SS50 race bike, still shaking down

The new season has started, heck, it's almost halfway over already, and I've been busy with work, and getting the bikes running that I'm forgetting to blog about it.

Well the main focus has been on the SS50 racebike, as this is the biggest technological challenge.
Over the winter, changes have been made, footpegs were moved back, fairing was added, tachometer was changed... and changed back again.









And then the season started and a lot more changes and tweaks were made.
-Because of the footpeg relocation, the front forks needed stiffening.
-The new mechanical tachometer couldn't keep up over 13k rpm, so the electronic unit was fitted again.
-The inner rotor ignitions weren't functioning correctly, so the old outer rotor battery ignition was refitted.
-The newly made 24mm carburettor turned out to be too small, so back to the 26mm
-The new 5speed dry clutch engine wasn't delivering what it should.

The dry clutch although looking and sounding cool, was a step back in handling, this combined with the last event in Gramsbergen, where I swapped the 5-speed motor (because of strange noises) for the old 4-speed before the second heat (which also developed some strange noises after that) meant that both motors were opened up fully and examined.



As it turns out, the 4-speed motor had a better cylinder head as i had been more cautious porting the other head.
So now a new engine has been built, with the 5-speed gearbox, wet clutch and cylinder head off the other engine, combining the best bits. In a small testrun it displayed 16k rpm on the tacho, while still pulling, so I'm looking forward to the next race, to see what it actually does.

clip-on's

Just finished a batch of clip-ons
Needed a set for the SS50 racebike and another for one of the CB50's that has been sold, but included in that deal was a front end swap.

A bunch of steel pipes


Some more small parts added, almost ready for brazing



after brazing, cleaning and painting


The observant viewer would notice one set missing, that was already mounted to a bike.

Some details not found in modern clip-ons are the closed ends, not with a plastic or alloy bung, but full steel construction, so that after painting, it is almost invisible how the ends were closed.
Just a single 8mm bolt, instead of 2 6mm bolts, just like original CR110 clip-ons, and other Honda's from that era.





Took a lot of work, but the result are some clip-ons that look deceptively simple and yet sophisticated at the same time.

CR lookalike

Just a preview of something I've been working on.
A Honda CB500f carburetor modified to work on a one cylinder bike and with some styling like the old CR carbs.



Still needs finishing and testing though.

and the season is already over

End of racing season, it went so fast, I forgot to post about it...

so a quick summary of pictures, courtesy of the CRT website. and JanAw as found on the internet.

The SS50(85) behaved pretty well for a new build, some teething problems, but very quick.

The RSC90 got a fairing half way through the season, because I had a complaint of not having numbers on the side...that I didn't have for all the time I rode it. But it was the push I needed to finally start on the fairing as was planned. needs finishing, but the beginning is there.

The C110 gave some trouble too, but at the end of season I found the issue, fixed it and it was running quicker then ever.

SS50 race bike ready for first event

My dad did a lot of work to make me an alloy fuel tank and it really finishes the bike.

Even though the tank isn't finished yet, it is ready for now. still needs some dents from construction taken out and paint, although I am liking the raw look.

What started out as a simple SS50 moped has now been modified all over and is really starting to look like a real race bike. As was the intention because I wanted this SS50 to look like it had the full RSC kit, if Honda would have ever made it for an SS50.











footpegs need to be changed and probably some more details, but for now I can enter it in "races" as my CB50 race bikes were sold and I had nothing left to ride for the 50cc class.

SS50 progress

Slowly, things have been progressing, but now I have to hurry up and get this one going as I have no more CB50 to ride.
Want to be able to ride this SS50 this season even.

this is the current state of things.




Fuel tank is only temporary, a long narrow aluminium tank is going to be made, but that will probably take a while.

hand made front mudguard

Working on the SS50 racebike again, as my CB50 was sold.

It needed a front mudguard for several reasons
- it looks good and old Honda race bikes had mudguards
- rules say you need to have one if you don't have a fairing (fairing is for the future)
- it can function as a fork stabiliser, needed because of the single sided front brake.

For the fork stabiliser bit, the supports are made out of steel and run over the top of the mudguard as one piece, not the prettiest, but I've seen this on original (race) bikes and it is very functional. And I like things that look functional even if they are "ugly"

The start, a piece of steel bent and cut to fit between the forks and 2 pieces of tube with the ends flattened with a special tool to get those ends just like Honda used to make them. Clamped together for braising.


Braised together and 2 cable loops added, just because, if this were original, Honda might have supplied a 4LS in the RSC kit and the mudguard would have been prepared for it. I will only be using one loop with my 2LS for now.


Parts primed and screwed together in preparation for riveting.


riveted and painted silver with a little bit of clear just for a little shine, to imitate that original look and not to go overboard on the clearcoat as so many replicas these days.

gearbox work

The SS50 racebike, a project that has been in a corner for a long time, is now getting a new chance.
The rules for 4-strokes have changed, allowing them to be 85cc in the 50cc class, and as my CB50 was sold, I need something new if I want to ride in the 50cc class again.
Well the SS50 racebike had an almost complete 85cc race engine made for it, so that would be a good start.

Just needed some gearbox work, as the first gear was too short for the rest of the custom made close ratio 4-speed gearbox.
It is put together from SS50, S65, Z50 and other parts and now getting a taller first gear consisting of a chaly gear grafted onto a chinese shaft.



seen in this picture, from top to bottom
- Takegawa 5-speed 14/33 first gear
- Custom made chaly / chinese 14/32 first gear
- Cut off chaly 2-speed gearbox shaft
- chinese 11t shaft for bearing type engine casings (of no use in my old SS50 cases)

New clutch

The motor I was building for the SS racer had a chinese copy of a CD90 clutch on it, for a racebike a bit to smooth I thought. So when I heard that a friend had a dry clutch laying around, I jumped at the chance. Thanx Eugen.
Had some issues fitting it, because Daytona uses an M6 bolt that threads into the main shaft, but luckaly the Takegawa main shaft was hollow so I could fit a threaded bushing in there.



Starting to look nice, now working on the cylinderhead, big fins, big valves, ported, now some final checks and to figure out which camshaft to use and valve spring tension.

Chinese head fits

The cheap Chinese cilinderhead I bought at a swapmeat as an experiment now fits my SS50 motor.
It needed some machining for it to fit, but it was possible to addapt it.



Just put it on to see how this big finned head would look, prety race-like.
The manifold and carb were just a quick try to see what would be easy and possible, but I don't like the looks of this, the carb is too strait.
I will probably use the 26mm carb of my motorcycle.

top yoke

This weekend I didn't do that much, I cleaned a chinese 125cc cilinderhead that will be adapted for the 85cc racebike and found out that it will need a lót of adapting to fit an old honda motor..... the chinese moved the top two cilinder studs upwards.
Didn't feel like tackeling that just yet, so I chose an easier project; the top yoke.
as seen before with handlebar mountings and so on, but now modified for a racebike:

Front forks

I've been collecting front fork parts to upgrade two of my bikes. I want my SS50 motorcycle to have thicker front forks, as it struggles with the original 25mm forks while at the same time I would like to upgrade the SS50 race project with stiffer yokes and better internals.
By now I've found pretty much everything, so I've started work on it.

These yokes will have the handlebarmounts removed to look like MT125R yokes, the clamp will be more stable then the bolted type.

Forktubes will be replaced by MT5 tubes that will be shortened, thes also have the big plugs on top that match with the clamped yoke. The internals will be made as a copy of an MT125R forkleg, which actually has some sort of damper. Sadly loose parts are not available, but I have a forkleg on loan to copy from.

As the forks were out of the frame, this was also the right time to weld on a fairing stay:


that was some slight progress on this project, I've also started on the front fender, but that is on hold again, as I had some parts for another project

Superhead

Yes I've gone over to the kitakkiewakkie-craft side....
I've traded a spare CL70 head, which are quite rare over here, against a takegawa superhead with worn valves and some more little issues.

Today my dad was looking around for something to do, so I gave him the cilinderhead to go and play with :P
Guides were reamed from 5mm tot 5,5, to fit standard S90 valves, seats were cut, head was glassbeadblasted and the valvelift was checked with the cam that came with it. This all looked good and it will become the cilinderhead for my SS50 racer project.
Now just to decide on a gearbox and clutch.

I've heard that a German friend might have a spare clutch, he races an SS50 engined kreidler, but I sadly can't find any contact information.
If you know this guy, or if you are him, could you give me an E-mail?

Kennen sie die fahrer dieser renn-Honda, bitte senden sie ein E-mail

Tank Coating, part deux

My tank is being painted, thanx dad.
We had a big can of red, so that's what color the tank is going to be. Decided to remove the old emblem mountings as they were pretty mangled, probably will look better with a classic set of honda wing stickers and some silver stripes running along the length, just like the old RC tanks.

I'm liking the way this looks, might just put it back on my SS50Z moped, to make it look more like the way it used to, long ago:

Same tank by the way, one or two crashes earlier...