Thursday, September 17, 2015

Starting joy ... definitely no sprag trouble

I finished installing the rebuilt starter motor too late last night to get the carbs and tank back on. So, after work today, I set to doing just that. With the carbs off, I was able to test the starter with the engine cold but my problems were with a hot motor. So a hot test was my main concern today, after finding out if the engine would actually fire up when cold.

I didn't replace the rear bodywork in case I had to get the sprag clutch out so Ruby looks a bit strange today.  It was after dark by the time I was able to do this the images in these videos are poor. But it is the sound that counts here.

video
The first video shows the cold engine, with the water temp gauge on zero and the oil temp (right-hand digital gauge) its minimum possible reading, 25 degrees Celcius. The engine spins with gusto and, on the second attempt, Ruby fired up beautifully.

video


The second video shows the engine hot, water temp at about one third of the range and oil temp just over 70 degrees. Again, the starter spins really well and ignition is great. So I'm confident I've solved my problem and can get out on the road again.




Great!


Starting woes - could it be the dreaded sprag clutch?


I successfully completed my biggest ever one day ride earlier this month. I'll probably blog about it some time soon. It put me and Ruby under serious strain. I think it's only fair to say we were both struggling at times but, unlike me, wobbly motivation wasn't part of the equation for this monumental motorcycle.

Tim's Carribean Blue Sprophy 1200
As my trip went on, I noticed Ruby became ever more reluctant to start with her electric foot. This reluctance appeared only when she was hot. After a mug of tea, she fired up straight away. My first thought was the ignition pickups. That's because, when they fail, they do so only when the bike gets hot. It seems to bring out a problem in the field generated by the spinning magnet on the end of the crank. However, Ruby rumbled into life perfectly with a bump start. This would not happen if it were a problem with the ignition pickups. I got to visit Tim on my way back so benefitted from his considerable wisdom (thanks Tim). The idiot lights seemed to dim more than normal on the starter, suggesting a large current draw. That means an electrical short or similar. But we couldn't think what would do this in the starter circuit. The solenoid is mounted in rubber and earths through the starter motor, so that seemed unlikely. I later thought it might be a short in the electromagnetic windings that activate the solenoid switch. Mysterious business. 

Meanwhile, I got a ride on Tim's transformed Trophy - now a Sprophy, courtesy of a neatly colour-matched and fitted 900 Sprint fairing - and his 1050 Sprint. Both great fun, despite the rain that had started to sweep across the country. More thanks to Tim. 

To cut a long story short, the need to bump start when hot got more and more common over the course of the trip. It made refuelling an issue unless I was stopping for a half-hour or more. Ruby's MOT was due at the start of October. I had an extra day off work after my trip so I took her up to the brill bike shop in my home town (it has been there since the 1960s, now run by the son of the original owner). I deliberately didn't warm her up beforehand - started fine, breezed through the checks, and passed without advisory warnings. Great. Then I thought I'd get to the bottom of the problem. 

Back in my garage, engine now hot, I tried the starter and sure enough it wouldn't spin the engine enough to get her running. More like chug - chug - nothing. However, with helmet off and in silence, I could here a nasty metallic ringing sound after the chug - chug. I persisted with the result that I got fewer chugs and more ringing, until I just got a click from the solenoid. The video above shows this but, since I lost my actual camera, is poor mobile phone quality. You'll get the idea. The idea is "Blast and confound it, this is horrible". Notwithstanding the solenoid click, the ringing sounded like the dreaded sprag clutch just spinning ineffectually on its shaft.

video

Denso Starter Repair Kit
Could it be I'd have to sort out the sprags for the first time? Expensive. Time consuming. Worrying. I sure hoped not. Tim thought it was more likely a problem with the starter motor, because of the dimming lights. 

So I rang Trevor. He said he thought it might be the starter motor brushes, but it could be the sprag clutch. 

So I visited Trevor to acquire a Denso starter repair kit, comprising brushes, brush holder plate, O-rings and nuts. He was as wonderful as usual. Sharing my pain and furnishing me with a rebuild kit. Plus a little tour of his premises so I could ogle his latest project - a fantastically compact Egli-type racing frame for T300.  

Americans say 'tear down' rather than
'strip down'. It did feel like that as I got stuck in.
Back at home, the strip down began. I decided to get down to the starter as quickly as possible, to replace the brushes and then to test the motor without reconnecting all the gubbins that have to come off in the first place. That way, if the brushes weren't the answer, I'd be half-way through the dismantling necessary for the sprag job. 

Slot cut in button head screw
Dismantling went well until it came to removing the starter itself. It is retained by two M6x20mm hex-headed bolts. I'd swapped the originals for stainless steel button head machine screws. They use a 4mm Allen key and one of them rounded out. I may have caused this by not draining the coolant down, thereby having to wiggle the keys around the coolant return pipe from the rear of the cylinder block. Blast and tarnation. I then removed the alternator, to improve access and cut a slot in the head of the offending button-headed screw before tapping it around with a hammer and chisel. At least things were reasonably clean and my original careful rebuild work - and use of copper grease - was rewarded with a straightforward strip in all other respects.

Lots of black dust in the
starter body
Charred brush residue
Comparing replacement brush holder (left) with
blackened and worn out original (right)
With the starter out on my bench, I split it down and was struck first by the smell - hot or burnt electrical - and the volume of black dust inside the starter body. I allowed myself to feel a bit encouraged. Then I saw the brushes. They were worn down practically to the copper braids that deliver them with electricity. Clearly and happily, it was true that they needed replacing. I could also see the copper segments on the armature showed evidence of pitting, which I would expect from electrical arcing. Fortunately, this was not deep and was dressed out with a nylon pad. 

Cleaned and polished
Replaced in the brush housing
A good clean up and reassembly with Trevor's kit left me feeling optimistic. I used plenty of electrical contact cleaner, a thin screwdriver to rake out the gunge between copper segments and wiped down everything with paper. 

But I was still worried that the metallic ringing noise could only be the sprag clutch. What could I do? 


So I reinstalled the starter, connected the battery, and ....


video


.... brilliant. The starter spins with gusto, no sign of metallic ringing, and is clearly a very happy electrobunny again. I then stopped for the night and will discover tomorrow whether the dear bike will in fact fire up cold and hot. I think the answer will be 'YES!'

Friday, August 14, 2015

Why do I keep messing about with this old dinosaur?

Gray, friend of this blog and proud custodian of another 1991 Triumph Trophy 1200, asked me:

"I've often wondered while reading your blog if you've ever considered selling Ruby and buying something more modern? I know you have invested a lot of time and effort into her but hasn't the lure of an ultra reliable high tech Japanese bike ever tempted you?"

That is a good pair of questions.The answers are easy. No and No. But they aren't really answers at all, are they? Both 'No's deserve a bit more qualification.

Even when I was really struggling to make Ruby run well in the early days after my rebuild, it never crossed my mind to sell her. There is no doubt that the technology is old, as is the fabric of the machine. I knew I was taking on an old bike when I took possession of her, back in August 2010. I was looking for a challenge. So I expected hiccoughs and grumbles as she shook off her slumbers and reawakened as a working machine. I did feel down in the first couple of months, especially when I discovered the failed fuel liner in the fuel tank, and suffered regular engine shut-downs after between 5 and 20 miles. And when all my fiddling with the carbs did not solve the misfiring when hot, I felt angry and dispondent. But I sorted it, along with the other age-related problems. I got through all that, as this blog testifies, more upset with my own inability to diagnose the problems than with the machine.

But the feeling I get when I put right the wrongs, when I am able to restore some sweetness to the way she runs, is very important to me. I have always liked tinkering with my bikes. When I bought my Daytona 900 in 1995, she was 18 months old and in almost as-new condition. I enjoyed riding that bike immensely but felt frustrated when I got home. No tinkering needed. No little jobs to do beyond cleaning. It wasn't enough to satisfy me. So I started modifying the bike, sometimes well, at least once very badly. But that Daytona became my bike. I still have 'Streak' but she is getting the in-depth renewal treatment now. The pleasure I derive from fixing and fiddling with old bikes is one very important reason for not wanting a new machine. I'd be bored.

It is true that I would enjoy trying some newer bikes. Maybe not new new (for the 'no tinkering' reason). Just new enough to allow me to play. Maybe five years old. But so many of them look like insects. I can't warm to the angular, lumpy appearance of them. The abdomen-thorax-antennae look doesn't work for me. I've had a sit on a couple of classic-styled bikes. They were OK. No fires were lit though. I did see a bright red Sprint 1050 in Trevor's tiny emporium around the time Tim got his blue one. I was hugely tempted. I resisted because I could not see it as a replacement for Ruby or Streak, my garage has no more room, and anyway I couldn't afford it.

The second answer to the first 'No' is to do with a sense of history. Ruby was, and remains, a monumental achievement for a tiny band of motorcycle designers and engineers. There have been several other really great achievements in the sense of a motorcycling dream being realised (Hesketh, Shenstone Norton rotaries, Brittan twins). Occasions when small concerns have fought off impossible odds to create something unique for the biking world. They have been idosyncratic, flawed in many ways, brave in many more. They have all collapsed in one way or another. All of them.

Except the T300s.

The T300s were the platform upon which the T500s were built, and the ethos which brought Hinckley Triumph its success. I've little doubt that the folks who work at Triumph understand this. When I visited the original factory in the summer of 2013, I met a great guy called Mark. Mark was in charge of warrantees and servicing. Though he started working for Triumph long after the factory was re-launched, he treated me like royalty. The T312 Trophy was the most monumental of the first T300s: the largest, the smoothest, the engine with greatest thrust, the rider's eye view the most world-conquoring. As I have written elsewhere, Triumph responded to the motorcycling press and public demand to change the T300s for the 1993/4 model year. In my view, some of the engineering purity was lost at that time, for all that many positives were introduced.



When I work on Ruby, or rumble out into the world on this big old red bus of a bike, I am conscious of these things. Rarely at the front of my mind, but deeper than that. I'm gifted with riding a piece of history. Even though I know few people think about the old 1200s this way.


The road is calling. See you out there. 

Friday, July 24, 2015

New cam chain at 53,000 miles

After cleaning out the carbs and re-oiling the filter, per my last post, I took advantage of the fact that the tank and fairing lowers were off to change Ruby's cam chain. I'd previously fitted a new tensioner spring, which had helped to quiet the cam chain quite a bit, but I'd decided that 53,000 miles was probably enough to warrant the cost of replacing the chain itself.

Cam chain replacement is not a difficult job to do on the T300s because the cam chain runs off of one end of the crank. Until the Kawasaki GPZ900R came along, it was typical practice is to drive the cams from the centre of the crank so changing the cam drive chain was a fiddle to say the least and typically was done with a split link. Having a cam chain that runs in a tunnel on the end of the crank means it is possible to use a stronger, endless chain - and avoid the risk of dropping bits of split link into the engine. Much better.

View of the cam cover (aka cylinder head cover)
protruding either side of the main spine frame tube.
The cam cover is retained by 10 mushroom-headed
Allen bolts, four are out of sight in this photo and
need care with a good Allen key to remove them 
I've previously written about removing T300 cams so won't repeat myself here. In short, the tank has to be off (watch out for the fuel lines and be careful in case the fuel tap is stuck open when you disconnect them), ignition leads removed (preferably coils as well - it will give you welcome extra room).

Wonderful T300 Green profile cams exposed,
cam chain emerging from its tunnel on the
right-hand side of the engine.
Remove the cam cover (use a good quality Allen key - access to two of the bolts is restricted by the main spine tube of the frame so you want to get really good purchase on these bolts), put the bike on its  side stand and remove the right-hand crank cover to expose the ignition pickups and cam chain drive sprocket.

Doing the last bit of the job on the side stand will stop engine oil running out. I was doing this along with an oil change anyway so losing oil was neither here nor there in my case. It also makes the job easier because this way the cam timing marks are tilted up for you to see.


Arrow mark on cam sprocket shown parallel
with gasket surface for cam cover. 
Make sure the bike is not in gear (it's on the side stand now, remember) and then use a big spanner or socket on a handle to turn the engine over. Do this with the large hex nut in the centre of the ignition rotor until the timing mark next to a letter 'T' aligns with the ignition pickup and the arrow marks on the cam sprockets are horizontal, parallel with the machined gasket surface of the cylinder head. The 'T' stands for Top Dead Centre - it means the point at which two of the four pistons are at their highest point in their never ending journey up and down inside the cylinders. The pistons work in pairs, cylinders 1 and 4 make one pair and cylinders 2 and 3 make the other.  It doesn't matter if the arrow points to the rear or towards the front of the engine. It is in a position either way which minimizes the load put onto the camshaft by the valve springs. This way, only the valves of one cylinder will be acting against the inlet cam and the valves of one other cylinder acting against the exhaust cam.

Next, remove the cam chain tensioner from the rear of the cam chain tunnel, and the steel arch that serves as a top guide for the chain. This sits between the two cam sprockets (not in these photos I'm afraid). Then gradually release the bearing caps on each camshaft. Do two turns on each bolt, working in rotation around all ten bolts as you go.

I use a good single hex 10mm socket on a 1/4" drive ratchet handle. Do this for the inlet camshaft first, lift off all the bearing caps and keeping them in a clean, safe place, then pull the camshaft up with one hand and unloop the cam chain from its sprocket with the other. Repeat for the exhaust cam, putting a bar through the chain to make it easier to remove later on.
The ignition rotor must be removed
by releasing an Allen bolt that retains
 a large nut, and refitted with thread
lock and to the correct torque
after the new chain has been fitted. 

Cam chain drive sprocket exposed. The ignition pickup is
the black lump to the bottom left with a round silver stud in
the centre. That stud is the reference point for valve and
ignition timing, when it aligns with the various
marks on the ignition rotor. 
The cam chain tensioner blade and ignition rotor must now be removed. The tensioner is held on by a single bolt left and just above the cam drive sprocket. Push as rag under the rotor now, before undoing that bolt, to make sure you don't lose the washers when you undo it. Pull the tensioner blade up and out of the cam chain tunnel.  The ignition rotor is a metal disk that is bolted onto the end of the crank shaft with an Allen bolt that passes through the large engine-turning nut. The Allen bolt will be tight because it is fitted with thread lock. Again, good-quality tools really pay off here. When the ignition rotor is pulled free, you'll see the cam drive sprocket. It is half the size of the sprockets on the cam shafts because the cams turn at exactly half engine speed.

Feeding the cam chain down the cam tunnel and
guiding it out, away from its drive sprocket. 
You can now remove the bar you put through the cam chain at the top of the engine and feed the chain down its tunnel and past the drive sprocket, before replaceing it with a new one. It is easiest to put your bar through the new chain and dangle it down the tunnel, using your other hand to loop it over the drive sprocket. Replace the cam chain tensioner blade (not the tensioner unit yet), feed  the cams through the new chain and lay them loosely in their bearings. Refit the ignition rotor and check that the T mark is still aligned with the ignition rotor.

Reassembly is, as they say, the reverse of the dismantling process. There is a trick with the tension though, and in settling the green cams in a way that keeps the timing correct. I'm out of time myself now, so more about these tricks next time.
Comparing wear in the old (top) and replacement (bottom)
cam chains by showing how much more lateral movement
is possible with the worn chain than with the new. 
 I find it very hard to measure wear in chains accurately. The photo above shows how much extra lateral movement the old chain has compared to the new one. This can only be accountable to additional play in the side plates. I think, for something like this, it's as much about peace of mind as being confident the engine is about to explode unless preventative maintenance is done immediately.

The new chain, coupled with new engine oil, has made the top end noticeably quieter and the engine feels taught too (not forgetting the carb and air filter clean). I used Shell Ultra 4T fully synthetic 10w40 oil this time. Any fresh oil is impressive, I've found, by smoothing out gear changes. I've ridden about 200 miles on it so far and it feels great. But then, it is Summer and I love my bike.

Wednesday, July 15, 2015

53000 miles: Fuel leak and carb clean

Yellow petrol residue on the alternator
I noticed I was arriving at home smelling of petrol. Although I find a bit of a petrolly whiff has its own appeal, it is not something my wife appreciates. There came a point when it was obvious that something needed to be done. That point was seeing petrol dripping onto my alternator. Not good.

I thought it was due to a faulty float bowl seal on the carburettor for number two cylinder so it was a case of getting the bank of carburettors off the bike and giving them a bit of a birthday. I figured the air filter could do with a clean anyway and, after 53000 miles, I decided it would be wise to change the cam chain (next post). So Ruby was going to get a big birthday.

24 years and 52,995 miles
As it happens, I think it likely that she was made in July or August in 1991. I don't know for sure. She was registered 1st of September 1991 but with chassis number 544, production having begun in March and building up to a rate of about 50 machines per week during the year, my guess is that she was constructed any time from mid June to Mid August. So happy 24th birthday, Ruby. She would be having a reasonable run out afterwards because I had an international trip to do for work, flying from Heathrow, and I had decided to ride there, stowing my bike gear in left-luggage for the duration of my time abroad. FWIW, that trip worked out well - free parking for the bike and £20 for left luggage.

So the full list of jobs were: diagnose and solve fuel leak, clean out carb float bowls, clean and re-oil air filter, change air box for a better second-hand part I'd bought from Trevor, change cam chain and check valve clearances. The first four are here.

I have found that the top of the motor tends to accumulate road grit over time. It surprises me because I have inner panels that sit in front of the exhaust pipes and fill the gap above the oil cooler and below the water radiator. Anyway, it is helpful to brush off the cam cover before removing the plug leads. I remember I'd got the coil low tension connectors muddled up when I first tried to restart the engine back in 2012. So when I removed the coils, was very careful to keep note of which connectors belong to which coil. 

It is always a bit of a fight to get the carbs out. There is not much room between the airbox and the inlet stubs, and the rubber is ageing. I don't rush at the job, straddle the bike so I can get a good grip on both sides, and put a block against the front tyre to guard against the risk that I'll roll the bike off its stand in my pulling and pushing. The air filter was satisfyingly dirty. 
I have had a bottle of RAMAIR foam filter oil for years. I got it for my old GS650 Kat. It has a solvent that evaporates to leave a tacky coating. Good stuff. It just needs engine degreaser to clean it up. I was lucky enough to have a sunny day so the filter dried out quickly and then took the RAMAIR oil very well. 

 The old air box was severely cracked and my attempt to repair it with filler rod and a soldering iron had finally given up. The replacement box was in great shape and, I realised, had a slightly different design from the broken one. It has a plastic frame that retains the filter and this frame has recesses for four long stainless screws that clamp the sides of the box.

Replacement airbox, with filter frame including
recesses for through-bolts on each side. 

 The carb float bowls contained a fair amount of a red dusty residue. The seals showed a bit of alloy fur but nothing that looked like a leak. Perplexing but I cleaned them up and reset the floats 1mm higher than before (15.5 instead of 14.5). The motor had been running a bit rich, from the colour of the exhausts, so I was happy to make this change regardless of the leak.

The carburettor floats being reset to 15.5mm.
Fuel pipes visible beneath 
 To cut a needlessly long story short, I reassembled the carbs, installed and tested them for leaks. The leak was still there - but this time, with the tank out of the way, it was clear that the leak was actually from one of the fuel pipes, just above one of the blue plastic T-pieces I had installed. So I replaced it with some double-walled 5/16 fuel hose. That really did fix the leak.

View of the reoiled filter through the left end of the airbox

Monday, June 8, 2015

Ruby in the Spring

Just a couple of gratuitous pictures of Ruby in her current state, as of June 2015:



Sunday, June 7, 2015

A tool to help strip Trophy, Trident and Sprint forks

In my last post, I referred to a special tool I had made to assist in stripping the forks on my 1991 Trophy 1200. They are the same as for Tridents and Sprints of the 1990s. The tool is not necessary if you just want to change the oil or the springs in the forks. It is only needed if you want to separate the stanchions (chromed steel legs) from the fork lowers (cast alloy 'sliders'). That's necessary if the seals are leaking and need replacing, or if you want to change the bushes. I wanted to do both so had to strip the forks right down.

A note on diagrams: Ling's has loads of exploded diagrams in the parts section of their WorldofTriumph website. I have found them helpful to see what goes where, quite apart from sourcing parts. However, it is a bit of a maze to follow the lines to understand the order of things.

The process begins with removing the topcap (number 17 in the diagram below); this is best slackened two turns before removing from your bike then, when the fork leg is off the bike, clamp the stanchion in a soft-jawed vice (I use a wooden Workmate-type of bench), bear down with your weight to counter the internal springs and wind all the way out. Pull out an internal spacer tube (16), fancy washer (15) and the fork spring (14). Warning: they'll be dripping in oil and possibly foul-smelling, depending on how long it has been since the oil was last changed. So you'll want a sizable container to stand them in as well as something to collect the waste oil. Unclamp the stanchion and then invert the leg over your waste oil collector. I like to flush out the dregs next with Parafin. About 100ml will do a reasonable job. Pour it in and work the stanchion up and down 10 or 20 times, then invert again to pour it out. It should be a satisfyingly horrible slush. Now compress the stanchion in the slider, making it as short as possible.
Image courtesy of Ling's 'World of Triumph'
To separate the stanchions from the sliders, you need to remove a spring clip above the top seal ( undo a large Allen-headed bolt (number 18 in the diagram) from the very bottom of the slider. It is hidden away by a rubber bung (number 23 in the diagram) and sits in a recess above the hole where the axle normally lives. This bolt winds in to the main damping component, the damping cylinder.

The damping cylinder (number 11 in the diagram) is cylindrical (!) but is easier to understand as a piston which moves inside the stanchion. It works as a damper because it moves through fork oil when the leg compresses or extends, thereby slowing and controlling the action of the fork leg.

It is difficult to remove the Allen bolt because the damping cylinder tends to rotate inside the stanchion when you try to undo the bolt. The cylinder is in nice slippery oil and the bolt is a tight fit so that's understandable. So something is needed to hold the damping cylinder still whist the Allen bolt is unwound. Triumph do a special tool for this (adapter, front fork cylinder).

Unfortunately, I was mid-job when I discovered the ineffectiveness of the various bodgy techniques I've got away with in the past plus the price of 'special tools' is usually much too special for me. So I thought I'd make one.

 I measured the size of the hex in the damping cylinder to find it was 30mm across the flats. A trip to Mole Valley farmers produced a pack of 30mm af nuts for M20 threads and they had  lengths of M20 threaded rod too. I can't remember how much these cost but less than a tenner all in. I measured down the compressed fork leg to see how much I needed and cut so the nuts would just protrude enough for me to get purchase on them. 18" (45cm) did the trick. Then to make the tool I locked two of the M20 nuts against each other at each end of the rod. That way, they would grip the rod when I wound out the Allen bolt.

A pack of M20 nuts that are 30mm across the flats,
M20 threaded rod, cut to length with two nuts
locked against each other at each end.

 Then it was a case of inserting tool into the compressed fork leg, carefully engaging the lower end into the hex of the damping cylinder, using a spanner on the nuts at the top end and an Allen wrench at the other. It was still hard work because the threads are tight and even compressed the fork leg is long to be wielding spanners at both ends. I clamped the calliper lugs on the fork slider in my workmate to hold it steady as I was doing this. If'you can get a helper to hold one of the spanners, so much the better.

Have fun!

Thursday, June 4, 2015

52600 miles: Nissin Four-Piston Callipers and front fork bushes rebuild

After 52,600 miles, 15,000 under my stewardship, the forks were leaking and a baggy feeling. The two-piston callipers had suffered over the winter and were binding. So I thought I'd give the front end a refresh. 

I did the brakes first. I thought I'd give the callipers from my dormant Daytona a bit of a birthday with a scrub up and use those for a while. That would allow me to spend some time on the Trophy two-piston callipers. The Daytona uses Nissin opposed-piston callipers, two per side of each disk (four per calliper, eight in total). This contrasts with the Trophy callipers, which rely on two pistons acting on one side of the disk, with sliding pins bringing a secondary brake pad into contact with the other side. Sliding pins are pretty notorious for getting sticky. Opposed piston callipers should be more robust, as long as corrosion does not creep behind the piston seals.  

Splitting one of the Nissin four-piston callipers,
and pleased to find it was in good shape
 When I split and dismantled the Daytona callipers, I saw that the anodised finish had been applied to the whole casting after machining. I'd never seen this before. The benefit is better corrosion resistance in the grooves where the rubber seals sit. So they didn't need too much work to clean up ready for reassembly with red rubber grease and a smear of copper grease on the edge of the pistons where they contact the brake pads.


I decided to replace the master cylinder piston and seals because they are 21 years old (the Daytona was made in 1994). They looked to be in good shape, with the exception of the dust seal around the piston. This had a small tear. I've see water accumulate behind these before with nasty corrosive consequences so it was worth changing this anyway.




Daytona disks stripped cleaned and centres repainted silver


 The forks were pretty straightforward to strip because I made up a tool to hold the Trophy's inner damper units when I did them first. These units are retained by a large allen-headed bolt through the bottom of the aluminium outer. The damper has to be held still with a hex-headed rod to undo the allen bolt. It can be a real pain without something that fits the hex. I found some big nuts - (30mm see next blog post) - and suitable threaded rod at an agricultural supplier. I locked the nuts against each other at each end of the threaded rod so they would not rotate on the rod and it worked a charm with a large adjustable spanner to keep it still as I cracked the thread on the allen bolt with a 3/8 drive Allen bit on a tommy bar.

There are two bushes in each leg: one is at the top of the aluminium outer, or 'slider', and the other is on the bottom of the stanchion. The bushes were easy enough to do, the top bush coming out with vigourous working of the stanchion in the outer, after removing a retaining ring, and using a small flat screw driver to spring open the lower bush to slide it off of the chromed stanchion. I had trouble plastic oil control rings that fit into the dampers - I bought the wrong ones for these forks. Doh! So I reused the old ones.
The bodywork always seems to come up well
with wax shampoo 
All shiny again, but more brakey!

Ride out in the dusk of a beautiful Spring day