Servicing the rear suspension on an APB is pretty much identical to that on an AM and very similar to that of the 60s Moultons. After extensive use the rear suspension pivot pin or bushes may wear or may seize if the original lube has been washed out. On very early APBs the phosphor bronze bushes were not as well lubricated as those made since 1992.
Spare parts are available through your local APB dealer. It is advisable to get a new pivot bolt, sleeve and pair of phosphor bronze bushes before starting a full overhaul. It is a good idea to service the rear suspension on a yearly basis if the APB is in regular use. In this case do not remove the phosphor bronze bushes. In addition to the normal tools you will need a vice with soft jaws if the phosphor bronze bushes are removed. If the pivot bolt is seriously seized in the sleeve we recommend that you take it to your nearest APB dealer. If there is some wear present but the bolt is not seized its replacement can be tackled at home.
1. With cantilever brakes, undo the rear brake cable from the cantilever arms and unhook the straddle wire from the other side. With V brakes, undo the inner cable clamp and pull the cable away from the arms. On derailleur models undo the pinch bolt holding the rear derailleur inner wire in place and release the hub gear wire if you have a 3 x 7 model. Similarly release the front derailleur inner cable on those fitted with a front derailleur. Pull all the inner cables through the outers so that no cabling remains attached to the rear triangle.
On 3 and 5-speed hub gear models disconnect the gear cable. With the 7-speed Sturmey-Archer hub gear, unscrew the wire behind the support arm, undo the cable adjuster completely, unscrew the connector at the frame join and the slide the outer cable away from the eye on the rear triangle so that the complete inner and outer are no longer attached to the rear triangle.
2. On some models it is necessary to remove the right hand crank. In almost all cases it makes access easier. Undo the right hand crank fixing bolt and using a crank extractor remove the right hand crank. Remove the rear wheel. With a 13mm spanner, hold the right hand pivot bolt head still and with another spanner unscrew and remove the nyloc nut on the left hand side. With a soft-faced hammer knock the pivot bolt through the sleeve; if it is very tight you may need to use a piece of steel rod to act as a drift.
3. Undo the four cross headed screws that hold the suspension rubber cone unit to the back of the seat tube. The rear triangle can then be removed from the frame. Support the rear triangle carefully and drift the sleeve out of the phosphor bronze bushes.
4. If the pivot is simply being serviced, leave the bushes in place. If replacement is required, each bush will then have to be carefully removed from the pivot in the rear triangle This is accomplished by using a drift on the inside edge of the bush. Smear the inner and outer surfaces of your new bushes with anti-seize compound, which is supplied with new bushes and pin set. Using the soft jaws of a vice, push each bush into the housing one at a time.
5. Using a soft-faced hammer, knock the pivot sleeve into place. It can be a tight fit. The pivot sleeve should protrude a small amount either side of the bushes when pushed into place. This may not be visible to the naked eye. Test for pivot bush protrusion by placing two straight edges against the bush. If a little movement sideways of the bush is possible before the straight edges touch the phosphor bronze bushes, there is sufficient protrusion. If not, remove the phosphor bronze bushes as described in 4 above, clean some paint from the edges of the pivot housing and reinsert the bushes as described above. Recheck for sufficient protrusion.
6. Place the rear triangle back in the frame. Replace the crossheaded screws that hold the rubber suspension cone in place and tighten. Push and then tap the pivot bolt through the pivot. Screw on the nyloc nut and tighten fully. Replace the right crank if removed. Replace the rear wheel. Reconnect the gear and brake cables and adjust as per their maker's manuals. Check that the gears and brakes work fully before riding.
Hi ,
I have a tsr 27 , and it looks like there is some movement from the pivot hole ( bolt) rear suspension,
I live in New York city, can you please tell me where I could find the new parts, and if it its in the UK how to buy it.
Thank you very much for your help
Happy new year !!!
(The following is from the perspective of servicing a TSR, not APB)
I’m surprised at the suggestion that the pivot sleeve should be a tight fit and need to be hammered into place inside the bushes. Given the location of the lubrication port, I’d assume that the intended bearing surface is between the sleeve and the bushes, so an interference fit would be too tight.
Hi there-trying to get replacement bushes but apparently Pashley don’t stock them–any ideas?
thanks
Paddy
Aug 2015: APB Rear Pivot Service kit off-the-shelf at Avon Valley Cyclery, Bath. (usual disclaimer) £29.99
Consists of sintered bronze bushes(2), bearing tube 1 off, (1/2in ODx5/16in ID), 5/16 in through bolt and nyloc nut 5/16 (1), anti-turn washers (2). Note that like much UK stuff in the 1990’s imperial threads were still in use. Regrettably almost all modern items now use the inferior metric thread system, where nuts and bolt have more association with mecano kits than precision engineering.
I bought my APB recently ‘as seen’ and on trial it steered strangely. On inspection the front and rear wheels were not travelling quite in the same direction, causing all sorts of instability, hmm.
On investigation, and after slackening the through bolt half a turn on the rear pivot, the rear swing arm was very loose and wagged about a lot. The previous owner clearly knew about this, and tightened the fixing bolt to hide the slackness. But I knew what I was doing when buying the wreck, and being an engineer I expected to do extensive repairs.
However when following the article procedure above it was clear that considerable force is required to drive out both the swivel tube and bronze bushes and I was afraid of doing great damage to the rear swing arm frame. Whilst everything else was seized, fortunately my through-bolt was not, so I could at least work on the swing arm on the bench.The technology of this pivot is about as advanced as a 1930 Austin 7. I despair when engineers use the threaded section of fixing bolts as the register in the locating hole, in this case the LH flange on the bottom bracket tube and was afraid that the seized bearing had fretted the slack side of the lug hole into an oval. The nice chaps at Avon Valley Cyclery warned me of this. Visions of brazing up the pivot holes and precision boring new holes were floating through my mind, but in the end it was not required.
When re-assembling the bushes I filled the central cavity with as much copper grease as I could (to avoid seizing in future) but completed the final assembly with Lithium grease which is moderately waterproof.
I found it impossible to fit the centre swivel tube and concluded that the above instructions are incomplete in that the newly fitted bearings needed to be reamed prior to fitting the pivot tube. Just like the King Pin bearing on that Austin 7! Others above have commented on this. So a new 1/2 inch spiral fluted straight hand reamer was obtained (next day delivery) from RDG Tools on Ebay, £12.70 inc P&P. A few turns on the reamer and the Bronze bearing assembly was shaved of just enough to allow the bearing tube to slide fit and smoothly turn. I was going to fit a tab washer to the fixing bolt but the kit came with hardened serrated face washers which dig into the head of the bolt and nut and the adjacent flange face. Thus the through bolt is firmly fixed in the frame lugs and cannot turn and act as the bearing. Also the swivel tube stands clear either end of the bearing set, so when assembled the tube is nipped by the lugs and cannot turn, and now my swing arm swivels on its pivot as smooth as silk. A good result, and even better when miraculously the front and rear wheels now line up and the bike now rides like a dream.
I love the ‘nudge’ you get when steaming along and the bike ‘nudges’ you along the arrow straight path of fabulous stability. The faster you go the more stable it gets, not like some of the tank slappers I have had in the past.
PS. I now have a 1/2 inch reamer (used once) that will probably forever sit redundantly in my toolbox until they come and take my hulk away.
MB, B.Sc. (Mech Eng), UMIST
Hi and BUMP! Its 2023.
I have just partially stripped the rear suspension of my FX8 bicycle which appears to be the same as the APB described in the document above. I am not an engineer so am to some extent at the mercy of instructions and guides. Unfortunately the guide above does not make engineering sense to me and I find that I am in agreement with Malcolm and Richard. My reasoning is below.
Looking at the parts the bronze bushes are press fit into the rear triangle with the bearing sleeve inserted between them. The junction between these three parts is serviced by a grease nipple which suggests to me that the junction between the sleeve and the bushes should be lubricated with grease and that the sleeve should be free to rotate inside the bushes or rather that the bushes and the rear triangle, to which they are fixed, should be free to rotate about the sleeve.
When the rear triangle is offered up to the frame it fits between two mild steel plates and fixed by a bolt that clamps the mild steel pieces to the sleeve given that the sleeve extends beyond the bushes by a few thou’.
The final result is that the sleeve and the bolt “become” part of the main frame and are fixed in place as much as the friction of the clamping action of the fixing bolt allows. The only movement that should occur when the suspension moves is the bushes rotating on the fixed sleeve. This action should be friction free and with minimal play. If the sleeve is a tight fit then it impedes the suspension action or worse causes the movement to be born by the mild steel plates causing damage in the long run.
So how did I do ? If Malcom, Richard and I are correct will someone please rewrite the instructions emphasising the importance of the bush to sleeve junction and removing the references to knocking the sleeve in and tight fits which is the opposite of how I believe it was originally designed.
I apologise for going on but “duff” information is worse than no information.