1978 KZ650 Project

Hey everybody-thought I would post the progress on my 650 build.

What I have done so far is install a 01 GSXR750 front end with a Hayabusa wheel via the stem swap method. On the rear I was planning to use a SV650 wheel in the stock swingarm but it is nowhere near fitting! So now I am thinking of fitting a SV650 swingarm but am afraid that it may not work.
With the bushing and all the KZ pivot tube measures 9 inches. The SV one, I have been told, measure 9.5. So either I would have to remove 1/4" from the frame or from the swingarm...which may not be too bad. Guess I'll just have to buy one and see what happens.

The reason I am trying to use a Sv650 rear wheel is the smaller width of 4.5 inches should make it easier to line up the sprockets. Any advice or comments are greatly appreciated! Thanks

nice project, that thing's gonna look tough!

Looking good! make sure you have clearance at the tank when the forks are turned.
Mark

Looking good so far.

With the Sv swinger, i'm not really sure about the fit however, it does have an offset shock mount. Be sure to take that into consideration when it comes to bulding the shock mount.

I do know a Suzuki Katana (1990-up) swinger will go in after you have 3/16 removed off each end of the pivot removed.I had one mounted in a project. It was easier to do that then to remove it from the frame. I opted for that in the event the bike went back to stock for whatever reason.

try a gsxr arm

Looks good! Curious though, why doesn't the SV wheel fit? Is it the one in the picture? Just wanted to find out. Looks like it is close if it is the one in the picture unless I'm missing something (which would surprise no one here ).

Well, went ahead and bid on an SV swingarm, just gonna see what happens. They're cheap, so no big deal. Convert, in the pic the wheel is just wedged in there...it hits both side of the swingarm taper. Just wanted to get a visual. As for the shocks, I'm not planning on doing a monoshock setup, but rather have some mounts welded onto whatever swingarm I end up using. A pair of ZRX shocks would be mighty nice looking
If I use the sv swingarm a half inch will have to come off somewhere and the tabs on the frame are exactly 1/4 inch on each side which would leave me with nothing...so maybe I could take 1/8 from the frame and 1/8 from the sides of the swingarm. Just worried about the bearings.

Well, I got the SV swingarm today. Looks like it will fit with a little work. I will have to remove 3/16 from either each side of the arm or from the frame. Or it may easiest to remove some material from each and split the difference. Any ideas for that one? A file and patience? Then have a sleeve and maybe bushings made.

Starting to look like a bike!

i would remove material from just the swingarm and leave the frame alone, remove equal amounts from both sides of the swingarm so it's centered in the frame, a grinder or a file would work but i would find somebody with a mill to trim the arm for you that way you know the ends are straight, thats what i did with my swingarm, and do the spacer caps off yuor 650 arm fit on to the new arms. you'll wanna try and use them if possible to geep the bearings some what shieled, oh yeah good luck on them zrx shocks they go between 150 225 dollars on ebay i've been watching them for over a year :ohmy:

Thanks for the advice! As for the only removing material from the swingarm...there isn't really much room to spare. I think I will have to remove some from the frame. The kz bushing/seals do not fit the new arm. Here are the SV bushings. With them installed the whole thing measure 9.5 inches. The spaces are 1/8 in thick with about 1/16 free play side to side overall.

Very nice so far I'm likin the front gsxr setup.
As for the frame fitting the swing arm I removed matterial from the frame to fit my swing arm. I still have yet to weld in the washers so I have a flat surface for the mounting of the swing arm.

Well, progress is slow...I have switched to using a 1st generation SV swingarm because it fits almost perfect in the pivot area, and it only cost 20 bucks. Just need to mill down the bushings a hair and have a sleeve made to accomodate the kz bolt.
Originally I intended to use traditional dual shocks...but the swingarm is made offset slightly to allow room for the sprocket carrier on the wheel. Consequently the shocks will mount on different areas or the arms. In other words one shock will mount right over the arm and the other will mount off to the side of the arm. I'm not sure if this will affect safety or performance at all. My other option is to go mono-shock, but I love the look of the old school shocks.