30 years ago we replaced them with off the shelf Timken tapered roller bearings. That helped. Also I replaced the swing arm bushings with bronze ones. The stock ones were regarded as SHT. There was a needle bearing up grade but they were new and expensive. That helped. The wobble seemed to grow when they happened. I got so I could tell when it would start and deal with it if I weren't in a turn or something. The most remarkable thing was at 93 MPH, it was prone to start, not 92 or 94-93! I would and still do my best to get past that point or stay below it. Some said it was the wheel base, others blamed the frame and weak swing arm. I welded bracing under the steering head and webbed the back bone on the original frame. This one I used L metal under the SH and welded some flat stock in three places on the back bones. I cut two out so my coils would fit right. They didn't seem to matter anyway. I have the metal stock I need for the gussets but I like riding so anything I do has to be bolt on. I'll take my time with the swing arm until I'm sure it's ready.
Meanwhile I'm going to RIDE THE PISS OUT OF IT. :woohoo:
Steve

swest wrote: With all the fantastic mods here, I felt left out. The Z1's were known for their high speed wobble. :ohmy: I've been in them and scary is not the word. :dry: All I could do was to give it a little more throttle, squeeze the tank with my knees and ride through it. I had one in Tehachapi last year, almost went down. Hopefully this will solve the problem along with some frame gusseting. :whistle:
Steve

Steve,
Nice cut, ballsy move, I like it. A little off topic, have you replaced your head set bearings with All Ballz bearings? I have heard it helps eliminate the warbles. I never had that issue but I replaced my bearings when I first bought the bike. Hit 120 mph multiple times and never had the issue, knock on wood.
Anyway, looking for 2 to your mod.

That's the plan. I should have checked the square of the blade on my 30 year old Skil saw. After I made the first cut I was committed and had to make the other cuts in the same direction. They mate well but look like SHT. Welded and gusseted, they won't be seen. :whistle: "Can't see it from my house." :lol:
The trick will be making it fit inside the frame and miss the brake control arm. It would have been easier if I had the one that was burned in the fire for a template. At that time, the whole area was being hit by scrap thieves. Anything metal was taken including a spare A/C unit I had in my front yard. I caught three of them scoping out my neighbors place. Illegal aliens. Oh, (undocumented workers) :dry: and when they saw me with my 44 hog leg strapped to my hip, they scurried away like rats. :woohoo:
I'll fit it as I had planed in the beginning, maybe cutting and making my own bushings and shims, then send them to Leon to match. I need to get another stock pivot shaft to work with. The ZZR shaft can be cut and washers brazed to it for mock ups. We'll see.
Steve

Sweet Steve.
I have never seen it done that way. Looking forward to whats next, are you going with Leons mushroom bushings?
/A

Looking into suspension heights/setups.
Photos show the kz440 tubes installed, adding 1.75" up front.

Trying to decide if I should add one or two inches in the back. One would give a little more room between the swingarm and brake pedal mount, but two is doable, and keeps an even lift front and back.
Had to shave down the inside of the passenger peg mounts to get clearance for the swingarm, but I think I'm good to go now.
Up two inches from stock:

Up one inch from stock:

Any wisdom as to which makes more sense? I'm assuming the 2" on both sides.
Any good 14.5" shocks? Dime city has a set for around $90 with the dual springs. Liking those currently.

There's still one on my watch list. $145 That money can be spent on other things right now.
Steve

If youre looking to keep your original wheel and not mess with the frame,why not go for a GS1100 arm? A common mod , from what I understand, and a pretty straight forward fit (couple of spacers)

Its from a GSXR600,not sure what year. It was on a list of fittable swingers that Leon posted .The gixer pivot bolt is very fat so I had a reducing sleeve made to take the original Kwak pivot bolt. Other than that, a couple of spacers to take up side play( I think 3 or 4mm +-)
I did need to grind off the rear footrest/exhaust hangers as they were in the way of the 'swing' and when I centered everything up,I also had to grind 1 or 2mm from the righthand side of the arm, also to give a bit of clearance twixt the frame downtubes and the swingarm.
At the back end,I used a Bandit 600 wheel which has the same diameter axle as the Kwak. The Gixer has a very fat axle so I needed inserts machined and pressed into the chain tensioners. I think I also used a slightly longer axle than the original but I was able to keep all the wheel bearings and the caliper mount and had a selection of wheel spacers to use (Bandit/Kwak)to get everything sitting right.
A couple of shock mounts welded on and that was it.
Hope this helps.

the side legs and crossmember where the linkage mounts are aluminum extrusions,way stronger than cast.
thing looks suspicously like the zx6/636 arms.except your arm has a solid steel center bushing/race.
whereas the 6/636 arms have an aluminum center bushing with separate race pressed on.



so what does that arm measure across the pivot?

leon

redhawk4 wrote:

z1kzonly wrote:

Nola wrote:

z1kzonly wrote:

531blackbanshee wrote: curious as to why you would put bronze pivot bushing in place of the needle bearings ????

leon

Leon, he might not be aware that the later year KZ swing arms have needle bearings already?

Correct sir.

Cool Nola. What a Score you got with that motorcycle! Good Luck with it all! I might be wrong with the 78's.
But the 80 Z1R had a double wall reinforcement up at the steering head coming down in the down tubes?
And a little history about the Z1R's. No one bought them in 78, they were called ugly. The Factory had too much inventory. Dealers still had new ones in stock to sell 2 & 3 years after their introduction. That's why there was not a 1979 Z1R.
Then they changed up the 1980. Different sized tank, 19" front rim. But that's about all I know about them.
Your off to a GREAT start!
Enjoy it!

It is strange to me how the Z1R is so popular now, because as you rightly say they were really poor sellers at the time, which is why they came up with putting the Turbo's on them to move them out of the showrooms. I really didn't like them back in 78, much preferred the normal KZ1000. However nearly 40 years later I find them much more appealing than I did in 78, I still recall looking at one in the dealer showroom and calling my friend over" look a Z1R" in those days just the fact it was a 1000cc bike was cause for excitement, but it was not really appealing to me. Perhaps it was ahead of it's time, we certainly weren't used to the "square look" back then and I guess others felt the same way based on sales. Am I right in thinking that as the 78 sold so slowly, there is no 79 model?

I'm not the expert, but while the Z1R was one year only...78...there was a Z1R 2....it was available in 1980 in the US. It was similar in appearance but better handling, and a better motor.

At least that's my understanding.