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Internal hub gears/Winter bikes
08-10-2011, 03:46 PM (This post was last modified: 08-10-2011 06:24 PM by Mark.)
Post: #1
Internal hub gears/Winter bikes
I'm bored shitless sat here doing not a lot, so I'm writing a sort of tutorial.

Bearing in mind I'm into the really obscure aspects of cycling, such as recumbents and 3+ wheelers, this is an incredibly tame topic as far as the eccentricity goes. There are VERY few resources on the web as regards to internal gear hubs, and the main one at sheldonbrown.org is slightly outdated (God rest his soul).

So, hands up how many people know about internal hub gears? Nobody? It's not really a surprise.

Click any of the links below to go to the relevant post. on that subject, any questions? Feel free to ask.

Because mcompute seems to splice posts together you'll have to CTRL+F for the navigation to work, but I've sorted that out below
• History •
• Sturmey Archer •
• SRAM •
• Rohloff •
• Shimano •
• Nuvinci •
• Schlumpf •
• Pros and Cons •
• Hybrid gearing •
• Winter bikes •
• Hub dynamos •
• Glossary •

I think that's about all I can tell you on the subject to be honest. Of course I'll have to go off and research the shimano gear systems a bit more but other than that, I hope this has helped.

[Image: Bulbasaur_by_bigsharn.jpg]
As you do...
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08-10-2011, 05:20 PM (This post was last modified: 10-10-2011 09:20 PM by Mark.)
Post: #2
RE: Internal hub gears/Winter bikes
[Image: zuzb6.gif]
Here's a brief history:
• History •
In the early days of cycling, people needed a way of getting up hills, the first few gear hubs were a flop, being only two-speed. The first people to come up with a viable, 3-speed solution was Sturmey Archer. The principle was simple, there were three gears altogether, a 66% gear, a direct drive and a 125% gear for going downhill. The system had an automatic clutch, similar to that on a semi-automatic car so was easy to operate.

[Image: 2rzrqy9.gif]
Insert more gears as appropriate

Hub gears started dying out in the 1980s in favour of the derailleur system, being able to fit a lot more gears on the bike in total. Sturmey Archer patented a 5-speed by 1987 but this was too little too late, as derailleur systems were already running 12 and 14 speed systems by then.
In 1995 another company called Fichtel and Sachs came up with the 12-speed Elan (now discontinued), with Shimano following with a 7 and later, 8 speed hub. The two gear hubs with the most speeds are the Rohloff 500/14 speedhub, which has 14 gears altogether and was introduced in 1998, and the NuVinci CVT hub, which has an infinite amount of gears (but more on that later).
Sturmey-Archer
• Sturmey Archer •
All Sturmey-Archer hubs have fittings for Disc braking systems, Drum braking systems and freewheels (for rim brakes).

The 8-speed hubs have a 325% gear ratio.

The 5 speed hubs have the above braking options, as well as a coaster brake version, and options for low and high flange hubs (basically for comfort vs speed) and a 256% gear ratio.

The 3-speed hubs come with a few more options, including fixed wheel gears (no freewheel) on a 160% ratio and the braking systems above, with coaster brakes on a 177% ratio.

There's also two 3-speed hubs with fittings for cassettes. This means you can get rid of the front derailleur system and have it all contained in a hub instead, or have a stupid amount of gears (explanation on this coming later).

The two-speed hubs sound like a waste of time personally, but nevertheless, Sturmey do 3 hubs with two-speed gear systems, the two kick-shift hubs with coaster brakes and the kick-shift with a freewheel. These have been introduced as kick-shift hubs as it saves a shifter space on the handlebars, and means there are no wires trailing from the front of the bike to the back.

They also do gearbox hubs, which are designed for use on utility bikes and load-carrying bikes. There is a 5-speed with a reverse gear, coaster brake and a gear ratio of 256%, a 3-speed with 177% ratio, reverse gear and a coaster brake, and two tricycle gearboxes with 3-speeds on a 177% ratio, one with a coaster brake and one without.
SRAM (Formerly Fichtel and Sachs)
• SRAM •
SRAM stock a 9-speed iMotion hub with a 340% range, and a 3-speed iMotion hub with a 186% ratio, both in disc, coaster and freewheel options.

They also stock what they call Dualdrive hubs, which are used for Hybrid gearing. They come complete with cassettes and therefore work as 24 or 27-speed systems with 541% and 578% ratios respectively. As for the ratio of *just* the hub gears, there isn't any information online. It also uses an external "clickbox" to change the gears, which is an unecessary external piece of equipment to go wrong.

The weird one is the two-speed automatix hub, with a gear ratio of 124%. It automatically shifts gear at a preset speed (either 12, 14 or 18Km/h) and shifts down gear as you slow. It also comes with a coaster brake as standard.
Rohloff
• Rohloff •
It has a few options as to a 14-speed internal gear hub. The total ratio is 526%, and comes with a rim brake or disc brake option. Weirdly enough it's the only hub in this list to offer a tandem version, with a longer shifter cable.
Shimano
• Shimano •
These gear hubs are a bit more complicated, and information isn't readily avaliable on some of the hubs (seriously, the website is atrocious).

There isn't a huge amount of information on the Alfine 11-speed, but it's a 409% ratio, avaliable in a disc, or rim brake version.

The Alfine 8-speed has a 307% ratio, with both disc and rim brake options.

The Nexus 8-speed also has a 307% ratio, as far as I can tell, only for rim brakes.

The Nexus 7-speed has a 244% ratio, and compatibility for a drum brake and rim brakes.

The Nexus 3-speed has compatibility with drum and rim brakes.

The Auto-D 3-speed is a completely automatic system, again, there's bugger all on the website apart from Drum and Rim brake compatibility, and that you need an external CPU to manage gear shifting speeds.

The Cyber Alfine (8-speed transmission) has a drum brake, coaster brake and rim brake option, and is shifted electronically. Again, nothing major on the website.
Nuvinci's CVT
• Nuvinci •
A bit of a weird one this, rather than the traditional planetary gear system, this is controlled by a belt system, therefore having literally infinite gears, so you can finetune it to your own needs. It has a 360% gear ratio (hence being called the N360) and is shifted by using a gear similar to a Shimano Revoshift system.
Schlumf Innovation chainrings
• Schlumpf •
Admittedly this is a new one for me, but the general idea is to have a planetary hub system (much like the original Sturmey Archers) inside the bottom bracket, so you can shift down or up without the need for a front derailleur system.

The options avaliable are the Speeddrive (1:1.65), the High Speeddrive (1:2.5) and the Mountaindrive (1:0.4), which can be used in singlespeed applications or with a rear hub gear system.
Pros and cons
• Pros and Cons •
Of course, internal gear hubs went out of fashion for derailleur systems in the 1970s. This is a shame because I believe internal hubs are a lot better than the derailleur systems, and here's why:

Low maintenance: All the parts are inside the hub itself. This means that the moving parts aren't exposed to the elements and therefore need a LOT less maintenance.

Internal clutch: Have you ever tried shifting gear while stationary? It doesn't work on derailleur systems, but because the gear hubs have an internal clutch, it'll change gear when stationary, very similar to on a car. It's useful for when novices are first riding a bike and may not be able to anticipate traffic, or there's a situation when emergency braking is necessary.

Long lasting: Nowadays you see post bikes from the 1950s that are still working without any issues, this is down to the internal gear hubs still working. I have a couple of hubs from 1970s that I haven't put to good use yet, but they're still in good working condition.

[Image: ojf6gy.gif]

Of course, on the other hand:

Price: Internal gear hubs are usually more expensive. Gear hubs can be up to £1000 each (Rohloff in particular), whereas an equivalent derailleur system would cost under £100.

Weight: Internal hubs are usually heavier than derailleur systems, in some cases adding 3kg onto the weight of a bike.

Complications: If you have a complication, gear hubs cannot be fixed by the side of the road (at least, for the mostpart). Usually you can tell when complications will arise, but this isn't always the case and if you get caught out 20 miles from home the taxi fare's not going to be cheap.

Compatibility: Bear in mind that most gear hubs are made for flat handlebars, so will only work as such. Mounting the shifters on drop handlebars or triathlon bars is a task to say the least, and with most of them being rotary shifters, using them is near-impossible on the two types of handlebar. There are ways around this using mountain bike parts and adaptions, but for the mostpart it's easier to substitute for a flat bar.

Compatibility 2: There are various gear hubs on the market all with carying amounts of spoke holes. Some are 36h, some are 32h and there are some which are 28h. Of course this means that you need to be careful what hubs you get. This isn't so much a con, as it's the same on derailleur systems, but it's worthy of noting.

The fact it's a hub: Gear hubs are, by definition, a part of the wheel. If you need to fix the hub, the entire hub has to go with it, very much like if a part goes wrong in a prebuilt computer.

Stupid Hybrid gear systems
• Hybrid gearing •
I mentioned earlier there is the capacity to have more than one gearing system on a bike. This is known as hybrid gearing and is incredibly complicated. The idea is to have a stupid amount of gears incase one combination goes wrong, or purely to say you have the most. The most you can possibly have is (81-6=75) gears on one bike, but because of the unusability, very few people use these systems.

The original idea of a hybrid gearing system is to eliminate the need for a front chainring, but a few folks have ignored this idea and just kept the front chainrings and shifters in. Unfortunately this leaves the bike with three sets of gear shifters and is therefore complicated to sell on and explain to others.

[Image: zya461.gif]

SRAM used to make specialist hybrid gearing systems, in the 3x7, 3x8 and 3x9 hubs (3 speed internal, 7, 8, or 9 speed cassette and derailleur) but discontinued the line in 2001. Sturmey Archer now makes a 3-speed-plus-cassette (compatible with Shimano or SRAM 8 or 9-speed cassettes) hub. How long before someone makes a hub capable of carrying a 10 speed cassette with more than 5 internal gears is anyone's guess... it's almost guaranteed that someone, somewhere is reading this article and getting ideas though.
Winter bikes
• Winter Bikes •
This is the reason that I love hub gears. you may remember in I WANT IT (part 9) I listed the Surly Pugsley as one of my WANT items. Well there's a reason for that besides the comical wheel size and cartoonish sizing, you can use TWO rear wheels on the frame.

[Image: b4ylhe.gif]

I know what you're thinking, madness, but think about it carefully. If you have a rear wheel with a derailleur system, and the wheel gets jammed, how awesome would it be to just whip it off, swap wheels around and get home on your spare single gear? Of course I'd use two hub gear systems to build wheels on, but it's the same principle.

Hub gears are unaffected by grit and the wet, so having internal systems is a hell of an idea for dodgy weather. There's also the idea of internal dynamos, which I'll go into in the next section, to have a fully functioning bike that works in any condition.
Needless to say, I'm looking into building one of these for myself in the very near future, hopefully I should have a build log up here before long
Hub dynamos
• Hub Dynamos •
I realise that this is a bit of a tangent off the original subjest, but it's along the same specialised lines so here goes:
Remember the old dynamo systems? You had a wheel rubbing on a tyre, slowing you down but powering your front light? There's a more efficient system now, in the way of a hub dynamo system. Buy a set of dynamo lights, wire it to your front dynamo hub (you can't get rear ones... yet) and you've got a bike in which you can be seen in all weathers.

There are plenty available from Shimano, Sturmey Archer, and SRAM. I've used a Shimano one befoe and it worked a treat... When it wanted to Smile
Glossary
• Glossary •
Coaster Brake - You pedal forwards, you move forwards. You pedal backwards, it triggers a coil that stops the wheel, internally.

Disc Brake - Like higher end mountain bikes and motorbikes, a pair of pads pushed against a disc rotor, which is secured to the hub, which stops the wheel.

Drop Handlebars - Like you see people racing on. The handlebars have a curved drop at both ends.

Drum Brake - Similar to a coaster brake, but you pull a brake lever, which pushes a pad against a brake inside the hub.

Gear Ratio - The difference in % between the lowest gear and the highest gear. eg. 1.25 is 177% of 0.75 in a 3-speed hub.

Rim Brake - You pull a lever, it stops the bike by pushing a two pads against the wheel rim.

Triathlon bars - Like drop bars, but rather than putting your hands lower down, you have your hands outstretched as far as possible. Usually with added elbow pads for comfort. Some say these are the most comfortable handlebars you can have, but they're also the most dangerous and the hardest for compatibility.

[Image: Bulbasaur_by_bigsharn.jpg]
As you do...
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08-10-2011, 05:26 PM
Post: #3
RE: Internal hub gears/Winter bikes
Boredom is evil.

Having long hair is great until you have to pull a footlong out of the dog's butt. flatank.blogspot.com
I. AM. LATCH.
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08-10-2011, 09:53 PM (This post was last modified: 08-10-2011 10:11 PM by CrazyT.)
Post: #4
RE: Internal hub gears/Winter bikes
OMG I HAZ MY OWN BRAKE!

[Image: nomnomnom.jpg]
;7$=v?%v%#5>v7v8994
The decrypt code is V, I could not make it any simpler!
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09-10-2011, 12:34 AM
Post: #5
RE: Internal hub gears/Winter bikes
(08-10-2011 09:53 PM)Drumm Wrote:  OMG I HAZ MY OWN BRAKE!

That is not how to spell boyfriend.

Having long hair is great until you have to pull a footlong out of the dog's butt. flatank.blogspot.com
I. AM. LATCH.
Reply
09-10-2011, 01:14 AM
Post: #6
RE: Internal hub gears/Winter bikes
I will read the west when I am bored. Im sorry its so long I couldn't do it. :/
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