[f104wart]

The direct route may be the shortest, but the detours that somehow lead to the goal are often more exciting.

There are a few such detours in this conversion. The goal was never left out of sight.

Have fun reading...


L´abono carrera ... is a play on words from Spanish and freely translated means something like
"The racing slurry"

The story begins on a business trip to Switzerland in December 2012, where I had a conversation with the customer on the drive from Birsfelden to Lugano. We discovered that we have a common hobby and Bernhard told me that he also has a 650 CX, among other things.

... and he even had a second one that he was ready to sell. We were talking about € 500, which in the end became 500 CFR, i.e. € 420.

But I couldn't see it, because it was in Bernhard's garage somewhere in the Swiss pampas. I didn't have a trailer anyway and we stayed so that Bernhard wanted to send me pictures.

On the photos she actually looked okay. Not completely and with a cross tire in the back, but otherwise not battered or something. ... And the parts that were dismantled were supposedly still there.

That it wasn't complete didn't bother me, because I didn't like the E (PC06 or RC12) anyway and since I had already planned to build a Caferacer out of it, I didn't care. The main thing is that I had the chassis and the engine.

... Yes, something was wrong with the starter and the clutch had been removed, but I didn't care because my parts store was well stocked. The starter wasn't the issue and a couple of new clutch plates aren't the problem either, I thought ...


It should turn out that in January 2013 I had to go back down to Switzerland.

So I named my trailer, picked Bernhard up again in Birsfelden and we started again towards Lugano. We made a little "detour" to Bernhard's house. Late in the evening - it was long since dark - we loaded the CX into the trailer. It all happened very quickly. With all the snow and the rose-colored glasses I couldn't see anything anyway.



A few days later, in my workshop at home, the rude awakening came. The "good piece" was badly messed up. The frame was crooked, the engine showed traces of the wild use of force, the air filter was replaced by a piece of foam, the electrical system torn, etc., etc. ...

... So the first inventory did not promise anything good.

But that was just the beginning and it was to get worse ...


When dismantling it turned out that one exhaust manifold was open, the other had a throttle plate in it. How the thing was running with it is still a mystery to me today.

The standpipes were totally tasteless and ripe for the scrap. ... Okay, the fork with the anti-dive fuss wasn't my thing anyway and didn't fit my concept. A sale in this condition was unthinkable an no option.

The frame went straight from the lift into the scrap. The fork, except for the dip tubes, too.

The ProLink leveraging was mercilessly jammed, was dismantled and overtaken by Alex "Güllenpumper". He is a lathe operator and specializes in overtaking ProLink. To do this, he manufactures new bushings and precisely fitting bolts and including powder coating.


The next step was to get a new frame and dismantle the engine ...


Basically I don't install a used engine without removing the rear engine cover, checking the timing chain and modifying the tensioner, if it's an automatic one.

... Yes, and this is what the timing chain looked like:

The tensioner was fully extended

...and the guide rail was broken

At first glance, it all looks pretty bad, but there is still room for improvement.



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[f104wart]

We remember the seller's statement that something was wrong with the starter.

After removing the flywheel to replace the timing chain, I also knew what it was.

Somebody had disassembled the starter freewheel and then failed to secure the screws during assembly. They then went into business for themselves and took care of some machining in their area.

... And this is what it looks like:

The freewheel itself only turned loosely in the flywheel and did not provide any frictional connection between the starter and the drive gear:

The oil pan didn't look bad either. At least that way any chips, which once sunk in the mud, are no longer taken by the oil and distributed in the engine...

...But, in summary, engine overhaul was "business as usual".



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[f104wart]

...meanwhile there was also a new framework with German papers found the way to me.

The first thing to do was to remove the main stand mount. ...And in this process I put "an egg in my own nest":

Since I never had a frame with a ProLink shock absorber in my fingers before and the ProLink was still on the way to overtaking, I immediately cut off the holder for the ProLink lever when I wanted to remove the redundant holder of the main stand!



...Gone stupid!!

You can barely see the spot where the hole was previously through which the ProLink is screwed.

... Now "good advice was expensive" and a creative break called for.


But then I´ve had an idea:

The threaded rod shows the position of the screw. The washers served as spacers and a marking aid.

Then the sheet metal was cut and grinded to the diameter of the disks and two 11 mm long sockets were turned.

The sockets were then fixed with a temporary spacer and welded in place. The whole improvisation is now more stable than the original and is no longer noticeable after painting.

 

[f104wart]

The Comstar rims of the 650s with the perforated aluminum arches don't look bad on their own, ...

... but to a classic cafe racer belong spoked wheels with polished aluminum rims.

The conversion kits offered with adapter rings couldn't really convince me. Apart from that, these are only offered for standard manure, but not for the CX 500 E or the 650 series. So another solution had to be found ...

Even the nice gentleman from TÜV was not really enthusiastic about the adapter solution and advised me to look around the Honda shelf first. For him the most essentially where the hubs. Installing a series part here saves a lot of money and paperwork ...


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[f104wart]

... Here in this forum I came across a Caferacer conversion in which the owner implanted the rear hub of a GL 1000 Goldwing of the first series in a CX 500. The toothing of the gold swing hub fits the final drive of the CX 500.

But my 650er has a different final drive that is completely different from that of the rest of the CX series, including that of the CX 500 E (PC06). Even if the wheels themselves look the same, the hub is completely different. The 500 series has a drive flange with internal teeth on the hub and external teeth on the final drive. Simply swapping the final drive is not possible because the housing, the mount on the swing arm and the connection between the cardan shaft and the final drive are completely different:

The two pictures above show the different toothing in the hub, the two photos below show the different final drives ...

... so with "just remodel" nothing works!

The next problem is the swingarm. The 650 (RC12) and the CX 500 E (PC06) have the central Pro Link shock absorber and rear disc brakes, the normal 500 series has stereo shock absorbers and drum brakes.


A conversation with a friend who deals with the GL series and who is currently in the process of restoring a GL700 Interstate that was never available in Germany, knew that the GL 650 Interstate (American Version) has the small final drive like the 500 and - here you go - it also has the Pro Link swing arm!

... that the GL 650 Interstate has a drum brake at the rear and the pivot point of the brake support is missing, should be the minor problem.


Micha even had a matching swingarm with a long cardan shaft in his pool and I was able to talk him out also a final drive with the large bore (the axle of the 650s is thicker than that of the 500s).

To the photos:
... at the top the "large" housing with 4-point attachment and below the "small" GL 650 Interstate with 3-point attachment.


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[f104wart]

... A few days later, an old rear wheel from a GL 1000 Goldwing also found its way into my workshop. The hub was "spoked out" with the Flex in 2 minutes and the fitting made my eyes shine and the corners of my mouth grow up to my ears.

The hub fits and sits in the middle of the swingarm !!

The gap between the hub and the final drive has nothing to say. The only thing missing here is the cover plate that is screwed to the final drive. At the moment it is still grinding a bit on the hub, but this can be remedied by turning the hub in the edge area.

A pair of matching spacers on the left for the correct offset of the brake caliper holder and good is ...:


The front hub I found at a partial dealer in France and took two at once. You never know if it´s needed or not. I also have a couple of 500s standing around and the right final drive is already on it ...:

The front hubs are identical to the CB 750 Four and the CB 500 Four:

The mount for the brake discs differs from the original rims in that it has 6-hole mounting, a different bolt circle and a slightly larger inner diameter (original 58.2 mm, here 60.2 mm). The brake discs of the GL 1000 and the CB series are too bulky for me, but I think you will find something suitable here.

...impossible is no option. What does not fit is made to fit!!


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[f104wart]

Since I don't have all the AntiDive levering on the dip tube, I got 37 fork legs from a Boldor fork.

The dip tubes were stripped of paint and polished.

... also the final drive

The beautifully flat and narrow aluminum fender at the front is only placed at distances that represent the final position in the photo. The bracket is still missing. It is made from stainless sheet metal and fastened with brass rivets.

The rear frame has now also been shortened. All unnecessary brackets have been removed.

There is also an aluminum fender on the back and a classic Lucas-style taillight:

... The goal is to really build a classic Caferacer and nothing else.



I've never liked the original tank of the CX 650 E and soI sold it.

At first I thought about tackling a tank completely myself, but I didn't want to set my goals even higher and then eventually capitulate to them. I think I already have enough work to do with this project.


On Ebay I found an inside rustfree tank from a CB 350 Four and I "shot" it for 90 €. In terms of the paintwork, it was a total meltdown, but the inside was absolutely rust-free.

....but, as expected, the tank was too narrow and much too short for my frame and the tank bottom didn't fit at all.


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[f104wart]

An old GL 650 tank was stripped for the bottom of the tank. The GL tank bottom has the same shape as that of the CX 500/650 E, but has the advantage that it does not have the hole for the fuel gauge sender and, just like the original tank, fits very closely to the frame:

The rear end was rusted and has been reconstructed.

The tank cap of the CB tank was removed and the nozzle was cut out with a hole saw.

The tank itself was stripped of paint and cut into four parts.

Out of 4 mm thick and about 12 mm wide aluminum flat material I cut strips with through holes and M5 threads in the counterpart. This means that the tank quarters are "jammed" with each other at the appropriate distance and are connected to each other in a very stable manner.

Everything also fits perfectly at the back of the transition

The line and the distance to the valve covers is okay

From below, too, everything looks very promising.

The distance to the motor mounts fits and not a single ml of the precious tank volume is wasted.

The arch in the lower edge of the tank looks as if it was made especially for these carburetors:

The bottom of the tank still needs to be adjusted a little, but in summary it fits.

 

[f104wart]

After a short "infidelity" with the topic of tank conversion, the hubs and brakes continue.

First I wanted to keep the original brakes. The new hubs have 6 instead of 5 holes. Adaptation was therefore difficult. The result did not meet my requirements and was discarded.

The rear disc of the CX does not fit on the hub either. Both the rear CX brake disc and the Goldwing were too heavy and bulky for me. I wanted to keep the unsprung masses as low as possible. So there had to be another solution.



... After some thought, I decided to implant the complete brake system from a CB600F Hornet. The discs also have a 6-hole attachment - albeit with a different bolt circle - are perforated as standard and look really chic on top of that.

Because of the 6 hole fastening, the disks already fit in terms of the hole pattern and the threads for fastening the disks fit in the middle between the original holes.

Since the disks have a smaller offset, appropriate adapter / spacer disks must be made. The necessary dimensions were determined using washers:

After all dimensions had been determined, appropriate sketches were made and the hub prepared.

The centering of the old brake disc was turned from 60 to 57 mm so that the adapter got a little more wall thickness. The surface was turned flat by 4 mm so that the hub is positioned exactly in the middle of the rim and I get enough material thickness for the thread to attach the brake discs in the adapter ring (L> 1.5 x D, with M6 therefore> 9 mm)

The difference before / after can be seen here very well:

The dust cover, which normally sits in the locknut that fixes the bearing, moves further outwards into the brake disc adapter. The speedometer drive can be omitted because of i´ll use a Chronoclassic Speedo from Motogedged.
Here, too, a dust cover will be mounted into the brake disc adapter.

With the sketch you can imagine it a little better:

...The adapters are ready:

After a trial assembly, the surfaces that were later visible were polished:

 

[f104wart]

The rear hub was also on the lathe and was turned a bit from the inside so that the dust protection ring fits.

The axis of the CX 650 is 17 mm thick. The GL 1000, from which the hub comes, has a 20 mm thru axle.

The spacer sleeves on which the bearings would then run would only have a wall thickness of 1.5 mm. That's not enough for me. The hub is therefore converted to bearings with an inner diameter of 17 mm. One is a completely normal 6303-2RSH, the other is a special size that is used in various Lichmaschinen from the VW Group and Mercedes and is 2 mm higher than the original 6304.

This bearing is designed as a fixed bearing inj the hub and is secured by a perforated nut, in which the dust cover sits at the same time. The thicker bearing must therefore move further inwards. To do this, the bearing seat in the hub must be turned 2 mm lower. But that should be one of the smaller problems on the way to the spoked wheel on the RC12.

When "repositioning" the bearing seat, the fit was simply turned back a little, as it is not absolutely necessary to maintain the exact fit dimension in this area.

Then new bushings were turned in order to reduce the whole thing together with the new bearings from 20 to 17 mm.

The fits at the ends of the left socket are used to accommodate the metal sheets that center the socket in the hub:

And this is what it looks like when installed:

 

[f104wart]

The mounting of the rear brake disc turned out to be a bit more demanding.

The discs of the CX-E or Goldwing are ruled out for reasons of appearance and weight. The Hornet brake disc has only 4 instead of 6 attachment points. It cannot be adapted because if the necessary thread lengths (> 1.5 x d) are adhered to, the adapter would be too thick and the offset would not fit.

In addition, the change from 4 to 6-hole fastening does not offer favorable conditions for an attractive look:

Ultimately, the choice fell on a brake disc from the TWR catalog, which has the same outside diameter and the same thickness as the Hornet disc, a 6-hole mounting and the same lure rice as the GL 1000.

Only the diameter, which is used to center the disc on the hub, is 5.3 mm larger than that of the GL disc.

The direction was clear and results from the TWR disc placed on the back of the inner part of the old GL-1000 disc, which has been freed from the brake disc:

This is what the plate of the GL brake disc looks like:

... and there it should go:

The M8 bolts in the hub were removed and M6 Ensat sockets glued in:

The holes in the brake disc adapter were also reduced to 6 mm with glued-in brass sleeves:

... And this is the result: Finished with a polished edge of the centering ring and mounted brake disc

... but, as I promised just at the beginning of the project, there are some detours to the final result, and this is one of them.


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[f104wart]

While I was still waiting for the spoke wheels, I did some "fine-tuning" and built a holder for the Motogadged chronoclassic speedometer.

For the instrument holder, I decided to use the existing design of the bought lamp holder instead of a usual plate ...

Therefor I organized a 5 mm thick aluminum plate.

First a drawing was made with Corel Draw, printed out to scale and glued to the plate. The holes were punched through the paper, the webs "marked" with a cutter knife and the holder then cut out with the jigsaw.

...Then a little filing, grinding and polishing and the instrumentholder was ready.

 

[f104wart]

The rest of the waiting time I spent with polishing my handlebar-armatures

 

[Deliverance]

Impressive work Ralf, high quality engineering.

 

[D-Fresh]

You're an animal!!! You are making it all look easy and we all know it is not! Nice craftsmanship for sure.

 

[CXPHREAK]

Wow!

🍿

 

[bahn88]

The rest of the waiting time I spent with polishing my handlebar-armatures


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..a new stainless-type sheen there.....

 

[CXapatite]

Mate......I'm delirious by your descriptions....and giddy from the glare...of your surgically shiny parts !

 

[f104wart]

Thanks for the positive feedback. I am happy that you like the project.


...In the next episode you can see the spoked wheels with the aluminum high shoulder rims



First the front...

and then the rear

The final drive and hubs are also polished and I think you can drive with that.



...Unfortunately it is the case that the beautiful 4-piston calipers of the PC 35 are too close to the spokes and the 5 mm distance required by the TÜV cannot be maintained. The dimensions couldn't actually be determined exactly beforehand and the leeway I had was limited by the distance between the dip tubes and the width of the fork.

The problem could have been solved if the hub had been spoked crosswise, but it was too late for that now:

So I had to switch to the 2-piston calipers of the PC 34, which are still more than adequate in terms of braking performance, but visually can't quite keep up with the 4-piston calipers. But I thought, I can live with the compromise.

Attempts to make a mockup of the brake caliper holder from an MDF board showed me the way, but I couldn't have made it myself because I didn't have a milling machine at that time.

And also any CNC machined parts were not an option for this Cafe Racer project.

...So I stopped the topic at this point and saved it for a later date


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[f104wart]

In between it continued with the impulse generator for the Motogadged.

Mounting it at the front and leading the cable up the fork was out of the question for me for optical reasons. So I decided to hide the pulse generator in the final drive.


To do this, a sheet of metal was cut out and welded to the dust protection ring:

A plate made of 3 mm aluminum was made for the magnetic screw, which is held in the rim with 2 of the 6 nuts on the driver. The nuts were turned off by 3 mm so that they do not protrude over the bolts:

The magnetic screw runs in an M6 thread and is locked on the back after setting. It will be shortened later and secured with screw locking during the final assembly:

Everything is very tight, but it fits.

The sensitive cable of the pulse generator was protected against the heat generated in the final drive with a fabric-reinforced silicone hose and, because it is bent by 90 degrees directly on the pulse generator due to the limited space, it was protected twice with shrink tubing:

To lay the cable I I came up with something special. In my pool I still had a 6-piece steel flex hose from an old natural gas odorization system with Swagelok screw connections on both sides. The cable is pulled through this flexible steel hose and laid to the central electrics under the seat bench.

A hole was made in the dust protection ring on the final drive into which a bulkhead screw connection was inserted.

Of course, the dust protection ring was then chrome-plated and now fits seamlessly between the hub and final drive.