How to make your own lightweight valve spring retainers

As the title says, lightweight retainers.
Seen on this blog before because I made them for my oldschool SS50 engine and my earlier C110 engine.
Now I'm rebuilding the original C110 engine that belongs under my C110, also with 60cc so I can keep up with modern traffic, and some more racing tricks, like lightweight retainers.

step 1:

Mount the retainers to a piece of perforated sheetmetal and spraypaint the other side.

step 2:

You now have the pattern of what to grind away, start grinding. I've used a 1mm cutting disc on an anglegrinder mounted in the vice, holding the retainers in vicegrips.

weight before:

weight after:

disclaimer: my scales ar not that accurate, when measured seperately one piece weighs 4 gramms and lightened 3 gramms.
So let's say you can achieve a 25-30% reduction in weight.
No titanium, but it only costs you some time and a little effort, no money.

And this is what it looks like, mounted in a C110 head

Maybe I should get some seethrough valvecovers...

picture day

I do like the stance with the kickstand.
homemade but modelled after the aftermarket stands from back in those days.
Bolts right on with the footrests.

chainguard

As mentioned before, the C110 will go for painting, so I want to get all the parts ready. As I might want to make it a little sportier, I bought an upper chaincase to modify into a small guard like the SS50's have. It can get painted with the rest of the bike and then I will be able to choose between a full case or only an upper guard.

An SS50 guard as a model for where to cut.

Cut, beadblasted, first testfit:

I had an old can of blue paint, so I gave it some color to get an idea of what it would look like. Although I'm planning to change the color to red.

Complete bike, note the new 18" wheels.

Yes, that spot on the floor came from the Honda, he marks his territory.
Time to build a new 60cc engine, I've got all the parts to make it go even faster....and not leak anymore.

Oudshoorn motor

My dad is also busy rebuilding the 700 motor for the Oudshoorn BMW.
The other enginecase cracked and the cilinders were made too short, so now a different case, which has not been completely chopped and a different set of /5 cilinders that were made to fit the /2 engine with studs going from the case upto the heads.
/2 racing motors have the problem of breaking cilinders, this is the reason of the long studs.


Dyna electronic ignition, /5 dynamo, 700LS pistons, R69 crank......and a lot more parts that do not belong together.

and another new project

Yes, as if I didn't have enough to do, I started something new.....again.
BMW R75/5 wreck to be rebuilt as an endurance racer.
We had so much fun last year at the 3hrs of Aalsmeer that we decided to build a bike for this year.

As it came in, with hardtail, the seat we put on to get an idea of what it should become.

Straightening the frame, with hydrolic pressure and tension.

First mockup; seat from ebay, tank from de knalpot, fairing I bought for my R90/6 but decided on something else, 38mm forks and 4ls 230mm grimeca my dad still had.

Hope to get it ready for the endurance events of the SAM this year.

Wheelbuilding

From the cancelled CR110 replica project I had some 18" alloy rims left over, so I decided to use them on the C110.
Found a set of original S90 spokes, old style spoke pattern, crossed over 6 (instead of the normal 2 or 4)



And this is what a wheel looks like when it's done.

Bridgestone AC01 racing tyre, will probably wear out pretty quickly with roaduse, but I do like skinny tires and there is no other option which looks and performes good.
The wheels look a bit flashy now, compare to the rest of the bike which is a little rusty and dirty, but soon it will be taken appart for painting.

Giuliari Knoscher

My beemer got a new seat, an original Giuliari.
It's a lot shorter and narrower then the imitation I had on there before.
I like it, it looks a lot sportier.
And even though it is used, all the markings are still clear, just a little cut at one edge and I will need to make a bracket to mount it, as it has gotten lost over time.



Other modification; knoscher rear sets.
Really like the ride now, you can really stear with your feet by applying pressure to one of the pegs. think this is because they are really near to the swingarm pivot.



All the ingredients for a caferacer a comming together.

C110 br(e)aking

It has been a while since the last blog, but that doesn't mean I didn't do anything.

The C110 has had its front brake stay replaced.
The balljoint system worked...until I really hit the brakes and the tab on the forks bent, causing the balljoint to end up between the spokes.



So I searched if I could find some bearings the size of the original silentblocks, but nothing really had the right dimensions. Luckaly my dad had some free time to spend behind the lathe and he created some teflon and stainless bushings.



This ads a lot of braking power, because non is consumed anymore for warping the silentblocks

new project

As if I didn't have enough projects, I started a new one, just to use some of the parts I have gathered over the years for the cancelled CR110 replica project.

It will be an 85cc racer for the SAM 50cc class (4strokes are allowed to have 85cc)

first time outside, the lengtened swingarm was just ready, made from a CL90 swingarm, now with needlebearings. Long wheelbase like the Van Veen kreidlers back in those days.


I plan on keeping it pretty simple, mostly using parts I have.
Also, the project is for sale, would somebody want to buy it and finish it themselves. That would give me more time for other projects.

CB50 caferacer

A bike I built, rode and then sold. Sometimes I miss it, it rode really nice, pretty comfortable, quick and it looked pretty cool.
Very retro 80's caferacer with magnesium wheels that just about everybody in the dutch 4-stroke community hated. I think they were just accustomed to the spoked wheels of the SS50's.

this is pretty much how I bought it and rode it for a while, the only modification by me were the sporty handlebars. It came with the giuliari seat.


Starting the transformation, this is a picture of one of the first complete mock-up's
When I bought the bike, it came with a lot of extra parts, including the tank with Bultaco stickers, I originally planned on riding it like this, just to piss people off with my "bultaco"


And the endresult, I changed the exhaust endcan later on, so the bike could breathe better, but I have no nice pictures of that.



some specs:
-ktm magnesium wheels
-CB750k1/6 front brake caliper and master
-50cc (still a legal moped)
-5speed xr80 gearbox
-CB50F camshaft
-16mm kei-hin carb
-slightly ported head and rounded valves
-adjustable clipons
-Ducati seat
-homebuilt rearsets with 10mm spanner as shifterpedal