I just machined some small spacers that go in place of the factory spacers they are just 16mm inside instead of 25mm made of stainless steel. Took me 10min and.I'm a novice any machine shop.could easily.do.it.and some off the shelf washers on eitheer side and ur done ill take some pics.of.them if u need

So another day of work. I couldn't afford les' swingarm so I found another one on craigist with a wheel tire brake rearsets and bolt on extensions. I payed 150 for all of it its off an 04 gsxr. I turned it upside down and machined some adapter to make my factory swingarm pivot bolt work and two stainless washers and she fits great. Mocked it up with the shocks just sitting on top of the swingarm. What do u think guys am I going the right direction???. Frame was sand blasted and sealed haven't painted it yet still some fab work to do

BohicaBob wrote: You should consider a number of things before proceeding. I'll use my Z1-900 as an example. Years ago I upgraded the stock spoked wire wheels to DID alloy rims and SS spokes/nipples, a 2.15" x 19" front and a 3.00" X 18" rear on the reinforced but stock swingarm. Handling improved as I changed the front fork damper rods to later model KZ900's along with Progressive front springs and Progressive rear shocks. So the stock geometry was not significantly changed from stock if at all by the changes. I braced the frame a long time ago by the way.

In 2006, I replaced the DID alloy wheels with wider 17" Excel alloy wheels wide enough (3.5" and 4.25") to support the use of radial tires, and added a GS1100 swingarm and a rear disc brake setup. Here I had to consider how this bike's geometry and total height/ground clearance would change along with its handling because of the 17" wheels. I even took into account the actual diameter and width of the Avon AV45 and AV46 tires I wanted to use, the resultant trail changes, wheelbase change (the GS1100 swingarm is longer than the OEM Z1 swingarm) etc. I missed one important item that surfaced with use of 17" wheels and OEM KZ1000 front and rear calipers: I will spare you the details for the moment.

im sure i can figure those out ,

i did find out this dose have front and rear disk, dual up front.
so that at least makes me feel some what better. how ever still would not mind finding something to do with the swing arm to make it a bit more stable and also help the performance on it. not looking for a drag bike, but like that look.

I copied this from a post from Jeff Saunders (owner of Z1 enterprises)

Motorcycle Wobble/Vibration Causes

There's a LONG list of potential area that can cause this.

These are not in any particular order

Wheel bearings

Steering bearings - repack grease, check tightness

Swing arm bushings/sleeves/bearings - replace if worn, repack grease

Fork springs aging - check spring length

Unequal fork oil - if seals leak, then your damping can be ineffective

Rear shocks aging, damper leaks - if you have oil leaking from the seals, the damping is toast.

Worn Tires/Mismatched tires/tire pressures/wrong size tires

Wheel alignment - don't trust the chain adjusters - I visually align the wheels.

Bent rims/broken spokes - get the wheels off the ground and spin them - check for run out/ damage

Balance the wheels- makes a big difference.

Check for wheel run out(out of round).

Front disc warped - check for run out (out of round)

Dragging brake pads

Steering & swing arm bearings are very common problems, but so are tire issues (pressure/mismatch) and wheel alignment.

You should consider a number of things before proceeding. I'll use my Z1-900 as an example. Years ago I upgraded the stock spoked wire wheels to DID alloy rims and SS spokes/nipples, a 2.15" x 19" front and a 3.00" X 18" rear on the reinforced but stock swingarm. Handling improved as I changed the front fork damper rods to later model KZ900's along with Progressive front springs and Progressive rear shocks. So the stock geometry was not significantly changed from stock if at all by the changes. I braced the frame a long time ago by the way.

In 2006, I replaced the DID alloy wheels with wider 17" Excel alloy wheels wide enough (3.5" and 4.25") to support the use of radial tires, and added a GS1100 swingarm and a rear disc brake setup. Here I had to consider how this bike's geometry and total height/ground clearance would change along with its handling because of the 17" wheels. I even took into account the actual diameter and width of the Avon AV45 and AV46 tires I wanted to use, the resultant trail changes, wheelbase change (the GS1100 swingarm is longer than the OEM Z1 swingarm) etc. I missed one important item that surfaced with use of 17" wheels and OEM KZ1000 front and rear calipers: I will spare you the details for the moment.

can any of you point me to the right direction for info on doing this swap? have a 79 Kz 750. would like to stretch the swing arm some and really would like to find a way to go with front and rear disk on it

Thanks Leon

I'll have it up on a jack as soon as my new rubber shows up and will check the front and rear ends thouroghly, I had a feeling the steering bearings might need attention, under takeoff I thought I could feel a bit of play. Tapered roller bearings were on the horizon anyway, the bike has a front end and rear swingarm swap in its future.

if you can get the bike up off the ground you can grab the front wheel and pull it back and forth and feel for slack in the steearing bearings.
myself personally,i ride the bike and squeeze the front brake and watch the steering stem nut for movement relative to the fuel tank,if you see front to back movement the bearings are loose.
chances are they have set long enough to condense some water in there and have pitted the races and you are feeling the balls roll down into the pits and up out which will try and hold it in the pits and then bounce em out.so they are effectively acting like detent balls.
if you turn it side to side while off the ground feel for notchiness as well.

same deal on the swingarm remove the shocks and try to move it side to side and watch where it connects to the frame and watch for movement that will indicate worn bushings/bearings.

changing fork oil would be prudent.i wouldn't worry about checking brake disk runout unless i did not find anything else that could cause the wobbling.

hth,
leon

So I've been doing some short rides on the 78 kz1000 I've got running, test rides close to home if you will. Too see what other things need attention after sitting for 17 years. I noticed a front end wobble at low speed when I let go of the bars, when I get it up to speed and let go of the bars it doesn't wobble. I'm guessing steering bearings are my first thing to look at, I have new tires coming within the week. While I'm at it I should drain and add fresh fork oil, check front rotor for trueness, rear swingarm bushing for wear and I'll check the wheel bearings once the wheels come off for new tires.

Anything else I should look into in regards to steering wobble?

Other things I've learned from my shakedown rides, new side cover bushings are in order. In 5 gear between 3/4 and WOT the side covers fly off, haha. The clutch feels like it slips till the bike warms up, was expecting some clutch issues with it sitting for so long. Float needles seem to be leaking when the bike is off, I shut the petcock off and noticed the clear fuel lines were empty after a day or two. Will change the oil again and check for gas in it and see if that helps the clutch slipping problem. Once it warms it doesn't slip, even under hard exceleration.

Man what a fun bike to ride, it sure has some guts for an old bike!

BohicaBob runs a 160 seach bohicabob it look sick with the 160

My novice understanding is that you will need a 4.25 - 4.5 inch rim for 160 tyre. You will probably need a 530 chain and spacers also