I haven’t posted here until now. Lets hope I’m not way off track, and that I am not covering old ground.
This is a quick one for those of you that have hit a brick wall trying to understand how a 3 speed hub actually works.
There are quite a few bits inside an internally geared hub. They can seem a bit daunting. This site gives some insight into what you can expect to find. But what about the fundamentals?
A 3 speed hub basically only contains ONE gear.
This is one reason why they are so reliable, and such a masterpiece of engineering.
One gear is cleverly controlled so that it is possible to switch input and output.
In addition to this, a “locked” or 1:1 (input = output) standard freewheel option is included.
With the one gear, plus the direct drive, 3 gears are available…
For arguments sake lets say that the one gear gives a 3 to 4 ratio, (hubs differ).
By swapping input and output on the one gear it is possible to achieve either a 3:4 ratio or a 4:3 ratio. When 1:1 is added you have 3 gears.
4:3, 1:1, 3:4. It’s that simple.
The internal workings of the hub are designed to control input and output around one gear, and to eliminate that gear to give you a 1:1 ratio.
So if you have been looking at the guts of your hub wondering where the 3 gears are, you are on the right track. They aren’t in there.
Ben Skinner, Hjulcompaniet.
It looks like that the belt technology breaks into the bicycle world. There have been many attemps to create a belt system which can replace a chain. They all failed! But now we see some of the big bicycle manufacturer using the belt drive…
The refernce according belt drive systems comes from Gates. A company who owns a broad belt portfolio mainly for industrial applications.
Their product is called GATES Carbon Drive.
This issue was already discussed at Bicycle Design.
Dobbybrain shows a beautiful TREK bicycle.
And finally the single speed guys from Karlsruhe / Germany try the belt.
Intresting to see on all the frames is the possebility to open the rear dropout to put the belt into the frame triangle. Let´s see which version will be the future standard.
All of them use the Gates system!
The guys from velojournal had the chance to test the Cannondale “On” concept. Here are the results in brief
- The Sram i-motion internal gear hub offers always the right gear. But with luggage and on long climbs gears with small ratios are missing!
- The chain is perfect capsuled.
- AVID disc brake performance is good
- Front suspension performance great (Lefty!)
- The folding mechanism was not realized and could not be tested
- No rear suspension
- Fenders missing
- Carriers missing
There are still some lacks to close for this bicycle concept. But based on design it´s a big step forward!
The bicycle will be produced in two years. The price will be around 6000 Euro!
Here is the “Google translation link” in English.
Here the original link to german text.
Peter Eland from velovision.com has written an interesting article about internal geared hubs.
Here is his conclusion:
It’s great to see internal gear hubs developing to
the extent we’ve experienced in these reviews. The
Alfine in particular has the ease-of-use and style to
charm everyday riders away from derailleurs and
to introduce them to the low-maintenance joys of
hub gearing. The SRAM too is a user-friendly hub,
but perhaps more aimed at the performance rider
who will appreciate the wider, more even spread of
gears and won’t mind the extra cost.
The Rohloff is in a different league in every
aspect: range, price, tandem rating and quality.
It shifts reliably but not quite as smoothly as the
Alfine, and the lower range noise is irritating, at
least on a non-worn-in hub. But it’s still the only
truly wide-ratio hub gear, and many will find it
well worth the money. Strong riders who break
other hub gears may well end up with the Rohloff
too, as the only hub they can’t destroy.
The NuVinci was a very pleasant surprise
– a novel transmission which really works. Yes, it’s
heavy, and perhaps a bit draggy, but it’s bomb-
proof and super easy to use for non-mechanically
minded riders: a welcome addition to the hub gear
world and one which deserves to do well.
More details can be found here:
The Cannondale Bad Boy bicycle was the fundament for this new bicycle: Cannondale RAW Plus:
- Shimano Alfine internal geared hub in combination with custommade coloured cranks in 26″ wheels .
- Fantastic looking Vredestein tyres.
- All bicycle parts manufacturer names are removed from the parts. (Except Brooks!)
- Extremly stylish!
- The chain fender is not capsuled.
Read here what the producer says:
Our world is in transition.
We are now more mindful of the planet’s resources. No matter which age, sex or society we belong to, we make our choices more consciously then ever.
Riding a bike is a choice. In fact, cycling is an attitude. the bike itself is a statement about its owner.
Finally, here is one of the first available pictures which show the new Shimano Nexus Inter 3 Speed hub.
Copyright: Daniel Fikuart
Shimano product manager Florian Nebel sees trendy urban bike concepts, Crusiers and children bicycles as the focus market for this hub. Focus region is the USA! Source is the german bicycle Magazin “ Aktiv Radfahren “. See also this post about the first realized bicycle concept from Specialized with the Inter-3.
The swiss bicycle manufacturer KATZ-Bikes has one objective: Maintenance Free Bicycles!
Here is the first concept for a maintenance free MTB.
The drivetrain consists out of a Rohloff Speedhub in combination with a completely capsuled chain drivetrain. The rear wheel can be removed without touching the chain. This is realized by a special couppling between the internal geared hub and the rear pinion gear. The rear pinion gear stay on the bike and is a part of the drivetrain.
The efficiency is pushed by the following details to a high level:
- capsuled drivetrain
- the chain has a wide overlapping on the chain wheel and the rear pinion by using to little guiding pinions. These two guiding pinions are on the untensioned side of the drivetrain with a low influence on the efficiency. The tensioned upper chainline has a straight effective direction!
- the chain will be tensioned by the two guiding pinions (like a derailleur).
There is a whole bundle of maintenance free details on this bike concerning other parts. A price is not defined but the bikes will be available next spring. Phil´s veloblog is also discussing the benefits of this concept.
The result of the coperation with the University Coburg/Germany (Productdesigner Gregor Dauth, Professor Gerhard Kampe) shows a 28″ wheel folding bike.
Here are the main features of the concept:
- CUBE has a sportive bicycle portfolio. So the customers are focused on a sportive urban bicycl concept.
- The lightweight urban bike can easily carried into the flat and the working place.
- Two folding links to fold the bike and transport for long distance travel (Car, train, plane)
- Interesting to see that also here a internally geared hub with 8 speed is used (See also Cannondale Sram Projekt ONE with a Sram i-MOTION 9 hub). The hole drivetrain is completely capsuled. This protects the chain from rain, dust,….. I cannot understand that there are so many urban bicycles on the market who disregard this fundamental necessity! The HEBIE Chainglider is a revolutionary invention and nearly no bicycle maufacturer uses this fantastic part. Also in this bike concept the essential urban fenders are missing. Who wants to ride with this bicycle to work on a rainiy day! Sorry!!!! Maybe most of todays urban bikes are looking better without fenders and capsuled a drivetrain but when you face real world the cool design will not protect the designer cloth from getting dirty.
- The 28″ rear wheel can be released out of the frame. The rear pinion gear and the rear brake disc rests on the frame. This means the rear wheel looks more or less like a front wheel. There are no additional parts on any side of the hub. This has the advantage, that no oil or dirt from the rear pinion gear can touch your clothes and it´s much thiner part to store.
- Also interesting to see that the rear brake disc is mounted on the derailer side. This is the opposite side compared to actual bicycles. Do YOU have any idea why?
This urban bike concept is another proof how bright the future of internal geared hubs is. Check also the Bicycle Design Blog for a deeper sight…
The Shimano Alfine hubstrip is online.
The hub was part of a Downhill bike. I estimate that the hub was around 400km in use. All internal parts are greased with a white grease. Even the filigree ratchets which is very unusual. On a few pictures you´ll see metal dust on the white grease as a result of a massive metal abrasion. This is a normal process in the beginning of a hub life. The internal parts are new machined and do not fit perfect into each other. In the first kilometers of usage this “shake down” process produces a lot of metal dust. For a long hub life it´s important to clean an regrease the hub.
To optimize the efficiency of the hub it´s necessary to use grease and oil for the different internal parts. Shimano uses 100% grease inside the hub. This has the advantage of long maintenance intervals. The grease will last a whole hub life!
But the efficiency is bad. For sportive purpose like the Alfine is designed it makes sense to optimize the lubrication and have a one or two year maintenance interval. I my eyes it makes sense to use grease and special oil for the different parts inside the hub. It would not be possible to go for 100% like the Speedhub because of the hub shell / dust cap seal. This seal is not designed to prevent that the oil will leake out of the hub. There is a fantastic article from Chester Kyle and Frank Berto published in the Technical Journal of the IHPVA issue 52. (Also interesting to read is the feedback from Bernd Rohloff in the following issues. A great scientific showdown!)
“The grease in the Sachs 3 and the
Sturmey Archer 3-speeds was replaced
with light oil, and unlike the other hub
gear transmissions, the efficiencies of
the Sachs 3 and Sturmey 3, compare
well with the best of the derailleur
transmissions (figs. 7, 9, and 12).
Also, these transmissions were worn
in, whereas many of the others were
new. Manufacturers would do well to
replace heavy grease in their hub gears
with light oil. Although oil wouldn’t
last as long as grease, the energy
savings would be significant. Unfortunately
commuters have a tendency
to ignore maintenance until something
breaks, so light oil probably wouldn’t
be a popular choice. “
I´ll give you feedback about my experience. One of my hubs is running since 7 month with special lubrication!
Check also movie 1 (original greased hub) and 6 (special oil lubricated hub) for the differences according ease of rotation.
Details are stored on the Alfine static page.