77 KZ1000 stock to modern fork swap

I've got a 1977 KZ1000 that I'm toying with doing the modern fork swap on. I can get all the machining figured out and done but there's a few things I can't seem to find info on. I'm looking for upside down modern forks that will work for the following. My plan is to find a set of forks and triples used from eBay so searching for forks by model,make and year would be helpful.

1.As far as handling goes will I get good performance in the corners if I use 18" wheels front and rear? When I say good performance I mean, as good as stock or slightly better because I have modern brakes and suspension. I don't need a bike capable of dragging knees at 100mph, I'm not that kind of rider.The reason for this question is, I'd like to try to do the swap and keep the stock look. My plan is to use aluminum rims, stainless spokes and stock hubs modified to receive modern brake rotors.

2.The answer to question #1 will effect the answer to this question. I really want the bike to sit at stock height when I'm done. Given that piece of info does anybody know of front forks that will do this with an 18" front wheel? How about with a 17" wheel if you're recommending 17" for the answer to question number #1. If you don't know of a fork that will fit the bill is there a website that has fork lengths associated with modern bikes?


I want to do this to get better braking, a more stable ride and because I can't leave well enough alone.

Im not sure which front end to use but I can say theres a much better selection of 17" vs 18" rubber out there to be had,everybodys geared towards the 17" sportbike rims for decent rubber these days.

Ive been drooling over magoos bike for many years,I believe he used some sort of aftermarket harley hubs with the wire wheels

^^^That's a beaut! There's something so right about spoked wheels, although I do like the mags with an inverted from fork and swingarm swap.

If you do your research you will find that you can use certain alloy rims and spoke kits allow you to go tubeless. Strength and style, a great combo.

List of fork lengths, www.customfighters.com/forums/showthread.php?t=53934

As for wheel size and handling, good 18" tires are near impossible to find, at least good compound ones and that in itself is a big plus towards handling. Also, with the newer usd forks, the offset is usually a lot less which adds trail which slows steering but improves high speed stability.
Here's a trail calculator to play with. www.rbracing-rsr.com/rakeandtrail.html
Most GSXR's have between 30 and 32mm, 1.181" and 1.260" offset, The ZX's have 24mm, 1.024" offset, stock KZ's have 60mm offset, 2.362".

Drop triple trees can gain some of stock height back



I will probably never run stock forks again after doing mine, except for restoration of the Z1, just the upgrade in brakes was worth the price of admission not to mention it is a visual plus.
Hope this helps, just keep asking if more info is needed.

Les

Kaw-a-holic,
Good point, I will keep that in mind when I buy rims.

Les Holt,
Great info, thank you. I didn't realize the offset would be so different. I see you've made a dual shock swing arm that bolts on. What's your price range going to be for those?

hey SeattleKZ,

mate if your looking to keep the stock wheel look, you need a set of Ducati sports classic or GT1000 wheels! they are 17" 3.5 front and 5" rear, but the best part is the front is twin disk with a 135mm spacing so they are perfect for modern USD forks!

here's a pic of how mine is sitting at the moment:


here are the wheels up close:


the standard GT1000 rims are chrome:




the bad thing is the fronts almost fuking impossiable to find..... the rears come up from time to time, your probablly looking at a $1500 a set, or you might get lucky if someone dosent know there worth....
i know Les is on the hunt for a set too. (hey Les)

No eBay APP ID and/or Cert ID defined in Kunena configuration


This is the setup I am using about as close to plug and play
as you can get

I had to get fancy and want to run my stock 19 front wheel
which takes additional fabrication that i am very close to
having.

Thanks for the info guys. Those Ducati wheels would be sweet. I'll keep my eyes peeled for a set.

Those forks are very reasonably priced. When the winter gets closer I'll have to grab a set.

I think i gave less than 100 for mine but they were rough (straight but rough) it took checking ebay every day for weeks if you could find a complete set on craigs list get a set of triples and you could
be riding it same day

94 to 97 zx9 forks r the longest i know of, in the upside down type.
the drop trees r a nice way of regaining ground clearance.