Reassembling final drive

I decided to gear the bike up for a lazier ride. So I got a 19 tooth gearbox drive sprocket, one tooth larger than standard, and a 42 tooth driven sprocket. 

It is impossible to torque up the gearbox sprocket nut to the required torque of 132NM without being able to stop the sprocket from rotating. I have found the best way to do this is to put the gearbox into first gear and to hold the rear brake on. That way, the gearbox sprocket is held still by a combination of engine compression and brake pressure. So it was time to fit the rear wheel.

Mushroom type spacer on right
of wheel. The wide end butts up
against the rear brake bracket

Rear wheel spindle, spacer, rear brake
bracket, bush and wire retaining clips

The rear wheel fits onto its axle between a small alloy spacer on the left and two spacers on the right.  The right-hand spacers are a large, mushroom type spacer that fits into the rear wheel, and a large aluminium bush that fits into the centre of the brake bracket.

The rear wheel, fitted with sprocket carrier and small, left-hand spacer, has the chain looped over its sprocket pushed well forward to maximise chain slack. The eccentric chain adjusters should also be turned so they are aligned to the same marks on the swingarm and pushed slightly outwards from the centre of the bike before being nipped up with an Allen key. This makes the gap for the rear wheel as wide as possible to help you get the axle through. It's easier to see what's happening this way.

The rear wheel spindle needs to be fitted from the left because it is isn't easy to manoeuvre the wheel into place, and the sprocket carrier side is the heavier of the two. I put a wooden block under the wheel to help support the weight.

Greasing the large aluminium
bush for the centre of the rear
brake bracket

Axle right through, bolt being
wound home. The gap between
eccentric adjuster and brake
bracket is visible here. 

I used plenty of Castrol LM on the mating faces of all the spacers, the brake bracket bush, and the axle itself. With a  bit of wiggling and the assistance of a rubber mallet, the axle through each of the components in turn.

The right-hand bolt is wound in with at 12mm Allen key, pulling the swingarm legs together against the spacers. I nipped up the axle bolts at this point before slackening off the eccentrics to adjust the chain tension, and to allow them to move inwards to their correct position.

132NM of torque for the gearbox sprocket

I refitted and bled up the rear brake and then was ready to torque up the gearbox sprocket.

It worked a charm but needed a steady hand and my largest socket (36mm). That just leaves the flattening of a tab on the gearbox lock washer  - that done, job's a good un. 

Refitting the swinging arm, rear shock and centre stand

The swingarm had suffered from scuffing towards the left-hand end. It also had pitting from corrosion in areas where water and salt had crept under the chain guard and gator which connects to the rear mudguard. I treated those areas with special metals primer, topped off with silver Smoothrite. When the mudguard and gator are replaced, they'll be hidden anyway - it's good for me to know they'll be protected from similar problems in the future. 

The main  suspension components for the swingarm include hollow spindles for two drop links that connect to the drag link. The spindles have grease nipples in their outer ends - these appear to have been used as intended.  The spindles fit through three short sleeves in the swingarm casting. These had suffered a bit. The drop links have needle roller bearings at each end and are both protected from the elements with decent seal arrangements.  The top bearings benefit from large steel and rubber seals, the lower bearings are looked after  by pressed-in rubber seals. All were in good condition. 

Drop links - Meriden-style
logo on these early castings

Needle roller bearing was in
great condition, visible here after
cleaning out the old grease with parafin

 I reassembled the drop links with new sleeves and a combination of Castrol LM for the needle rollers and Rock Oil rubber grease for the seals. Torquing up the spindles is a bit tricky - the trick is to use a socket for a 12mm spark plug because these are 18mm across the flats.

The chain has to be looped over the left-hand leg of the swinging arm first. The swingarm slides in between the frame outriggers and steel castings. The castings should be left loose at this stage - a bit of movement is helpful to get the swingarm positioned properly. The swingarm spindle is inserted from the left because it makes it easier for dealing with the chain. Stop when the spindle gets to the first steel casting. An alloy spacer must then be inserted between the steel castings. 

Alloy spacer in place between the two steel
castings. The return springs for the centre
stand are visible, hooked on to small
protrusions on the castings. 

 The rear shock is best mounted after the alloy spacer - there is very little room for manoeuvre when the shock is in place. I supported the rear of the swingarm with bungees looped over the frame. This helped maximised the room I had for wiggling the shock into position, and then to line up the shock's lower eye with the bottoms of the drop links for inserting the drag link spindle.   I put lots of grease on the edges of the drag link that would but up against the drop links and shock. There was a fair amount of corrosion on the drag link there, especially to the left of the shock mounting point. I'd seen this on all three of the drag links I'd looked at previously so it's well worth the trouble of slapping on the LM at this stage.

Inserting the drag link spindle from the right-hand side
through the right-hand drop link, shock lower eye
and then manoeuvring the left-hand drop link into place.

The large hex bolt with grease nipple about
to be wound in to the left-hand end of the drag link spindle. 

I decided to polish up the eccentric adjusters for the rear wheel. They were scarred by heavy-handed attempts to refit the rear wheel in the past. I got most of them out with wet and dry abrasive paper on thick pane of glass. Then I polished them with drill and mops. 

 The centre stand fits to the lowest holes in the steel castings. I found it easiest to attach the return springs by looping a 12mm ring spanner over the lower ends - it meant I could get a good grip to pull them over the prongs on the stand.

All sorted, ready for the rear wheel.

Swingarm repair and shiny new parts

The swinging arm has returned. It has been repaired with aluminium welds filling two nasty grooves near the rear right-hand wheel adjuster.  I shall tidy them up a little, give it a light polish and then call it job done.

Lings, aka World of Triumph, has an online parts catalogue for the early Trophy models. This is a great resource because it includes exploded diagrams - very helpful for seeing how all the components are supposed to fit together. Replacement parts for the rear suspension are pictured below, including drag link needle roller bearings and seals, and collars for the top drop link bolts.

I also ordered up the last of the parts I think I'll need to complete the rebuild, in the hope of saving some postage money. Prior experience suggests this is wishful thinking - there's nearly always something that crops up when it comes to reassembly - but there you are.

From top left in the image above, they include:

• a couple of mirror spacer pads (these set the mirror arm at a better angle than if they are just bolted straight to the fairing, as well as protecting the paintwork on the fairing)
• two bushes for the gear and rear brake pedals to eliminate slack in the movement
• two needle roller bearings for the rear suspension drag link
• five grease nipple covers
• two fork seal retaining rings - mine are corroded though I've yet to strip the forks I've got these in anticipation
• two rear axel bolt retaining rings - missing on my bike
• two seals for the drag link bearings
• a couple of plugs for the handlebars because one of mine had snapped at some point and was poxily glued back
• a rear brake pad spring - mine is split in two, brakes being the other main job on the list of things yet to fix 
• (in the centre of the image) four collars for the bolts that hold the top of the rear suspension drop links to the swinging arm