Hub gear expert and aficionado Dave White has kindly contributed three more articles to the Sturmey-Archer section of this WordPress site. They deal with the dating of Hercules and Brampton 3-speeds, the design of Hercules and Brampton 3-speed triggers, and the possible use of BSA pinions to replace worn ones in Sturmey-Archer type A and F/FN hubs. To access this material, simply go to the home page, scroll down and click on the appropriate link: https://hadland.wordpress.com
This WordPress blog is the descendant of a website that went live nearly a quarter century ago, on New Year’s Day 1998, and which for many years was known as Hadland.net. The website soon started carrying information about Sturmey-Archer hub gears that was not then available anywhere else on the internet, including how to repair most models produced prior to 2000.
Much more information on Sturmey-Archer hubs has been added over the years. This includes hitherto unpublished material provided free of charge by leading authorities on old hub gears. These authors include Jim Gill, John Fairbrother, Peter Fuller and Vernon Forbes.
Today (30 July 2021) new information from David White, on axles for the Sturmey-Archer types A and FN, has been added to the end of the existing article on axles, accessible from here.
The Tricoaster hub, a combination of back pedal brake and three speed hub gear, has certain desirable qualities. The first is that there should be no freewheeling ‘no gear’ position between the gears, which would of course be very dangerous if found while braking. Secondly it is an advantage if braking is always applied through the Low gear train for maximum braking force regardless of the gear in use. Finally, as with any hub gear, it is an added bonus if a snapped cable does not leave the hub in High gear.
The model C Tricoaster of 1907 and the N and FN models that followed from 1910 to 1921 possess all the qualities listed above – on these hubs a snapped or slack cable gives Normal gear. Of the Tricoasters that followed, the KC of 1922-35 and the TCW series of 1952-72 did not apply the brake through the Low gear train regardless of the gear selected, and a slack cable gave High gear. The S3C, introduced in 1970, was a little better – it did have a ‘no gear’ position between Normal and High but this could not affect braking since in the S3C braking is always applied through the Low gear train, but a slack cable still left the hub in High gear. Of all the Tricoasters Sturmey-Archer designed up to and including the S3C of 1970, the earliest C, N and FN models were perhaps the best.
I had been having trouble with the back-pedal brake component of the Tricoaster on my 1914-15 Raleigh Special Roadster. It is fitted with an FN, an N type Tricoaster with the ‘fine’ axle thread adopted in 1914, becoming standard thereafter. The problem with my hub was that the back-pedal brake would only engage in warm weather. When tested on a sunny afternoon it would work fine, but tried cold the following morning the brake would not engage, the pedals just freewheeling backwards. Knowing, therefore, that it was temperature related, I hoped that a good clean up was all that was needed. I also knew it had not been serviced for about 10 years and that at its last service modern Sturmey- Archer gel had probably been used to lubricate it.
So, armed with an exploded diagram, I stripped it down to sub-assembly level (Fig. 1). I could not remove the screwed-on sprocket to service the right-hand ball ring since it appears a special tool is needed to do this.
The brake is applied by a worm drive, which was nicely gummed up in line with the diagnosis (Fig. 2). I cleaned everything up and set to work re-assembling using my preferred lubricant, SAE 30 four stroke lawnmower oil.
This is where I ran into trouble as these hubs do not go back together like the later types. In particular, adjustment of the right-hand cone is very different and although this expertise must surely reside somewhere in the club’s knowledge base I could find nothing online.
The procedure for adjusting the right-hand cone on almost any S-A hub from K Series on will be familiar to many – screw the cone up finger tight, back off half a turn, fit special lock washer, fit lock nut. On the FN Tricoaster the r-h cone/clutch screws up all the way until you run out of axle thread, without ever reaching a registration point. Scouring the early Sturmey-Archer catalogues on their Heritage website turned up unhelpful advice like ‘never disturb the right cone’, or worse ‘the right-hand cone is a fixture, and must on no account be meddled with’.
A lengthy session with the exploded diagram and a description of the workings of the similar type V hub revealed that the three speed element of these early hubs works quite differently to later models.
These earlier designs operate by moving a sliding pinion along the axle. Normal and High ratios are achieved by engaging the sliding pinion with internally toothed ‘clutches’ at either end of its travel, Low being activated when the sliding pinion is in its central position disengaged from either clutch.
With the cable slack the sliding pinion is in its left-most position and engages with the internally toothed clutch in the compound planet cage giving Normal gear. One click on the lever pulls the sliding pinion out of this engagement, taking it out of play but enabling a Low gear train. A second click pulls the sliding pinion even further to the right engaging it with the internally toothed clutch in the r-h cone/clutch and providing High gear. The progression of gears on tightening the cable is therefore Normal-Low-High, dictating the design of top tube and handlebar levers to accommodate this in a logical way (Fig. 3). There is no ‘no-gear’ position with this sliding pinion design.
The sliding pinion principle is used in the C, N and FN Tricoasters and the V and A type three speed hubs. Generally, from the K series onwards, the familiar sliding clutch method is used to change gear.
The key to adjusting the r-h cone/clutch correctly on the axle is that it should be screwed on just far enough that the sliding pinion teeth are flush with the upper face of the internally toothed clutch in the compound planet cage (Fig. 4). The upper pinion seen is the fixed pinion, part of the axle. The teeth of the sliding pinion can be seen just below it, correctly adjusted flush with the surface of the internal clutch teeth in the compound planet cage.
If the r-h cone/clutch is not screwed far enough along the axle the fixed pinion could engage with the internal clutch teeth in the compound planet cage and probably lock the hub. If the r-h cone/clutch is screwed on too far, the sliding pinion might not be pulled to the right far enough along the axle to engage High gear. When it is correctly positioned on the axle, it should look like the one shown in Fig. 5.
Since I could find no servicing instructions for these hubs, I have documented the process below. I am pleased to say my hub is reinstalled in the bike and the brake has worked consistently since.
Sturmey-Archer FN Tricoaster strip and rebuild
The following notes refer specifically to the FN Tricoaster Mark 1 1914-1918. In terms of re-assembly, the 3 speed section at least could be adapted to apply to the C and N Tricoasters and model V and A three speed hubs – the sliding pinion group of hubs of that era. Part names and numbers referred to relate to the exploded diagram (shown below) of the FN hub available on the Sturmey-Archer Heritage website at:
I am not aware of any sources of spares for these hubs and would be pleased to know of any. These notes reduce the Tricoaster hub to its main sub-assemblies only, sufficient for cleaning.
To dismantle the FN Tricoaster Mark I to sub-assembly level
1. Remove the axle nuts and any spacers. It is useful not to disturb the relationship between N25 r-h cone/clutch and its star locking washer – to preserve this setting fit a spare axle nut to hold the star washer in place. If this setting has been disturbed refer to the reassembly instructions.
2. Unscrew and remove N6 l-h indicator rod and N7 r-h indicator coupling. N126 indicator spring may come out with the l-h indicator rod.
3. With the wheel horizontal, left-hand side up, remove the l-h locknut and N192 l-h adjusting nut/cone.
4. Lift off N152 brake plate & arm assembly and the N150 brake cone.
5. The axle complete with temporary axle nut, locking star washer, r-h cone/clutch and sliding pinion is now free to drop out of the right-hand end of the hub. It will be needed in place for step 8.
6. Loosen N34 r-h ball ring in the usual way using a punch and hammer. It has a two-start right hand thread. (At this point Sturmey-Archer instructions require you to mark the relationship between the r-h ball ring and the hub shell so that they can be refitted in the same orientation – I understand this to be a moot point).
7. Turn the wheel horizontal again left-hand side up and unscrew the mechanism by hand from the hub shell, keeping the l-h end uppermost. Note: the internal clutch nut N149 and Low gear cage (c/w worm drive) N164 are not secured – they could fall off if the mechanism is not kept left-hand end up.
8. With the axle in the mechanism and kept vertical, l-h end uppermost, clamp the r-h end of the axle in a vice.
9. Lift off N149 clutch nut assembly and N164 Low gear cage (c/w worm drive) assembly.
10. Remove the remaining mechanism from the vice and remove the axle assembly from N22 compound planet cage and driver and N34 r-h ball ring/drive sprocket assembly.
11. Unscrew N10 axle (internal) grub screw to remove N8 main axle spring if required.
To reassemble the FN Tricoaster Mark I
If the relationship between the right-hand cone/clutch, star washer and axle has not been disturbed proceed to step 5.
To check or reset the relationship between the right-hand cone/clutch, star washer and axle proceed as follows:
1. Screw N25 r-h cone/clutch onto the right hand (slotted) end of the axle. Clamp the axle vertically, left-hand end uppermost.
2. Drop N22 compound planet cage and driver and N34 r-h ball ring/drive sprocket assembly over the axle, drive sprocket down.
3. Observe the level of N197 sliding pinion teeth relative to the upper face of the internally toothed ‘clutch’ of the compound planet cage. The r-h cone/clutch is correctly adjusted on the axle when the sliding pinion teeth are flush with the internally toothed clutch of the compound planet cage (Fig. 4).
(If the r-h cone/clutch is not screwed on far enough, the fixed pinion could engage with the internal clutch teeth and probably lock the hub. If the r-h cone/clutch is screwed on too far, the sliding pinion might not be pulled far enough along the axle to engage high gear.)
4. Screw the r-h cone/clutch along the axle until correct alignment is achieved, fit the star lock washer and hold it in place temporarily with a spare axle nut.
5. From this point on assembly is the reverse of the dismantling procedure. When refitting N152 brake plate and arm be sure to align the actuating peg on N153 brake lever with the corresponding recess in N150 brake cone and remove the temporary axle nut that is retaining the star washer on the right-hand end of the axle.
The information provided here is presented in good faith, it worked for me but is not warranted – please use this information at your own risk.
Tony Hadland, The Sturmey-Archer Story, 1987.
Norman Richardson, for help and advice.
This article first appeared in The Boneshaker, journal of the Veteran-Cycle Club, Number 213, Volume 22, Summer 2020. It is reproduced with the kind permission of the club and of the article’s author, Peter Fuller.
NB: It is important to note that these instructions were written in the mid 1980s. Many items that were then current or easily available may no longer be so. The article is based on Appendix B of The Sturmey-Archer Story by Tony Hadland, published in 1987 by John Pinkerton.
Converting an FW into an S5/2
By far the easiest way to convert an FW to ﬁve-speed operation is to obtain a complete axle assembly for the S5/2 (HSA 329, HSA 330 or HSA 331, depending on axle length). This comes ready assembled, complete with sun pinions, dog ring, axle key and associated springs. The FW is merely rebuilt around the S5/2 axle assembly.
This conversion offers a gear which is virtually identical to the current five-speed hub. In the past Sturmey-Archer disapproved of five-speed conversions but, at the time of writing, the company is prepared to issue a list of the necessary parts for rebuilding FWs around S5/2 axle assemblies. They also market a retro-fit list consisting of the complete S5/2 internals and accessories for fitting into an FW shell, or an AW shell made before April 1984.
Converting an FW into an S5 (original pattern)
It is also possible to convert four-speeds to the original S5 style of operation; this involves a push rod in the left end of the axle, rather than the toggle chain used in the S5/1 and S5/2. The following conversion instructions for the FW were written by Denis Watkins of Castle Bromwich, after the discontinuance of the S5 and before the introduction of the S5/1.
1. The FW is really a five-speed hub in which, to permit its control with only one lever, only four speeds are used.
2. The extra low gear of the standard FW is brought into play by pulling the two sun pinions K409 and K408 to the right such that the dogs on K408 engage with the axle dogs.
3. If, when the FW is in top, it were possible to put K409 and K408 into the same position as in 2. above an extra high gear would be obtained.
4. To obtain both extra high and extra low, movement of K409 and K408 must be controlled by an additional lever. This can be done as follows.
5. Compression spring K8l3B is not required and must be removed.
6. Axle key K526A must be replaced by axle key K526 (used in AW).
7. Coupling/indicator rod K807ZA must be replaced by the type used on the AW.
8. Replace axle key K402 by a further axle key K526 and file ends of latter flush with surface of pinion sleeve K406.
9. Remove indicator rod K804 (K804A) and replace by a suitable push rod with end threaded to suit axle key K526. This is the only real difficulty. It is possible to use the rod portion of K504AZ (indicator for AW with long axle). It might be better to cut the outer end off an AW indicator rod and have a bit of similar rod welded “end on” to provide a total length such that, when the rod is pushed in to move K408 into engagement with the axle dogs, the outer end of the rod is flush with the end of the axle.
10. The push and release of the rod is conveniently controlled via a bell crank. Shimano have a very nice bell crank arrangement on their three-speed hub. Unfortunately it is threaded for a standard 3/8” (9.5mm) axle and there may be insufficient metal to permit drilling and tapping to Sturmey axle size.
11. A very important point; in early versions of the FW, K408 was made with parallel dogs. This is OK for conversion. Later versions of the FW had these dogs chamfered on the one face to facilitate engagement. These are unsuitable for conversion (unless an old type K408 can be obtained) as, if attempted, it will be found ‘ratcheting’ occurs in extra high gear and no drive is possible.
With regard to 11. above, the later FWs can also be converted if the larger sun of an S5 (HSA 269) or of an S5/1 (HSA 317) can be obtained. Of course, Sturmey-Archer produced a bell crank and push rod for the S5 (HSJ 679 and HSA 297 or HSA 288) but these are no longer available. The design of the bell crank evolved through three versions; plastic, pressed steel and machined steel. The latter seems to have been the most reliable. Some riders replaced the push rod with a modified flat-headed nail for smoother and more reliable operation.
An alternative to the bell crank was devised by Jack Lauterwasser. The push rod is made from a section of 12 gauge spoke and protrudes from the axle end by about 20mm. Threaded onto the external end of the push rod is a brass bush (made from a solderless nipple), drilled to permit the control cable to pass through freely at 90 degrees to the rod. An oversized tear-drop shaped brass washer is fitted to the wheel axle, with the pointed end of the washer pointing 180 degrees away from the cable fulcrum clip. The pointed end of the washer is cut out to house a solderless nipple, ﬁxed to the control cable.
When the control cable is tightened, its far end cannot move because it is anchored to the tear-drop washer. The cable therefore straightens itself and, because it passes through the end of the push rod, pushes the rod into the hub, thus shifting the suns. The system works very smoothly.
The cable anchorage cut out, being keyhole shaped, permits quick release of the cable, merely by depressing the push rod whilst unhooking the cable end. Because the cable end is ﬁtted with a solderless nipple, the push rod remains attached to the cable – with the bell crank system it is fairly easy to lose the push rod. The biggest disadvantage with this system is the risk of accidental damage to the exposed end of the push rod.
A somewhat similar system was devised by Mr P. Pottier of London during the 1950s. He used a Sturmey-Archer toggle chain, the end of which was riveted to the pointed end of the tear-drop washer; the chain passed through a steel bush push-fitted onto the end of the push rod. The control cable was attached to the toggle chain in the usual way; hence, when the cable was tightened, the chain moved the push rod further into the gear.
Non-Standard Controls for the S5
Many riders using the S5 type converted four-speeds use a derailleur lever for the left changer. This gives good ‘feel’ to the change (which, unlike that of the S5/1 and 2, is not designed to cope with crash changes) and reduces the need for cable adjustment.
Some riders advocate use of a derailleur lever also for the right hand changer; a practice greatly disapproved of by Sturmey-Archer because of the ‘no gear’ slip position between high and normal gears.
The Californian cycle engineer, Ernest Rogers, devised a Duo-Trigger Shifter for five-speed hubs. This consists of two of the metal three-speed triggers (not the current bulbous plastic type) bolted one on top of the other, the clamp of the top trigger body having been first removed. The effect is somewhat similar to the triggering arrangement on a double-barrelled shotgun.
For more details and to order this book, follow this link: https://v-cc.org.uk/about/club-sales-2/the-hub-of-the-universe/
You may have seen elsewhere on this site (in the comments on John Allen’s hub gear table in the Gears section) that Wiel van den Broek has created some very useful Excel spreadsheets for gearing choices involving hub gears and bracket gears. You can enter the tyre format, chainwheel and sprocket sizes and instantly compare the results given by different gears.
The gears covered range some more than 100 years old to others that are in current production. There is a metric (distance travelled per pedal rotation) chart and a gear inches chart (equivalent direct drive wheel diameter), both of which you can download from here: http://fietssite.jouwweb.nl/downloads
Many thanks to Wiel for creating these spreadsheets.
“Next, unscrew the right-hand ball ring but because it has a two-start thread and must be replaced in its original position, that position must be marked. String or adhesive tape may be attached to the spoke nearest to the letters ‘SA’ which are stamped in one of the notches on the ring.” (From the 1956 Master Catalogue, sub-section 4, page 15, paragraph 1.)
This collection has now been dispersed but before that happened, Arnfried and I recorded it for posterity. Enjoy the slideshow!
Instructions for a wide range of Sturmey-Archer hubs from 1902 to 2001. Includes the original 1902 3-speed, the type K series of the 1920s and 30s, the T and TF 2-speeds, the ever popular AW, the SW, SG, SB, AB, AG, TCW, AM, AC, ASC, FW, FG, FM, FC, BR, GH6, S3B, S3C, all 5-speeds, the Columbia 3-speed, the BSA 3-speeds (based on a Sturmey-Archer design) and the hubs in production when Sturmey-Archer ceased to be British-owned in 2001. Also included is information on the DBU and FSU accessories for use with hub dynamos. The files are in Adobe Acrobat format, making them zoomable and easily printable. (Content last added 21 June 2016)
In the beginning
K series 3-speeds (K, KS and KSW)
An 18-page PDF file that includes Jim Gill’s analysis of the type K, design changes during its production run, cutaway drawings, Jim’s simplified instructions for dismantling and re-assembly, and S-A’s parts lists for 1925 and 1935.
K series S-A hubs
K series 3-speeds with drum or coaster brakes (KB, KC and KT)
A 13-page PDF file including Jim Gill’s description and analysis of the type KB 3-speed and drum brake, and S-A’s 1937 maintenance instructions and parts list.
Type KB 1937
A five-page PDF including Jim Gill’s description and cutaway drawing of the type KC 3-speed and coaster (back-pedal) brake, plus S-A’s 1925 parts list, Jim’s dimensioned drawing of the hub shell and his handwritten notes on (and sketches of) the type KC.
A single page PDF showing S-A’s exploded drawing of the type KT 3-speed and drum brake for tandems. Also included are details of the special brake lever fittings.
S-A 1930s drum brakes without gears (BF, BR, BRT and BFT)
A two-page PDF showing cutaway drawings of the 1932-36 versions of the type BF and BR brake hubs.
Type BF & BR 1932-36
A nine-page PDF including S-A’s 1937 maintenance instructions and parts list for the BF and BR hubs.
Type BF & BR 1937
A four-page PDF with cutaway drawings of early and later versions of the BRT and BFT tandem drum brakes.
Type BRT & BFT 1936-41
From the 1956 Master catalogue
Fitting and adjustment
Use and maintenance
SW wide-ratio 3-speed (See also Brian Hayes’ paper)
SB wide-ratio 3-speed/hub brake
SG wide-ratio 3-speed/Dynohub
AW wide-ratio 3-speed (see below for later AWs)
AB wide-ratio 3-speed/hub brake
AG wide-ratio 3-speed/Dynohub
TCW wide-ratio 3-speed/coaster
AM medium-ratio 3-speed
AC ultra-close-ratio 3-speed
ASC fixed-wheel 3-speed
FW wide-ratio 4-speed
FG wide-ratio 4-speed/Dynohub
FM medium-ratio 4-speed
FC close-ratio 4-speed
BF & BR hub brakes
Dry Battery Unit & Dynohub wiring
Instructions from various dates, 1960s – 2001
S3B 3-speed with small-diameter hub brake
S3C 3-speed coaster
S5/2 and Five Speed Alloy 5-speeds
S52 1988 modifications
5 StAr and 5 StAr Elite 5-speeds
Columbia ‘no-slip’ 3-speed (Jim Gill’s documentation)
AB/C & BF/C 90mm hub brakes
AWC 3-speed coaster
AT3, VT and ST Elite hub brakes
Sprinter 5-speed hub and Sprinter 5-speed Elite 5-speed hub brake
Sprinter 5-speed coaster
Sprinter 7-speed hub & Sprinter 7 Elite 7-speed hub brake
Sprinter 7-speed coaster
Steelite SBF, SBR & SAB hub brakes
All information provided here is done so in good faith. It is as written by the original authors and has not been modified by Tony Hadland. No responsibility can be accepted for any loss, damage or injury of any kind sustained for any reason arising therefrom. Our thanks go to Sturmey-Archer Limited and Jim Gill for permission to reproduce their material.
The first seven of the following files provide amazingly detailed information on Sturmey-Archer hubs, from the earliest models to the present day. They were compiled by English engineer and hub gear enthusiast, the late Jim Gill. Although some of the material was originally published by Sturmey-Archer, the vast majority is Jim’s own work and was first published here.
Also provided is the late John Fairbrother’s simpler approach to fixed-wheel conversions. John was an engineer and bicycle restorer based in Hampshire, England.
Newly added in summer 2021 are various useful and interesting technical papers by eminent hub gear specialist David White. Information from David on type A and FN axles has also been added to the axle charts.
The files are in PDF format, making them zoomable and easily printable. Please note that where a drawing is said to be “actual size”, this only applies to the original hard copy. The size you see will depend on your screen size, the PDF zoom setting you use or your printer settings.
Epicyclic Gears – some theoretical considerations
Engineer and hub gear enthusiast Jim Gill explains how various hub gears work. Includes zoomable diagrams.
Sturmey-Archer Hubs – reference tables
Zoomable dimensioned drawings and tables of pawls, drivers, axle keys, pinion pins, gear teeth, ballcups, hub shell dimensions, indicators and more.
Sturmey-Archer axle charts
Zoomable dimensioned drawings of axles for Sturmey-Archer hubs. At the end of this article is information from David White on the type A and FN axles, added in summer 2021.
Sturmey-Archer Hubs – cone charts
Zoomable dimensioned drawings of cones for Sturmey-Archer hubs.
Sturmey-Archer Hubs – spring charts
Zoomable dimensioned drawings of springs for Sturmey-Archer hubs.
Sturmey-Archer Hubs – triggers
Zoomable dimensioned drawings of triggers for Sturmey-Archer hubs. Includes how to convert triggers for use with fixed-wheel hubs.
Jim Gill’s fixed hub conversions
Jim Gill’s compilation of how to convert a 3-speed to 2-speed fixed-wheel and how to convert 4-speeds to 3-speed fixed.
Jim Fairbrother’s fixed hub conversions
Modifications to Sturmey-Archer hub gears to produce fixed wheel gears
Engineer John Fairbrother outlines another approach to fixed-wheel conversions.
Fixed hub trigger conversion
Modifications to Sturmey-Archer triggers for use with fixed wheel gears
More good stuff from Jim Gill.
Variations in Sturmey-Archer K hub drivers and right-hand ball cups
The first of a series of illustrated articles by eminent Sturmey-Archer enthusiast David White.
Early K-type right-hand ball cup
Photos and comment by David White.
Ratchet plates for Sturmey-Archer triggers
David White adds to information from the late Jim Gill.
Making a replacement indicator for a Sturmey-Archer ASC 3-speed fixed hub
Referring to Jim Gill’s indicator sheet, David White shows how to make a replacement for this rare component.
How to make a replacement indicator coupling for AM, AR or AC hubs
David White shows how to make a replacement indicator coupling for these three hubs with through axle bore.
Keeper for Sturmey-Archer Dynohub magnets
David White provides all the dimensions you need to make your own keeper. No good for zoos or brothers but works a treat with Dynohubs.
Sturmey-Archer shell sizes 1930s to 1970s (and perhaps longer)
David White’s annotated drawing with the key dimensions.
Clamping tool for holding Sturmey-Archer hub shells
Don’t squash your hub – build yourself a proper clamping tool by using David White’s illustrated instructions.
The Sturmey-Archer ‘wavy’ emblem on hubs
David White investigates the evolution and variations of this classic logo.
Variations in pre-WW2 AW hub logos and stampings
Detailed research by David White into the stampings and logos on early AW 3-speed hubs.