Here is a list of swingarm pivot to axle lengths for swing arm swaps that people may be considering. I collected these for my KZ650 but the lengths are still useful for others.

Swingarms axle to pivot distances / Pivot mount width / Hub mount width
ZR550 - 20.5" / 9"
ZX636 (2003) - 22" /
ZR750 (2000) - 21" /
GPZ750 - 20.5" /
ZX600 (1986) - 20" / 9.125"
GSRX750 (1990) - 20.7" (in the forward axle position) / ?
ZRX1100 (1999) 20.7"/9,25" (width not confirmed)
GS1100 21.25" (not confirmed) / 8.6875" / 10.25"
CB1000 (1994). 23" / 11" /

Any others that I've missed that are common for swapping in on the KZ's?

On another forum I'm a member of they have a winter build-off that runs from Nov 1st to May 25th. I thought maybe I should enter it so I thought I'd have a better chance of winning if I did something a little different. I had originally bought this bike to flip but I'm going to sell my Gsxr and focus on this one as a play toy. It's a '83 Gpz750 that I picked up cheap from a kid who needed money for a car. The bike didn't run, had a title issue, and was sitting outside in the rain when I picked it up.



The starter motor was fried so I picked up a used one from a newer Zr7 only to find out the carbs were full of crud and some jelly looking stuff. So I'm in the process of cleaning them. I'm waiting on some parts and then I'll try to button them up.




When I picked up the bike I did a quick once over for what it needed. First thing was a front tire as it was dry-rotted and leaking, The next obvious items that needed replaced was the sprocket and chain. The rear sprocket was missing almost half of its teeth. :blink:


So I did what any normal person would do, I started browsing Craig'sList and found this.


After a few hours in the garage last weekend, I removed the swingarm and linkage.



A little grinding and massaging I ended up with this.





Just for fun I threw the 19T 5/8" offset 530 sprocket from my 900 build on to check the chain run. (The chain is the old VFR chain so it's junk which is why it has a curve to it.


Next up I made a jig to properly locate the suspension pick-up points from the VFR frame.


The shock ran into the original shock mount so I started de-tabbing the frame.




And the VFR shock roughly located with the jig.


Now, I'm waiting on material to make the swingarm pivot spacers and upper shock mounts. I still need to de-tab the lower cross member before I can start on the lower mounts.

Later, Doug

Looks like a great project spdygon I think it would be a good idea to start a Build Thread in the "Projects" area


To fit the GSXR swingarm is straight forward enough and can be done with Suzuki parts. If the swingarm bushes are in good condition all you need is two bearing bushes and Dust caps from a GS750 1000 GSX etc you can then use your KZ swingarm spindle If you have any lateral play use shims under the Dust caps

spdygon wrote: Doug......just view your post on the kx900. I did not see what it take to install the swingarm. Was it a direct fit...did you have to shave one side to line up the spockets or wheel. my is a 93 I think it was the first year there were watercooled so maybe motor was different then the 92 aircooled.
Thx for your help

The '92 swingarm is just slightly narrower than the 900 frame. The '93 should be the same width as the '92. I put a '94 Gsxr750W arm in my '89 Gsxr750 so the Gsxr swingarms of that era are all pretty swappable. I used pivot inner races from a '87 Gsxr750 in my '92 arm to fit the Kz frame. The pivot bearings are the same, so the races OD are similar but the earlier Gsxr use a 15mm axle (same as the Kz's). I can't remember what the bearing size is for the '93.

I have not dealt with the wheel yet. I'm going with a 6" Hayabusa rim so I opened up a real can of worms for myself. You have a 5.5" rim so you'll probably have to grab a 5/8" offset from sprocket and see how the rear sprocket lines up.

I'll try to help you as much as I can, but unfortunately I haven't conquered all the hurdles myself.

Later, Doug

FWIW, I wouldn't tackle the swingarm swap unless you have access to a lathe, or a generous sole who has a lathe. There will be plenty of new round parts fabricated in this swap, along with handy mockup parts to check fit before cutting the actual parts. However, you're ahead of the game by having a matching wheel and swingarm. As Doug mentioned, look at the project threads to get an idea of how the swaps were tackled with other arms. The process will be similar. The new arm will need to be bushed to fit your pivot bolt at a minimum. You may need to narrow the new arm to fit between your frame. Once you have the arm mounted, throw the wheel on so you can project the chain line forward to the output sprocket. This will probably show you need more offset than there's room for without modifying the frame. Then look at the Cush drive to see how much room you have to shave off, paying attention to the chain not rubbing the tire. Before I cut anything I mocked it all up based on my dimensions. Spaced the wheel over the amount I planned to remove from the hub, and spaced the output sprocket over so I could double check alignment. Then threw on a chain to triple check with my eyecrometer. Maybe more work than necessary but I hate throwing scrap parts across the shop screaming in disgust.

Take measurements and make drawings. Plan out what you want to cut and fabricate and keep track of the dimensions. One part change ripples through the design more than you know. Try to think far ahead on each part so you don't box yourself in the corner. Above all, you want solid parts built to last. The last thing you want is a bike you're afraid to ride.

Alan

Thanks for the kind words everyone. I really enjoy riding the bike as much or more than looking at it.

BTW, before the side cover and tail section repaint/striping in August, I rode this bike from Omaha to Jackson Hole, WY and back. Some of you may recall from the KZ Rider Flag Relay threads. I swear the bike ran stronger each consecutive day on the trip.

The KZ has been returned to mostly original condition. The only mods of any consequence are to the chassis; Race Tech for springs and Works Performance Steel Tracker shocks. If anyone has the same year KZ and are interested in these shocks(they can be chromed), the swing arm is a different length than later years. I was the first to have shocks made confirming dimensions. Let Works know you want the same shock as their customer, Forrest White. PM me if any are looking to improve the handling of your KZ. I believe it is the single best upgrade/mod one can perform on these vintage bikes.

Thanks again to all the advice & positive feedback during the last 4 1/2 years!

SeattleKZ wrote: Cool thanks man. Unread skittle but of this thread and saw that aligning all that stuff can be a challenge but it's good for me somebody already did it.

If you ping Leon (531BlackSheep) I think he is making a shaft I designed to slide the ZRX swinger in place in the KZ chassis. Just need to slice about 1/8" off the right hand side of the swinger pivot tube and push the seal in until it is flush. Slide this shaft in place and run two grade eight 5/8" bolts in from either side and your done. Then comes chain alignment....

Cory

Current state.

Its always easier if you have both the GSXR and the KZ in the garage side by side.

I did not have that luxury so that you can compare measurements easily. I do have a good friend with a ZRX so we did a great deal of measuring before we started the swing arm swap.

I have seen a few KZ's with the Gixxer motor installed, it seems to look reasonable. Winter is coming it is time to start on the KZ project again. Ten years now I have been working on this thing.

ok on how to insert a pic......thx
So started on taking apart the donor bike and ran into a locknut on the chain side of the swingarm.
I was ablout to remove the main nut and the bolt but the locknut on the left seems like I need a special socket to remove it.
Any Idea.......tried a flat screw driver and tap it but did not turn.
Donor is a 93 gsxr.