Topic: CB 836cc f1 turbo - spoked kickstart street turbo

[Medyo Bastos]

looking good, are you keeping the flanged rims?  i might be interested in them if you decide to sell 

[Ilja]

neat, those cast wheels loked to modern indeed
hope you used heavy duty spokes!

I always wanted wire wheels but yeah, didnt have the funds when I started the project. 😂
The rims are also hard to find for a good price..

Next up is the wm4 for the front!

[Ilja]

looking good, are you keeping the flanged rims?  i might be interested in them if you decide to sell 

Ohh the flanged wm4 rim is going on the front.
I bought it of ebay from a shop in Italy... they have more.

But I do think they secretly came from asia as theres no markings on the rim and there was a small paper in the box with chinese text.
However quality looks to be very good...  

To be honest I suspect those undrilled WM rims that everyone sells are the same ones.

http://www.ebay.co.uk/itm/253056656830

I work in semiconductor industry and we have a lot of machines in asia for example for iPhone production and things like that, they are most of the times the most advanced ones and sold with bucketloads in one go if they invest. Its almost scary..
But theres huge differences in quality control and knowledge from factory to factory... one sells garbage crap, the other sells better quality than western companys.

[Medyo Bastos]

interesting, thank you for the heads up 

[PeWe]

I have heard about copies of the copies from that part of the world. That can explain some is good while others looking the same is crap. Industrial technology grows fast over there with plenty of industrial robots and line builder. Before ABB, Fanuc, Kuka, Yaskawa, Kawasaki and Comau that ruled. Soon Chinese knock-offs?
Foxconn has several huge plants with 50.000-250.000 workers living at the plant.

[Ilja]

Well I did some more work on the bike.

I wanted to get a few sets of rear shocks powdercoated... but theres a holiday period now and all powdercoaters gave me a delivery time of 5 weeks... and 125 euro quote on top.

So I decided to clean all the rusty #$%* off the springs with electrolysis and coat them with spraymax 2k spraycans.

Heres a small vid of the first test.

Later I changed the Anode side (the +... your parts are connected to -) to a much larger piece of steel beam and it drew way more amps through the charger, and the reaction became stronger.
Spring thats showed on second pic was completely brown of rust...

Left it over night, then cleaned in citric acid for a while and this were the results:

[Ilja]

I *think* these rear shocks came of a 1994 cb750 but not sure about that.. got them a few years back just as spare..
They are a bit longer then the stock cb shocks (2-3cm) and nice when you have a longer swingarm as with the F1.
But, it requires some bracket at the swingarm side as the bottom mount is a rubber bush on the shock and not the clevis type.

I also bought a VTR1000 firestorm front fork (for 75 euros)... which is about the same as the cbr600 f3 fork (41mm and 296mm discs).
I plan to use it with the original front hub and original front discs... as they are also 296mm!
But I will need an "LSL superbike top yoke"...which are a bit more expensive.

This fork is also slightly longer *modern* fork at around 76-77cm because originally the clipons are mounted on top on those bikes!
So its perfect for these older bikes as they originally had longer forks then newer sportsbikes!

[Ilja]

Heres another electrolysis movie.
I also had movies of my eventual setup but somehow I managed to delete them of my phone...

[Ilja]

Shiny parts... and I immediatly also coated the new fork black. No polishing and painfull fingers later on....

[Ilja]

Fowrk!
Now to find a superbike top yoke...

[Ilja]

Hmmm... no replacement top yokes available for cbr600 or vtr forks.. only bolt on top yokes...

So I bought a cb750 sevenfifty rc42 41mm triple set.
It even has the mounting points for the gauges and stuff.. 

Edit: Fawrkkk! Its bend as hell.. 
I hope the shop that sold it to me has another one thats straight as otherwise it seems to fit perfectly.... stem is also the right length.

[Ilja]

Woke up in Italy this morning after a week of working, flew home and laced up an 18" wm4 to my cb750 f1 front hub with some 4mm ss spokes...

And I found out cb900 rotors will fit with an easy spacer! Almost same bolt pattern!!! Its half the thickness of the oem front rotors..but the same outside diameter of 296mm.
I was worried that the original 70ies disks would not fit the 4pot calipers for the fork, but if one can just use the cbr ones on the spoke rim thats even better!

Ordered a Michelin Pilot Activ Front 110/80 -18 TL/TT 58 V since it can be used both tubeless and with tubes.
Tube Type tires have a more sturdy sidewall so the tire doesnt flatten as much when riding and chew up the tube. And its smoother on the inside.

For the front it needs to be correct, as these rims also dont have a bead to hold on to the tire. If it pops you are screwed. 

[Ilja]

Rim trued up within 0.5mm.. only the weld area shows but thats quite normal.

Ive attached a drawing of the spokes ive used...for any one thats looking in converting to 18"..so its for an f1 front hub and 18" wm4 rim.
I had to slightly chamfer the dimples in the rim to slightly correct the spoke angle.

These 4mm ss spokes were custom made at a wheel shop over here for 66 euros inc. nippels. Got them within 2 days.. 🤘

[Ilja]

Ahhh #$%*balls..
I just found out the 4pot calipers ( cbr900 etc) will not clear the front wheel spokes. They stick inside around 4cm but theres only around 25mm of clearance. I can space out the disks 5mm extra each side but thats about the max.

So I need some older style calipers like the 2pot ones with no piston on the inside. I hope theres a 41mm fork with these calipers as the vtr1000 legs probably wont bolt up...
I think the cb750 sevenfifty rc42 legs will work but they are not adjustable .

[Ilja]

However... some people got it to work.
Hmmm.... maybe those are smaller then the cbr900 ones.. 🤔

[Ilja]

Allright, after an evening of scavenging part fiches and messageboards I''ve found that both the vfr750 rc36 and cbr600 f3 rc31 both have 41mm forks with 2pot "slider" calipers and use 296mm discs.

Those calipers should clear the spokes.

So the recipe will be one of those forks with a cb750 1994 triple tree... 

The 4pot calipers will only clear the spokes if the disks are around 140mm apart.. but then they touch the fork legs.
I think this is why some people use custom front hubs with the spoke flanges closer togheter.

[Ilja]

Underswung 296mm disc rear caliper

[Ilja]

Its quite low to the floor.... 😂

[Ilja]

Yay.... cb600 pc31 fork with hornet calipers and cb750 rc42 sevenfifty triple tree and top yoke...

Now to fit the fork gaiters and make some wheel spacers...

[Ilja]

Fitting front bearings for 20mm axle. (Stock = 15mm)

[754]

18 in Yamaha mag was what I used to get a 6 piston caliper to fit on a Ceriani... more clearance than the wire wheels.

[Ilja]

Well the front is in....partly..
Gauges, headlight, front discs and fender to be fitted.

[Ilja]

Headlight and gauges stuff fitted.. its close to how I want it now.. only needs a clean oil cooler.

[seanbarney41]

This bike is awesome!  I really like it.

(I actually liked it better with the cast sportbike wheels, but it is still cool AF!)

[Ilja]

This bike is awesome!  I really like it.

(I actually liked it better with the cast sportbike wheels, but it is still cool AF!)

Thanks.. 😃
Well for me personally the spokewheels look better in the flesh because of all the shinyness and stuff and the cast wheels look less good in reality...or something haha!
And I now have a 150 rear instead of 180 so no more dodgy offset sprocket which is nice for the spline.

Just figured I might as well keep this one as classic as possible for me, since its such a beautifull bike and I already butchered my kawasakis 🙈.