Eelco's Darmah

MartinW

MartinW

New member
As some of you may know from my newbie welcome post, I bought a Darmah from a friend whose partner had died unexpectedly. My first job after pulling it out into the daylight was to get it home, so with the help of MMT (My Mate Tim) we pumped up the tyres and pushed it up the ramp into our hired van (AA van hire Bradford - highly recommended). It moved easier than expected for something that hadn't been touched in 5 years but I was far too excited to look at anything else.
After making room in a crowded garage I started the research process to see exactly what I had. From the lists of engine and frame numbers on the bevelheads site and bits of Falloon's book on the internet I seem to have a 1978 bike with 40mm carbs but sadly 4 engines away from when they changed to larger manifold bolt spacings.
The side-panels have gone and so have the original clocks but as a bonus I have a complete new stainless exhaust and a pair of K&N pod filters.
From witness marks on the rear disc the pads were stuck to it for a long time and the caliper was split in two which is howcome the bike rolled so easily.
With lots of the parts of the caliper missing I took it off and started to take it apart. The pads are rust city so I started to think about which bits I need and that led to a whole journey of discovery...
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The best value looks to be a big pack from Bevelheads that has all the missing parts of the caliper including the cover, pins etc and works out at about £80 delivered but with the uncertainty of tax and vat from a US supplier to take into account.
Then I see some adaptors to fit newer four-pots and a cunning plan is formed: If I buy a pair of 900ss calipers off ebay I can get MMT to make me adaptors and use all the bits of my front calipers to repair the rear - result!
I know that I'll need a Master cylinder but that is stuck anyway and I can pick a replacement with the best bore size so I start to scour the bay.

In the interim I remove the rear Master cylinder and tackle the seized piston within.
 
Hi Martin,

I bought a SS darmah about 3 years back, been stood for 15years, your photos take me back, I finished bike about 2 years ago fully rebuilt and is a cracker. I rebuilt all calipers and kept original disc bike was 100% as, however on ridding it I found brakes crap!! I first replaced calipers with Ap units I had, not much better I then put old refurb calipers back on with fully floating 280mm disc from early 600 Tricoloure 851. now they are perfect. Giving good feel and progressive stopping all with refurb calipers.
Good luck with project, keep us updated.
Regards
RWG
 
Thanks RWG,
I started on the rear Master cylinder today. The outside was quite good after a clean but the piston was well and truly stuck down at the bottom of its travel. I first tried the approved 'drift through the J*ps eye' technique but it wasn't moving, so I drilled and tapped the piston to take a 6mm bolt and used that acting through a washer on a socket as an extractor. It turned out that the corrosion was very limited and cleaned off so I might get away with a seal kit. Just in case I needed the piston, I loctited a steel bolt into the hole I made and then filed it off flush, taking the opportunity to put a larger radius on the end of the piston and a corresponding one on the actuating arm. It now moves with a reassuringly smooth transition and I am officially a saddo.
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The pin that the actuating arm moves on was quite rusty and the C clips had rotted away so I was delighted to see that said item was still available! The euphoria lasted until I saw the price, so I fished out a stainless allen with a shank that will act as a pivot and stuck that in.
Piston and seal kits turned out to be cheaper from Guzzibits than online Ducati stores (Cheaper being a relative term for those used to car part prices) so I've sent for one of those.
With a pause to mow a lawn and a trip to Odsal and the opportunity to marvel at the selfish stupidity of drivers at my local tip, I couldn't resist the opportunity to tackle the front Master Cylinder.
Seduced by the fresh fluid that came out when I unbolted the banjo I unscrewed the reservoir top and found a molten mass of half-chewed Pontefract cake, or rather the remains of the rubber inner seal.
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Looks like two types of brake fluid have been used, so the seals are probably suspect and quite probably the lines as well.
A newish looking lever is always a sign that the bike may have hit the deck and when I removed it the piston fell out, having no crush washer or circlip. Despite that it looked ok except a portion of the lever mount had been filed back straight, but shorter than the other. Then I turned it over and saw a smooth white line across the casting
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Inside the bore of the cylinder is a corresponding lump where the casting has been cleverly welded.
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That decides it, then, I'll look for a couple of later 900ss calipers and a new master cylinder. I'll post on the wanted section, I think.
 
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The seal replacement kit arrived from Gutsibits for the rear master-cylinder so I popped it in, cleaned up the banjo bolt with a wire brush, added a couple of copper washers and bolted it back on the bike so it didn't get lost. The picture shows the old and new parts. The old bits don't look bad, but the seals are 'mushy' and you never know. Unfortunately I have spotted a hole in the big blobby rubber seal that sits inside the reservoir so that will have to go on my list of ridiculously expensive bits I need.
Now I have to look at the calipers but curiously seem to have to have an argument in the 'For sale and wanted' section first before I can finally decide.
 
I decide to take the front calipers off and they were in much better condition than the rear.
frontcaliper.jpg

The problem I have is that I want to put new seals and pistons and stainless pins and new nipples in and the cost just goes up and up. A nice guy on the Britchopper (misspent youth) site dug me out three calipers from his Guzzi stock but they looked about the same and some had snapped nipples so that if I bought them I'd just be adding to my stock of worn old bits. I'm still looking longingly at 4-pots on Ebay but of much greater concern is the big lip on the edge of the discs. If they were on a car I wouldn't worry but I need to find out what the wear-limit is on 4-bolt cast discs since I might need to find some of those as well.
The stainless steel hoses ran between the fork-slider and the mudguard but I realised from looking at a drawing that they should be rigid at that point so there's a little more evidence of change in the past. It's like Time Team!
 
Decided to ask the oracle, my mate Tim, about the great brake dilemma. Following his sage and practical Yorkshire advice I bought a couple of K75 BMW Brembo calipers for just under £50 on ebay. They look the same.... He's going to surface-grind my discs (or something) to get rid of the lips and see hwere, or rather, wear, we are. Now I just have to find a better front mastercylinder. I have my eyes on a nice radial one with a square reservoir that looks older than normals. The breaker hasn't got round to measuring it up for me yet though and I can't find what size it is by the usual sneaky ' look at the size of the repair kit' means - cause I can't find anybody who does a repair kit yet.
 
Broke out the cheap digital calipers and have over 5mm on each disc-result! MMT came round this afternoon and persuaded me that the Darmah is just a big flat-tracker so I should fit cowhorns like his Bonneville. Nether of us like the Raask Jotabars that came with it, but I am veering toward Vincent flats which I have always liked. I made some out of dowel covered in duct tape just to get a 'squinty' look and quite liked 'em.
 
Took both wheels out and glad I did. Every bearing is well-wobbly so its down to Spen Bearings tomorrow to get some replacements. The sprocket bearing that I can see does look to be spinning in its housing but very smoothly, so that might just be an optical illusion.
I did feel that the back axle is undersized - it has loads of play in everything it goes through, from the swing-arm holes inwards - time to call MMT perhaps, for a second opinion.
The new back sprocket I got on ebay (genuine gold '80's supersprox - very retro) has 36 teeth but the one that came off has 34, so maybe owner number 6 did the high miles that his pannier rack fittings suggested and wanted more relaxed cruising. I'm going to need a new chain anyway so the two 'extra teeth won't matter. I think that I'll stay with standard gears to begin with.
 
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Pulled the fork gaitor off and found this 'involuntarily castellated' fork top. The bottom of the two seals was well butchered and there was a rust pit in the stanchion so I'll be looking for one of those. He didn't think the sloppy fit of the axle was a problem once I got new bearings in so there's some good news. The sprocket bearing is spinning in the housing but he thinks that loctite'll sort it, so that's another result.
Mt has taken away my discs for grinding and the kickstart for blasting and sleeving so that's a bit of progress. He reckons he can turn up an alloy sleeve to hold the top of this slider together so I'll let him have a go at that, too.
 
The mastercylinder is now over £50, but in looking for it I saw a pair of side panels (mine were missing) and so I bid and won!
I have way exceeded my personal monthly ebay allowance and will have to stop. MMT rang to say that he'd blasted my discs and was grinding off the lips but it was taking a long time because they were so hard. Now we are looking for a good local hard-chrome plater, like someone, for example who replates hydraulic rams. Then we can repair my stanchion and the ones off his '67 Bonneville dirt-tracker. In the meantime it's Rufforth on Saturday and I have a list!
 
Thanks for that Derek, yes, that is exactly the kind of place we were looking-for. MMT brought the discs back and they look as lovely as newly-blasted cast does. I had half a mind to clear-coat them with heat-proof laqueur but decided on semi-gloss black instead so a tin of that ended up in the over-thin blue carrier bag I rustled around Rufforth with. I also scored a battery for my trike and costed up a Darmah battery at £65 from the ever-helpful battery-man and his side-kick. A few odd stainless fasteners plus a hi-flo oil-filter for £2 added to my load, topped-off with some AA batteries, a litre of full-synthetic fork oil for £5 and a blow-torch for Edwina the Contented Older Womans (C.O.W.) cinder-making (cookery) classes.
I have been looking for a more rectangular rear light so got one from an XS650 and it actually fits but hasn't the look I was after.
On the subject of wheelbearings it seems that 42x20x16 is an old size and so expensive, even at the bearing factors. On the other hand, 42x20x12s are only £4 each for name brands, so I've sent off for some of those and will ask MMT to make up some spacer-washers to take-up the width.
I'm off working abroad again tomorrow so things will slow down a bit but at least I'll be earning to pay for my shopping habit.
 
darn it, missed a front mudgurd on ebay through my boss calling me whilst I was trying to watch the closing moments at work - bit inconsiderate I thought. My mudguard has been inexpertly shortened at the front, probably as part of the crash damage that did for the original clocks. I don't actually like the square profile of the original guard and think it was intended for a 19" wheel so I may search for a more rounded, 18" one and rivet it to my bracket.
 
Thank you Chicken Bob! I just saw that the rear master cylinder went for £205.00!!!!! is Sammy Miller restoring Ducatis now? The same guy (DucatiPaddy) on ebay who had the front mudguard, has a fine pair of Tomaselli headlamp brackets and I was looking lustfully at them but they seem to be heading skywards as well so I think that I'll revert to Plan B, which is to look for a pair of brackets similar to the originals that I can restorate or Plan C: do something clever with the mounts for the front brake-line splitter, (which are substantial) and the bracket I'm going to make for the clocks.
 
£205.00 !!! That's what the master cylinder went-for. Is Sammy Miller restoring a Ducati? I think we should be told. I'm looking at a pair of headlamp brackets by the same seller but I think that they look like going the same way. Never mind, back to Plan B.
 
Same post three times- like an echo! That will teach me to try and post from a third-world dial-up. Cheers
 
Ahh, back to the first world and the insanity of nearly £30 for headlamp brackets - Plan B it is, then. MMT came round today on his AJS/Suzuki
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and we knocked-out my wheel bearings so he could measure up for the washers to space out the 12mm bearings. I rebuilt the rear caliper with parts from the pair of BMW ones that I bought on e-bay. The 'pair of calipers' were a pair alright - a pair of 'lefts' and from different years! The mounting bracket was heavily corroded and looked like it had done duty as a sacrificial anode in a chrome factory. I wire brush and flap-wheeled it to within an inch of its life and then painted it with alloy wheel silver.
We looked at the knackered fork-slider top and sucked our teeth and gave it a good coat of thinking about. MMT's idea of machining a new top and bonding it on may give way to something more like a reinforcing ring - we'll see.
 
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I had a drive over to Gutsibits after buying a pair of 38mm stanchions during a rush of blood to the head. It turns out that not all 38mm stanchions are the same. These have a smaller internal diameter so my innards don't fit and a small relief hole built into the lower end. In addition the top caps are a different, finer, thread. I think that they may actually be Ceriani. Needless to say Gutsibits aren't open on a Saturday, except for next week when they have an open-day, so I carried on over to MMT's house to show him my latest common sense failure.
After a severe mugging by his varied collection of dogs for the cat-treats in my jacket-pocket, we retreated to the Aladdin's cave that is his garage and he gave me these:
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Although it might not look too exciting, these are the spacers that allow me to fit cheaper, narrower bearings to my wheels, so if the rain holds off (I have to empty my garage outside to work) I can get cracking tomorrow. He's kept the drawings in case I need to do any more wheels in future.
We looked again at the fork lower legs and the corrosion on the 'castellated' one is worse than I first thought. He thinks that he'll have to create a whole new top from a slug of alloy and then slide it on over a turned-down old leg. I just gaze in wonder and nod my head...
 
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He must be one of the last people who did the proper apprenticeship with the thrown hammers and swearing and stuff. He is still at the same company although things are changing so it may not be for ever. His first apprentice job was to file a round-bar square. To this day he hand-files with a skill that I can only marvel-at. I was trying to persuade him that the best way to repair the slider would be to make a fork brace but I think that that might be a wish too far when he has so many other things on the go. Proper renaissance man, I think, and a good mate, too.
 
I continue to watch this thread with interest.

As Pict said elsewhere - "Hacksaws and files - proper bike building!"

Keep the updates coming :)
 
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