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Hi, I'm new here and have never submitted to a forum before, I am not new to motorcycles tho, I own a 1995 Harley Flt, also a 1980 cb650 cafe project, but this past fall I picked up a sweet 78 Kz650 sr with only 10,000mis on it, originally I was going to leave it stock but thoughts of a street fighterwere creeping into my head, I had a front end from a 1990 Suzuki gsxr750also the rear wheel. I still wasn't sure I wanted to cut up a nice stock bike so I carefully removed the stock front end and just installed the gxsr one(no bearings or spindle mod yet)just to see if it would work, it did and I liked the way it looked. The beefy front end really changed the bikes attitude, I also didn't want to keep the stock rear suspension and have decided to go with a mono-shock I got a 1988 Suzuki 600 steel swing arm from e-bay, cleaned of all the unwanted brackets, trimmed 5mm from each end of the pivot tube, the stock Suzuki needle bearings would then be too long, but with a little research I found that they make them in various lengths so I ordered a set from All Balls along with neck bearings. I want to keep the same wheelbase so I will have to shorten the swing arm by 3" I pan to take it out from in between the cross brace and the pivot tube, also I plan on using a non linkage shock so I will have to fabricate an angled brace from just in front of the axle up to where the bottom of the shock will be located. I still need to find a suitable shock, any ideas on what to use?
Ok I took some pics, and I am going to attach them to this thread, I'm not sure if I'm doing it right so here goes....................

welcome.
it looks like you are well on your way.

leon

Nice start barry ! Thats going to make a nice bike

Welcome to the site

Welcome Barry.
Looking forward to your project.
Coming along well so far.

I got a little more done on my street fighter build, so it"s time for an update, first I got the swing arm shortened by 3", I would have had to go 4" to keep the original wheelbase but there just wasn't enough room between the pivot tube and the cross member to take that much out and make it strong enough for my peace of mind. I made a stepped cut in both sides added plates on the inside of both tubes, welded and also plug welded to the plates. I ground the welds down as far as I was comfortable with, I will take care of the cosmetics when I get ready for paint. I had a local race car shop bend me up some .095 wall 1" tube to transfer the shock load up to the bottom of the mono shock. I got an 07 Ducati mono shock from a friend for about $160.00. So I spent the last 2 days getting everything fitted up and tacked into place(didn't want to weld anything permanent until I was happy with the ride height. I also had to open up the rear axle slots to accept the 20mm axle.

that all turned out nice !

real sanitary lookin,keep us posted.

leon

Thanks Leon, it's coming along nicely. however I am concerned that the upper shock mount isn't strong enough. The cross tube I added is the same .095 wall steel tube I used for the swing arm loop, do you think I should tie it into the end of the main back bone tube with a gusset or a piece of tube somehow? so it more directly transfers the shock load......

Why not? What about your battery? Two small ones one on each side maybe? Looks good enough for a 1000cc machine.
Steve

I'm planning on using a Ballistic battery under the seat tail fairing.

that upper shock mount isn't going anywhere.
the way you have that tube coped and fit.
once it is welded in you would have to tear both ends of the cross tube out.
short of jumping out of skyscrapers that frame will never see enough force to do anything.

having said that,
a plat with two dimpled holes fit and welded into the opening above it would tie it all together very nicely and give another lil chance to let your fab work shine through .

that's my .02 fwiw,

keep us posted,

leon

p.s. killer lookin project.

It's been kinda cold here so I don't get to work on the kz much during the week, however I did some fine tuning to the swing arm this past weekend(pics to come soon) I had to notch the left side about 6mm to try to get the wheels to align, but it only got me close. The rear wheel is still not on the same plane as the front, they are parallel but the rear is offset to the right about 4mm. I have read a lot of posts about this and most seem to say it won't be a problem, in fact H-D's have an offset from factory. Does anyone have any input on this?

i have my rear wheel on my 80 z1r offset 3/8's of an inch(9.52mm)it runs straight as a string down the road and turns in the same both right or left.
lottsa bikes come from the factory with some offset,even some gixxers etc.

leon