KZ750H to E conversion - Rake and trail ?

Hi,

Long story short, I have been weighing the pros and cons of converting my KZ750H LTD towards a KZ750E (I cannot really do anything about the tail fairing so the best I can do will be a KZ750E front and tank with a LTD seat and rear).
During my search, I have been able to find info on the forum in the following threads:
- www.kzrider.com/forum/5-chassis/618095-kz750e-vs-h?start=0
- www.kzrider.com/forum/13-bike-related/60...kz750e-and-kz750-ltd

From this info, it looks as if there is no problem in swapping the front end of the LTD for the E's (as long as it is done entirely), allowing for a larger fuel tank.
But, and that is the reason of this post, is there a problem in terms of rake and trail and am I doing something stupid and potentially dangerous with this swap ?

According to the service manual, here are the specs of each model:
- 750 E: - rake: 27º
              - trail: 108 mm
              - front and rear tire: 3.25H-19 4 PR and 4.00H-18 4PR
              - wheel travel front and rear: 160 and 95mm
- 750H LTD: - rake: 30º
                    - trail: 121mm
                    - front and rear tire: 3.25H-19 4 PR and 130/90-16 67H
                    - wheel travel front and rear: 180 and 100mm

I will swap triple trees, forks, headlight bracket, meters and tank.
I would really appreciate your input on this as I never did any modifications on the bikes I worked on before, usually sticking to original specs.

Cheers



 

As I understand it the E tree's push the forks forward which gives you the clearance for the bigger gas tank, the H has leading axle forks which push the wheel forward. As long as you use the E fork lowers (as a minimum -  if you want to keep the extra length of the H forks) to compensate for the trees and pull the wheel back geometry shouldn't be an issue - happy to be corrected if I'm talking s*^t 

Thank you for your input Wookie.

Would you happen to know if the rake difference between the E and LTD is just a matter of different forks and back wheel diameter then ?
I read in the other topics that the E and LTD frame are the same (except for the tail), so I guess that the steering axis has the same angle if that the same.
If that's so, it means that I am just going from a 30º to a 27º (or rather a 28º-ish since I am keeping the LTD 16 rear) trail ?
Feel free to correct me if what I say is rubbish.

I don't have an E frame handy, would anybody who has both an E and LTD frames be able to compare the steering axis angle ?

The rake would be impacted by the shorter forks from the E which would lower the front so a complete E front end would get you somewhere in the middle

I guess my first question is why you want to make the switch?  Did you damage your front end?

hardrockminer wrote:

I guess my first question is why you want to make the switch?  Did you damage your front end?

A couple of the guys have done this now, they wanted to fit the E tank but you need the pushed forward E trees to get the clearance with the bigger tank

I’ve done this EXACT swap. Everything said here is true, need E steering stems to clear the wider E tank. I’ll be honest with you, there is no steering difference using the H fork lowers. Maybe on paper but it’s absolutely negligible behind the bars.

That was my thinking as well.  The difference would be minor at most.  The trail would shorten a bit.  i'm guessing the forks are the same length.

Thank you all for your input. I feel much more confident in attempting the swap.

Hardrockminer, the why is a combination of various factor actually, the most important being space. I don't have much space home to store several bike so getting a E is not an option for me. I could sell the LTD to free up some space but truth is I already invested more money in it than what I would get if I sold it, since those are not that very sought after in France. Also, I know what I did with that bike (bearings, starter clutch, dynajet ignition, chain, electronic, paint...), so instead of getting a new bike where everything would have to be checked and replaced (which is a lot of fun, of course, and a big reason we are on this forum), I know what I have!
Here, the idea is to have a 750 that I can transform into a LTD or a E whenever I want, just swapping the front end, tank and side covers. The tail is the only hiccup, since the tail fairing of the E cannot be mounted on the LTD frame, but my plan (still a little way to go) is to create a seat looking as closely as possible to the 650SR's using a LTD one piece seatpan and a 650SR seat cover – I really like the look of the 650D SR but they are either hard to find in France or very expensive, even in poor state.
So, for now, the aim is a 750E SR

PS: I am currently looking for a 750 LTD seat in one piece, so if somebody has one, feel free to PM me.

So it sounds like you will have two bikes in one, without requiring extra space for a second one.  It's an interesting solution!

I'm currently space limited with four bikes.  One has to sit on the lift at all times.  

 

Yep, that's exactly the idea ! I have four too, and for some reason I can't seem to be able to let go of any...

Here’s a pro tip for anyone looking to do this swap. If you are unsatisfied with your angles after the steering stem swap you can adjust the angles if you rear end a 2006 Toyota tundra going 30 miles an hour. This is my personal fix for the problem.