After a couple of years without a old Kwaka race bike, I am toying with idea to build one up.
Have spent a bit of time trawling through this forum and the net to get some ideas.
I have a 81 GPZ1100 frame and most of the motor in the shed and thought I would utilise it.
As it would be log booked for Period 5 (bikes from 1st Jan 1973 to 31 Dec 1982) racing in Australia, there are a few rules I need to follow to be eligible.
So at this stage, I am looking at a ZRX swingarm as I can run up to a 5" rim. Hopefully they will allow it, otherwise I will have to go with something more period friendly.
We are allowed 41mm forks, so I was thinking that a ZR750 front end would be good. It was mentioned that it is a straight swap. Does anyone know anymore about it?
There are a couple things I am not too sure on, and I was hoping someone might be able to help or point me in the right direction.
Firstly is frame bracing. Anyone know where is best on these frames or if there is anyone in Australia to see about it?
Secondly is brakes. They need to be from the period or replicate those manufactured in the period. Does anyone know what the best from that time frame is, that are relatively easy to source?
Any info or advice is welcome.
Once I get everything figured out and parts sourced, I will do a build thread as well. Thanks.

I am reading all I can here on forums, digesting as much info as I can.
I will be going through frame up restoration, frame will be powder-coated.

Initially I didn't think about making changes, but reading here I am considering it especially that I do want to tinker/weld
Another question is rear swing arm. I read somewhere that those were weak from a factory prompting aftermarket versions. So, I was wondering if it was a DIY to maybe reinforce that somehow as well "while in there"

If you have any pointers, pictures, drawings, I will appreciate it.

After a lot of thought, here is my plan to modify my mistake on my swing arm. In the picture, cut #1 will go all the way through the tube. Cut #2 will only be part way through, starting on the outside, but leaving the inside edge intact. #2 will be a pie shaped cut. I will bend the tube outward, and insert a short tube section in the gap at cut #1. I am thinking it will be 3/4" to 1" wide. This will move the brace outward, giving the chain the clearance it needs. After welding, it will get ground smooth. Then it will get stripped and re-powder coated. Unfortunately this will cost me four new pivot bearings, as they will not live through the process. I will need to remove the bearings before hand, which will likely ruin them. The goal is to keep the shape of the tube as intact as possible so it doesn't look butchered. It will end up non-symmetrical on the left, but chain clearance is by far more important.

Do not sandblast the inner sleeve. It is a bearing surface and is precision ground from the factory. If you cannot find a replacement polish it with sandpaper as best you can. you do not want roughness here it will prematurely wear the needle bearings.

Aloha guys.

I needed to change my course in my rebuild due to this COVID, decided to take my stock swing arm and rebuild it. Long story short, I got swing arm off, and it's all apart now. naturally, both needle bearings are dead, Shaft sleeve is rusted pretty bad on one side (I'm gonna keep this and see if I can salvage this. I have a small sandblaster cabinet so gonna try blasting it.

Anyway, my question is, just how do you clean the inside the swing arm side of the sleeve/tunnel? Bearing receiving ends will get blasted, as well as outside of the swing arm. Inside the arm, I couldn't see if there were any rust, but just in case, I want to sand it if I can, with something like 320 or 380, maybe with 400 wet paper. As of now, I did look inside and does not seems to have any rust build up. At least not the bad ones that you can clearly see with rust build-up.

Any suggestion on this?

zed1015 wrote:

Mikaw wrote: Zed1015,

Thant you, reassuring to hear you mention a 5/8 inch offset counter sprocket also, that’s also what Les recommend. Without having a tire on the rim I put it briefly into the GS 1100e swing arm and as long as the tire is not much wider than the rim this looks like it will be a fairly easy conversion. I will need to find bearings that match the Ducati rims bearing boss OD with the 20 mm axle that the GS1100e swing arm uses.

I've done tons of these Z's with 17" wheels and have five of my own done the same so i know what works and the details and measurements are pretty much etched on my brain.
These are the latest two i'm slowly working on.
The 1000A uses ZX7R wheels with 5.5" rear and the Z1R has ZX12R wheels with a 6" rear and 200 tyre.
The Z1R needed the frame scalloping for the chain run and would have needed a 7/8" offset but i extended the gearbox output shaft instead so i can use a plain stock sprocket and save cash when it's time to replace them.

Zed, do you have a build thread for the Z1R ?

Hi Steve,

Dafrusty has a lot of knowledge about this swap (and other things.) You might want to message him.

www.kzrider.com/forum/5-chassis/614483-z...-on-81-gpz550#836290

Still making progress... slowly... was gone for a few weeks for work....

Ordered some new fuel system components as the intank style pump was a pain. I bought a Walbro GSL393 (which is what the 750turbo guys use as a replacement) as well as some other fittings and filters to finalize the mounting of it all: fuel pump, pre (30 micron) and post filter (10micron), flex fuel sensor. The hardest thing to find are some 90deg fittings. ebay had some nice swivel m10x1 to 5/16 barb 90deg fittings, so i hope those hold up as


the exhaust tubing (stainless 304 sch10 1" nom pipe) and a few bends has arrived for the turbo header. still working on the turbo flanges and head adapters (Kawasakik1e is helping with these ) .

I saw these neato half clamps that a 750turbo guy made....grey part is the kaw cylinder head, blue is a machined piece that mates to the head and is clamped on by two of the yel/purp assemblies.


Ported the turbo so it can go together for the last time.


I have a 60301N facet pump for the turbo oil return (low current... 1.5A, check valved) or I can use a mechanical scavenge pump....Im working on mating a h*nda 50 oil pump to the secondary shaft cover like the turbo bikes do.



Theres other misc stuff too: swing arm bearings, oil cooler, turbo oil filter, zr7 oil pump, needle bearing clutch pusher.

truedisk, indeed. Thanks for the tip guys. Never heard of them before.

The hunt for suitable wheels continues, but I soldier on with OEM for now. Forks rear wheel/axle handed over to my machinist friend who will refresh the forks & knock up spacers for the rear wheel in the GS swingarm.

Onward!

Bozo wrote:

slayer61 wrote: I like the idea of the 3 spoke wheels, so I've been scouring fleabay for some "modernish" replacements. Something from the second half of the 80's!

The Swingarm is officially on it's way out, as an aluminum replacement from a Suzuki is inbound from a member on GS Resources.

Brakes will have to wait until I find out exactly what wheels end up on it. I can recommend the 16mm radial brake MC from Braking. I have one on my bike & I like it a lot.

Thanks for letting me share fellas.

I know this might be a bit late but my Frankinstein GPZ1100 has GPZ900R front end. I used a radial GTR1400 master brake assembly (cheap on ebay) and the brakes are nothing short of incredible, on par with the Yami blue spots (for general road use)

Thanks Bozo, but I'm firmly stuck on 18" wheels. They are difficult to find & not very popular, but that's what I'm after. The OEM forks have all the needed parts for a refurb. It's just shop time now.