KZ1000 is op rear shock mounts

Thanks and sorry about the pics, first time. Your thoughts on where would you put the mounts. I think the bottom is dictated by the weld and cast part. The top, I'm thinking (reluctantly) move. I have looked at a lot of pics of other mods and,of course, AC Sanctuary builds, and probably 99 put of 100 have them moved, but I wanted to know why. I what this bike to handle like it should and not scare the hell outta me in the corners. I live in East Tennessee so there are a bunch of corners here! Just want to it right.  Should this be moved to the "projects" forum topic?  
 

How do I fix the subject line to read: KZ1000 top shock mounts?  Damn auto-correct!!

WoodheadB2 wrote:

Where the shock is sitting on the swinger, it is 1 inch shorter than stock from the pivot to shock.... The  swinger is also 1 in longer than stock at half adjustment. I think with the 17 in wheel that would drop the axle about where it needs to be for the ride height to be close to stock.





 

Here are some thoughts.  It seems to me that your current mount is about 1" closer to the pivot, but also about 1" higher given that the aluminum swingarm is thicker vertically than the original.  If you were using the stock shocks, this seems like no matter what you did with the spring this new geometry would lower the arm at full extension (sag), and limit your vertical travel when fully compressed.  But if you are planning to buy new shocks, it seems likely you have the option to purchase shocks that are shorter than the original set.  This could allow you to correct the overall range of motion, as long as the shock has both the correct overall length and enough travel.

Given all of that, it seems to me that you need to research what the ideal full down and full up wheel positions need to be when you're done, and what options you have for shock travel and shock length.  Once you have that you can figure out if you can buy the correct shock, or if you the only way you can make it work is to move the top mount.

One other suggestion that may allow you to move the lower shock mount back a bit.  You could make the lower mounts somewhat hook, or "J" shaped, to move the pivot point behind the existing weld line but keep the bracket itself in the same place.  The lower brackets on zed1015 bike have a bit of this kind of offset, but it seems like you could add more. 

The japanese guys use some kind of adjustable upper shock mounts.

 

Hey DOHC: I understand what you're saying. I think what I'll have to do is get tires on it and get it sitting on the ground (on jack stands) then find out how it's gonna sit with the 17 inch wheels. Then (maybe?) I can figure out shock position and length. That's a good idea about new lower brackets. I can make those easy enough and move the lower close to stock length from the pivot. Thanks for the input. By the by, my brother-in-law restored a Z1R. it was flawless when he got done with it. he did an awesome job. One of my all time favorite bikes. I loved the shape of the tank and the tail section. Absolutely beautiful bikes. 

My opinion is that the stock top mount is ok and that if the bottom mount is the stock distance from the pivot the height of the rear end will rise slightly but most of the difference will be countered with the smaller wheel. The added leverage from the bottom mount to the axle could be countered with a stiffer spring/shock combination

Well Wookie, that's kinda what I was thinking. Where the swinger is sitting now would be the same extension as stock with the bike on the center stand. Now if I can clamp the shock in that position and get it on the ground to see where the sag makes it sit, then I should be able to see how the rear ride height is. If all is good, bring on the welder!  Or see about fabbing new brackets as DOHC suggests. Thanks for the input, much appreciated again. 

On my Kz1000 Superbike road racer the rear shocks have been laid down. The lower shock mounts on swing arm are in the stock location. The top mounts have been moved about 3 3/4 inches if I remember correctly. That gave me just under 7 inches of wheel travel. I checked the travel without the springs being on the shocks. I had to remove a few pieces from the frame that got in the way of the rear tire at the upper ends of the swing arm travel. Even had to remove the top half on the inner fender too!! The major advantage of having all that wheel travel is the bike basically floats over most of the bumps and rough pavement that I ran across on the street!!!! On the track the rear tire seemed to stay in touch with the pavement a lot more than the bike with the limited shock suspension travel!!!! This was a common modification done to all of the early Kz1000's that were running in the Superbike class some 45 odd years ago!!!!! Funny its the same modification that AC Sanctuary does to their mega-dollar Kz1000 builds today!!!

Here are a few photos of my Kz1000 with the rear shock mount moved to give more rear wheel travel.

 
 
 
 

Doc when it comes to superbikes you are definately "the man" and I don't doubt the benefits of your mods, would you agree that in this case where the OP wants to maintain the option to return to stock at a later date then my suggestion would probably be a reasonable compromise

Hey Dr Gamma and Wookie, if I go jacking up the rear won't that just exacerbate the the front being to low and tighten up the rake even more?  

WoodheadB2 wrote:

Hey Dr Gamma and Wookie, if I go jacking up the rear won't that just exacerbate the the front being to low and tighten up the rake even more?  

Absolutely, my suggestion would only increase the rear height by the difference in the depth of the swingarm box section compared to the stock tube (I am guessing around 20mm) which I don't think would have a significant impact on rake. As you are planning to go aftermarket for shocks you can probably buy the right length to compensate for the raised height of the lower mount

I think your original plan will work you just may need to stiffen up the shock preload a bit. In my case the shocks I was using worked with the longer swing arm but I had to adjust the preload to it's stiffest setting. When I switched to the KZP shocks it was too stiff so I lowered the setting and they work great. I still have two more softer settings left. 
As I see it KHI used stiffer springs to compensate for the steeper angle and longer swing arm while keeping the 14" shocks. 
It worked for me.   
Steve