Archive for September, 2007
The german bicycle magazine “Aktiv Radfahren” announces new Rohloff hub prototypes. On the Eurobike 2008 the german gear hub manufacturer will show first versions of a 14 gear hub with:
An overall gear transmition ratio of 580% (today 528%).
The hub shell will be 20% smaller.
The weight will be reduced from 1700g to around 1400g.
Rohloff will restrict the use for tandem and “hardcore” use for the Speedhub09.
Picture copyright ROHLOFF
There is a new gear hub version from Shimano. It´s based on theNexus INTER-3 internal gear hub but comes now with the option for a disc brake mounting. The new 2008 Specialized Globe Centrum Elite IG3 is one of the first (maybe the first) bike which comes with this new hub.Picture copyright SpecializedHere we see a new trend towards modern city bicycles. The manufacturer realize that the benefits of a internal gear hub (Check this post!) are recognized by the end customer. In the last years this kind of city bicycles were equipped with 24 or 27 derailleur gears. More gears were better! Easy marketing.But the end customers have more experience and are better informed. It´s great to see Shimano and Specialized realizing this idea. Respect!I couldn´t find any details on the hub yet. That´s all:REAR HUB Shimano IG-3 speed, discSHIFT LEVERS Shimano SG-3C41 IG3-SpeedREAR BRAKE Shimano BR-M415 mechanical disc
The main manufacturer of internal geared hubs use different synonyms. I had a look into the manuals, brochures, handbooks,…
Which is your favorite synonyme?
Here is the result:
- Internally Geared Hubs (Shimano)
- Internal Geared Hubs (Shimano)
- Geared Hubs (Sram)
- Internal Gear Hubs (Rohloff)
- Gear Hubs (Rohloff)
- Getriebenaben (Sram, Shimano, Rohloff)
- Nabenschaltung (Sram, Shimano, Rohloff)
- Versnellingsnaven (Sram)
- Versnellingsnaaf (Rohloff)
- Ensembles de moyeux a vitesses intégrées (Sram)
- Moyeu a vitesses intégrées (Sram)
- Moyeu a vitesses (Sram)
- Moyeu de transmission (Rohloff)
- Invendige gearnave (Sram)
- Navgear (Sram)
- Gear nav (Sram)
- Växelnav (Sram)
- El buje de cambio de alto rendimiento (Rohloff)
- Il cambio nel mozzo (Rohloff)
The danish bicycle company CENTURION offers pure sportive bikes with internally geared hubs. This bike concept is special and different. The bicycle look clean and tidy. No hanging bowden cables… I prefer this kind of bicycle concept. They come with Shimano and SRAM internal gear hubs. Also longlasting rollerbrake models are available. Also two single speed version with a coaster brake!
They come with horizontal dropouts for chain tensioning. So I would prefer the rollerbrake or coaster brake versions. Because a V-Brake has to be always adjusted after a tensioning the chain. Another reason is the low maintenance of the coaster and rollerbrake. A V-Brake needs new pads, adjustment and from time to time a new rim is necessary!
The swiss company velotech promotes a great bicycle:
It has a three gear Shimano Nexus internal gear hub with a coaster brake. It´s uptodate equipped. I missed a bike concept like this before. Normally well equipped bicycles come with a Inter 8 Nexus from Shimano or a i-motion 9. In my opinion 3 gears are enough when these are the right ones (according ratio). Then you have the advantage of a good price and a simple and longlasting construction. In case of rubbery it has not that huge effect on your wallet!
So in my opinion a great concept reduced to the essential parts with a clear cheerful design for daily commuting (Don´t forget adding a light!)
Torpedo Duomatic (2 gear)
Manufacturer / Location:
Fichtel & Sachs / Schweinfurt, Germany
The Duomatic hub production started in 1964. This was the time of the german “Wirtschaftswunder”. This was the time with a strong economic growth after world war two. The germans bought the VW Käfer (Volkswagen Beetle) and loved the new freedom. But how to transport a bicycle in the Beetle? This was the point where the Klapprad was invented.
A 20″ bicycle with a foldable mechanism in the middle of the frame. Like today the bowden cable for gear shifting and braking was a constructive challenge. The fabulous solution was the Torpedo Duomatic two gear hub.
A coaster brake without any bowden cable and a fantastic two gear shifting mechanism. The link between the hub and the rider was not as common today a bowden cable. The new link was the chain! By pedaling a little bit backwards the shifting mechanism switches from one gear to the other. While using the coaster brake the hub shifts also from one gear into the other. This makes sense! When you ride in the fast second gear you´ll start accelerating again in the slow first one because of the coaster braking. Perfect!
This invention made it easy to fold the bike without any problems of bowden cables! Why? Because there were none!
The 20″ Klapprad wheels are the reason that nearly all Duomatic hubs came with 28 spoke holes. There were a few hubs sold mainly in the Netherlands and Scandinavia with 36 spoke holes. Because this bicycle country with cold winters recognized the big advantage to use this hub for a maintenance free commuting bike. With this hub there were no disrupted and frozen bowden cables anymore.
After a few miles you are familiar with the shifting behaviour after a brake. Because while braking the hub switches to the next gear. What will happen is quite similar to fixed gear cycling. Your attention goes up and you´ll think forward. The options: Do I use the front brake and stay in the second gear or do I brake with the coaster brake and start accelerating with the first one.
- 28 spoke hole version
- 36 spoke hole version (very rare!)
- older versions come with a 10,5mm axel diameter and two flat sides of the axel (Duomatic 102)
- version with common 9,5 mm axel diameter (Duomatic R 2110)
I found a 30 year old 26″ Tandem with a Fichtel & Sachs Torpedo Automatic hub on eBay.
The interesting thing is that the hub is designed for the power of two cyclists! That means there is a much higher mechanical spare inside the hub. The static weight of two riders and the momentum into the hub is doubled here!
This is one reason for the long durability of the hub.