The AG Hub and Dynohub:
To dismantle:
- Unscrew and remove the indicator rod from the axle. Then extract
the 'Dynohub' unit as follows:
- Remove the dynamo cone locknut, adjusting washers and spacing
washers (if any), making a note of their arrangement so that they
can be replaced in their original positions
- Remove the four magnet-fixing nuts and lock washers from the
back of the hub shell and then remove the four magnet-fixing
screws.
- Hold wheel parallel to the workbench and with a mallet tap the
end of the spindle. This will cause the complete 'Dynohub' unit to
drop out. There is a shim washer between the cone and the
armature, and it must be replaced when the hub is re-assembled.
- The magnet spacing ring can now be lifted out of the hub shell.
- Unless it is essential to do so, the armature and magnet should
never be separated. If they are to be separated, a keeper ring
should be used as otherwise the magnet will rapidly lose its
magnetism. Even a moment's separation will cause loss of magnetism
and a spanner placed across the magnet is useless as a substitute
for a keeper ring. To separate the magnet and the armature,
hold the 'Dynohub' unit in the
left hand with the terminal plate across the palm. Then fit a
keeper ring over the armature and lightly tap the keeper with the
palm of the right hand. The magnet will then slide off the
armature on to the keeper.
- At this stage it is wise to test the armature with a test
meter. If there is no reading on the test meter there is a break
in the winding. If a test meter is not available, a battery and
bulb may be connected as shown in the diagram, and if the bulb
does not light a break in the armature winding is indicated. A
second test is to disconnect the lead from one of the armature
terminals and touch the outer edges of the armature with the bare
lead. If the bulb lights, this indicates a short circuit.
- Unscrew right-hand ball ring from the hub shell and withdraw the
gear internals as described in the general
instructions.
- Remove the low gear pawls, pins and springs. The pawl pins are
easily pushed out of the planet cage to release the pawls and springs.
- Place the left-hand end of the axle in a vice and remove the right
hand locknut, washers if any, cone lock washer and cone, making a note
of their arrangement so that they can be replaced in their original
positions.
- Lift off, in the following order, the clutch spring and cap, the
driver, the right-hand ball ring and the gear ring.
- Remove the gear ring pawls, pins and springs. The pawl pins are
easily pushed out of the gear ring to release the pawls and springs.
- Pull off the thrust washer and thrust ring.
- Push out the axle key and remove the sliding clutch and sleeve.
- Lift off the planet cage complete.
- Take out the pinion pins and remove the pinions from the planet
cage.
- If necessary, because of a worn bearing surface or ratchets, the
left-hand ball ring may be removed from the shell by means of special
tool (DD10565).
Re-Assembly
- If the left hand ball cup has been removed from the hub shell,
replace it by screwing anti clockwise (it has a left-hand thread).
- Prepare the following subassemblies:
- Fit the ball cage into the driver, with the ring of the
ball-retainer facing outwards and the recess in the dust cap also
facing outwards. If a new ball retainer is being fitted, the dust
cap also should be new. If the sprocket has been removed, see No.
23 below.
- Fit the balls (only 24) and the inner dust cap to the
right-hand ball ring, making sure that the balls can revolve
freely with the dust cap in place.
- Fit the pawls, pins and springs into the gear ring as described
in the general instructions to 'The
Re-Assembling of Sturmey Archer Hubs'. (The planet-cage
pawls, pins and springs are not fitted at this stage.)
- Smear grease in the channels of the dust cap of the driver and
in the recess of the right-hand ball ring. Do not use grease
anywhere else.
- Hold the left-hand end of the axle in a vice, so that the slot for
the axle key is above the sun pinion, and fit the planet cage.
- Ad the planet pinions and pins. (The small ends of the pins
protrude.)
- Fit the sleeve (flange first), the sliding clutch with the recess
over the flange of the sleeve and the axle key (with the flat of the
key facing upwards), and screw in the indicator rod to hold them in
that position.
- Fit the thrust ring and washer, making sure that the flattened ends
of the key engage properly in the slots of the thrust ring.
- Fit the previously prepared gear ring sub-assembly.
- Fit the previously prepared right-hand ball-ring sub-assembly.
- Fit the previously prepared driver sub-assembly.
- Drop the clutch spring over the axle.
- Fit the cap and screw up the right-hand cone finger-tight.
Then slacken it back half a turn and lock it in that position with the
special washer and locknut. On no account must the cone be unscrewed
more than half a turn, as that would throw the gear mechanism out of
adjustment.
- Invert the assembly in the vice and pour about two teaspoonfuls of
good quality thin oil into the planet cage, then fit the planet cage
pawls as described in the general instructions to 'The
Re-assembling of Sturmey-Archer Hubs'.
- Screw up the left-hand cone.
- If the magnet and armature have been separated, take the magnet and
keeper ring in the left hand and, with the right hand, lay the
armature alongside it.
- While holding the magnet with the chamfer facing outwards, push the
armature and the keeper through so that the magnet slides from the
keeper on to the armature
- Fit the card disc (carrying patent numbers) inside the cover plate,
with its notches opposite the magnet notches.
- Fit the cover plate over the magnet, chamfer inwards, making sure
that the four holes in the cover plate are in line with the notches in
the card and the magnet.
- Fit the metal spacing ring into the hub shell.
- Fit the shim washer.
- Push the complete dynamo unit into the hub shell, making sure that
the holes in the cover plate are in line with those in the hub shell.
- Fit the magnet fixing screws, washers and nuts.
- Fit the spacing washers, adjusting washers and dynamo cone lock nut
in arrangement noted when dismantling. Check wheel adjustment.
- If the sprocket has been removed from the driver, fit the outer
dust cap over the driver before replacing the sprocket, and see that
the dust cap is properly centred on the flange of the driver. Replace
the sprocket and spacing washers in the arrangement noted when
dismantling, and add the circlip.
- Replace the wheel in the cycle frame and adjust the gear as
described in 'The Fitting and Adjustment of
Sturmey-Archer Hubs.'
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