Folding Bikes - GEARS: Rear Derailer vs. Internal Hub

It seems that the vast majority of folding bikes with gears ship with rear derailers.

The advantages of derailers are (1) generally less expensive than internally geared hubs; (2) you can inexpensively replace a cassette and change your gearing, but if you don't like the gearing of your hub, you have to replace the whole hub.

The advantages of the internal hubs are (1) much luss vulnerable to abuse or damage, whereas it's not hard to bend the cable jockey arm on a derailer, (2) requires less maintenance; (3) you can change gears while stopped.

My road and mountain bikes have derailers, of course, but I'm worried about having a derailer on a folder. I'm concerned that the constant folding/unfolding/storing, etc., will result in tearing up the derailer. Am I paranoid? Who on this forum has damaged their derailer? Or knocked it out of aligment so that it required maintenance? There are sure lots more choices if one is wililng to buy a folder with derailer.

I have never damaged the derailleur when folding or unfolding my Birdy. I have also not had to adjust the indexing after a knock - others may have though...

My derailer got knocked-out of alignment, not so much from the folding, but from the daily rigors of commuting on the train. Being that the derailer hangs lower on a folder, it's susceptible to being whacked by the wheels of other bikes as all frantically jocky for position on a crowded commuter train. I recall on several occasions having to stop an bend my derailer back after deboarding the train. Sucked.

I obviously don't have that problem anymore. ;)

Yes, you're paranoid. :D

You forgot to mention that derailleurs are lighter, quieter and more efficient, by the way. Also, while internal hubs are generally more robust and need less maintenance, you're pretty much SOL if it does break, 10x if it breaks on the road / on tour.

Also, internal hubs are better for inclement weather and muddy environments, as the transmission will stay much cleaner.

Internal hubs are best for commuting and some people like them for touring. But I wouldn't worry at all about using a derailleur on a folder. If they really didn't work for folders, you wouldn't see them offered on so many folding bikes.

RD or internal?, that was the burning question I faced when I decided to buy a used Swift from Peter. I felt (perceived) more comfortable with a RD since I planned to travel with my folder overseas. Regarding damage after folding, I think in general, you have to be pretty careful where and how you store the bike.

The Sunrace M50 on my DT FS met its gritty end in a right-side fall in wet roots on a corner on a woods trail. I got scratched up but the RD got mangled. I was thinking, what fun, good speed, then wham, the bike and I are on the deck (that was the start of my search for a better fork). If you ride off-road on a 20", a gear hub is better.

My vote is for the hub on a smaller folder for mixed mode commuting and trunk use.

I have never damaged the rear derailleurs on any of my folders. The front derailleur on my BF got damaged once when it was packed in the suitcase for airline travel, but that isn't within the scope of the original question.

Hub gears are a good choice if you can get the range of gears that you want (not necessarily what someone else thinks you should want).

It seems that the vast majority of folding bikes with gears ship with rear derailers.

The advantages of derailers are (1) generally less expensive than internally geared hubs; (2) you can inexpensively replace a cassette and change your gearing, but if you don't like the gearing of your hub, you have to replace the whole hub.

The advantages of the internal hubs are (1) much luss vulnerable to abuse or damage, whereas it's not hard to bend the cable jockey arm on a derailer, (2) requires less maintenance; (3) you can change gears while stopped.

My road and mountain bikes have derailers, of course, but I'm worried about having a derailer on a folder. I'm concerned that the constant folding/unfolding/storing, etc., will result in tearing up the derailer. Am I paranoid? Who on this forum has damaged their derailer? Or knocked it out of aligment so that it required maintenance? There are sure lots more choices if one is wililng to buy a folder with derailer.

Advantages: Internal hubs --- usually higher geared but this can be fixed by installing a much larger cog but you lose the high gears. Usually less expensive if you're planning to use a Sturmey Archer AW-3 or Nexus 8, Sram 7 etc. The only really expensive hub is the German Speed hub.

Advantages: Derailluers ---- You can get the lower gears that an internal hub owner can dream. Less expensive to fix on the road. Can stand on the pedals.

I only owned 1 folding bicycle so far, but I like the 5-speed internal hub gear on Dahon Vitesse D5. I chose this model rather than Speed or some others, because I wanted to avoid derailluer and its associated problems discussed above. It has good gear range for city and bike paths. No problem with bridges, pedestrian overpasses with ramps, etc. I could use higher gears to ride faster on flat road, but that's not very esseintial.

You forgot to mention that derailleurs are <snip> more efficient... I saw a paper on an investigation on the *total* efficiency of drive trains, and it turns out a Sturmey Archer AW is as efficient as a good derailer system, and more efficient in 2nd gear. In general, the efficiencies of both systems are very similar. Derailer systems are lighter. So it counts a tiny bit going uphill.

Our Dahon SpeedPro folders have both, a rear derrailleur AND hub gearing (so no front derailleur). The RD on the older SP is shot, funny you should post this thread, so I'm replacing it. I'm not sure what caused it to wear out the way it did. I suppose when I do the replacement could try to disassemble it for a better understanding (search in the Mechanics thread if you want the details).

I am solidly in the camp of the internal hubs at this point especially on the smaller wheeled bikes. On the 20" wheels my choice would be the Nexus 8 spd premium hub I have on a few bikes as it is very efficient and it shifts better than any other hub under load. Shifter to lower gear is amazingly quick and easy. I love being able to shift when stopped. I have a good gear range too.

For 16" wheels the hands down favorite for me is the Sturmey Archer 8 spd. It the best usable gear spread using normal sprockets of any internal hub on this wheel. It 1st gear is a 1:1 ratio so I don't have to use huge or tiny sprockets to get the gear range I need.

Efficiency on the latest internal hubs is so close to RD as to probably be an almost moot point. One BIG plus for me is no rear derailleur hanging down being a dirt magnet. Riding on the beach and on unpaved trails with my RD setup collected dirt, sand, twigs, etc.

I only have one folder left with a rear derailleur and it will soon be gone.

Efficiency on the latest internal hubs is so close to RD as to probably be an almost moot point....
With all due respect, I'll believe that when I start seeing internal hubs on road bikes. ;)

Efficiency on the latest internal hubs is so close to RD as to probably be an almost moot point.



With all due respect, I'll believe that when I start seeing internal hubs on road bikes. ;)


I believe you would start to see internal hubs on road bikes if the wheel weights were comparable... there is no getting around the the newest 8 and now 9spd hubs make up a much heavier wheel than one fitted with a lightweight cluster... to me, that is the biggest difference.. I have retrofitted 2 8spd hubs into 406 d/r bikes and would never convert back as the benefit on those bikes offset any spinning weight issues.

Bruce

Some roadsters like to have extra rear wheels to mount, so internal hubs would make these a lot more expensive.

Fixing flats can also be an issue. A friend of mine went to solid rubber tires with a gear hub. Her neighborhood is a road debris showcase.

I'm thinking about removing the derailleurs on my folder and installing an 8 speed Nexus hub with a Schlumpf speed drive crank. The weight and small efficiency loss is not a factor for me.
But one question i have is, how reliable is the Nexus Hub? Would you take it on short tours in distant remote lands, where there is little or no hope of getting a repair?

I'm thinking about removing the derailleurs on my folder and installing an 8 speed Nexus hub with a Schlumpf speed drive crank. The weight and small efficiency loss is not a factor for me.
But one question i have is, how reliable is the Nexus Hub? Would you take it on short tours in distant remote lands, where there is little or no hope of getting a repair?

I did that exact thing with my JetXp.. I wouldn't hesitate to take my Dahon just about anyplace... if the cable snapped or the hub gear shift arm somehow broke, the hub would automatically revert to it's lowest gear ratio... with the addition of the Schlumpf, you would at least have two speeds, low and 1.65 overdrive... I've never heard of a catastrophic failure with the new Shimano hub, others may have though...I'd contact someone who sells a lot of them, like Sheldon Brown.. or even Joe Breeze Breezer Bikes (http://www.breezerbikes.com/bike_details.cfm?bikeType=town&frame=d&bike=uptown).

Bruce

Bruce: It was a joke, my friend. :D I don't think you'll ever see an IH on a road bike. The only place where extra weight will really slow you down is on the wheel, yes? An IH would need to be substantially superior in efficiency and performance before anyone puts it on a bike where performance is the primary objective.


One thing I noticed about this issue is that Bike Friday, which I think we can all agree is one of the premiere folding bike manufacturers, doesn't configure any of its bikes with any type of IH other than offering the SRAM Dual Drive (which is an IH + derailleurs). I'm actually surprised by this, as I'd imagine their touring customer base would appreciate the reliability of an IH. I'm sure they will build a bike with an IH if you ask (although IIRC they don't like Rohloffs, for several mechanical reasons). But I'd say this is a testament to the reliability of a derailleur on a folder....

Bacciagalupe,
there are actually quite a lot of Fridays with Rohloffs. My Llama has Rohloff specific braze ons, but i don't think i'll install a Rohloff because i didn't like the noise, and the test hub already had 6k miles, so not a big hope of it getting quieter.
I asked BF for a semi-horizontal dropout, but was disappointed that they won't do them, even on customer request. They said I'd want a tensioner anyways, so the chain doesn't flop off every time I do a quick fold. True, but i'd still like the option of going without a tensioner if i want to.

Advantages: Derailluers ---- You can get the lower gears that an internal hub owner can dream. Less expensive to fix on the road. Can stand on the pedals.

Umm, so your saying one cannot stand up with hub gears? I don't know which gears you have had the misfortune of trying, but I find that mine work just fine when I stand up and sprint hard...

/. Magnus

Bruce: It was a joke, my friend. :D I don't think you'll ever see an IH on a road bike. The only place where extra weight will really slow you down is on the wheel, yes? An IH would need to be substantially superior in efficiency and performance before anyone puts it on a bike where performance is the primary objective.


Obviously performance is not the primary objective in doing long brevets. I did Paris-Brest-Paris on a F&S Duomatic hub-geared Moulton (last I heard, it was a road bike). I finished in fine shape and had no problems keeping up. The SA 8sp hubbed Moulton I rode last year didn't seem any slower than my 700C Frezoni (S&S, to keep the obligatory folding bike content). :rolleyes:

. . .One thing I noticed about this issue is that Bike Friday, which I think we can all agree is one of the premiere folding bike manufacturers, doesn't configure any of its bikes with any type of IH other than offering the SRAM Dual Drive (which is an IH + derailleurs). I'm actually surprised by this, as I'd imagine their touring customer base would appreciate the reliability of an IH. I'm sure they will build a bike with an IH if you ask (although IIRC they don't like Rohloffs, for several mechanical reasons). But I'd say this is a testament to the reliability of a derailleur on a folder....

Not just dual drives and Rohloffs. Bike Friday has actually built bikes with Nexus 7 hubs in the past, and I'm sure will build them with 8 speed hubs. It's not one of the standard sample configurations that they show on their web page, but if you call them with a clear idea of what you want, they'll usually find a way to make it for you.

I saw a paper on an investigation on the *total* efficiency of drive trains, and it turns out a Sturmey Archer AW is as efficient as a good derailier system, and more efficient in 2nd gear. In general, the efficiencies of both systems are very similar. Derailer systems are lighter. So it counts a tiny bit going uphill.
Did you notice that they said it was more efficient when cleaned of grease and lubed with light oil?

That's what I did and it is still working well and has remained pretty clean. It's nothing really, but I just get a tiny amount of seepage around the driver element which attaches to the 14 tooth sprocket, but apart from that it is dry and clean. When I did this I thought the oil would spew out, but I was wrong. I have about six teaspoonfulls in there, so it's a good amount. I'm using sae 10/40. It is possible that 10/30 might be slightly better. I'll run it like this with the 10/40 for a few months and do a clean out and an oil change with the 10/30 grade oil.

I'm quite pleased that your paper suggests the sturmey 3 on oil is as efficient as a good derailier. I hate the thought of wasting effort.

Thanks for that reference by the way Jur. An interesting read.

Umm, so your saying one cannot stand up with hub gears? I don't know which gears you have had the misfortune of trying, but I find that mine work just fine when I stand up and sprint hard...

/. Magnus
I stand on mine all the time and have made a front derialier system for changng chain wheels. It's still a narrow gear range though.

The old Sturmey SW hub was VERY likely to jump out of gear. The modern Sunrace Sturmey gears are completely reliable. If you strip and examine them, you can see it is not possible for it to come out of gear because there are no neutrals. The nearest I have come is when the cable was maladjusted and it occasionally flipped down one gear. That problem was easily sorted. I stand on my pedals on every hill and hammer it with confidence - mind you, I'm not bult like Tarzan or anything - I doubt I put 300 watts into it EVER, usually about 80 - 200 going on my speeds and the calculations from here -

http://www.kreuzotter.de/english/espeed.htm

On Sunday I was riding along a path with my Merc, there were tree roots and stones that had to be dodged. After a while there were four young people with their hybrid bikes in front of me asking advice from a lady that obviously new the environment. I stopped behind them and listened: ”There used to be a better path here – these are no mountain bikes, we can’t ride this path”. Then I stepped the pedal hard and speeded past them. I now and then ride Merc standing up and there has never been trouble with gear slipping, and I often jump from street to curb with the bike. Last summer when I was riding my rear derailleur equipped bike in an environment described before, a stick got entangled somewhere between rear derailleur mechanism – it took time and effort to get it off – and bending derailleur arm back. This can’t happen with internal hub. I have been very happy with S&A 3-speed hub and think to update it with a second front sprocket, like EvilV described – I think it is a great combination, benefits of both types.
If you want to read about reliability of internal hub in far away countries check out this http://www.foldabikes.com/CurrentEvents/Story/Alex.html and http://www.foldabikes.com/CurrentEvents/Story/Tibet.html

On Sunday I was riding along a path with my Merc, there were tree roots and stones that had to be dodged. After a while there were four young people with their hybrid bikes in front of me asking advice from a lady that obviously new the environment. I stopped behind them and listened: ”There used to be a better path here – these are no mountain bikes, we can’t ride this path”. Then I stepped the pedal hard and speeded past them. I now and then ride Merc standing up and there has never been trouble with gear slipping, and I often jump from street to curb with the bike. Last summer when I was riding my rear derailleur equipped bike in an environment described before, a stick got entangled somewhere between rear derailleur mechanism – it took time and effort to get it off – and bending derailleur arm back. This can’t happen with internal hub. I have been very happy with S&A 3-speed hub and think to update it with a second front sprocket, like EvilV described – I think it is a great combination, benefits of both types.
If you want to read about reliability of internal hub in far away countries check out this http://www.foldabikes.com/CurrentEvents/Story/Alex.html and http://www.foldabikes.com/CurrentEvents/Story/Tibet.html


These tales of Alex the Brompton world traveller have kept me amused for over an hour. There are many more than these you have quoted accessible from Channell Wasson's site at foldabike.com.

Thanks for giving the links to Alex's travels.

I've been reading this thread with great interest, since I plan on buying my first bike with an internal gear hub (Rohloff Speedhub 500-14 CC EX). Two things made me reconsider:

1. The standing on pedals issue. I guess it was established that this is not a problem with internal hubs, but I can't get enough reassurances here. I stand up all the time and push so hard that the chain slips even on a normal bike after some year's daily wear.

2. Someone wrote that internal hubs have a low gear range. The one I plan to buy has 14 gears with a gear ratio from 1.8 to 9.5 Meters (5.9 to 31 Feet), which seems pretty good to me. (I would prefer less gears with the same range, but it seems this is what most ppl want.)

The bike I'm thinking about is this:

http://www.stevensbikes.de/2009/index.php?bik_id=593&lang=en_US

It's a whole 800 euros cheaper (1120 USD) without the Rohloff internal hub.

I will commute as well as tour, and I like it fast. I like the idea of less maintenance and not so many parts sticking out from the bike, plus the idea of owning my first internal hub bike. More advice and experiences always welcome.

1. The standing on pedals issue. I guess it was established that this is not a problem with internal hubs, but I can't get enough reassurances here. I stand up all the time and push so hard that the chain slips even on a normal bike after some year's daily wear.

2. Someone wrote that internal hubs have a low gear range. The one I plan to buy has 14 gears with a gear ratio from 1.8 to 9.5 Meters (5.9 to 31 Feet), which seems pretty good to me. (I would prefer less gears with the same range, but it seems this is what most ppl want.)


1. I have had three gear hubs in the past two years. My old Sturmey-Archer 3-speed would sometimes slip me into that phantom neutral, so standing on that one could be dicey, but it was old: 1972. I replaced it with a Fichtel & Sachs 3-speed torpedo, and have not noticed any problems with standing on the pedals. And I fully intend to build that old SA hub into a better wheel, because I think with the right adjustments, I'll be fine riding on that as well. On my full sized bike, I have a Nuvinci. There is no issue with hammering on that hub, either. It lays out a minimum gear range, and I haven't moved outside of it, but I've never felt the slightest slippage on that.

2. When people talk about narrow gear ranges in IGH's, they usually mean "except the Rohloff." It's easily got the widest gear range of any hub and, I think, has a comparable range to most derailleur bikes. I have also heard that it's very reliable, and (and I may be making this up) I even think there maybe a designated touring bike designed to run with a Rohloff. That means at least someone thinks it's reliable enough to tour on. I'm sure if you dig around you'll find some people talking about their Rohloff hubs, and I don't remember reading anything negative about them apart from their price tag.

Ye gods! There is so much ignorant twaddle bandied around about the inferiority of gear hubs.

A 1960s S-A hub can slip if maladjusted, but if you can keep it away from the derailleur crowd who believe in twiddling the adjustment instead of setting it by the rod position, you won't have a problem. I have had a 1960s derailleur snap on me with eye-watering results. Compare 1960s with 1960s, not with current stuff.

A modern Sunrace S-A hub simply does not slip. I use one on a cyclocross bike that gets plenty of abuse offroad.

As for the "heavy" weight of a gear hub, has no-one weighed a full derailleur set of the standard fitted to most folding bikes?

Life expectancy of a properly looked after S-A gear hub is the life of the bike, whereas almost all the parts on a derailleur system are consumables (more so at the folding end of the market) and usually the cost of replacing the drivetrain means that the bike becomes disposable.

As for the "heavy" weight of a gear hub, has no-one weighed a full derailleur set of the standard fitted to most folding bikes?

I've posted a detailed comparison here (http://www.bikeforums.net/showpost.php?p=8970415&postcount=81).

Life expectancy of a properly looked after S-A gear hub is the life of the bike, whereas almost all the parts on a derailleur system are consumables (more so at the folding end of the market) and usually the cost of replacing the drivetrain means that the bike becomes disposable.

I hope this is true of S-A gear hubs. I know it is not true of Nexus 7 and 8 speed hubs. (FWIW, I do think that 3spd hubs are much more robust than 7 or 8 spd hubs with the same form factor).

I have never heard of a Nexus 8 breaking... has anybody? AFAIK they are some of the sturdiest components on the market.

I'm not bult like Tarzan or anything - I doubt I put 300 watts into it EVER, usually about 80 - 200 going on my speeds and the calculations from here - No you are more like one of Tarzan's chimps EvilV :D

How are you you mad Geordie? Merc still going strong with you 'hammering' it? Fantastic!

Regards
The Irish Chainbreaker

I hope this is true of S-A gear hubs. I know it is not true of Nexus 7 and 8 speed hubs...
Are they actually breaking? The "broken" hubs I have seen are actually poor shifting caused by twiddling neanderthals. Proper adjustment restores things so long as it hasn't been ridden too much in this state.

Twiddling adjustment so the gears sound ok is fine for crude devices like derailleurs, but geared hubs need to be set up precisely, and have the markings to enable this to be done.

Thanks for the breakdown of the weights, Pibach. When I converted my Dahon to a single speed the bits I took off weighed almost 1kg and that's not accounting for the bit of chain, or the fact that the hub remained.

An interesting illustration of the so-called weight difference is by comparing the Dahon Mu P8 and the Mu XL Sport. The hub gear bike is 200 grams heavier but is equipped with mudguards which would weigh more than 200 grams.

Reading TS (Thread Starter) consideration, I think single speed/fixed gear folding bike is the compromise?

My bike has both RD and internal gear (SRAM DualDrive).

The internal gear requires virtually zero mentenance, shifts quickly and can shift while standing. The RD is dirty, bulky, requires frequent tuneups and causes cross chaining at the extreme gears.

My next bike will have internal gear only (Rohloff, more riding, less tweaking) though dealing with a DR was a great technical learning experience for me.

Kam

I hope this is true of S-A gear hubs. I know it is not true of Nexus 7 and 8 speed hubs. (FWIW, I do think that 3spd hubs are much more robust than 7 or 8 spd hubs with the same form factor).

S-A gearhubs have gone through some changes over time, but we can hope that most of those changes have been in a positive direction. And given the number of 40 year old S-A gearhubs still in use, I think that bodes well for S-A hubs in general.

I do seem to remember reading about some issues with the previous batch of S-A 8-speeds. I think a couple of people managed to kill them, so I'm hoping that's sorted out with the new batch. The gearing seems great for a small-wheeled bike, and I hope it's still possible to swap out some of the nuts to get a narrower spacing because I'd love to incorporate an 8 speed hub into an old folder I'm working on.

Reliability is a key concern with gear hubs in general because repair/replacement can be more complicated then a derailleur set up, but I love my gear hubs, and only my wife's bike is running a derailleur, and that could change if I find a good gear hub for her.

@datako, Rob E -

Both gears (on two separate Trek Navigators) were destroyed beyond repair; I think it took about 9 months for each gear. The guy riding the bike was larger (6'1, 250 lbs), rode 6-10 miles most days, generally on a screened gravel MUP that went to his work (the Illinois Prairie Path, to be specific). He suspects that his weight, plus perhaps some of the fine dust from the path, combined to destroy the gears. He was generally good about maintenance, and took the hubs to be serviced as soon as they felt hinky (especially the second one!), but there was really nothing that could be done. There are some similar complaints you can find on the internet; mostly, I think, involving 200 lb + riders; it's interesting that Trek's Navigator line no longer has IGHs.

I think that the basic problem is that the 8 IGHs have to be made much smaller to fit inside the same space that used to house 3 speed hubs, and that the smaller parts just aren't as durable. And it may well be that there would be no issues for a 160 lb rider who mostly rode on paved streets - but an advantage of IGHs is that they are supposed to be robust and reliable...this was certainly true of the older 3sp SAs.

None of this stopped me from getting a dual drive hub for my BF, and I have had 0 problems so far; I love the design. It is also a 3 speed hub, of course, and I'm about half the weight of my friend. (Also, the SRAM hub has a slightly better rep than the Nexi, AFAICT). But I can't help thinking that there is may be something inherently weaker about 8 speed IGHs that means that they can't be as bombproof as older 3spd hubs.

Ye gods! There is so much ignorant twaddle bandied around about the inferiority of gear hubs.

A 1960s S-A hub can slip if maladjusted, but if you can keep it away from the derailleur crowd who believe in twiddling the adjustment instead of setting it by the rod position, you won't have a problem. I have had a 1960s derailleur snap on me with eye-watering results. Compare 1960s with 1960s, not with current stuff.

A modern Sunrace S-A hub simply does not slip. I use one on a cyclocross bike that gets plenty of abuse offroad.

As for the "heavy" weight of a gear hub, has no-one weighed a full derailleur set of the standard fitted to most folding bikes?

Life expectancy of a properly looked after S-A gear hub is the life of the bike, whereas almost all the parts on a derailleur system are consumables (more so at the folding end of the market) and usually the cost of replacing the drivetrain means that the bike becomes disposable.

I agree with all of this. The modern SA kit (and I am sure the other manufacturer's products too) don't slip into neutrals like the old SA ones did.


EDIT:

As above for the longevity issues. It seems obvious that fitting lots of smaller cogs into a similar space makes the seven and eight speed hubs a less longlived proposition than the three speeders. One way around this might be to mate two front chain rings to a bomb proof three speed. This works pretty well on my Merc, but I do get some repeat gears so that I only end up with four unique gears rather than the six you might expect.

A modern Sunrace S-A hub simply does not slip. I use one on a cyclocross bike that gets plenty of abuse offroad.

As for the "heavy" weight of a gear hub, has no-one weighed a full derailleur set of the standard fitted to most folding bikes?

A SA 8-speed certainly does slip. Overall, I don't think that the SA8 hubs are bad, but I don't think that they are great either. Performs fine on the Mini in my experience, but I wouldn't use it on any other bike.

Three speed hubs are pretty robust across the board.

Peter Reich told me that the SRAM Dual Drive added about 1-1.5 pounds to a derailer based drivetrain and that the Nexus Red Band added yet another pound to that.


I have never heard of a Nexus 8 breaking... has anybody? AFAIK they are some of the sturdiest components on the market.

I have never personally seen a broken Nexus 8. But I have talked to mechanics that have. Long story short, I don't think that most mechanics see enough of them to get a good idea of their robustness.


My bike has both RD and internal gear (SRAM DualDrive).

The internal gear requires virtually zero mentenance, shifts quickly and can shift while standing. The RD is dirty, bulky, requires frequent tuneups and causes cross chaining at the extreme gears.

My next bike will have internal gear only (Rohloff, more riding, less tweaking) though dealing with a DR was a great technical learning experience for me.

Kam

Three speed hubs are very robust. Rohloffs are robust too; although if you ask around you can find people that had them fail. Some of it depends on the definition of "fail" and whether you include people with tandems and so on.


I agree with all of this. The modern SA kit (and I am sure the other manufacturer's products too) don't slip into neutrals like the old SA ones did.


EDIT:

As above for the longevity issues. It seems obvious that fitting lots of smaller cogs into a similar space makes the seven and eight speed hubs a less longlived proposition than the three speeders. One way around this might be to mate two front chain rings to a bomb proof three speed. This works pretty well on my Merc, but I do get some repeat gears so that I only end up with four unique gears rather than the six you might expect.

As I wrote above, SA 8 (WRF? ... I can't remember the designation) hubs certainly do slip and can be very touchy about adjustment. Mine works OK for a multimode commuter.

Personally, I find derailers to be extremely robust and very easy to repair. Although there are certain circumstances where I think an internal hub is preferred.

An interesting illustration of the so-called weight difference is by comparing the Dahon Mu P8 and the Mu XL Sport. The hub gear bike is 200 grams heavier but is equipped with mudguards which would weigh more than 200 grams.

Did you weight both bikes? Dahon's specs are very unreliable.
Also you have to compare like for like - and there the Nexus Premium is at the level of an XT dereilleur system - allthough it is more expensive.
Interestingly the Mu SL is almost 3kg (!) lighter than the Mu Sport.
But this is partially due to wheels, crank set&axle and handlepost.
Honestly I liked the SL much better than the Sport.

Did you weight both bikes? Dahon's specs are very unreliable.
Also you have to compare like for like - and there the Nexus Premium is at the level of an XT dereilleur system - allthough it is more expensive.

Their weights are no more unreliable than most other makers. They would use the same protocol for weighing both bikes so the weight difference is likely to be reasonably accurate.

I am not aware of any great difference between the Nexus and Nexus Premium in weight, and in this case it was the weight difference between a derailleur system and a hub gear system on more or less the same bike I was commenting on.

I agree about the MuSL, my son has one. It's a lovely bike - but it is a SL version of the Mu, and should be treated like a lightweight racing bike and saved for sports riding. Commuting on it over poor surfaces would soon cause it to deteriorate in my opinion. (That applies to the superlight version of any bike)

As I wrote above, SA 8 (WRF? ... I can't remember the designation) hubs certainly do slip and can be very touchy about adjustment. Mine works OK for a multimode commuter.

Personally, I find derailers to be extremely robust and very easy to repair. Although there are certain circumstances where I think an internal hub is preferred.

the post I was replying to was talking about the old SA three speeds notorious 'neutral's problem. I was talking about the modern three speed SA and probably ought to have made that clear. I have no experience of the 8 speeds or any of the hubs with more than three gears. Descriptions of them failing make it unlikely that I would ever have one, and also the fact that cascading the sets of planetary gears adds to inefficiency. Like most of us, I like my effort to go into propulsion rather than twirling multitudes of small cogs plastered in grease. When I was 18, or 28, I wouldn't have cared much about a few watts of inefficiency, but at 58, I care more.

An interesting illustration of the so-called weight difference is by comparing the Dahon Mu P8 and the Mu XL Sport. The hub gear bike is 200 grams heavier but is equipped with mudguards which would weigh more than 200 grams.

But there are several differences between the bikes. For instance, I wouldn't be surprised if the folding pedals were considerably heavier than the MKS pedals.


Their weights are no more unreliable than most other makers. They would use the same protocol for weighing both bikes so the weight difference is likely to be reasonably accurate.

Maybe. But marketing pressures might be quite different for various makes and models. Moreover, if Dahon is executing a price discrimination scheme then they would have reason to bias estimates to change the relative attractiveness of models.

They would use the same protocol for weighing both bikes so the weight difference is likely to be reasonably accurate.

Same protocol, maybe. But the specs are full of errors. Weight, geometry, gear ratios (see the Mu XXV, for example), many numbers are just wrong. I think most errors occur because of cut & paste.



Commuting on it over poor surfaces would soon cause it to deteriorate in my opinion. (That applies to the superlight version of any bike)
It has the Kinetix Pro wheels, they are very sturdy. I did put Big Apples on it (I am 95kg). All the rest is as solid as on all the other Dahons (or even better). The Pantour hub configuration (<2008 models) does handle cobblestone quite well. Makes a perfect all round commuter. Dahon categorizes it as "urban performance", new in 2009, as before it has been promoted as road bike.

But there are several differences between the bikes. For instance, I wouldn't be surprised if the folding pedals were considerably heavier than the MKS pedals...

I would be surprised if they were weighed with pedals. Very few manufacturers do this. Some continental manufacturers weigh without saddles too. Pedals and saddles being personal choice items and most likely to be changed on purchase.

However I used these Dahons as a convenient example to illustrate that the weight differences between similar bikes fitted with a gear hub and one with a derailleur was not significant.


Same protocol, maybe. But the specs are full of errors. Weight, geometry, gear ratios (see the Mu XXV, for example), many numbers are just wrong. I think most errors occur because of cut & paste...

All manufacturers specs are full of "errors" and I would regard them as a guide to what will be on the bike rather than holy writ. It has always been thus, and generally the differences are minor. I buy my bikes from the shop, not from catalogues, so it doesn't bother me.

However I used these Dahons as a convenient example to illustrate that the weight differences between similar bikes fitted with a gear hub and one with a derailleur was not significant.

I understand. I am writing that they are not similar enough for a good estimate of the derailer versus internal hub weight effect. From memory of a quick read, I believe the handlebar post is different; the seat post is different (one includes a pump), and so on.

The weight estimate I got from Peter Reich is also the estimate I got from Bike Friday in regards to the net weight effect of derailer -> SRAM DD -> Nexus Red Band. I have not run down the specs, but there are enough things that change -- the amount of chain, cable, and housing, for instance -- that I don't have convenient estimates to simply take their word for it.

Now, for most purposes, I don't think 2 pounds is significant. Although that is a long standing discussion that I don't have the patience for today. ;)

BTW, I always thought that if a bike came with pedals and a saddle it would be included in the weight estimate unless explicitly defined otherwise. But AFAIK, there is no official standard.

EDIT: I just took a peek. The Mu SL lists that the weight is w/o pedals. The other bikes omit the description. What does it mean? We can only speculate.

All manufacturers specs are full of "errors" and I would regard them as a guide to what will be on the bike rather than holy writ. It has always been thus, and generally the differences are minor. I buy my bikes from the shop, not from catalogues, so it doesn't bother me.
Yeah, so we shouldn't rely on these specs, that's my point. My calculation indicates XT derailleur vs. Nexus Premium is a 750g weight difference. 750g doesn't sound much, but it sits in the rear axle. Quite recognizable. Of course there are primitive dereilleurs which are much heavier. And also some very expensive ones much lighter. I like the clean setup of the hub. And the gear hub has advantages in winter. But I would prefer something lighter. And more efficient.