On my Kz1000 Superbike road racer the rear shocks have been laid down. The lower shock mounts on swing arm are in the stock location. The top mounts have been moved about 3 3/4 inches if I remember correctly. That gave me just under 7 inches of wheel travel. I checked the travel without the springs being on the shocks. I had to remove a few pieces from the frame that got in the way of the rear tire at the upper ends of the swing arm travel. Even had to remove the top half on the inner fender too!! The major advantage of having all that wheel travel is the bike basically floats over most of the bumps and rough pavement that I ran across on the street!!!! On the track the rear tire seemed to stay in touch with the pavement a lot more than the bike with the limited shock suspension travel!!!! This was a common modification done to all of the early Kz1000's that were running in the Superbike class some 45 odd years ago!!!!! Funny its the same modification that AC Sanctuary does to their mega-dollar Kz1000 builds today!!!

Here are a few photos of my Kz1000 with the rear shock mount moved to give more rear wheel travel.

 
 
 
 

I put a KZP swing arm on my Z1 that is 1 1/2" longer. That changed the angle of the shocks and lowered the bike. I had to do a fender extension so the tire wouldn't hit it. My shocks were 13" where stock is 14" so the bike was riding real low. One shock came apart at speed and I saw it in my mirror passing me at 70MPH.   Had to put on a cheap set of RFY shocks I had just to ride the bike again. Picked up a stripped down KZP and switched the shocks for a set of repop Z1 shocks and all is good. Turns out the bike is more stable at a ton and the angle is close to the one on the KZP. They moved the top mount forward on the frame but there is a place for a shock mount further forward that's not being used. 
What I'm trying to say is you change one thing it affects other things as well.   Not just plug and play.. 
Steve
rumble.com/v4rugm9-broken-shock.html

Welp, the first thing I had to do was to take it all apart, because, um, you know,                                                                            because.

Next I figgered some better suspenders were in order. First, my buddy that I bought them from offered me a GS1100 swingarm that he had saved for a three-wheeler project that he had lost interest in. I decided to have it modified to take KZ style shocks, because, you know, because. I then ordered these--
 

Both the ZRX1200 and 1100 swingarms need to be narrowed to fit the frame. The good news is that the swingarm bearings sit quite a long way inside the pivot area, which means the bearing location/seats can remain unchanged. The ZRX pivot bolt is thicker (20mm I think) compared to the 16mm of the Z1000/Z650. I use top hat spacers to make up the difference.
This part of a video I made shows how they work..

I bought this bike as a roller for $200 in 2015. This is what I started with :



Not the best pic (its from the sale add) but I got everything shown except the motor and tail/side covers... I also got the kick start lever, all the motor mounts/bolts, and the clocks. 

It is a early 77 B1 frame modified to accept C1 wheels/brakes/swing arm. I had most of the parts to make it a complete bike in my spares bins so this is how it started.

A couple of weeks after I brought this home I found a used 1982 Vetter Quicksilver fairing without the mount frame for $40 local to me. This is how the touring idea started.



It took me a while (2 years) but I eventually found some used 1980's? Shoei hard bags local to me for $40.



I got the bag frame mocked up on the bike and welded up a luggage rack using that frame as a base.



I also found a NOS Vetter mount kit for the 650 on Ebay for $80. I attached dual Fiamm horns.



I had some off road mountain bike LED lights I had fabricated years ago and used those as running lights under the fairing.



I used some replica MK2 turn signals on all 4 corners, on the rear I mounted them like a KZP.



At first I installed a stock KZ650 engine and rode it for a few days, but after years of riding a 831cc version I just needed more power
After searching locally in 2018 I quickly found a 1982 KZ750 Spectre engine complete for $160. Upon picking up the engine the guy also sold me a spare head and barrel for another $20!





Fast forward to 2024 and I have only put about 130 miles on the freshened 750 conversion (shaft drive to chain drive) and am still working on this bike to improve it. The Spectre is a mild cam version of the GPZ engine and is rated at 78HP to the crank. I adapted some CVK34 carbs from a 1990 750 Ninja and it has a stock exhaust system from a F2 KZ650.



The bike as it sits right now has used Progressive rear shocks and I just added a small oil cooler. I also painted the tank late last Summer.

I just pulled it out to get it running again to ride to my annual swap meet in mid June. I will update with some new pics when I get a chance.
 

As a novice at this I thought I'd start a build thread and show my progress, or lack there of. It's just kicking off so here's where I'm going with it. I have acquired the swingarm and forks from a 2004 ZRX1200 so I will be using the brakes/wheels from same model. Perhaps I should have chosen an easier route with GS swinger but nevertheless I think I can do this(with all of you helping of course). I have a nice set of instruments from a 77 KZ but might go with the ZRX pods. I also have purchased a J model 1000 that will get headwork and a 1075 kit. That's about it so far and I will ask questions/post pictures as I go. I have read through some of the ZRX swingarm installs and have gained a little confidence. 
 

I have decided to use the Zephyr 1100 swingarm on my 78 KZ build . I am in need of the axle, bushings/bearings and the chain adjusters. Are Zephyr 750 components compatible? Are the ZRX components compatible or will I have to source all used through eBay. Thanks for any info, Cody 

Injected wrote:

The bead breaker worked fine, got the old rear tire removed but it was on there pretty good. I needed to use dish soap solution and a combination of the breaker bar and tire spoons. I have not put the new tire on yet.

The rims/wheels on the project are 81 GPZ550 (forks,swing arm,rims,brakes) I believe the PO had it set up for road racing because most of the bolt heads were drilled for safety wire.

The 550/650 rims are smooth on the inside.

Are you referring to those rubber tube locks on the rear tire? Both have them but I don't run them, I closed up the rim holes with plastic plugs.. 

The rear rim I have came off a KZ750 G.  It's strange they used a ridged rim on the 750 twin for such a underpowered bike. 

 They are a bitch to get over. I was hoping the bead braker would handle them. 

We'll see soon. 

 



 

The bead breaker worked fine, got the old rear tire removed but it was on there pretty good. I needed to use dish soap solution and a combination of the breaker bar and tire spoons. I have not put the new tire on yet.

The rims/wheels on the project are 81 GPZ550 (forks,swing arm,rims,brakes) I believe the PO had it set up for road racing because most of the bolt heads were drilled for safety wire.

The 550/650 rims are smooth on the inside.

Are you referring to those rubber tube locks on the rear tire? Both have them but I don't run them, I closed up the rim holes with plastic plugs.


 

Decided to go ahead and start my 73 Z1 build thread since technically I've already started. I'm starting with a 73 powder coated frame and swingarm and a 73 motor that came from a different bike. A NOS OEM Kawasaki gas tank I was told was manufactured in 83 and a 73 rear wheel assembly missing the sprocket hub. I've got the cases split on the engine and so far have only had use two or three outer gear bearings from a '76 motor I've torn down to replace rusty ones on the 73 that was missing the inner and outer sprocket covers. All clearances in the crank and the gearbox that I could measure are all within normal limits. I'm in case prep mode now and will hopefully get it reassembled in about a week.