already a tank, but a lot might not be worth it.

2. There are a lot fewer gears; how does that work out in very hilly terrain? I test rode a bike with IGHs a few months ago, and it seemed to climb well enough, but I wasn't trying to get up the hill at speed, either.

3. I have vertical dropouts, so I apparently would need a chain tensioner. How does that affect efficiency?

4. A big concern is expense. Is a Shimano Nexus 8 okay? Are Rohloff and SRAM/Sachs so much better that they're worth the extra cost?

5. My last concern is demographic: Is there a good reason that derailleurs are installed on about 98% of all bikes? What's the advantage of derailleurs over IGHs, if you're not racing road bikes?

I'd love to hear what people have to say about this.

ax0n

1) Negligible or maybe LIGHTER if you consider the fact that you're ditching a front and rear derailleur as well as potentially two chainrings up front.

2) Things like NuVinci and Rohloff have a very wide gear range with some models being comparable to a standard road bike if not a touring bike. Nexus hubs don't have the gear range you're used to, but that doesn't make it unusable by any means. You may have to work a little harder up the hills or you might have to sacrifice some top speed to get the low end of the ratio where you want it.

3) Chain tensioners won't affect efficiency that much. You're already losing some just through the hub. If you're not running a fixed-wheel setup, a chain tensioner is going to be the least of your drivetrain efficiency concerns.

4) Nexus 7 and 8 are fairly beefy. I know guys that've logged tens of thousands of miles on them. Again, the more expensive ones often have much wider ranges and many more gears (or in the case of NuVinci, a constantly variable setup)

5) Cost and maintenance. Derailleurs are easier to work on and much more abundant. They cost less to manufacture and they've suited their purpose well over many decades. The pro's of IGH are elongated maintenance intervals, less problems with shifting and better resistance to weather, dust, etc.

ax0n

It's worth mentioning that I'm actually about to pull the trigger on converting my winter beater over to a Nexus 3. It's an old mountain bike that's going to need new front and rear derailers, new rear wheel, chainring and cassette anyways. The build-out will probably cost less this way, and the 3 speed will get me where I need to go this winter.

breadgeek

I'll hit most of your points, but for #5, the main reasons IMO that IGHs are not popular are the economies of scale and familiarity that derailleurs have, more than anything else. They should be more popular than their technical qualities would have them otherwise be.

I have 2 IGH bikes, one a nexus 3 coaster and the other a rohloff. They both work well, but they are far from in the same camp -- duh.

Neither has a chain tensioner of the aftermarket variety, the nexus being in a cheap frame with horizontal dropouts requiring a frustrating sequence to get the chain tension right, the wheel centered properly, and then tighten the nuts tight enough so it won't de-tension when I brake without stripping them (stripped 2x in a year, but the tensioning won't stay otherwise). Oh, and then there's this rear portion of the chainguard that I often forget to re-mount and I have to start all over again.

I blame the frame and myself for the hassles, not the IGH. I have been trying to upgrade that to a nexus red band 8 or even the alfine 8, largely for the range, largely for my knees.

The rohloff is heavy, perhaps detectably inefficient, but worth every penny. Its range is great, will last a *really* long time and is robust enough for MTB usage, unlike most of the other IGHs. Chain tensioning on that bike is achieved by the special horizontal-sliding, but otherwise vertical dropouts for its QR. No comparison to my cheap frame having the nexus: way easier, way more expensive.

Efficiency I lament only in one gear in the rohloff (7th), which feels like I am pedaling through a puddle of molasses. No deraiileur hanger to bend, though. It is a process of give & take. Were I to have a frame built for an IGH bike or buy a new frame, I'd get something that uses sliding or cantilevered dropouts that allow for chain tensioning instead of eccentric BBs or aftermarket tensioners.

ItsJustMe

You probably don't need to actually BUY a chain tensioner. Just adjust the stops on your derailler so that it's stuck right over the top of the cog on the IGH and run the chain through that.

If you have a real nice RD, you might want to go buy a cheapo $20 model to use as a tensioner though, rather than run your nice one all winter in the crud.

closetbiker

I'd say in the long run, cost and maintenance runs in favor of the IGH.

Winter weather destroys drive trains and a single IGH will out last multiple chains, cassettes, and derailuers that will have to be replaced from all the road grit that grinds them down. Sheldon Browns page on Nexus hubs said,

"The Nexus hubs are packed with a very special grease. They are quite well sealed, and should only require service at very rare intervals. The great majority of mechanical problems that I've encountered or heard of have been the result of "preventive maintenance" including re-lubrication with incorrect grease."

I'm looking forward to not having to clean my drive train after every bad weather ride this winter with my new Nexus hub.

If you have a coaster brake attached you'll even save on brake pads and wear on the rim (I've broken through rims from the wear of multiple pads squeezing the rim)

Torrilin

If I rebuilt my Breezer with a derailler *and* took off all the goodies (bell, rack, lights, generator etc), I could probably get it down to 25 lbs. It lists at 32lbs. Looking at relative weights, I'd guess the goodies are the majority of the weight.

On a rebuild, I wouldn't expect things to be as nice and tidy. My bike was clearly specced by someone who was watching weight, so a lot of bits just aren't all that heavy... just there's a lot of little shiny objects, and it adds up. If your starting bike is already pretty heavy, it might be a good idea to check if there are some spots where being a weight weenie would be beneficial.

I'm riding a bike with a Shimano 7 hub. That's about 270% range, and the low gear is around 30". For me, this should be fine for up to 5% grades, and beyond that I'd need to improve the engine. (yeah, I'm a pretty lousy climber) The SRAM 7 and Shimano 8 hubs have about a 300% range, and the SRAM 9 is even higher range. So on those hubs, if the low gear is something sensible, hills should not be a problem.

If you're looking at a 9 or 10 speed derailler setup, you probably have more than 300% range. IIRC those can be set up for up to 450% range. So on one of those, proper gear selection *should* mean you can climb steeper hills. If you know you have a 15% grade to climb... I'd count that as a clue.

(fwiw, because of the riding conditions I'm usually dealing with, on a derailler bike I end up stuck with *less* range than on an IGH... lots of stop and go traffic means I have to be careful about upshifting. so I tend to spend way too much riding time in a very low gear. if this sounds familiar, IGH *might* be a better choice for you than it looks like on paper.)

No idea. I find that "efficiency" is a very slippery thing to calculate, so I tend to focus on things I can get reliable and accurate measurements for. Figuring out a hill's grade is doable, and the gears and gear inches I'm using is doable. And distance is very measurable.

I made my decision by working out what gears I used most often on my derailler bike. I knew what the lowest low I used was, and what my usual cruising gear was. I even broke it down by common trips and common cargo weights, since I had a clear idea of *exactly* what gears I usually use to go over to a friend's house or to get to the library. For the longest trip I usually make, a 3 speed doesn't *quite* have the low range I use. Some of the older 5 speed hub designs would have been enough tho. If I exclude the longest common trip, a 3 speed is enough gears. That made things very easy for me.

The 7 speed hub I have has a low gear that matches with the lowest low that I'd use for banging my head against the one 5% grade hill I know of in town. So it is more than enough gears for anything I'd expect to see. The SRAM 7 speed hub is a little nicer to ride (tested both), and is supposed to be rather sturdier than the Shimano... and it's cheaper than the Shimano hub with the same range. Eventually, I'd like to move to it.

If you keep notes and can get a good idea of how you use your gears on various routes, you'll probably find you have some decided habits. Then you can spend some quality time with Sheldon's calculator, and get a real feel for the minimum and maximum you'd need. The answer may come out that IGH won't suit you... and in that case for the love of little fishes don't buy one!

If most of my riding were outside of the city, I'd probably like deraillers a lot better. If I'm riding on WI's state trail system, there are few stops and you can get up quite a head of speed. And county highways offer similar advantages... once I've done the 3-10 miles of riding to get outside of town.

The other main advantage is a derailler is pretty easy to fix. If it's a little off, or someone knocks your chain off, no trouble. Changing a tire on an IGH bike can be a giant pain. On a derailler bike a flat isn't a big deal. So if you're the sort of person who is always having mechanicals no matter what you do... IGH is probably not for you. (I'm the sort of person who likes fixing things, and fusses endlessly over her pretty mechanical things... so my stuff just doesn't break much... and an IGH bike isn't much inclined to have trouble in the first place)

deez

Slightly off-topic question regarding IGH's

can I use a regular non-indexed friction shifter on a 3 speed hub rather than the indexed twist grip that comes with the Shimano Nexus 3 speeds?

ax0n

Unofficially, my answer is "yes" however it's a really, really bad idea. They like to be perfectly adjusted and if you're the slightest bit off, they get finicky and slip or skip. I'd imagine it's also really hard on the internals and it's probably damaging something. You'd be best served to use the OEM twist shift. If you want to be a geek and try to rig up a 3-speed front derailleur trigger shifter or something, the cable pull lengths are almost assuredly different, but you could probably fix it by fabricating a pulley system of some sort. That's the kind of strange thing I would do, actually...

ItsJustMe

Yeah, I think if you were a bit off on an IGH, it might be putting all the stress on just the back half of a gearset or something. You wouldn't be able to notice it (no grinding, or whatever) but you'd be wearing the thing out pretty fast.

I read that some IGHs can be used with indexed barcons (and maybe other shifters) if you install the right travel agent.

mechBgon

Part of it is simply status quo. But since you ask, here are some advantages of derailleurs:

1) very flexible gearing options. I have a full "jump chart" in Excel showing various cassettes I might want to run, and I have so many options, it was hard to choose one! At the moment, the road commuter runs a fairly tight-ratio cassette with small jumps from gear to gear, because my road commuting route has lots of slight changes in grade and wind direction. I could also slap a wide-range cassette on there, or a triple, or both, or go the other way with a closer-ratio cassette if I like, and still could do a triple, compact double, standard double... I have options.

2) I tend to be an aggressive power-shifter during acceleration from a stop (hence the avatar). Derailleur systems tolerate that fairly well.

3) Derailleur systems are simpler when it's time to change a rear flat.

4) Derailleur systems are lighter overall, at least at the level of equipment I use. Not that this should be a major factor on a bike that could be hauling 20 pounds of baggage, locks, etc, but whatever.

5) I have lots of off-the-shelf shifter options.

For me, the main benefit to IGH would be when my cassette starts to pack up with slush or ice in serious winter riding. That's not a very frequent condition for me, actually, even when riding in snow.

closetbiker

I found that last winter.

It doesn't snow much in Vancouver, but when it does, it's a nightmare for traffic. Luckily for me, I live right next to a MUP trail that leads almost directly to my work so when it snowed last year, I rode the bike into work on this trail but found the longer I was riding in the snow, the more problems I was having with the drive train. The snow built up in between the cogs, compacting into ice, and eventually the chain was slipping because the ice was built up so high, the the chain couldn't grip the cogs anymore.

mosquito

Get it. I had it for a year. Only problem was the nuts supplied didn't prevent the axle from sliding, i corrected this with a surly tuggnut. It's tricky, the anti rotation washers were put inside. Aside from that problem, it is perfect for city riding.

JayTee705

My primary commuter is a single speed, but if I move farther out or into the hills, I'm likely going to want gears.

IHGs seem very commuter friendly, except for the oft-mentioned caveat about the difficulty of changing flats.

I'm having trouble envisioning the problem and even more trouble understanding why the manufacturers don't address it, since commuters seem like a natural target-audience for IHGs.

Can anyone explain the former, if not the latter? When I get time, I'm going to head to an LBS with an abundance of IHG bikes to see things in person...

markhr

1. small weight penalty, some people will whine because it's all concentrated on the rear hub but, at least for the Rohloff, it's not that big an overall change.
2. due to gear overlap, especially with the Rohloff and Nuvinci, you actually gain useable gears, i.e., in a 2byXX or 3byXX derailleur setups there are multiple redundant gears that overlap.
3. careful gear selection can stop this, i.e., search the FG/SS forum for "magic gear" or "half link"
4. Rohloff have a reputation for lasting a lifetime, Nuvinci seem to be heading that direction, why not spend the extra cash so you don't have to keep forking out?
5. because of economies of scale and the good old "everyone else is so why can't we". Fortunately, this seems to be changing as there are more and more IGH bikes on the market, even Rohloff and Nuvinci ones.

ax0n

On point 4: Rohloff is relatively new. NuVinci is REALLY new. I know people who are using their grandfathers' Sturmey Archers and almost all IGH are pretty resilient if you keep them adjusted properly. I don't think you have to shell out the big bucks to get a reliable setup.

rhm

The main problem with IGH's is, in my opinion, that one gets to like them so much. First I had a Nexus-4 on my commuter bike... which I replaced with a folding bike with a Sturmey Archer 8... then I put a NuVinci on my Xtracycle... then I put a Nexus 8 on my touring bike... and now I want to put IGH's on every bike I, or any member of my family, owns. It gets expensive.

And once you forget how to shift a derailleur, you don't want to re-learn.

Rob_E

That's my concern, too. I want to convert my commuter to an IGH, and hopefully I will before long, but I do have the concern that suddenly my rear wheel becomes more valuable than the rest of my bike, especially if I were to go with Roloff (unlikely with my budget) or a NuVinci, so I'd have to re-examine my locking strategy. I usually catch the frame and front wheel in the U-bolt and run a cable to the back tire, but that may have to change if my back tire becomes the most expensive part to replace. I'm also thinking about getting some Dutch-style wheel locks.

mparker326

Regarding fixing flats on IGH's - if the hole is the typical tiny pin hole, I don't even take off my wheel. I just take off one side of the tire from the rim, pull out the tube & patch the hole.

Even if you have to take off the back wheel, on my SA, I just unhook the spindle (it has a lock nut marking the spot to tighten it back to), unscrew the bolts & take off the wheel. No big deal, all it means is carrying a small adjustable wrench in my bag.

Honestly, I have a harder time changing a flat tire on my mountain bike with quick release than I do with my IGH.

fender1

I ran a Red Band Nexus 8 hub on a converted road bike for 100's of miles. I did not find the weight that big of an issue. Also the gearing range was very manageable and easy to change by swapping the front chainring. What finally killed the fun/practicality of IGH's for me was changing rear flats, at night, in the cold. I had 2 and it was such a struggle with cold fingers, I opted not to continue using them.

Part of the issue was the Sun CR-18 rim that was used when the wheel was built. Getting a Specialized Armadillo on that rim was extremely difficult. In the cold, I broke 2 large, Pedros tire levers. The cable connection for the Nexus hub can be a bit of a challenge in optimum conditions. Add darkness, cold/snow (24 degrees F) wind, and a full body sweat going cold, I found I had a limited amount of time before things got difficult, fast. YMMV.

Bat22

I have an 06 Novarra Fusion with 4200 miles on it. It is a great commuter and faster than I thought it
would be. The issue I had was changing a rear tire flat. I practiced on a workstand at home and it took
me a half hour to figure and take the rear tire off. The bike came with assembly instructions but no
practical pm of the Nexus inter 8. I used an old style (heavy) tool roll with adjustable wrench,screw driver
and 10 mm closed wrench to get it done.
I only use it as an errand bike now. I don't think I have the ability to fix a rear tire flat and get
to work on time 16 miles way. If I lived 6 miles away..maybe then.
I've been told the 7 speeds and lower are easier to get off.

mickey85

call me stupid, or perhaps I just have an easy bike, but on my 3 spd Free Spirit, you unbolt the rear wheel like normal, then if you have to remove the entire wheel, you unscrew the shifting mechanism from the end, or if not, just pull it out, and you can spin the wheel to get the tube out...if new ones are more complicated, I apologize, but this one doesn't seem to be too difficult to maneuver...

rhm

Yeah, this is a good point. Fixing a flat in cold, dark, wet conditions is no fun, and an IGH only makes it that much more difficult. The best solution is to not get punctures, but you can't always control that. But I prefer to interpret this an argument for better tires, liners, etc. rather than against IGH.

MichaelW

The Sachs/Sram IGHs use a clickbox containing all the indexing gubbins that slides inside the hub. To remove it you pull it out and to reattach the cable you push it in, thats all.
My Shimano Alfine seemed OK to remove in a practice run on a summers day. No cables to unbolt, just unhook the cable from the gear changy thing (cassette joint) as illustrated. I can see it being more difficult with frozen fingers. Shimano recomend you keep a small allen key to engage a specially placed hole to rotate the cassette joint

I-Like-To-Bike

Oft mentioned and just like other urban legends, not a fact because it is repeated often.

Whatz so hard about it, at least on S-A or Sachs 3, 5 or 7 speeds? I've changed tires, fixed flats on all of 'em with no unusual difficulty. Maybe the lack of a quick release nuts and using a wrench is off putting to the racing set because reconnecting the gear shift cable is no more difficult than getting the chain correctly around a rear derailler and rear spocket. I also have a bike equipped with a Shimano 7 speed hub but have yet to change the tires or fix a flat so I can't speak from experience about that model.