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Cross-section of wide-ratio Sturmey-Archer five-speed drum-brake hub
Sturmey-Archer has manufactured many 4- and 5-speed hub models over the years, and six 7-speed models. Another article on this site covers topics common to many Sturmey-Archer hubs. Please read that article to learn about
There are also articles on this site covering
Sturmey-Archer 4-, 5- and 7-speed hubs all are of a similar basic design using compound planetary gearing. They have two or three sun gears, and only one of them is locked to the axle at any time. The planet gears are stepped gears (two or three gears of different sizes, side by side, made of a single piece of metal so they all turn at the same rate). The large end of the planet gears engages the small sun gear, and the small end of the planet gears (middle section on the 7-speeds) engages another, larger sun gear and the gear ring. These hubs have a middle, direct drive ratio, and a choice of wider or narrower ranges depending on which sun gear is locked to the axle.
These hubs, or at least the older ones, have a "neutral" position when shifting the sun gears, because engaging two sun gears at a time would cause the hub to lock up. A sluggish or misadjusted shifter cable can allow the hub to freewheel or lurch forward. The older hubs also have a "neutral" between direct drive and high.
These hubs work best if the second-highest gear is the level-ground gear, around 70 gear inches (5.2 gain ratio, 5.5 meters development) The top gear is used for downhill and downwind riding. With a 7-speed. you might want to set the gear range a bit higher, as the steps between gears are smaller. If the terrain is all up and down, you might want to set the gear range lower. There is more detailed information on sprockets and on setting the gear range on another page.
Sturmey-Archer has announced a new seres of rotary-shifting 5-speed hubs as of late 2013; overall range 242%; no spedifics available as of Jaunuary, 2014.
Sturmey-Archer's currently available 5-speed hubs shift with a pullchain and have a wide range, as follows:
The steps between the three middle gears of current hubs are the same as for Sturmey-Archer three-speed hubs.
The outer steps are narrower than the inner ones. That is desirable so that the step from the fourth gear to the top gear is not too large.
The table below includes links to technical information about these hubs, from the Sturmey-Archer Web site's listing of hubs, the Sturmey-Archer 2010 catalog, and a Web search. Technical information is available for most current Sturmey-Archer 5-speed hubs.
|C50 series||Coaster, disk, drum, freewheel; rotary shifting, 242% range.||Announced 2014, see BikeRumor page|
|QS-RC5(W)||Gearbox for tricycle. Has reverse gear.||No information found. Probably like S-RC5(W)|
|S5C(W)||Coaster brake, steel shell||Installation, parts list|
|S-RC5(W)||Coaster brake, aluminum alloy shell||Installation, parts list|
|S-RC5(W)(N)||Coaster brake, aluminum alloy shell, 9-spline driver||Like S-R5C(W)|
|S-RF5(W)||Aluminum shell, freewheeling|
|S-RF5(W)(N)||Aluminum shell, freewheeling, 9-spline driver|
|XL-RD5(W)||Aluminum shell, 90 mm drum brake||Installation, parts list, exploded drawing.|
|X-RC5(W)||Aluminum shell, coaster brake, large flanges||Installation, parts list|
|X-RD5(W)||Aluminum shell, 70 mm drum brake|
|X-RF5(W)||Large flanges, aluminum shell, freewheeling|
|X-RK5(W)||Large flanges, aluminum shell, disk-brake fitting|
|X-RK5(W)(N)||Large flanges, aluminum shell, disk-brake fitting. 9-spline driver|
Now we move back earlier in time -- 1991-2009 hubs had ratios as in the table below:
The 1991-2009 hubs were never very common, are no longer sold and can be tricky or impossible to repair, due to parts un-availability. But who knows, you might have a couple of these lying around so you can cannibalize and keep one going.
The first of these hubs were the "5-Star" (5-Speed Sturmey-Archer) hubs, introduced in 1991. The 5-Star hubs had cantilevered planet-gear axles, that is, the axles were only supported at one end, a Bad Idea. They were shifted by dual pullchains: the one on the right for high, middle and low, and the one on the left for a wider and narrower range.
"Sprinter" hubs, introduced in 1993, had single-cable control and a sturdier planet cage.
Later versions of these hubs, sometimes called the Summit series, included a patented "ball locking" mechanism for the sun gears. Some continued to be made, or sold out of remaining inventory, until SunRace/Sturmey Archer rolled out a new wide-range series of 5-speed hubs in 2009. Model codes for Summit series hubs followed the pattern X-RD5, where R indicates rear, D a drum brake and 5 the number of gears. The ball-locking mechanism was reportedly unreliable in the 7-speed hubs: please see comments below. Whether the ball locking mechanism was as unreliable in the 5-speed hubs, I [John Allen] don't know.
|5 Star||1991||Two cables: unreliable, cantilevered pinion pins|
|5 Star Elite w/drum brake||1991||Two cables: unreliable, cantilevered pinion pins||Parts list|
|Sprinter||1993||Single cable||Technical information
|Sprinter w/drum brake||1993||Single cable||Parts list|
|Sprinter coaster||1994||Single cable|
|SAB-5 Steelite w/drum brake||1998||Single cable||Parts list|
|AB5, w/drum brake||1999||Single cable, ball locking||Parts list|
|Summit X-RD5 w/drum brake||1999||Single cable, ball locking||Technical information|
Now we go even deeper into the past. The FW four-speed hub was first offered in 1945. It had all but the top gear shown in the table in the previous section. In 1967, Sturmey-Archer began making the S5 hub, which offered all 5 gears and was an easy upgrade from the FW. Unlike the later hubs, these hubs could "walk" out of high gear position into the intermediate (neutral) gear during a hard sprint -- see comments by Jobst Brandt. I [John Allen] still use an S5 hub, and you may be lucky enough to find one in an old wheel.
This site now hosts Sutherland's Handbook of Coaster Brake and Internal Gear Hubs, with excellent rebuilding information on the hubs in this series. Boldfaced items in the table below are on this site. Other information linked below is mostly from the Sturmey-Archer Heritage site and Tony Hadland's Web site.
|FW||1945||Four speeds, single cable||Technical information
Parts list and exploded drawing with annotations
|FG||1946||Like the FW, with Dynohub generator||Technical information
Parts list and exploded drawing
|FB||1949||Like the FW, with drum brake||Parts list and exploded drawing
|S5||1967||Two cables, bellcrank on left||Technical information
Parts list and exploded drawing
More information from Sheldon
|S5.1||1977||Indicator spindle, pullchain both sides. Unreliable.||Technical Information
Parts list and exploded drawing
More information from Sheldon
|S5/2||1983||Indicator spindle, pullchain both sides.||Technical information
Parts list and exploded drawing
More information from Sheldon
|S5/2 II||1988||Axle modification||Technical information|
The FW four-speed hub used the wide-range sun-gear setting only to provide a "super low" gear. The shift from normal "low" to "super low" ("2" to "1") required a very strong pull on the gear cable to overcome the spring that controlled the sun gears. This hub used a two-part indicator spindle whose adjustment is described here.
The right side of this hub was identical to that of the AW hub, and it would fit into an AW shell. The planet cage and axle assemblies were different.
Generator and drum-brake versions followed in 1946 and 1949. They used a narrower planet cage, to make room for the generator or brake.
Many cyclists converted the FW four-speed into a five-speed by adding a separate shifter for the sun gears. This was a hot ticket for a club-riding bicycle, back around 1950.
Sturmey-Archer also made other four-speed hubs with narrower ratios, to appeal to club cyclists and racers, but they are outside the scope of this article. You may read about them on Tony Hadland's site and the Sturmey-Archer Heritage site, and in John Allen's documentation of gear ratios. John Forester's writeup about these hubs is now on this site.
The S5 5-speed hub worked like the converted FW hubs. Most of the internal parts were the same as for the FW, and the right side including the gear ring remained the same as for the AW. The S5 used two cables:
The original 5-speed hubs used a bellcrank to push a rod inward to accomplish the sun-pinion shift.
Best type of Sturmey-Archer bellcrank, with 2 7/16" stock pushrod
The S5 was sold with three different types of bellcrank, reminiscent of the story of the Three Little Pigs. One type of bellcrank was made partly of plastic and failed quickly. A second type used a flimsy steel stamping, and bent easily. Only the sturdy, forged type with internal threads is reliable, but it is rare. I've had some success modifying Shimano bellcranks to fit. I did this by re-threading them to fit the Sturmey-Archer axle. Taps for this purpose are not readily available, so I made a tap out of an old axle.
The bellcrank had to face forward to connect with the cable, and so it could not be tightened to secure the axle in the dropout. A separate axle nut was needed. The bellcrank works best with a 6 1/4" axle. Grinding a recess in the side of the axle to secure the Shimano bellcrank's grub screw and drilling out that bellcrank to fit over the threads also might work. A bellcrank could be fabricated from the flared axle nut used with a Sturmey-Archer indicator spindle.
5 3/4" and 6" axles also were sold, but they are not long enough when used with the good bellcrank if there is any spacing washer under the left-side locknut. The 6" axle is longer only on the right side. A pushrod for the good bellcrank can be made from a ten-penny nail by cutting it to 2 15/16" long (or 2 11/16" for the shorter axles) and grinding down its head to fit inside the bellcrank.
The weak point of the 2-cable 5-speed hubs was the shift control units. The S5 hub offered an excellent selection of gears for urban cycling, but it required a taut cable to prevent the primary sun gear from disengaging from the axle in first gear. Sturmey-Archer went through a number of top-tube mounted shift levers, which were never very satisfactory mechanically. The left-side cable needed to be very carefully adjusted, and the actual mechanics of the click stops in the two-lever controls were too weak, so they were quite unreliable, even though there was no real problem with the hubs.
Also, unsophisticated cyclists had trouble mastering the shift sequence of the two separate levers. It could also be confusing that the S5 must be pedaled forward at more than first-gear speed when shifting from second to first.
Later 2-cable versions reversed the spring loading on the sun gears, and used a conventional indicator spindle/chain to shift the sun pinions. The first of these, the S5/1, would not reliably stay in gear. The last version of the S5 hub, the S5/2 II, was also sold as the S5 Alloy and with a drum brake as the AT5. It was reliable, and it would shift into all gears without pedaling forward, but the problem with the shifters remained.
Sturmey-Archer eventually made a large and very complicated single-trigger control that would operate the two cables, but it was also very temperamental and required a lot of force to operate. The best control arrangement for a 2-cable 5-speed hub is a standard 3-speed trigger for the right cable, and a friction-type derailer shift lever for the left cable. The use of the friction shifter on the left gets around the problem of critical adjustment of the left cable, since you just pull it until it stops.
[I use a trigger on the left, in the 2nd and 3rd gear positions. Its latching in the 2nd gear position holds the cable taut. The cable does need adjusting occasionally. I have used the original S5, and the S5/2 II, each for years, and had no problems with them except when the cable is misadjusted -- John Allen.]
Newer 5-speeds (described earlier in this article) use a single cable, and rather different internals.
In 1997, Sturmey-Archer introduced three models of "Sprinter 7" 7-speed hubs -- brakeless, or with a drum brake or coaster brake. These were the first production Sturmey-Archer hubs with rotary shifting. They are relatively rare. Ratios were as follows:
7-speed hubs were also produced in the "Summit" series, with a ball locking mechanism for the sun gears, under different model numbers, in 1999 and 2000. These hubs did not remain in production after Sturmey-Archer's move to Taiwan.
These hubs were installed on some Moulton bicycles, and may have been reliable enough with the low-torque conditions of a small-wheel bicycle, but a cyclist who used them for heavier service in a hilly city reports:
The weak point of these hubs was the sun gears, and the system of fixing them to the axle. The original system used a sliding key, similar to that used in the Sachs/SRAM hubs, but one-sided (projecting from one side of the axle instead of both). This key and the notches that it engaged were prone to having their corners rounded off and then not yielding proper engagement. The next system used small ball bearings that would retract or protrude from the axle and engage the sun gears. Unfortunately, under extreme torque the sun gears tended to override the balls, either becoming permanently engaged with the axle or shattering. Back to the drawing board, eh?
|S7||Steel shell, no brake||Technical information
|AT7/ Sprinter 7 Elite||Aluminum shell, drum brake||Technical information
|S7C||Aluminum shell, coaster brake||Technical information
|X-R7||Aluminum shell, no brake, ball locking||Like X-RD7|
|X-RC7||Aluminum shell, coaster brake, ball locking||Like X-RD7|
|X-RD7||Aluminum shell, drum brake, ball locking|
The Web sites linked below are very helpful for older hubs not covered on this site. The Sturmey-Archer Heritage Web site has a wealth of historical and technical information. Tony Hadland's Web site includes an exploded drawing and parts list for nearly every Sturmey-Archer hub ever made up through the 1980s, as well as rebuilding information for many older hubs. The service manuals include general information (such as how to replace pawls) not covered in the rebuilding information for individual hubs.
Rebuilding instruction for several hubs on Jane Thomas's site
Sturmey-Archer 1951 Service Manual on the Sturmey-Archer Heritage site.
Sturmey-Archer 1951 Service Manual on Vancouver Van Touring site
1956 service manual and 1902-2001 information on Tony Hadland's site
|Three-Speed Parts from Harris Cyclery|
|John Forester on five-speed hub gears|
|English Three Speeds, Care and Feeding|
|Sturmey-Archer Hubs, General Information|
|Sturmey-Archer 1935-38 Catalogues|
|Evolution of the Raleigh Sports|
Sheldon's Moulton MK3 with
S5 hub and hybrid gearing
|John Allen's spreadsheets of internal-hub gear ratios|
|Martin Hanczyc's roadster pages.|
| Tony Hadland's Sturmey-Archer Pages
including the 1956 master catalogue and
a Web page with technical documentation on some of these hubs, among others.
|Hubstripping web site|
|SW Hubs by Brian Hayes|
| Jane Thomas's site with
Sturmey-Archer service manuals.
| Menotomy Vintage Bicycles
Chat forum on English bikes.
|Articles by Sheldon Brown and others|
Last Updated: by John Allen