The International CBX Owners Association

I bought my CBX just over 12 months ago, it had been imported from South Africa by the owner in Queensland, Australia.
He was ex Sth Africa as well.
After fixing a few minor problems and balancing the carbs, it has been running well.
Being a retiree, I have plenty of time on my hands.
About a two months ago I decided to upgrade the wheels to 17” items, which also meant replacing the std instruments.
I was able to purchase the wheels and rear caliper/bracket from a Kawasaki ER6N and Yamaha R1 Blue spot front calipers from a bike wrecker 1.5 hours away.

While the front wheel was out having 5mm removed from the disc mounts, to allow them to fit between the forks.
The fitting of the rear wheel went surprisingly well. I had to machine a 13mm approx spacer for the LHS, while a 12mm spacer I already had fitted into the RHS. The ER6 axle was the same diameter as the original. A 4mm spacer on the outside of the 17t Yamaha R1 sprocket allowed both sprockets to align well.
Now using a 520 chain. The std ER6 sprocket is 46t, will need to be replaced later.

Once the front wheel returned the two std spacers had to be reduced in width by almost half.
The housing around the bearings had to be re-profiled with a Dremel to clear the forks.
Plywood templates were made of the custom brackets for the Blue spot calipers.
Several had to be made to get the fit correct.
Then I made up the RHS bracket out of some 12mm flat bar, there are two machined spacers at the back.
The LHS was made as the reverse. Spacers for both were slightly different.
New high tensile cap head bolts were ordered, as the old ones were too short.
New bolts were ordered for the bracket, in M10 fine, as were the nyloc nuts.

Then the rim had to be taped up for painting, after removing the paint around the edge.

Extra photos

The front rim was painted to cover up the green. The rear rim had the paint removed from the edge.
While waiting for the tyres, I proceeded with relocating the fuses to the headlight.
This was necessary so that the std handlebars could be replaced with normal items.

Nice work! Have you decided how a new rear tire will clear the Pro-Link linkage?

Dave

Hi Dave
I had taken measurements from my BMW wheel to give me some idea and from some American tyre brochures where the diameter is listed.
Also the previous owner in Queensland had already done this conversion and provided some tips.

The next step was to buy some handlebar supports, I was lucky enough to find some at the local wreckers, bought for a project but never used.
With the fuse box removed, I had to make up some 3mm steel plates to fit under the triple clamp, held in place by the fuse box screw, except from underneath.
A 3mm aluminium plate was shaped to fit where the fuse box had been removed, holes in the plates were matched up.
Initially I used brass tube as supports, these made way for a machined boss, which was profiled on the belt grinder to fit the hole.
Once completed the clamps were bolted into place and the handlebar fitted.
A piece of copper tube was machined to cover the large retaining nut, nylon was machined to fit in the top as a cover, while a small piece of nylon was machined to fit inside the steering stem as a push fit. It was threaded to take an M5 bolt and retain the cover.
Then painted black.

With the tyres fitted it was time to see everything would work.
No problems thankfully, just a temporary one.
The front wheel was suffering from friction, till I realised that I had transposed the spacers, once rectified it was fine.

The 520 chain went on easily, no need to rivet the links.
The brake stay arm was modified to suit the Kawasaki bracket.
I wanted to remove the old fork air hose and replace it with something more modern and easier to disconnect when required.
Pneumatic fittings worked fine, with 4mm tubing, colour may change later.
I had to machine two adaptors to suit the fork caps, which have an M8 x 1.0 thread, reusing the o’rings.
A low pressure gauge was repurposed from my old 1975 R90S (which I sold years ago).

The next item was to install the Acewell digital speedo/tacho.
I had bought this via Gumtree, the seller had never used it, I did some research on the Acewell Australian site and it seemed to be suitable, but not completely, the site information was a conglomeration of several models, due to poor web design.
It was too late to do anything about it.
I made up a pinout of the CBX connectors and marked these onto the Acewell wiring diagram.
Then the peculiarities of the CBX wiring became apparent, especially the number of items activated by connecting to ground.
This meant a number of the warning lights couldn’t be used.
I bought a grey box from Jaycar to house the wiring and a small breadboard for the many power and ground connections.
A piece of aluminium plate became the main support for the Acewell unit and other lights.
As the neutral light and rear suspension pressure warning light are ground activated I had to add some extra LED’s for these.
The tacho line needed the optional resistor put in place to make it useful.
The main problem I had was with the indicators, they would not flash, this was resolved by attaching a 470 ohm resistor to this line and connecting it to ground as well.

More

The speed sensor magnet was glued into a hole on the front right disc using JB Weld, it was quite fiddly getting the sensor itself aligned with the magnet. The only place to mount it was off the fork clamp bolts. Works though.
Took out the tach drive and put a rubber chair tip over the thread (10 mm size), quite a tight screw on fit.
I have temporarily fitted the old front guard, will be replacing it with a CB600F item.
After several test rides I haven’t found anything terrible, the front brakes are much better than the old ones, causes the front to dive, very progressive feel. The rear brake is no better than the original.
The handlebars are quite comfortable.
I have a better neutral light on order and will have the option of fitting a gear indicator.
I also have on order replacement connectors from the wiring harness, these are unavailable in Australia, I had to buy two used ones at the wreckers and due to their age are breaking down.
To hide the grey box, I have ordered a small screen, in carbon fibre look.
That will probably be the end of my upgrades, just happy to ride and enjoy the CBX.

Great work, and well-documented as well.
Good on ya

Going great. Does an r1 front sprocket fit fine ?