bragi

I've been toying with the idea of putting an IGH on my touring bike (which is my only 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.

Cave

WTF is IGH?

TIA,

D.

badmother

Internally Geared Hub

I like them more and more. Got too many bikes, so the problems you describe is x 20 for me.

Picked up a dumpster bike last week, steptrough Shimano Nexus 4 gears. Been riding it since. Found I use only 1, 2 and 3 gear so I am changing the rear cog from 16 to 18 teeth.

Not sure about the tensioner thing, I`we been thinking the same.

I think 1/2 links for the chain and "ex- center" BB`s is also a way to go. Not sure how it works.

I`d say the Nexus (8) is more than good enough. There is always something more or better or bigger you can buy. If you want to spend money better to get another bike and make sure gears /purpose is differen from the one you`we got. Maybe one fast one more utility type. One of them could be a folder that you can enjoy travelling with (do some research in the folder forum).

Most important is not how many gears you`we got but what gears you`we got and what gears you really need. I am sure you are not using all the gears on your present setup.. And what is wrong about getting off and walking once in a while?

More about IGH here: https://www.bikeforums.net/showthread...68#post7487868

wahoonc

IMHO not enough to notice unless you are having to carry the bike up a set of stairs, in which case I would go with the Nexus 8 vs the NuVinci or Rolhoff.

Depends on your riding style and the number of gears. I ride my 3 speed everywhere I ride my 27 speeds. There is only one hill about 1/4 mile long that I cannot ride up, I walk it when using the 3 speed. If you are used to using the gears to ride at a constant cadence you may have problems adjusting to the larger distances between gears on the IGH.

Not enough to worry about.

Hard to beat the Nexus, Shimano has done their homework well. Also take a look at the new generation of Sturmey-Archer. Availability and repair parts is going to be the issue.

Dérailleurs were introduced to provide more gears for racing, they are cheaper to make (especially the low end stuff) a few pressed pieces of metal vs a hub full of machined gears. But to me they are more likely to wear out and need periodic maintenance.

My preference is the IGH, once properly adjusted they are all but maintenance free. I have an old Raleigh Sports with in excess of 30,000 miles on the original hub and it has never been torn down. AFAIK it still has the original rear cog on it. The chain has been replaced a couple of times. The bike was used as a sole source of transportation for 5 years and used in a car light mode for several more.

Aaron

flatboarder

At my Italy tour lately the Shimano Alfine 8 gear internal hub proved very useful for me, again. Cheap, rather lightweighted compared to other internal hubs, durable (I have got three of those hubs in different bicycles), no problems so far. Riding my Surly Big Dummy lots of uphill with light baggage up to 220km a day. I was surprised I did not miss derailleurs at all for such distances.
However, there are some important issues you need to check. There is a limited transission range. You need to initially decide, whether you would like to be prepared for slow uphill or fast plain/downhill riding. Choose cogs ratio accordingly. The bigger your cogs ratio gets, the worse you will realize inhomogeneous gaps as like Alfine gear 5-6. I use 34/20 which is sufficient for pedalling speeds up to 38km/h. Pedalling faster becomes kind of cumbersome, which does not really matter to me, since I will simply stop pedalling and wait some time. This is very much related to your riding style as well. But definitely, it works well for my needs, and I may recommend trying it out.
BTW one thing I like very much is the totally silent operation of the Alfine hubs.

I have done quite some onroad and offroad riding with these Alfine hubs, also several thousands of km with an inter-8 redline hub and I had a chance to try out a rohloff for a short time.
Rohloff is the most versatile hub with very convenient transmission range and real good durability. Alfine looks nicer, is a bit lighter and by far cheaper, is easier to install but removing rear wheel is a bit of hassle. And finally the inter-8: use SG-8R35 current version (redline). I would not recommend previous versions (SG-8R20 and SG-8R25) due to inner corrosion and other issues. I cannot tell about any other IGHs.

All in all, I may say I have completely converted to using IGHs with one exception: at my 8kg road bike I would definitely not switch over to using a gear hub due to weight and gear ratio reasons.
I would upgrade my BD to Rohloff as soon as I feel any need for it, but currently there isn't.

Juha

The number of gears is not a problem. Overall gear range may be. If you find yourself struggling either for lower gears in the uphill or spinning out when riding fast, you can play around with rear sprocket/front cog size to optimise the IGH's performance for you. If you have trouble in both, IGH may not be for you. I believe Rohloff has the biggest overall gear range of these (>500%) and evenly spaced 14 gears accross that. So if you're looking for wide overall gear range and small increments in between gears, Rohloff may be worth the cost.

Depends on demographic. Around here the ratio in LBS showroom is closer to even, and if one considers numbers of actually sold bikes it might be in IGH's favor. I have no statistics to back this up, just anecdotal evidence from my LBSes and commuting rides.

--J

vik 

1. Weight depends on what you are taking off and what you end up using. If you are stripping off a 3 x 9 derailleur system and replacing it with an IGH you may end up actually saving weight. If you keep your front derailleur/chainrings than you'll likely add some weight. Since your bike is a tank I don't think the small difference either way is something I'd worry about.

2. I think a city bike can be geared low enough with a Nexus 8 to ride hills as long as you are a reasonably strong rider. If you vary your cadence at both ends of the speed range you should be able to ride happily at slow and reasonably fast speeds. Obviously if you gear the bike low going uber fast will be an issue as you'll spin out at some point since your high gear won't be huge.

If you are a strong touring rider who doesn't carry a silly amount of gear I think you can tour with a Nexus 8, but your top speed will be limited. Personally I'm okay with that as I use the 38T x 11-34T range on my touring bike 95% of the time, but if you want to pedal down a mtn pass as fast as possible an eight gear IGH won't cut it. If that's you get a Rohloff for a very wide gear range.

3. The vertical dropouts will require a chain tensioner. This isn't really a problem for efficiency, but it will mean you won't get as much chain wrap around the rear cog and you'll need to deal with a worn chain faster than a bike with no chain tensioner. Not a deal breaker in my books, but a bike with an eccentric BB or horizontal drop outs allows for a nice clean IGH setup.

4. A Nexus 8 is okay in that it is well made, shifts nicely and offers a decent gear range. Will that range be enough for you? Depends - for city riding, most likely, for touring maybe- see my comments above. I can't speak about the SRAM product, but the Rohloff is worth the money if you are really committed to an IGH. If you follow the manufacturer's care instructions the Rohloff hub should work until you can no longer ride a bike. If you want the Coles Notes answer get a Nexus 8 for city riding. For touring you will most likely need a Rohloff or you could just at a double or triple chain ring to your Nexus 8.

5. Derailleurs are cheap [can be at least] easy to work on or replace, efficient when new and clean. They wear out/break relatively often - pro if you sell/service bikes! I think IGHs are a great option for practical riding & touring with one caveat - when something goes wrong you're dead in the water as there will be no service available from a LBS and likely no parts available either without doing some mail order. Of course to understand that risk in context you have to calculate what the likely/possible problems are with an IGH - very few frankly so your risk is quite small.

Allen

Don't forget about the NuVinci. Best hub next to the Rohloff.

kevbo

I built up a bike with a Nexus-8. The range is just over 300%. About the same as an 11-34 cassette.

What this means, is that you have to be very careful when selecting the bottom end of your gear range, because the top end moves 3X as much. I currently have the bike geared 40/19, giving a range of ~30-91 gear inches. If I were to lower the bottom end to 25", then the top end would move down to 75 inches.

invisiblehand

Not much to add other than if you decide to go with a chain tensioner, you can always use a double up front and switch to the small chainring if you really need a low gear for that 5% that everyone seems to reference.

kevbo

Actually, I have been thinking about trying to fabricate a double rear cog that would allow me to use a second chain ring without needing a tensioner or FD. Hills I can't handle with the current gearing are rare enough that it wouldn't be a huge hassle to manually move the chain to switch ranges.

This idea is staring me in the face, because my bike with the IGH was a 70s/80s 12 speed with a double crankset, and I am currently running on the inner 40T ring with the outer 52T still in place (as ballast). 40/31 + 52/19 should work fine with the same chain length, Would offer a wider range than teh Rohloff, and pretty much handle anything I'd want to try climbing. (~18" granny gear). I haven't been able to find any torque limitation specs on the Nexus 8 though.

wahoonc

We used to do a manual thing with the SA hubs. The cogs are dished, if you removed the spacer and put the raised sides of the cogs face to face you were good to go. You had to be very careful with chain length, if done properly you could get both a 16t/22t combo. It only took a minute or two to loosen the wheel reset the chain and readjust the hub. Not the greatest system in the world but for kids with no money it worked great.

Aaron

flatboarder

Lowest permissible gear ratio for Alfine 8-spd. is 33/23. According to Shimano the Alfine hub must not be used for cargo bikes or tandems.

If you do not mind German language you might want to check Trekkingbike magazine article about several IGHs (there are several technical charts there).
Regards, Phil

Juha

There's also the Schlumpf 2 speed BB. Probably too expensive for the occasional need, but very elegant.

--J

kevbo

Thanks, that is good info. That would get me down to ~21" gearing on a 700C wheel...sounds low enough. Interesting the cargo bike restriction. I believe the Nexus-8 is supplied on the bakfietsen sold by Clever Cycles. <googles> Ayup! Shimano does say something about a roller clutch shifting mechanism for the Alfine. I'm pretty sure the Nexus uses pawls. (I know the Nexus 4 does, but I have not been into an 8 speed)

Note to those following this: Most IGH hubs have gearing restrictions so you don't overload the internal parts. One way to get granny gears out of this would be to use a 20" wheel. Larger wheels deminish the torque at the road compared to what the hub must endure. Of course smaller wheels have thier own issues....just food for thought.

vik 

There is a lot of drag in the Schlumpf overdrive/underdrive [depending what model you get] adding this to the higher drag of an IGH would make it a PITA to use. Plus if you add $500 for a Schlumpf to a bike why not just get a Rohloff and be done with it?

kevbo

I agree with the effiency issue. On price, the Nexus-8 street price is well under $200. Adding a $500 Schlumpf to that still only brings you to around half the price of the Rohloff. The $700+ difference is what many people might budget for a complete bike.

flatboarder

But then, why not take an SRAM Hammerschmidt or similar (there is at least more to come, Nicolai I believe). I would prefer those over Schlumpf drive.

kevbo

I haven't yet seen a price for the Hammerschmidt, much less anything from Karlheinz Nicolai. I have also heard a rumor that the Hammerschmidt requires a special bottom bracket. (the frame, not the bearing set) But I have been unable to confirm this.

I do like the cable operation of the Hammerschmidt better than the foot operated Schlumpf. I would hope it is less expensive than the Schlumpf...it is mass produced vs. the low volume manufacture of the Sclumpf.

flatboarder

You will need an ISCG mount at drive train side of bottom bracket to take up the torque, but those are available for bottom bracket mount as well (though I do not know whether they would be strong enough). I am quite confident SRAM will deliver such items for any sort of bicycles, since the Hammerschmidt really bears some potential, I guess.
BTW here is a short clip about climbing 30% of slope with Big Dummy and Alfine 8-spd. internal hub, no front derailleur, 34/20 cogs ratio, very light baggage. Unfortunately it appears quite difficult to make that slope visible. But riding up there is _really_ steep. No I did not push the bike
Regards, Phil

vik 

If a Nexus 8 or SRAM 9 speed doesn't work for your application I'd submit even a $500 Schlumpf is out of the $$$ range of folks who can't drop a lot of money on a bike. At that point a MTB drivertrain is still the best option for cost vs. performance. $700 for a lot of drag in your drivetrain is not an improvement over cleaning a MTB derailleur setup.

Although a Rohloff costs twice a that of a Schlumpf + Nexus 8 - you'll still be using it when someone else is on their 3rd set of Sclumpf & Nexus 8 drivetrain. In the long run it's less expensive.

I-Like-To-Bike

Any details/references on how you established the alleged bullet proof long term maintenance/service life of Rohloff hubs? Seems a lot of hot electrons have been expended boasting about at best, a short term track record.

vik 

They've made a 100,000 hubs. The longest serving one is over 190,000km in late 2007. I'm not sure where you are getting a short term track record from they've been in production since 1999.

If you want some empirical evidence just go to a Rohloff forum [Thorn and MTBR.com both have one] and ask people how many kms they've had on their Rohloffs.

I should point out there are wear items with a Rohloff that will have to be replaced as they are worn out:

- shifter
- cables
- cog
- internal oil bath

Ashen

I wouldn't bother, I'm pretty sure ILTB is the same person I remember from other threads who is completely sure that Rohloff is nothing but a waste of money. No convincing possible.

I-Like-To-Bike

No I'm the one who is skeptical of unsubstantiated claims that an extremely expensive hub, marketed only since 1999, to a relatively tiny deep pockets crowd has a superior maintenance/reliability record over other IGH hubs, like Sturmey Archer, with a track record of reliability and freedom from maintenance under all conditions for over 50 years. Especially given that Sturmey Archer and Sachs hubs are sold worldwide to people who are not as likely to run to an LBS for routine "servicing" as those buying a pricey hub on a pricey bike.