1984 gpz1100 swingarm question

Good Evening All,

Just a quick question or two.

Does anyone off hand know the width of a 1984 GPZ1100 swinger at the pivot?

Has anyone attempted to use this swinger on a 79-80 kz1000 as a mono shock starting point?

Thanks to any and all replies!

Kris

I have an 84 GPz1100 arm off the bike buried somewhere and will check in a day or two, but I'm 99% sure it will fit in your KZ1000 as a bolt - in for the pivot width. As far as being a good choice for a mono - shock set up, I'm less convinced. Unless you already have a GPz arm available, including all the shock linkages, axle, chain adjusters, etc. with it, I would look elsewhere. Most Suzuki swing arms up to 2003 have narrower pivot areas than Kawasaki, Honda, and Yamahas do, so installing something like a Bandit 1200 arm typically only require machining spacers (on a lathe) for end play in the KZ frame. Early GSXR arms are plentiful, too. My buddy recently installed a 2000 GSXR-1000 arm in his 81 GPz1100 frame and it was a direct swap, according to him. The Suzuki arms will fit tires as wide as 200 on a 6" wide wheel, and you can use the GSXR light weight wheels and modern brake.

If you do decide to use the GPz arm, I'm again 99% sure the 83 - 85 750 and 83 - 84 1100 are the same part except maybe in small details like the chain guard mounts. I also know that an 88 ZX10 4.5" wide x 18" wheel fits in the arm with little effort (I have one of those, too). It is possible to mount up to a 170 tire width on an 18" wheel, and some 180 tires will fit on a 17" wheel in the GPz arm, again, with some minor modifications. Chain alignment and clearance around the tire and in the frame will be bigger issues to resolve with tires wider than 160 on any KZ1000. Switching to a 530 chain will help.

Thanks for the reply sir!

I have recently purchased a stretched complete swinger from an 84 uni-track and am patiently awaiting it's arrival...and I'm not real good at patiently waiting.
I'm mainly hoping it will not require extensive modifications to adapt to an 80 LTD project I have recently started...however if it does Im pretty sure I can make it work. 20 years plus as a fabricator/welder and the ability to tig weld heavy aluminum at home sure helps.
Spacers I'm not too concerned about as I have full run of a well equipped machine shop at work....
My main concern is it being far too wide at the pivot which would necessitate milling significant material off the end of the pivot tube or cutting it out completely and turning a new one and welding it in place.
I currently have a 6" zx7 rim on the shelf that I am hoping will fit if I go 520 chain and an offset sprocket...I guess time will tell.
Thanks for taking the time out of your day to make such an informative post...I really should have just gone gsxr with it....I really just wanted eccentric adjusters cause of the "different" factor.
Off I go to patiently await the mail man again...boo

Well, your metalworking skills will be required - I just measured my spare 83 /84 GPz1100's swing arm across the bearings and it is about 9 15/16". That is about 7/16" wider than the KZ1000. Still, it should be possible to take of 7/32" off a side (approximately) to make it fit. I remember I had put a GPz750 Uni-Track swing arm in a friend's 82 CB750F around 1985, and remember doing only minor work to get it to fit, so I'm surprised that the GPz1100's arm is wider at the pivot than my 81 CBX's swing arm. On the other hand, my 79 CBX's arm is just a hair under 10" wide at the pivot. Maybe my memory isn't that good, or the 750's arm was narrower than the 1100's....?

The 1990 ZX-11 had a very sturdy extruded aluminum swing arm with eccentrics. It will fit tires up to about 240, and most wheels with ample room. It is even wider at the pivot than the GPz1100 - about 10.3". It requires you mill the ends down and install new sealed bearings at both ends to fit the stock pivot bolt diameter from the frame....if you want eccentrics....

Often you have to make extensive frame modification so the chain will clear and the wide arm can clear foot-peg bracket mounts and such when it sweeps through the suspension's travel, too