1989 BMW R100GS-Paris Dakar Restoration

Yes, I had been looking at similar devices to these on eBay and the hexagon heads would be better. I'll have to take my vernier caliper along to the local Screwfix tomorrow. Thanks for the tip.
Today I had a go at my nemesis, spray painting with aerosols. The clutch lever had worn away some of the matt black on it and the brake master cylinder must have been leaking for years brake fluid - probably from the aged O-ring beneath the reservoir. There was a lot of milky-coloured gunge which I cleaned up and scraped off before cleaning them with brake cleaner. I applied etch primer first but I always apply the stuff to heavily, and the fish-eyes appeared. They obviously weren't damn well clean enough! Then I'm too impatient to wait a good twenty minutes for it to dry before wacking on a coat of ordinary primer and then satin black. They look terrible, lots of fish eyes, so tomorrow I'll rub them down, wipe down with thinners, and then try again. I've seen people have good results painting entire bikes with aerosols yet I cock up just a couple of bits :blast

My new rear number plate arrived today from Demon Plates and it looks a cracker. The text style is called 'Domed Black' vinyl on a yellow reflective back ground, and I asked for a red pin stripe around the edge and the slogan '1989 BMW R100GS-Paris Dakar' along the bottom. I shalln't be drilling fixing holes through this. (www.demonplates.com)

I took the 40mm Bing carbs over to Dave Cunningham at Sevenoaks to get them ultrasonic cleaned. Whilst the price on his website www.tsrvapourblasting.co.uk looks reasonable (£50 a pair) he went on to explain that really the carbs needed dismantling, cleaning, then after the numerous O-rings are checked, all put back together with a note of what to replace if anything. It was clear from what he said that the YouTube examples I'd watched of entire carbs being dunked in cleaner for a few minutes simply does not work well enough with dirt still being trapped inside. Oh well, why spoil the rebuilt engine with gummed up carbs?:nenau
Yes John, thanks for that. I was thinking more of a narrower expanding bolt much like the ones which came out but of 12.5mm diameter, and hadn't thought of bar end weights which would do the job.

I could turn down the existing expanding bolts as I have a lathe but the bolts have two pieces with 45degree slopes half way along and I haven't figured out how they could be held in the chuck. No rush. I may well go with the Screwfix expanding bolts as these are more like the originals.
I spent much of today re-furbing the pillion footrests. The PO had them attached to 4" long lengths of steel bar, presumably his wife had long legs. All of the bracketry was bent and rusty whilst the steel pins had seized solid into the alloy footrests requiring me to saw them off. I drilled the remains out and shall fit stainless steel M8 bolts in their place. The remaining steel was straightened, cleaned up and sprayed with good old 'Silver Wheels' and lacquer.

This evening I have been reading up about repositioning the oil cooler. After seeing the Touratech prices I shall make the brackets myself. I've also heard about mobile fitters who come around and make up braided hoses on your doorstep although I can't seem to find one local to me. I like the idea of using the Aeroquip hoses coated with a plastic coating as the braided SS may well act like an Abrafile unless properly tied down.

The old hoses have seized onto the old oil cooler and no amount of WD40 wants to loosed them. I can see that if I use too much effort, a slip and the cooler would get damaged. So it'll have to be heat then.
Paul - not sure where you are but I have used Pirtek loads of times for various different types of braided hoses made up on different sites.

Maidstone, Tom, in the Garden of England. I have found a firm (Hydraquip) only a mile and a half from me. Perhaps what I'll do is install the oil cooler and then ask on here what the new lengths of hoses will be, then check they tally with what I will have. It'll be a lot tidier and more protected under the headstock.

By the way I removed the swinging arm and as I was attaching the gaiter to it rather than to the gearbox, I noticed that it was a bit split probably as a result of me tugging the damn thing around. I contacted Motorworks for the umpteenth time this year to discover they do a modified gaiter (currently not in stock) which is easier to fit on as it's made to slightly more generous proportions.
This project is becoming a bit of a money pit as I half expected. My way of looking at it is that I've never owned a brand new bike and this will be the nearest to one. At least I am spending the money in dribs and drabs rather than one great lump, and I am getting a lot of satifaction doing much of the work myself.

Yesterday I took over a pile of parts (crash bars, roo bars, pannier frames, timing cover, etc) to my favourite powdercoaters in Dartford, and they should take a couple of weeks to do. Those Touratech frames certainly add a lot of strength to the rear subframe and are well made.

I spent quite a while struggling to remove the old short braided oil hoses from the oil cooler as I intend to fit it under the headstock. The steel hoses are screwed into alloy nipples at each end of the oil cooler and they'd both seized on. It's SO EASY to damage the oil cooler by heaving around with big spanners but after a couple of days soaking in WD40, one side reluctantly came undone. The other remained seized. I've tried grinding the side of the steel nut but stopped as I'm worried about damaging the alloy nipple. My gas gun has a broad flame which is useless for this sort of work so I'll see a friend today who has oxy torch. Last night I looked up the prices for a new oil cooler and longer braided hoses and nearly feinted. It's funny how some parts of this rebuild have been astonishingly cheap (powdercoating £85) and other parts have been eye wateringly expensive (engine - FFS!).

Shortly I am going to have a go at rebuilding the wheels after getting monstrous quotes (£900 & £650) from firms. That should be theraputic:eek:

No success in finding secondhand SS exhaust pipes so far. All of the usual sources tried without luck.
Right, mudguards and side panels off to the painter. The quote I got a couple of weeks ago at a motorcycle show from another professional was £220. My friendly painter = £100. If there's one thing about the red & white R100GS-Paris Dakar is that there's too much red and white. To me it looks unco-ordinated, so I am going for Marakesh Red (BMW Paint Code 222) for both mudguards and the side panels. No white. The petrol tank (red & white) and the fairing (Alpine White BMW Paint Code 146) are in good condition so will stay as original. A turn round of ten days.

Oil cooler. Well after 48hrs drowning in WD40, the end of the hose STILL wouldn't budge, so ten minutes with a Dremel and a tiny burr and off it came. The alloy nipples must be made of the softest of alloy known to man. Oil cooler now shiny silver rather than matt black.

Front Brake Caliper. When I briefly had the bike on the road six years ago, the front brake was so appalling I followed advice I found here and fitted a four-pot Brembo caliper (from a K1100 bike?) and an EBC Pro-Lite floating disc, so the braking performance went from 'bad' to 'poor'. The front brake should have been much better but as the bike was put in storage for six years, I would look into it later. Today I decided to dismantle (or disassemble if you are a Merrycan) the caliper. It all came apart pretty well although I shall fit new stainless socket head cap screws and locating pin as they were pretty rusty. The pistons took a while to come out. Using an airline from a compressor I was a bit taken aback at the force one piston shot out of the caliper. I replaced it and held it in place with a G-clamp (or if you are a Merrycan, a C-clamp) then more air and that also shifted. The two on the 'backside' of the caliper really didn't want to budge, but g-clamping in then undoing one at a time and with more air they started to come out in a controlled fashion. Two pistons (are they 'ceramic'?) have just the tiniest amount of corrosion but after dressing them with a really fine file I've decided to replace them anyway. The bores look fine and I can't see any marks on the seals but I shall replace these and the O-ring. I will be nice to have a front brake which improves from 'poor' to 'good'.
Is the K 1100 caliper a straight fit or do you have to machine the lugs that hold it to the fork leg ,and is it compatable with the original disc .Thinking of upgradeing mine .Cheers John
I've read an old post from Judge saying that Motorworks used to sell modified K1100 Brembo calipers but stopped doing so for fear of litigation. Fortunately I bought mine from them before that became the case (if that is the case). Yes, the casting needs machining by a tiny amount to get the centreline of the caliper to line up with the disc. If you want, I could measure the existing thickness of the lugs on mine so you'll know what to get machined off (That's if you are fitting the Brembo 4-pot to an R100GS-PD or something similar.

As for compatibility, I replaced the original disc with the floating disc so they were compatible with each other, and with the modified Brembo fitted, rode the bike for a month or two before taking her off the road. No problems other than the front brake was still poor.

I didn't find the conversion that good even with the floating disc and a braided brake hose, but this time I am properly overhauling the master cylinder internals and replacing two pistons and the seals in the Brembo. Hopefully that will do the trick. The brake pad pin is pretty corroded so I'll replace that and the bolts with stainless.

Have a look at this link. No mention of how much material to remove but you'll get the drift -

It aint pretty but it is cheap.

I bought a late 1150/1200 caliper on ebay for £30 and then made a bracket from Dural - £35 all in. The pads have lasted over 20k and are still only half worn.

I've just measured the modified thickness of the lugs on my Brembo and they are 12.28mm thick and milled to an 18mm radius around the two mounting holes.
Right. I telephoned Motorworks this morning and discovered that the caliper pistons for the K1100 caliper originally came with the back of the pistons covered by a ceramic disc, and that as this disc is fragile, it can often break then the piston is removed. Hence all of my pistons I took out of the Brembo caliper were bucket-shaped yet the new ones are drum shaped.

I have no idea what purpose these little discs have as the front brake worked well enough (but not brilliantly) like that.

I must take an image of the two as clearly not many people understand what I am talking about.

Well what a strange day. I received a couple of small parcels from Motorworks who have (in error) sent me TWO gearbox gaiters plus the overhaul kit for the master cylinder. I am going to have a good front brake even if it kills me.

Motorworks now supply a slightly oversize gearbox gaiter which is easier to fit. In fact I think the rubber is a little thinner which makes it very difficult to fit rather than impossible. 1 1/2hrs later (Jeez!) it was in place.

Next the Bevel drive. Well that was impossible. I even had the central heating man around who was once a motorbike mechanic and try as we might, we just couldn't get the male and female splines to engage. After two frustrating hours I put everything away and went to phone Jim Cray. Jim tells me that this is one of the most frequent problems from Airhead owners. Half the problem is at the Bevel Drive is heavy and one needs two pairs of hands. He tells me that the technique is to fit a couple of wheel bolts in the bevel drive to help turn the male splines (already done that) and to fit the torque arm bolt. This then will allow me to pivot the bevel drive around the torque arm bolt and line the male and female splines.. Then it's a matter, he says, of gently jiggling the female splined UJ with a screw driver and turning the wheel nuts. It should take between zero and five minutes (he said). I will go back to it tomorrow.

I also, using the repair kit, fitted new seals and ceramic pistons in my K1100 4-pot caliper. The seals are a bit fiddly so I needed good light and the internals of the bores were immaculately clean and lubricated with the sachet of Brembo lubricant provided in the Motorworks kit. I was amazed at how difficult the pistons were to replace as I've refurbished car disc brake calipers in the past when just thumb pressure get's them back. Not this time. The pistons are also dead easy to to get cocked so needed checking regularly as I squeezed them in in the vice with lots of rag to protect them. Quite a bit of pressure was needed to get them home.

Incidentally Motorworks DON'T recomend seperating the halves of the caliper, as it seems they are difficult to properly seal again afterwards. This is contrary to what the Haynes manual states. That's why the tiny O-ring where the brake fluid passes from one caliper half to it's neighbour is not provided so the old one has to be re-used. I also applied a very thin film of Hylomar sealant between the halves and tightened the socket hd cap screws down with a torque wrench, something I rarely bother with. The screws and caliper pin I bought from Chris Shaw Engineering (www.shawstainless.co.uk). The head are all turned down to remove the lettering and are immaculate. First class service too.

See the differences between the 'old' ceramic pistons and the new ones?

Well that's the K1100 Brembo caliper sorted - new pistons, seals, ss bolts and pad pin.
Nice one Paul ,looking the biz,I,m more than likely gonna follow your caliper path as my orioginal is very slightly binding and one of the pistons is damaged thanks for the pics very informative.:beerjug:

Well at the second attempt, and following Jim Cray's advice, I eventually got the male and female splines to connect. It took twenty minutes and I thought it just wasn't going to happen. This time I attached the bevel drive to the torque arm and placed the pair into a wooden block. Then pivoting around the bottom bolt, it worked.

I have cleaned up and re-used the Hagon shock absorber as it still functions OK although the spring has been powder coated. Pillion foot rests have had their steel spindles drilled out as they'd seized in the alloy. Now with stainless steel nuts and bolts, they are an improvement. I am going to modify the rear brake lever by following Simon McCarthy's (Sorebums) mod of cutting off and repositioning the top to get a straighter pull on the brake cable.

The horn has been cleaned up and repainted today.
HOW TO MODIFY THE REAR BRAKE PEDAL (With thanks to Simon McCarthy)

The original end of the rear foot brake pedal.

Hacksaw end off as shown and turn through 90 degrees....

...and weld back as shown. I bevelled the edges prior to welding for better penetration.

I have enlarged the small foot pad area as shown.

And this is the end result. I have drilled a tiny 3mm hole in the boss to enable me to oil the bronze bush properly once the pedal has been re-installed.

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