KZ1000 Muscle Bike Build - ZRX Swingarm, ZX9R Fork

Loving the bike, I will be following for some ideas for my build :silly:

Johnno wrote: Thanks! Everything is in varying stages of completion, and there is always more to do, but it finally feels like it is coming together.

The zx9r disc does have the same bolt pattern as the street bob wheel, but there are two issues:

1. The center of the zx9r disc is larger than the shoulder cut in the street bob hub, so you have to self-center the disc. This isn't a show stopper, but just takes a little more care to align the disc.
2. However, the zx9r disc has an offset, where the harley wheel is set up to have a zero offset disc. With the offset, it pushes the front wheel off center, so they are basically unusable in this application.

I'll probably end up using the harley disc that came with the wheel (ugly, but functional and I already have it) or looking for some zx10r discs at the junkyard, I hear they have no offset.

Johnno,

It appears you are using the standard mid width hub which should be 5" from brake rotor mount surface to brake rotor mounting surface. I found this ended up being too wide with ZRX/ZX9 rotor offset. The Narrow Glide hub is 4" and I had to turn two spacers that are 1/4" (.250") wide to set the rotor spacing and centering the wheel. The 77-84 narrow glide hub also has a wider center ring that matches the ZRX/ZX brake rotor center hole ID. The only catch to this is it uses taper roller bearings that are 45mm OD. So I had to machine the bearing bores to fit a 47mm roller bearing that had a 25mm ID to fit the ZRX/ZX axle. You also have to cut a simple inside bearing spacer. So if you have a lathe and are willing, pick up a 77-84 narrow glide hub off EBay and relace you wheel.

www.kzrider.com/forum/11-projects/539557...200r-build?start=280

I hope this helps as I know the want for fat tires and modern spokes.

Cory

Thanks Cory!

I spent some time at the salvage yard today looking at brake rotors, and I think I have a working solution for the 5" hub that I'm going to test out. I will have to forgo using the zx9r rotors, but so far it seems to be working out. I'll post some pictures tomorrow of what I came up with.

In other news, the rearset posts that I made ended up not working out. The threaded portion at the end of the posts interferes with the swingarm pivot on the ZRX swingarm. I'm going to have to cut off the threaded section and weld them in. No big deal.

But the big progress was mounting the swingarm. I used Cory's swingarm pivot bolt design from his build thread, and it is really great. Here's the completed pivot bolt:



in the swingarm:



bolts in the demonstrate how it works:



and finally on the bike.



Major props again to Cory. This design is rock solid.

Ok, quick update. I got the rear wheel in and got the tire mounted on it. It is a Dunlop Roadsmart II 170/60ZR17.

For the rear end, I have a couple of issues that I'm working through. The first is brakes. I picked up a caliper off of a ZRX1200, which obviously works well with the swingarm, but the stock harley brake rotor is 11.5" and the stock ZRX rotor is 10". It seems like the front rotor off of a 78-83 Harley Sportster will match the bolt pattern and is 10", so that is what I've got lined up right now.

I picked up a .25" offset rear 530 sprocket and a 1" rotor spacer to align the chain and the rotor, which should be coming in the next few days.

The front end is a different story, and I know I said I'd be showing my solution, but it didn't end up lining up as well as I thought. I'm going to try going to spacer route on the front, too, so we'll see how that works.

Finally, I need to machine a bracket to offset the exhaust a slight amount. I've got a Kerker 4-1 exhaust, and it just barely clears the swingarm, but if I go over bumps I fully expect it to hit and rattle. I'm going to make a bracket that will push the exhaust out .5" away from the arm, which should be plenty.

Here's how it is currently sitting. I'm pretty sure the swingarm needs to get powder coated black, but I'll worry about that once I get all of the mechanical items figured out.

Very nice John! BTW the ZRX rear disc is 240mm.

Cory

oh yeah this is looking good! :evil:


leon

Heck ya man! Nice Fab work. Loving the spokes on it. Looks great

Thanks guys!

No pictures tonight, I'll grab some later. I just did some light futzing around. I moved the tach mount underneath the top triple tree brace, so it now sits almost flush with the brace.

I also checked out the rearset linkage. I was originally planning on having the linkage run underneath the shifter pedal, but it ran into the kick stand when it was in the upright position. I flipped the linkage to run over the shifter pedal, and now it clears fine. Because of the parts I picked up, I'm faced with an issue with the linkage rod itself. It is about two inches too long. Both sides of the linkage are reverse threaded, and the rod from the GSXR is too long. I don't have reverse thread taps to make a new one, so I'm probably going to be picking one of those up and doing a modification.

On the plus side, the exhaust mount worked out great. I'll have pictures of that soon.

-John

could always cut it and slide a piece of small tubing over it and weld it up. :whistle:
not quite as nice,but effective. :pinch:

or just use the right hand tap to thread it further down the shaft and cut it off.

eon

Some parts showed up last night, If everything goes well on the lathe tonight, I might be able to take it for a test spin tomorrow. Here's some shiny bits.

So where did you get the wide flange 84' and earlier flanged spacer?

Cory

Well, its actually a 2000+ flange on that spacer, but I bought it oversized so I'm going to turn it down about 1/4". I'm hoping to machine in the correct flange in that process. The rotor also has countersunk holes that allows it to self center when you use flat head bolts.