Im in the same boat myself. Have a gsxr swingarm but find myself wondering what the best fork swap would be for my 79 kz400...

Im sure everyone who reads this will roll their eyes... The bike is hardtailed via the swing arm. this is the reason I have not mentioned the swing arms bushing/bearings or the rear suspension.

The front end is off a kz550. Today I checked everything and wanted to take the bike around the corner to see if the anything I had done had affected the wobble. As soon as i got on the bike I notice the forks where not properly dampening. oil is 10w bel ray and air pressure was set to factory specs. i just changed to seals two weeks ago and no oil is leaking and the air pressure hadnt changed. any ideas? hopefully its not the spring.

Al- that's ok, I'll take a look at the page. I took a look back into by flee-bay receipts, and it looks like the guy labeled the mount as the wrong year. From 96-97 was one mount, 98-99 was another, and 2000+ was another mount. My swingarms (the 600 and the 900) are the same width at the axle, so I shouldn't have an issue with things once I get the proper caliper mount in. The calipers are interchangeable throughout the years, so I'll be ok there. It's just frustrating when you almost have something done, and then someone else's mistake throws a wrench into everything...

Ignore that last post, something went wrong in the posting. Here it goes again.

Got a bit of work done on the bike today. Dropped the old swingarm off, ground the pivot tube tabs out a bit to hold the new Ninja 600 swingarm, had everything ready to line up, check clearances...

And then there's an issue with the rear caliper mounting up. I either don't have one of the spacers (but I checked the parts diagrams, I have them all), or the caliper I was told was the right year isn't...

It took away about 2 hours of checking diagrams, flipping spacers, making sure things were in the right spot, and still no luck... It's times like these that really slow things down and make you scratch your head. It's a roller for now, and that's all that matters to me.

The swingarm fits into the chassis now, and is temporarily mounted up. The suspension feels a little "woody" right now (see pics) haha.

Rear end propped up, old rear off




Just a rough idea of what the end product is going to look like




Swingarm is a little greasy from dirty hands, but it's all polished up and ready to rock




Nice side view- the ride height will be lower than this- this is just with the 2x4 in place to keep the ass end up




Pretty mean looking, if you ask me





Hopefully I get this issue sorted out soon. More updates will follow with progress.

Devin

You all bring up some good points. Still to me chain is in the same catagory as carbs vs fuel injection and points ignition vs electronic. Guys always said the same thing about these things when they do rarely have problems for sure the simple points and carbs will be easier to fix than fuel injection and electronic ignition and much less expensive when they do fail, which is more frequent. To be honest I've never had a chain failure either in all these years, but still don't like chain drive and don't want any more of them. Some motorcycles with shaft have had big problems for sure, that is a fact. I've seen pictures of a couple BMWs with the single side swingarm where the whole swingarm snapped. That will leave a dent in the wallet for sure.

Got a bit of work done on the bike today. Dropped the old swingarm off, ground the pivot tube tabs out a bit to hold the new Ninja 600 swingarm, had everything ready to line up, check clearances...

And then there's an issue with the rear caliper mounting up. I either don't have one of the spacers (but I checked the parts diagrams, I have them all), or the caliper I was told was the right year isn't...

It took away about 2 hours of checking diagrams, flipping spacers, making sure things were in the right spot, and still no luck... It's times like these that really slow things down and make you scratch your head. It's a roller for now, and that's all that matters to me.

The swingarm fits into the chassis now, and is temporarily mounted up. The suspension feels a little "woody" right now (see pics) haha.

Rear end propped up, old rear off


Just a rough idea of what the end product is going to look like


Swingarm is a little greasy from dirty hands, but it's all polished up and ready to rock


Nice side view- the ride height will be lower than this- this is just with the 2x4 in place to keep the ass end up


Pretty mean looking, if you ask me



Hopefully I get this issue sorted out soon. More updates will follow with progress.

Devin

You haven't mentioned your swing arm.

I don't know what year you have but the first ones didn't have roller bearings they use a bushing.

Ether way if it wasn't greased regularly they will wear out and cause slop .

How many miles on her and how long have you owned it ?

What does your chain and sprocket look like ?

JD

Ed beat me :pinch:

NickMac wrote: My kz650 has had a wobble since the day I first rode her. Symptoms occur upon initial acceleration (wobble in one direction) and taking turns at higher speeds (40-50mph) I have changed fork oil/air pressure, balanced tires, aligned wheels, checked for play in the wheels (wheel bearings), and turning is smooth (steering stem bearings). At this point Im not sure what else to check. any input is greatly appreciated as this has been a recurring and unfixed problem.

thanks for you time and input.

-Nick

KZ650 bikes should have ZERO wobble from 0 - 120 mph. If there's wobble, here are the likely suspects:

Tires - these can look great but cause wobble. I had Michelin Macadams do this to me, and it had nothing to do with tire balance - they were perfectly balanced. If your tires are not new I would replace them and see if wobble goes away. Fixing everything else below can help mask a tire problem but will not completely eliminate the wobble if the tire is at fault.

Rear shocks - toss originals, get QUALITY shocks (I use Hagons.)

Swingarm bushings (or in later models bearings). Raise rear wheel, disconnect shocks, try to twist tire left/right, check for any play at all. There should be NONE. Replace bushings / bearings if in doubt.

Steering stem bearings - replace originals with tapered roller bearings and be done with that possibility.

Fork oil - purge old oil - fill to the CORRECT level with quality fork oil (I use 15w Bel Ray).

Wheel bearings - repack them or better yet replace them (especially if they don't feel dead smooth).

Wheel alignment - front and rear tires must run parallel.

Wheels - if your wheels have spokes check the wheels with dial indicator to make sure they run true.

Brakes - make sure disks aren't warped and contacting pads irregularly.

If all the above are done and wobble persists you make have bent forks or frame. Ed

Welcome and I agree if its not too late 1075 goes along way
there are tons of options on the front and rear otions I piece mealed
mine with an 02 zx 6 swingarm and mono with zx7 front end the ride is amazing

as I am sure any upgrade would be with todays springs and shocks.

my conversion started out almost identical just wanted a little larger rear tire
complete mono conversion later a 190 tire. one thing led to another led to another
led to another...good luck feel free to ask if I can be of any help

I am in Seattle, I love this city. Thank god I'm moving though haha, moving to a suburb of Seattle this October. Been in this vary apartment attached to the balcony pictured since November 2010, which is when I moved to Seattle. Time to switch up my life.

Now about that seat, I threw it out already haha, I am redoing it as well as making the bike a simple monoshock using the swingarm that's on the bike. I have a shop space now with a welder (professional retired welder) which I am stoked for. I am not making the bike crazy or anything but there will be some cutting, more simplifying and an ungodly amount of CLEANING

All I am doing to the engine is replacing pistons to the 1030cc, replacing the cam chain components and cam bearings, maybe the cam shafts. But all OEM nothing unreliable since every damn part for these bikes cost's a first born child.

Like I said, Mostly cleaning though still staying close to the café style. I want it to look like its 5 years old rather than 33 years, cleanliness wise.