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Sturmey-Archer 3 Speed Hub Gear Stripdown

William Reilly- Pioneering Epicyclic Engineer...

The 3-speed AW hub deserves a position in the museum of National Treasures. An elevated position on a velvet cushion with lights shining on it. It truly is an iconic machine. The Sturmey-Archer factory made literally millions and millions of these hubs to essentially the same design and shipped them all over the world. For nearly a century, bicycles have been pedalled incalculable miles via Reilly's system of small epicyclic planets revolving around an even smaller sun gear. Despite being called "watchwork" by some heads-down-no-talking clubmen in the twenties, the outstanding feature of Sturmey's AW is it's astonishing robustness and longevity. These hubs rarely receive adjustment or attention with an oil-can. They suffer the impetuous gear changes of paperboys, Raleigh Grifter riders and well, people who do not really understand what gears are for. Despite the neglect, abuse and harshly applied force, virtually all AW's carry on regardless.

...forgotten

One might suppose that the inventor of such a successful machine, with so many brilliant innovations, would become a wealthy man. William Reilly, through an unfortunate series of circumstances, remained unrecognised and unrewarded for his innovation, a National Disgrace. It may well have been partly his own fault, being prone to getting into disagreements with his associates. But after all, he was an inventor, and possibly a little highly strung. At the very least, a Blue Plaque should be erected for him.

Back to practicalities. Although the AW is durable and tolerant of neglect, it is a good idea to take it apart and check out the state of the oil. Often, you will find very little oil at all. Clean it up, re-lubricate it in fresh oil, grease the bearings and you will prolong your hub's life by years. The AW is simple in design, one of the simplest hub gears available. Springs are not going to jump out over your shoulder. The four planets are identical, so if you can cope with one then you can manage the other three.

Another good thing is that if you find any missing parts, or for example, worn bearings or clutch, you can easily get hold of another AW mechanism to cannibalize. Generally speaking, the manufacturing tolerances are wide enough that parts from many different eras of hubs fit together. Sturmey-Archer advise against mixing parts, but what have you got to lose? I have large tubs of hub gear parts that I dip into from time to time with impunity. There have very rarely been any problems, but some minor issues will be described on another page.

You can take any hub to bits on the kitchen table, but it is easier if you have a vice handy to fasten the axle pointing vertically upwards. Also, if you can get hold of a Sturmey-Archer cone spanner, the process of bearing adjustment is simple. And this should really be perfect.

The Sturm..., I should say Reilly, AW is the ideal starter hubstripping project.

This is the hub that we will dismantle.
Note oily dirt. this could be cleaned off.
However, all the internals will be cleaned in any case.
The date of manufacture is always stamped on the shell.
For comparison, a dirtier hub. This indicates good external lubrication.
If the dirt was cleaned off, the shell would be very shiny.
These dirty hubs are often a very good prospect for refurbishment.
This one is not so good and has rusting on the shell. Luckily it is only light.
The internals from an AW where the bike has been left outside.
This would still clean up well with a degreaser like Jizer.
Same hub. Note that the sprocket has actually had very little wear.
Back to our project AW hub. Work on newspaper. Lay parts out in sequence removed.
Unscrew the toggle chain. Take off the nuts and any loose washers.
Hold the axle in a vice with the sprocket end vertically upwards.
Use a small screwdriver to prise off the wire ring.
Lever off in all three cutouts and remove.
Pull off the spacer rings and the sprocket.
Remove the dust shielding ring.
Using a 15mm spanner, undo the slim locknut.
Take off the locknut. You may need to prevent the cone from moving.
Take off the thin anti-rotation washer.
Unscrew the cone with a 17mm or Sturmey-Archer cone spanner.
Unscrew the left hand cone and check for wear.
If hub is not in a wheel, hold the right hand flange in a vice with protected jaws.
Hit the square cutout in the ball-ring with an old screwdriver to unscrew it (anti-clockwise).
Finish unscrewing by hand and withdraw the entire gear mechanism.
Note an almost total absence of oil on both the mechanism and shell.
The larger mechanism is the AW, shown next to one from the SB3. All parts are the same apart from the planet carrier. This is also true of the AG rear 3 speed with Dynohub.
Pull out one pawl pin in the left hand end. They are in the planet carrier.
Remove the pawl and the small spring and store in a safe place.
Repeat this process for the other left hand pawl pin. These drive the shell in first gear.
Pawls removed.
Put the left end of the axle back in the vice and unscrew the locknut.
Take off the cone locking washer.
Unscrew and remove the right-hand cone.
Take off the driver. This is the part the sprocket drives.
Pull off the collar and the mainspring.
Lift off the ball-ring.
View so far. Note the high-gear pawls are different from the low-gear pawls and not interchangeable.
Lift off the annulus (internal ring gear).
Remove the thin washer. Not all AW hubs have this.
Lift off the collar that fits around the axle key.(Thrust ring)
Push and then pull the axle key out sideways.
Axle key out. This part sometimes gets bent or very occasionally, broken. Replacements are available
Pull off the four-pronged clutch and the clutch operating sleeve.
View of the clutch alone. The prongs sometimes get worn or chewed by clumsy gear-changing.
View of the clutch sleeve alone.
Pull out a planet pinion axle.
Followed by the corresponding planet pinion. Repeat this for the other three.
Lift off the planet carrier.
The plain axle devoid of components. Note differences with FW axle.
Gear parts laid out in sequence on the bench. Right to left, then underneath right to left.
Use a small screwdriver to lever the pawl pins from the annulus.
Remove the two pins, pawls and springs and store in a safe place.
Progressively lever off the ball-ring bearing retainer with a small screwdriver, using several locations.
Retaining ring removed, showing the correct number of balls.
Temporarily replace sprocket and hold in a vice to allow you to lever off the axle bearing dust cap.
Dust cap will release to allow removal of bearing ball cluster.
Note slight wear on high gear pawls from heavy contact with clutch. Still serviceable with sharp edge ground off.
Use identical method to take off hub shell dust cap.
This dust cap should not be mixed up with the cap from the drive end. They can be slightly different sizes.
Here's the very oily hub cleaned and polished.
The hub was probably covered with grease decades ago.
Forty-five years old and will run for thousands of miles more.
The rusty hub. Note USA Patent number. This is an FW.
Sturmey-Archer- Hub of the Universe.
Here is the hub that looked like it was covered in sand.
With all the rust wire brushed and reddish oil cleaned off it will be fine.
This is the hub that we will dismantle.
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Last Updated on Sunday, 07 November 2010 22:37