MANUFACTURERS – INTRODUCTION
This section is about the most important hub manufacturers. Many internet sites with useful background information already exist so we restrict ourselves to compare manufacturers and their hub according to the following criteria:
Design: the basic question is – what are the external features? The hubs – are they either shaped mostly simple and cylindrical or rather ‘curvaceous’? Which manufacturer offers the largest hubs or the smallest ones?
Technics: This addresses the question of the internal features. In which way was the power transmission mostly applied? How were clutches engaged?
Innovation: How originative was a specific hub manufacturer? What were the highlights? Did there also exist other designs besides coaster brake and freewheel version?
STURMEY-ARCHER
Sturmey-Archer – founded 1902 – was the first one among the best-known manufacturers to introduce a 3-speed hub onto the market. In 2000 the company was taken over by the manufacturer Sun Race and the production was relocated to Taiwan. Sun Race now produces hubs – with and without internal gear – as well as other bike components under the brand name Sun Race Sturmey-Archer.
Design
What is initially striking here is that during over 100 years of company history Sturmey-Archer hubs were mostly designed as simple and cylindric – at least in standard versions with freewheel or caster brake. There were of course some exceptions, e.g. some historic hubs with coaster brake comprised brake bands (e.g. model C) with a stepped diameter of the hub shell there. Only a few hubs had a slightly increasing or decreasing diameter (e.g. model KSW) – but apart from some ‘outliers’ (e.g. model V or T) most of the hubs were cylindric with a smooth surface. Furthermore it is distinctive that almost all Sturmey-Archer hubs continuously contained a screwable ball ring at the sprocket side – except the very first historic model and the model T/TF. Some hubs also contained a screwable ball ring at the brake side. Many Sturmey-Archer hubs had a pretty lightweight construction and a small diameter: when comparing e.g. the 7-speed hub S7C with the Fichtel & Sachs Super 7 it turns out that Sturmey-Archer is 0.2kg lighter and 9mm smaller in its diameter.
Technology
Interestingly, Sturmey-Archer always transferred the power flow from the gear members to the shell by pawls or directly (in fixed gear hubs). They never applied a roller ramp clutch or a cone ring like e.g. Fichtel & Sachs. In addition, the pawls of the ring gear always were pivoted in pins – except for the model SW using crescent-shaped pawls. The pawls for the planet carrier were also pivoted in pins until the AWC hub appeared which contained pawls for the brake cone according to the ‘Fichtel & Sachs’ type. As already mentioned in previous submenu, Sturmey-Archer hardly ever pushed pawls out of engagement, but they pushed them inwards. Fichtel & Sachs, however, more often pushed them out of engagement. Finally it should be mentioned that Sturmey-Archer built hubs with differential planetary gear trains in a very early time period – already since 1936 with its model AR. With its model Elan Fichtel & Sachs also launched a model containing a differential planetary gear train – but about 60 years later.
Innovation
Sturmey-Archer produced 62 differgeent models during its more than 100 years of company history – including all versions, apart from many other gearless hubs. During the roughly same period Fichtel & Sachs introduced approximately only 30 different geared hubs. This variety was evident firstly in the display of its hubs. There were some hubs with extremely close gear ratios, e.g. the 3-speed model AC with 115% range – whereas a Fichtel & Sachs 3-speed hub never had a range below 150%. Additionally with the model SW a 3-speed hub with extremely wide range was available – unfortunately it was not very successful. Secondly the variety was reflected in offering hubs with more than three speeds in an early time period. Fichtel & Sachs introduced the first 4-speed hub already in 1912 – unfortunately not very successful and thus only available for a few years. Sturmey-Archer, however, offered a 4-speed hub since the 1930’s for about 35 years with different gear ratios. In 1966 a 5-speed hub was already introduced. Thirdly, Sturmey-Archer had some exotic types in their program. There were some ‘fixed gear’ hubs and some dynohubs – 3-speed or 4-speed hubs with built-in dynamo.
FICHTEL & SACHS
Fichtel & Sachs was founded in 1895 but the Double Torpedo – the first hub 2-speed hub – was released 1904. In 1997 the Sachs bike divison was taken over by Sram and the successful 3-speed, 5-speed and 7-speed hubs were sold under the brand name Sram with slightly different modifications.
Design
Sturmey-Archer’s hub shells were mostly designed simple and cylindric – whereas Fichtel & Sachs hubs were mostly more ‘curvaceous’. Many of them were staged, e.g. the Doppeltorpedo or the model 29 as typical examples. At a later date several cylindric hubs, eg. the models 515 or the duomatic were introduced but the hub shells still were not smooth but remarkably grooved. Sturmey-Archer’s ball rings were mostly screwed-in – whereas Fichtel & Sachs applied this principle less frequently – e.g. in the models 55 or 515. For this reason it is mostly easier to open Sachs hubs. You will take a special tool for opening SturmeyArcher hubs or it takes some tricks. As already mentioned in other chapter many Fichtel & Sachs hubs had a heavier construction and a larger diameter – but there were also some exceptions: the Duomatic and Automatic hubs as well as the Torpedo H3111 were smaller in diameter than the average 3-speed Sturmey-Archer hub.
Technology
Sachs did not use pawls for transmission power to the hub shell but the applied roller ramp clutches in their early days – which are mentioned in another section. It took a while until pawls came into play. Sturmey-Archer’s pawls of the ring gear were mostly pivoted in pins, whereas Sachs turned to use easier and smaller pawls after the model 55. They were pulled out of engagement together with the ring gear which needed a longer toothing therefore. In the Sachs Elan, however, the ‘Sturmey-Archer principle’ was applied in the joint planet carrier with pressing pawls inwards for deactivating them. Sturmey-Archer built hubs with differential planetary gear trains in a very early time period, whereas Sachs realized this technology only in the Elan hub. The Elan contained two stepped gear trains coupled together, however, achieving a very uniform gear gradation. Moreover, the principle of cam rods was very innovative from a technical point of view – but the triggering was pretty complicated and built rather large. The technology applied in the famous Duomatic and Automatic hubs is also very well-done. Though Bendix had some hubs in their program which changed gears by pedaling back some years earlier – the Sachs hubs applied a mechanism with pawls first.
Innovation
Sachs offered considerably less models of geared hubs than Sturmey-Archer. They never designed fixed gear hubs or dynohubs. The first 5-speed hub was available in 1987 – Sturmey-Archer has been more than 20 years ‘faster’ there. Nethertheless there were some very interesting innovations: The Duomatic and the Automatic are still much sought-after today – Sturmey-Archer never had Automatic hubs in their program. With the model Orbit a combined hub was introduced onto the market – Sturmey-Archer never offered combined hubs. A 7-speed hub was offered some years early than Sturmey-Archer. Finally some praises can be given to the model Elan – though it was not that successful. The special gear structure and the switching mechanism with cam rods have been very imaginative from a technical point of view. Until then there did not exist a hub with 12 speeds!
SHIMANO
Shimano was founded in 1921 in Japan and started producing freewheel hubs. In 1957 the first 3-speed hub (model 333) was introduced. Shimano has a leading position among the manufacturers of derailleurs for bikes. Other products are fishing reels etc.
Design
Shimano’s earliest multiple speed hubs were designed merely cylindrical, but without grooves. The design of the model Change hub – which appeared at the beginning of the 1980’s on the market – strongly reminds of the Sachs Orbit hub, but it was not a combined hub. In the 1990’s the hubs got a little bit more curvaceous – but they are also a little bit heavier than Sturmey-Archer models with the same number of speeds. In contrast, Shimano’s hubs do not have any screwed-in ball rings which makes it easier to open them.
Technology
Technology lovers get their full money’s worth with Shimano. The hubs are teeming with gear wheels, small pawls and other parts – we’ve already published lots of photos in this series. Shimano’s 7-speed hubs achieve a smaller gear spacing with two stepped planetary gear trains connected in series. All other well-known manufacturers of 7-speed hubs apply one single stepped planetary gear train. Shimano’s principle of a rotary gear selector with shift drum is exceptionally innovative and very interesting, it allows an easier gear changing under a moderate load. The Nexus Inter 4 with rotary gear selector does not require an external clutch or a driver. Furthermore, Shimano hubs often apply roller freewheels instead of pawls for driving the hub shells – it saves one internal toothing. All hubs of the Nexus series with coaster brake contain spreader rollers instead of brake screw and brake cone.
Innovation
Until 2000 Shimano offered significantly fewer hubs compared to Sturmey-Archer – because its hubs were only active on the market from 1957. But these hubs need to be paid a lot of attention! You can ‘feel’ a whole lot of technology there. Shimano already had an Automatic hub in their program in the 1970’s. What makes it so special: modifying the tension of the spring for the flyweights allowed adjusting the switching point! Shimano’s ‘change hub’- Japan’s response to the Sachs Orbit so to speak – at the beginning of the 1980’s is designed a little bit easier than the Orbit. According to the ‘Sturmey-Archer principle’ pawls within the hub shell get pressed inwards by a simple sliding clutch. The Nexus Inter 7 was quite revolutionary at the beginning of the 1990’s – Shimano was the first manufacturer launching a 7-speed hub with rotary gear selector. There was no protruding clickbox anymore which could be easily damaged. Using spreader rollers instead of brake screw and brake cone for the coaster brake was technically pretty innovative – it leads to a more uniform load of the brake band. The Nexus Inter 4 is another positive example – it is graded closer and more evenly than a 3-speed hub.
SRAM
Sram was founded 1987 in Chicago and in 1997 it absorbed the bike division from Fichtel & Sachs. Meanwhile Sram is an important manufacturer of bike components and its geared hubs are produced in Schweinfurt- the same city where Fichtel & Sachs once produced its geared hubs.
Design
Sram at first continued producing the popular 3-speed, 5-speed and 7-speed hubs from Fichtel & Sachs with minor technical modifications only, but the design was changed. Sachs hubs were shiny chrome plated with more stepped contours. Sram hubs, however, are satin chrome plated with smooth transitions containing a plastic ring with a lettering of the hub type on the shell. Many hubs are also available in different versions: The successor of the Torpedo H3111 for example is also available as i Motion 3 Disc Brake with a built-in disc brake. Sram’s new hubs such as the i motion 9 or the Automatix are basically cylindric, the i motion 9 has a slightly reducing diameter of the hub shell. The I motion 9 is relatively heavy and large, it weighs 2.4kg with coaster brake whereas Sturmey-Archer’s 8-speed hub only weighs 1.8kg.
Technology
Sram changed the design of the Fichtel & Sachs hubs but the internal gear unit remained almost the same. The display of the 5-speed and 7-speed hubs was increased by slightly modifying the number of teeth of the stepped planetary gear trains. The i Motion 9 is a technological highlight: all gears are shifted centrally by only one cam sleeve – even under load. Besides a driver – which divides the input torque to different gear components – there also exists an output clutch which allows the different output members to be connected to the hub shell.
Innovation
The Automatix and the i Motion 9 are to be praised here. The Automatix is designed similar to the Automatic from Fichtel & Sachs, however, some improvements have been made: There also exists a freewheel version. For the coaster brake version spreader rollers are applied. The flanged sleeve for the power transmission between the ring gear to the hub shell is built more solidly – this was a weak spot in Sachs hubs. The sun gear and the axle are made of one piece and it is possible to replace the bearing cone. The i Motion 9 reminds a little bit of the Sachs Elan, but it contains a lot of new ideas. To shift all gears by means of one single cam sleeve is pretty innovative. The mechanism for converting the rotary motion of the cam sleeve into a lengthwise movement and transferring it to the output clutch is very well thought-out.
Other manufacturers
There were of course some other manufacturers – and there still are some. Among the historic geared hubs Bendix and BSA should be mentioned. Among the contemporary hubs the NuVinci hub needs to be praised. Finally a continuously variable bike hub! Also the genius of Mister Rohloff will be reported at a later date.