Stripping down a Moulton

First, do no harm

Not all Moultons can be disassembled in one day. Anything that has been regularly serviced can, and most Bradford-on-Avon bikes will also come apart quickly. A Kirkby bike that has lived outside may take several days. Don’t rush the job.

Buy a can of Plus Gas. Other releasing fluids are available but don’t work as well. Spray every fitting on the bike, including the wheel nuts, cotter pins, mudguard bolts and the three self-tapping screws on the end of the main spar, and let it soak in. Also get some down the stem and the seatpost, assuming you haven’t already moved them.

Moultons are relentlessly imperial, so forget your metric spanners. There isn’t an allen key fitting anywhere on the bike, either. You will need AF spanners/sockets or a good adjustable spanner. A 2BA socket is strongly recommended, and you will need a selection of screwdrivers: a fairly wide flat screwdriver for the mudguard and rack bolts, one very long Philips no.2 (this is vital) screwdriver and, for reassembly, a long flat screwdriver. A fixed cup spanner or other means of removing the bottom bracket RH cup will be needed if the frame is to be sent away for repainting. A drill and a suitable HSS steel bit is needed to remove the heads of the four rivets at the rear suspension block. A lockring spanner (C-spanner – the size you might use for a fixed gear lockring is good) and a mallet complete the list. At some point, you are going to need drifts to knock out the rear pivot components, and you will have to hunt around for something round and metal that is a good size. A long M8 and M10 bolt are suitable.

Stripdown

At this point, do NOT remove the front brake – leave it on the fork, although you may remove the retaining nut and the mudguard. Don’t worry, as the front brake will not fall out, the reason for which will become apparent when we dismantle the front suspension.

Most components remove in an obvious way, and there is nothing unconventional about the handlebar and stem. Even steel stems can be stubborn, twisting but not pulling out. Add more Plus Gas if necessary.

The rear rack is normally fastened by two struts, the clamp around the “spike” of the frame, and a small self-tapping screw under the very rear of the rack, which is easily missed (and often rather rusted). To minimise damage, prise the clamp slightly apart as you pull the rack off the spike. Later racks, post-Raleigh takeover, are only fastened with two large bolts and a U-shaped clamp, very similar to a scaffolding clamp. They are also stamped from U-section steel, and quite nasty. On these later bikes, the upper and lower struts are permanently brazed to the frame and the lower strut is not adjustable.

Depending on the generation of Moulton, the rear brake bolt can be slightly hard to reach. You may need to remove the lower mudguard fixing bolt first, if present.

The bolts most likely to be stuck are those 2BA bolts holding the mudguards to the frame, and the mudguard stays to the mudguard blades. Use a lot of Plus Gas and leave overnight if necessary. In bad cases, it may be necessary to drill the heads off (with the attendant risk of damaging the blade) or to file them off, if the bolt is raised on a washer.

Cotter pins usually succumb to Plus Gas and one judicious stroke with a hammer. Loosen the nut first so that you are striking the nut rather than the threads of the pin, which can mushroom it. Difficult cotter pins can be pressed out with a large vice and a receiving socket for the head of the pin, if you have these available. Some older bike shops may have a cotter press, which is the best tool.

The bottom bracket is not usually very tight and just needs a lockring spanner to get it apart. If the adjustable cup is stuck, a pin spanner may be needed, but this is really unlikely. The fixed cup can be removed with a fixed cup spanner (and a few taps of the mallet), or the “bolt” method.

Fork removal, as a unit, is completely conventional. Undo the locknut with a large adjustable spanner, pick out the tab washer and unscrew the adjustable race by hand. The 1/8″ ball bearings will fall out everywhere, as they are uncaged and there is unlikely to be much grease left to stick them in place. You will, of course, want to buy new ones from a bearing supplier. Pull the fork out of the head tube, dislodging more ball bearings, and it can be worked on separately. Put a good dose of Plus Gas into the top of the steerer and let it soak in.

Rear swingarm removal

To remove the rear swingarm, ensure the three self-tapping screws have been taken out of the main spar. Two of them also hold the “foot” of the lower rack strut. Now undo the nut on one side of the pivot bolt and remove it along with the washer. Apply more Plus Gas and wait a few minutes. It is best to lay the frame on its side on grass for the next step, to ensure it is well-supported.

Using the mallet, knock the bolt out of the pivot. It may take moderate force, but be prepared to apply more Plus Gas and leave it to soak. If you muller the bolt too hard, there is a real risk of knocking the brazed-in pivot tube right out of the frame, ruining it for good. When the bolt has disappeared into the pivot you will need a drift (M8 bolt) to push it all the way through and out, making a neat hole in your lawn.

In some cases – only 25% of the bikes I’ve done – the bolt is rusted solidly to the inside of the sleeve and the sleeve will move with it. This is a problem, because the sleeve will not fit through the hole in the swingarm, and the “ear” of the swingarm will start to bend. If you see this, the best solution is to hacksaw through the bolt and sleeve on both sides. This doesn’t take long, but do be careful of damaging things.

The swingarm can now be taken off the frame and put aside. The steel sleeve now needs to be knocked out with your larger drift. Apply a lot of Plus Gas first and let it soak in. The same caution about not using too much force applies even more here. The sleeve is often corroded to the bushes, especially if they are the older bronze type. Be prepared to wait several days rather than write off the frame.

Once the sleeve is out, the bushes can be knocked out from the inside using your wide-bladed screwdriver as a drift. Plastic ones will pop out easily but the bronze ones may (you guessed it) take a few days of soaking. I have never had to drill out a set, but it is a possibility.

None of the pivot parts will be reused, so you can bin them or keep them as a souvenir of the worst part of the job.

To remove the rear suspension block, drill the heads off the rivets and carefully bend only the bottom wrapover tab of the block with a wide-bladed implement until the block can be popped off the swingarm.

Fork overhaul

Work over a clear surface, such as a workbench or swept garage floor, as you are likely to drop components during this process.

Firstly, hold the fork upright and pull the front brake off. This will take a bit of force as the brake bolt is holding the main spring in place. With the brake out, the spring abutment (a steel cylinder with a hole for the brake bolt) and the main spring (rubber wrapped in a steel coil) should pop out with some force. If not, you probably have a Kirkby bike. Was the front suspension seized? A stuck spring abutment can be prised out carefully with a screwdriver, and a really stuck main spring may need to be dragged out with pliers on the end of a long self-tapping screw (which does little damage to it, as a wine corkscrew doesn’t much damage a cork).

Now carefully disengage the bellows at the top and slide them down out of the way. The lower bearing cup needs to be unscrewed using a lockring spanner. It unscrews clockwise as you view it from the top, anti-clockwise from the bottom. Apply Plus Gas and secure the fork carefully in a vice. To avoid stress on the splined connection, only clamp the steerer tube (A Black and Decker Workmate is ideal for this). You may need to tap the lockring spanner gently with a mallet to get the cup to start turning.

Once the cup is off, there is only a small 2BA Philips screw holding the bare metal steerer to the “real” fork inside. To unscrew this, you will need your long Philips no.2 screwdriver. Look down the steerer with a torch and check the screw head is reasonably clean and that it appears undamaged. If it is a terrible mess down there, flush it out with Plus Gas and a bottle brush until the screw head is as clean as possible.

This is the little screw (from a very rusty 1964 Speed) that causes all the problems

Now proceed with extreme caution.

Locate the screwdriver on the screw head carefully. When you are happy it has engaged with the cross on the screw, give it a couple of light taps with the mallet to ensure it is seated as well as possible. Pushing down, see if you can unscrew it with light to moderate effort. The screwdriver must not slip. If it feels stubborn, apply more Plus Gas and be prepared to wait. You do not want to round off the head of this screw, as that leads to a world of pain.

Once the screw starts to move, unscrew it fully – it takes a lot of turns – and you will normally find that the two halves of the fork can be separated. Ensure you recover the screw and its small anti-shake washer from the top end. From the lower end, the rebound spring stop and rebound spring should fall out.

In extremely bad cases, the two halves may not separate even when the screw has been removed. This means the rebound spring stop has rusted in place. To free it, use your long flat screwdriver in its slot (use a torch to see what you’re dealing with) to give it a few rust-dislodging taps with the mallet, and/or use Plus Gas. It took me three days to be able to pull one fork apart.

The only thing between you and complete disassembly is now a tiny circlip that retains the top nylon bearing bush. Use a small thin screwdriver to prise the circlip open at the split (wipe it clean first so you can find it), while prising the circlip up with another screwdriver. This can be fiddly. Don’t lose the circlip – it is probably irreplaceable.

With the circlip removed, the top bush, the splined bush, the lower bearing cup, the bellows and (if not the integral type) the lower bellows retaining ring can be taken off the fork.

The full fork assembly from a 1964 Speed, cleaned. First column (from the top): circlip, top bush, bellows, lower splined bush, lower bush retaining cup. Second column: rebound spring, rebound spring stop retaining screw, anti-shake washer, rebound spring stop, main spring, spring abutment, brake bolt tube (only on early bikes). Third column: fork with splined connection and integral lower bellows retaining ring. Fourth column: outer steerer with headset crown race. Later bikes have a separate pressed steel lower bellows retaining ring, which the brake bolt passes through.

It’s now time to clean everything up and see what you’ve got.