Friday, December 11, 2015

Time Flies...

It's been almost 4 months since my last post!

That could imply two possibilities - you'd either think that I messed it all up and gave in (way more likely) or got bored of writing. 

The answer is: neither. In the meantime, the Beemer took up most of my free time, even my working hours! (My boss does not need to know that, really!) But, most of the effort was in the form of thinking, searching, reading and further thinking dead loop, so the visible progress is virtually nonexistent. 

Normally, this post would be a sequel to the "Three Special Tools" series. The designers developed a number of special service tools to remove certain critical parts. Few different "special tool catalogues" from sixties can be found in scanned form in the net. As a matter of fact, I should gather a list of references to the most important information sources on the web. 

So the engine block was supposed to be straightforward...

You can see my second "special tool" in the photo, the small plates that hold the flywheel thus the crankshaft so that you can work on it. I know, it is not so special, and not quite a tool anyway. But it worked pretty well. I had four of them made, but two were enough for the job.

My first defeat was to the big bolt at the center. I couldn't make it move even a bit for days or weeks, no matter what I did. Finally, I took the whole thing to the metal shop that previously did a great job with the front fork bolt. Well yes, just a good hammer blow and it was loose.

In the front side, I removed the case that held the voltage regulator circuit and the rotor coils. It is obvious that I will have to replace the old and tired wiring inside. That's okay, the case itself needs a good treatment, too. Luckily, there is an amazing resource about the electric circuitry on the web.

Then came the front cover loose. Now I exposed the timing chain and the sprockets. The gasket is a mess, but I already have the complete set ready.

Is the chain too loose or what? On the screw hole just below the sprocket, you can see the big dent on the aluminum wall. It seems that the loose chain dented the block over time. 

It is not just the chain's fault. From R26 on, which is the next model, they added a simple chain tensioner to the design. Luckily it is backward compatible so I'm considering buying one.

Here's the first round of the "special tool" game, starting by removing the bearing using a suspiciously cheap puller I bought some time ago. 

Some technical info - a puller is a tool... umm... that pulls. It's used for removing bearings or sprockets that are fixed on a shaft by heat difference. When cold, the metal contracts and completely removes the gap in between. So you heat up the part, hang the puller's two (or sometimes three) feet to it and the big bolt on top to the tip of the shaft. As you rotate the center bolt, it slowly pulls the bearing step by step, until it comes loose off its seat.

This was the first and last success of this puller.

Right below those holes in the photo, there are two flat screws holding the timing shaft cover. 

It wasn't as easy as it looks. Both screws were so stubborn that it took me a whole evening to remove them. This time, I used all the tricks that I saw at the metal shop. First a good deal of WD-40 to loosen the rust and oil residue. Then I heated up the area and then came many hammer blows over an old screwdriver. This time it was a success! (I believe I need two new screws, though.)

In the meantime I removed the oil pan. It took me several rounds to clean the slimy mess, which is a good indicator how the poor old chap was mistreated.

And that's despite using my fantastic oven cleaning foam!

The service manual (which is also printed in sixties) mentions about special tools in three critical steps while removing the engine block. First one is to remove the flywheel from the shaft below the large bolt in the photo at the top, second one is to remove the timing shaft cover which we removed the two screws from, and last one is the crankshaft cover which is the last obstacle before removing the entire crankshaft.

Naturally, there is no way to find the original tools. Even if there were, I can imagine they would be unaffordable. Although I found a tool set in USA that does the same job as a number of BMW special tools, including the three I mentioned above, it is unfortunately too expensive even without the shipping. And while I fully appreciate the research and design efforts, all in all it consists of just a few nicely laser-cut metal pieces and a few nuts and bolts. Scratched it out. But I must admit that examining the photos of the tool set contributed a lot in the neat and affordable solution that I finally came up with.

After that, I began thinking about how I could manufacture such a tool set myself. All in all, it was just a couple of carefully drilled metal pieces. I almost ordered a bench drill and even a welding machine. They aren't very expensive compared to what they can do, but most probably it would be a one time use for me. Even worse, I was not sure that I could properly produce the tools at all.

Now let's fast forward. I spent weeks with those thoughts and design attempts. I read everything relevant, wandered around in the hardware stores, surfed countless online stores, and I'm not dramatizing too much. At last, I saw the light in such a way that the solution to my problem did the job perfectly well and costed significantly less.

Here you see another puller, just a little different the previous one.

The round part below, the jaw, is to fix behind the bearing or sprocket you want to pull. When you tighten both nuts aside, you attach the "legs" to the screw holes on the sides of the jaw and screw the bolts to stabilize the legs on the body. Then, as you screw the center bolt, it gradually pulls the part in a similar fashion.

The flywheel is first to go. Here, I do a small hack; instead of the leg bolts, I use bolts that fit to the screw holes on the flywheel, that are made for attaching the "special flywheel puller tool" and start pulling. Flywheel: check!

Timing shaft is the next, along with another hack. This time, I use only the body of the puller. There is a bolt hole in the center of the sprocket. I screw the bolt way through the hole on the puller body, into the timing shaft. Then I start screwing the nut in the opposite direction in order to pull the bolt and the attached shaft up. After a few rounds, all come loose. Timing shaft: check!

Last stop is the engine block cover, which holds the crank intact. It uses the same principle as the flywheel, but with thinner and longer connection bolts. The length and position looks okay, so after a quick heat-up, I start screwing the center screw. Rest of the entire engine: Check!

Monday, August 24, 2015

Chopping Off

After weeks of scorching hot, finally a good opportunity to get outside and make use of the stuff I have been shopping around...

The day may well end up as great fun, or as a complete disaster. My grinder is getting out of its box...

It's time I got rid of the three ugly iron foot pegs, one welded instead the left passenger bracket and two next to the rear shock brackets, for the comfort of the second passenger! Let's see how it will work out...
No, I'm not confident at all - I've never needed to do any metal work ever. This will be my first serious experience with the fancy power tool.

I'm aware that it is not a toy. I don't want to get myself into stupid trouble, so I've got my plastic eyeglasses, good and comfortable working gloves and an old Buff as my "protection gear". I had a mask as well, but it directs my breath right into the glasses they get fogged up like crazy. Ridiculous...

Anyway, it's the Beemer who's in real deep trouble, not me.
I begin with the cut off wheel. First I'll get rid of the chunky parts of the pegs and then go on with finer work. The power tool is indeed so powerful, cuts through the strong iron like butter.

Great power comes with great responsibility. Especially the rear pegs are located in a crowded position and it's pretty narrow to work in there. If I accidentally touch the frame, there may be no way back. I must work very carefully.

First I cut off the chunky and easy part of the left passenger peg, observing and getting used to the behaviour of the grinder in the meantime. 

The colours in the cutting surface can give an idea how hot it gets during the work. 
And this is the second passenger's left footpeg. 

The grinder is actually quite aggressive. If I cut too deep, the powerful rotating disc catches traction on the side walls of the cut and throw my hand in the direction of rotation. Not hazardous for myself at all, but the sudden loss of control may may dent the frame at an undesired location. So I proceed parallel to the frame as much as I can, then vertically cut off the piece hanging above the dent. This makes my life pretty easier.
This is the right side. It's even more difficult here, there's the rear shock lower bracket on one side and the sidecar mount on the other. The mount is not needed, but leaving a visible damage for nothing would be pointless. 
With that method, I removed most of the bulky parts. 

As I didn't ever properly cleaned the frame, the shock mounts are covered with the old grease almost all over. As I work with the grinder, the grease melts dowm and starts dripping. Even with my thick work gloves, it gets way too hot to hold the frame around the working area. 

This is the best I could achieve with the cut off tool. Let's get to the second stage.

I remove the cut off disk and take the grinding disc, which is thicker and stronger. It's easier to use, does not have sudden aggressive reactions and as it is only for grinding, I can take different positions as I prefer and make use of most of the surface. 

So I managed to have a fairly smooth surface with just a little bit of fine work.
And this is where the broken passenger peg bracket was. I like the result here, too but I didn't work too precisely here. I'll find the bracket from a donor and have it welded here, so the work will depend on its shape. 

I'm not saying that I did a perfect job. No, I had a couple accidents and harmed the frame here and there, but they are not critical damages at all. Will not be noticeable after the paint job. 
And lastly, a before - after comparison.

The large disc on the right is the grinder and the one on the left is the cutter. When I started working, their diameters were equal! 

By the way, you don't notice at first, but the machine is pretty heavy already with the rotating mass, and puts the right wrist under huge strain. As the work is completed, my right hand became almost totally numb.

I'm very happy with the outcome. I learned dealing with the grinder, which is not so difficult to use, and I got rid of a significant step that I should have done long time ago. Now it's only up to the missing bracket to go into the sand blasting and paint job. 

Saturday, August 1, 2015

Two Nasty Bolts: The Front Fork

I haven't been updating since two months. Now after all that time, for those of you who might think that I'll pull a red satin cloth before the audience to reveal the shiny bright as new R25/3 - always keep your rose-tinted glasses on!

I managed to overhaul the final drive the last time, renewed all the gaskets, seals and bolts on it. It's been waiting for the moment that I finally fill it up with fresh oil and mount it where it belongs to.

I classified the Beemer into four major "systems", if you recall. After I'm done with the final drive, I decided to move on with the front forks, as they are the only step left before the paint job, and also I thought it'd be rather straightforward. After all, it hardly takes me an hour to take out, replace the oil and redo the front forks of my 2008 bike, which basically work with the same principle. How difficult can this be?

Guess what - I was dead wrong again...

How about some theory first?

The front forks have a very simple mechanism. Two pipes one inside the other, made oil tight with a seal, a spring inside to absorb the shock and oil to damp the oscillation by compressing the air gap. 
The bottom part (shiny one in the photo) holds the front wheel, where the upper part is attached to the handle. Of course, we have two of these. 
And this is the spring inside and the steel rod that keeps it aligned and also holds the bottom part attached. At the very bottom, you can see the bolt that attaches the bottom part. And at the top, the big bolt to attach to the handlebar piece.
Right here. The bottom clamps hold the forks, while the rod in the center goes through the chassis and gets fixed at the top, connected to the top clamps. Thus, the two forks get fixed at two points and form the whole front assembly. Of course, with the two bearings, at the top and bottom of the rod, for rotation. We'll get to that soon.

French poet and writer Antoine de Saint Exupery, best known with his novel The Little Prince, once said

“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.”. When you compare the two fork assemblies produced 50 years in between, you notice that the newer one is build much simpler, also using fewer number of parts, even though they are still based on exactly the same principle.

"Yeah, right, enough with nonsense, so what have you been doing the past two months?" - all right, I'm getting to the point.... 

These huge bolts on top the the springs are the ones that fix the forks ot the top clamp. So I have been fighting with these very bolts for two months, trying to loose them.

They are exactly 45mm wide. For that size, I had just a huge old fashioned wrench. It did not take so long to give up with it and go get a 46mm head for my wrench. Oddly, there is no such standard size as 45mm anymore. Whatever, it's just a millimeter, it shouldn't be that precise.

Just a regular bolt, and it shouldn't be that tight there anyway, right? As I push down the wrench, the opposite end of the 10kg frame rises. If I were into acrobatics, I could have stood on the tiny wrench handle. The only thing that doesn't move a tiny bit, is the bolts themselves. I don't know how many evenings I spent wrestling with it.

Yeah, I've seen that before, with the strange shaped bolt that was holding the final drive. I'll take the same way. With all my determination, WD-40 and hot air gun, I confront the two problems once again. After several evenings of failure, half a can of WD-40 and the odd smell of the hot air gun in the entire house, one of the bolts finally give up. Such a relief.

Great, so one down, one more to go. I keep on with the same approach for days, but every single attempt fails, without the slightest hint of progress. Until last weekend. 

I have a friend of mine, managing a car service shop. After countless failed attempts, I decided to visit him. So I took the frame and hit the road. I took the gearbox with me in a plastic bucket, as I had two broken bolts there. The guys took me to a small metal shop nearby. 

The guy was a real old school expert. Instead of my pathetic hot air gun, he carefully heated the bolt with his blowtorch until it glows red. Then he quickly cooled it down with water, then heated and cooled again. You can see what remains from the black paint.

Then while I was holding the frame tight, he gave the bolt a very strong but precise hit with his hammer and chisel right at the corner of the hex bolt. I guess it was the first time after maybe 30 years that the bolt moved at all. After the second hit, it came loose enough to go on by the hand. Then he removed the gear lever bolt with a suitable pin, and the little speedo wire screw by welding a steel rod on top and unscrewing it. A great demonstration how experience and proper tools make it look easy.

Can you guess, from the photo above, which of the two bolts was the nasty one?

I came back home and unscrewed the whole front end. As I removed, the steering head bearing balls all came loose. You can see the remaining balls stuck onto the grease in the photo. You can see the bottom end of the bearing right at the bottom of the steering head axle.
The top cap looks the same with its bearing and balls. (Say hi to the good ol' WD-40.) Despite the mess, the bearings are not in a bad condition. But they will be replaced.

The mechanism remains exactly the same, but we have a more reliable and better design, called "tapered roller bearing" instead of these.  Probably they weren't developed yet back then.

Now it's time to get brand new steering head bearings, fork seals and get rid of those ugly welded footpegs on the frame. Then we'll be ready for the paint job.

I must admit that when I was doing the research and trying to learn the detals of the Beemer, I was't aware of what sort of a challenge I was going to take on. I simply underestimated the effect of such a significant amount of time even for human life, let alone for an industrial product. Facing all such difficulties and low pace of work, I often feel overwhelmed, but I am not by any means disappointed or discouraged at all. As I slowly progress, it gives me more courage for the next big obstacle. The long periods of silence are probably very boring to follow, but this routine will go on until the happy end.

Next stop: the frame...

Saturday, June 6, 2015

Three "Special Tools": Final Drive

For the past months, I'm completely stuck in a research-read-hit an obstacle loop. On top of that, it seems that my shopping frenzy of tools is still going on and there is no sign that it will be over in the near future.

Speaking of shopping, although lot of the parts of the Beemer can be handled using everyday tools, quite a few tricky points require rather extraordinary stuff. Furthermore, some important parts can only be removed using "special tools", literally specific to the brand and model. You'd better get used to this term - you'll hear it very often.

I sort of broke down the bike into four major "systems", while I'm stuck to one or more "special tool" needs. These four systems are the engine, transmission, final drive and the front forks. Although I found possible solutions for all four, it will be very stupid to attack all at once. I should start with the relatively easy one - the final drive.

Now, these special tools are not things you can buy at a hardware store, I decided to adapt the most critical ones myself. As, unfortunately, my skills with design tools do not quite exceed MS Paint, I asked a friend of mine from Istanbul, who designs and manufactures stainless steel products, for expert support. I don't want to turn this blog into a collection of "Zen and the Art of Motorcycle Maintenance" type of philosophical essays, but I should say I find it really amazing how the motorcycling bring together so different people from different professions, profiles, even cities. Just this alone, makes it such a special and valuable hobby. 

So my friend Ünsal converted my beautiful hand made in MS Paint designs into proper CAD format, and got them laser cut and sent me. The first one you'll read about is a kind of wrench for removing the big dented bolt which keeps the final drive together. You can see the "before and after" in the picture, my fancy design and how it should look in the CAD drawing.
The result looks perfect. The internal diameter is just the way it should be, and the dents are right where they are supposed to be. Well, here comes the "but" part - I've just overlooked a small detail...
This is what the beautiful tool turned into, in just a few tries. So can you guess what this tiny little detail was? That it's been sitting there without being touchede for ages! Oil, grease, dirt mud, collected in decades makes it stiff as concrete. My petty tool did not even tickle it.
So I went shopping again and bought this hook wrench. It serves the same purpose, with a more generic shape. In my opinion, it is not as elegantly designed as my tool, but far stronger.

Well then, what did this one do? Nada! The bolt did not move even the tiniest bit, even the edge of the dents on the bolt got slightly deformed. I got confused, perhaps it is not the right way to open it up. So back to the computer, for more and more research. But the outcome only confirms it. That bolt must be removed.

So there's only one way out. I'll use everything that can help and attack the "problem" with sheer brute force. I heated the body with the hot air gun, until it can't be touched with bare hands. Then, attached the hook wrench as good as possible and literally started jumping on the damn thing. After a few very disappointing tries, in the fourth or fifth, the bolt finally gave up and started to move. 

Note for the young enthusiasts: Your most precious assets are the hot air gun and patience...

Result is good. The input shaft joint looks pretty nice and clean. The bearings are intact. I left it aside as there's nothing to replace or service here. 
The output joint looks the same. They are immersed in oil anyway, so no need even for cleaning. 
And the body. The large gear in the above photo sits onto the big bearing in the middle. The input shaft then slides into the hole at the right side. It is how the axial movement is rotated by 90 degrees and directed to the rear wheel.

The photo makes it look very dirty, but it's just the remains of the paper gasket. I'll clean the surface before putting a brand new one.
This is the inner side of the body. The big bolt and the hole is where the brake pads sit. The dirt is just the remains of brake pads over time. Nothing important.
Of course, this doesn't mean that I won't touch it at all. So back to the bucket. No matter how "clean" it looks, remains of oil and dirt is very significant. The water was crystal clear the day before, when I immersed the final drive.

Next step is to buy brand new bolts and put together now cleaned final drive with brand new gaskets and oil seals. This will leave me with just three "systems" to go.

Tuesday, March 31, 2015

Shopping Mayhem

I know that it's been more than a month, but no, I didn't give up! I should admit that I didn't do much in the meantime, if at all, but I'm still going on slowly but steadily.

You remember my long and ever growing shopping list. During my "silence", I worked to fill it in with as many check marks as possible. I believe I'm pretty successful, of course until the next surprise.

I started the first wave of shopping in Germany. Uli's Motorradladen is a parts specialist for all sorts of old Beemers, located in Frankfurt. They have got a huge inventory, are very supportive, helpful and very fast. (The last one is a rare virtue in Germany) I purchased a lot of parts, especially the essentials to revert to the original state. Unfortunately, they are very expensive, even if you would earn in Euros, but the parts are such good quality that they still deserve it.

The headlight glass for instance. On the lower part, you see the original Bosch logo used until 1955. So the Chinese plastic that is glued with plenty of silicone can go to where it belongs to - trash.
I mentioned about the poor footpegs before. One is still usable, one is completely replaced with a steel piece welded to the frame and needs to be cut off, and the remaining two are in the photo. One resembles the welded one and the other is welded to the side stand.
They all must be sorted out. Now I've got three brand new footpegs.

The rubber pieces, not just the footpeg rubber in the picture, but everything including the air filter hose, handles, battery belt and a few smaller others, are made by a local rubber shop in another city. Very good quality, but the ones on the two sides of the tank did not fit. Must be some kind of model confusion.
The top covers of the rear shock were dead, too. The new parts are not cheap, but it would have surely taken much more to recover the old ones. I believe, if I had known an aluminum shop, I could have made them much cheaper. Anyway, money has to go, not much to do about that.
This is my favourite. Replica of the Everbest fuel petcock. Just a little detail, but so elegant and in such a harmony with the rest of the bike.
The original ignition key and the ignition cover in the photo. I got the whole lock assembly as well.

Here's a fun fact - although the key has changed a few times, but up until seventies, all bikes were provided as "one key fits all"! That means, if you've got a key, all Beemers were yours!
The ignition assembly has been replaced with a cheapo lock, probably ages ago. They had to modify the headlight body to fit it in. So one of the very expensive parts that I bought is the original ignition circuit assembly. There is no apparent reason to be so expensive, not even a single electronic part, very straightforward build, but probably just because it is so specific. I'll need to correct the headlight body to fit it in.
This is another piece that costs way more gold worth its weight. The switch for the headlight and horn. Incredibly expensive but so neat and elegant, just like the others.
I bought a new left lever clamp, too. It's amazing that you can find absolutely any part for the 60 years old bike. I don't think you can have that abundance with any other brand at all.

The new left and old right together in the photo. Right side is okay, just needs a thorough sanding and matt black paint.
I also ordered the gasket and seal set for the engine, transmission and final drive. I could have had them made way cheaper here, but as I didn't have anything that I could use as a sample, or the sufficient knowledge about the parts at all, I let myself to the German precision. This one is for the engine block.
Here's the transmission. I thought about taking them to a specialist to be replicated, but well, how often would you replace engine gaskets at all, right?
And the final drive.

Last week I overhauled the carburetor. It wasn't complicated at all, but of course instead of cleaning and putting all together right away, I left it there to make sure I forget how I removed what!

The little plastic bag in the foreground is the carburetor gasket set. There were a few gaskets missing in the carb, I hope it will work better with the new set.
And last Saturday, I left home for the Ankara part of my shopping. First, I went to the infamous industrial area packed with all kinds of car mechanics and found an engine shop to show the valve head, piston and cylinder. Good news is that the valves are good, but the piston and the cylinder are not. The guy cleaned the valves, too. He suggested that I should definitely replace the piston, and preferably rectify the cylinder to the next half millimeter, too.
I left there to find an even more infamous classic Beemer handler, in another, way larger industrial district in the city. I had the address but it took me two rides up and down in the street until I realiyed the three hand painted letters on the brick wall in a side street. The guy used to be the first authorized BMW mechanic in Ankara, and then decided to collect and restore classic bikes. In the net, people say that he's such a grumpy old guy and you should be careful not to piss him off. Well, he didn't turn out to be a sweet grandpa anyway, but we got along quite well.

He offered me a newly rectified cylinder block and a matching piston in good condition in return for my cylinder block. It saved me all the fuss with the engine shop, and will look much better after I clean it up and paint with matt black spray paint. Above, the old and new pistons and the cylinder block. On the right, you can even read the diameter markings on the pistons, 69mm on the old one on the left and 69,50mm on the right.
Also got my "torpedo" model exhaust muffler. Looks beautiful.
And last but not least, a used piston arm to replace my cracked one.

So the most significant shopping is over. What's still left is "just" the bearings that I'll decide to replace, and every single nut and bolt, and that's it!
I also spent quite a lot on various tools. A grinder to cut off the mess and clean up the frame, and the polish set for the Dremel.
I tried it very briefly on the old left lever clamp. The first photo with the dirt and rust of the past half century.
And this is the other side. I roughly experimented with the toolset, without any care or precision at all. I did not even use any polish. I like the result, I believe, with some more practice it will get much better. I have a lot of parts that must shine at the end, the exhaust pipe, wheel hubs, handles, etc...

Now that we're in the daylight saving time and the days are geting longer, I hope to proceed more steadily without being this lazy anymore. Let's see...