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. 

Trophy 1200 Rear Wheel

A previous owner had painted the wheels. I really liked the idea of having red centers with silver edges for the wheels. Unfortunately, the paint was lifting in places because it seems not to have adhered terribly well to the original silver paint. After I'd given them a good scrub down, with gunk, then Jif cream cleaner, then lots of clear water, I felt I could get some good results with a rattle can. 

I found Halfords do enamel paint in two shades of red, one of which was a good match for the bike's Lancaster Red. I'm thinking of it as a temporary measure, pending getting them powder coated some time later on.

I'm keen to get riding so I'm starting to make some small compromises now, thinking I can rectify them after using the bike for a while. I freshened up the silver with a brush, steady hand and Smoothrite. To get an even finish, I put the wheel up on axel stands. That way, I could slowly rotate it on its spindle and rest my hand on the stand whilst applying the paint. I think the results are pretty good considering.

Right-hand side of the hub: disc carrier. There are six threaded holes on the right-hand side of the wheel for the chromed allen-headed bolts that retain the rear disc. I lightly smeared lithium grease around the edges of them to stop the disc from sticking to the paint. I then used non-permanent thread lock on the thread of the bolts to keep them in place and copper grease under the heads to prevent them from seizing. I had found a build up of dirt and rust in these special bolts which made them difficult to remove. Also, the rust had started lifting the chrome where the finish had presumably been damaged in previous tightening. So I put blobs of grease in the bolt heads and banged in plastic caps to prevent corrosion from building up in them in the future.  

Grease around the disc bolt holes to stop the disc
from sticking to the new paint ...

... and thread lock to hold the bolts firm after torquing them up. 

Plastic caps to prevent corrosion from building up in the bolt holes.

Left-hand side of the hub: cush drive

Installing rubber 'cush drive' blocks

Installing a greased spacer into the
sprocket carrier.  

 The left-hand side of the wheel hub contains a housing for the sprocket carrier. The housing has five alloy vanes which are driven by five larger vanes in the sprocket carrier via rubber 'cush drive' blocks. The rubber blocks serve as a drive-line shock absorber. I coated the vanes and O-ring joint with rubber grease.


A rubber O-ring sits in a machined groove around the wheel bearing so I put rubber grease around it to help keep dirt and dust out. It helped me to ease the sprocket carrier into the hub as well because it is a fairly tight fit. I'm very pleased with the finish I managed to obtain on the sprocket carrier - very satisfying indeed. I'm hopeful it will be a permanent (whatever that means on a motorcycle) whereas the wheel paint is more of a stop gap measure.

Installing the sprocket carrier to the rear wheel hub. 

I decided to fit a 42 tooth rear sprocket. There are plenty of options, courtesy of the modular nature of the range. I'm looking forward to a relaxed, torque-laden feel to the ride and figure this will be conducive to wafting along at low revs when I want to.  Copper grease on the studs and some more heavy duty torque wrench action (85NM), and all is as it should be.

There is a small alloy spacer that fits into a rubber seal just outboard of the left-hand wheel bearing. The action of the rubber seal rotating around this spacer tends to wear a groove in it. Plenty of grease should help. Job done.

Sprocket and rear brake carriers

The driven sprocket is bolted to a casting with five vanes on the rear side. These vanes then push against a set of rubber blocks with provide a degree of shock absorbing to the rear wheel. The casting bears the marks 'SNW', a Japanese company that produced wheels and ancilliaries for Triumph, and is date marks: 2|0 |9 8|9 - the 20th of September 1989. 

The sprocket carrier had been painted red by a previous owner, along with the wheels. The paint had not adhered well in some places, and was damaged in others. So I decided to strip it off and then to repaint it silver. I like the red on the wheels though so will be repainting them in the same way as the previous owner decided. 

 Despite the paint having fallen off in some places, it was very hard to shift from others. Isn't that always the way. So I gave it two doses of stripper with a good scrub each to boot each time.

Even after that, some of the red paint was still ingrained in the casting, leaving a pink blotchy appearance.

 I gave it a dose of Hammerite Special Metals primer. I also did the rear brake carrier whilst I as at it.

 As I have written before, the Special Metals primer covers very well indeed but does not flow terribly well. So I had to rub it back afterwards. I used wet and dry 400 grade paper for that. The blotchiness reappeared the primer was thin but I felt it was an adequate key for the silver paint I wanted to use.

 Ages ago, I'd read in that wheel paint works well on Japanese castings in a classic bike magazine ( I think it was Classic and Motorcycle Mechanics but can't be sure). That article said the high aluminium content in wheel paint meant it was also pretty resistant to temperature so could be used on engine cases. Anyway, the formulation is intended for application to alloy wheels so I figured it would work well on these components too.

The paint went on very well - good coverage and flowed well, tolerant to runs. However, the surface had quite a bit of texture to it (looked great, felt rough) which would be hard to keep clean.

I topped it off with clear enamel lacquer made by Japlac. I've had good results with this before as a top coat for brake callipers. The final result is below: