1981 KZ 1000 LTD trees interchangeable with 1978 KZ 1000 LTD?

Does anyone know if the front trees of a 1981 KZ1000 LTD would fit on My 1978 KZ 1000 LTD without modifications? knowing this, could save me a lot of time and hassle, as always, Thanks!

My understanding of your question is that you want to use the triple tree (both pieces) from an 81 K version bike on a 78 B version bike, but you plan to use the forks from the '78.  (I don't think you can use the forks from the 81 because the wheel mount is different.)

You will need to check a few things.  Are the fork tubes the same diameter?  Are the offsets the same?  Are the mounting holes for the gauge brackets the same?  Are the mounting holes for the brake splitter the same?  Is the diameter of the stem on the lower tree the same?  Is the stem length the same?

You could swap an entire K front end onto you B frame by swapping the stems. If the stems are the same length, you might be able to make the swap with a custom bearing set. Before you do either, you need to insure that the frame rake is the same on both models. The K forks are leading axle style, while the B forks are not, so the geometry of the clamps, and maybe the frames, are noticeably different.
I do not remember reading about any front suspension swap that was 100% bolt on and go.

The frame rake on an 81 is different from a 78.  So is the trail.

OK, I have a 1978  KZ 1000 ltd, that front end needs a lot of refreshing, I also have a 1981 kz 1000 ltd doner bike, with a "good" compleat front end. I was hopeing to move the compleat front end over to the 1978. Im aware of the leading axle, and the newer forks are about 2mm thicker, that is why I want to mount the `81 trees. I also have a nice set of `81 kz 750 front shocks, without the leading axle that are 2mm thicker then on the `78 ltd. could a person possably stuff them in the `78`s trees. again Thankyou!

Terms matter… “Thicker”?….Wall thickness? Or outside diameter? 

The forks must be the same diameter that the clamps were designed for. Two millimeters one way or the other will not work. Even if they did fit, there would likely be a host of problems fitting the axle, wheel, speedometer drive and getting the brake rotors and calipers to line up.
There are not many common parts between the 1000B and the 1000K.

wrote:

Does anyone know if the front trees of a 1981 KZ1000 LTD would fit on My 1978 KZ 1000 LTD without modifications? 

I figured I'd mention that the 1981 KZ1000 was in many ways a completely new design. 

The 73-80 Z1/900/1000 share the same basic frame design and engine design.  For the 1981 model year the frame was completely redesigns, the engine was substantially redesigned, and most other major parts were also redesigned (brakes, wheels, and on and on).  The 1980 and 1981 models are very different motorcycles underneath.

Since the frame is a different design, it's hard to say if the front end will swap.  And you'll need to do some careful checking to make sure you end up with the correct steering geometry.

Sorry, out side diamater, I was wondering if i could back off the pinch bolts, possably wedge the  holes open a little and push the larger diameter legs in. I believe lt could be done with a 1mm differance, probably not with 2mm. Money is tight, and im checking with what I have to work with before buying new parts. thank you.

wrote:

Sorry, out side diamater, I was wondering if i could back off the pinch bolts, possably wedge the  holes open a little and push the larger diameter legs in. I believe lt could be done with a 1mm differance, probably not with 2mm. Money is tight, and im checking with what I have to work with before buying new parts


. thank you.
BAD IDEA

Why not see if the whole front end will bolt up? Might extend the wheel base but might not be a bad thing. Rebuilding just the 78 forks Isn't so bad. 
Steve

When you say complete front end I am assuming you also mean the front wheel and triple tree from the 81.  (Front axles would be different.). In that case you would need to check overall length of 81 forks to 78 forks.  Also, I'm not sure the triple tree will bolt up to a 78, but it probably could.  You would have to use the gauge mounting plate from the 81 unless the bolt holes are the same as on a 78.  Also, check your trail, as the 78 has a 26 deg rake but the 81 has (I think) 29 deg rake.  I suspect you will be OK because the 78 has a 90 mm trail and you should be more than that, but if not you might have high speed steering issues.