1982 KZ750H Build

Hi all, thought i'd get a build thread going for my build now that it's in full swing. The project started out life as an affordable, o.k. running KZ750 ltd. I went pretty directly into small mods (Slimming down the gauges, clip ons, lowering the rear) and just getting it running well.

This winter i'd decided to dive into a more substantial build starting with a 06-08 GSXR front end conversion and rear end rework. The rear loop has been brought up and leveled to fix the "broke back" look the 750 LTD's seem to have for a cafe build. I've attached those photos below.

I'll be updating the entire front end in regards to spoked wheels/brakes/controls etc. I'll also be mating a spoked rear wheel, custom seat, full electric rework and motor rebuild. Let me know your thoughts so far and i'm sure I'll have a lot of questions coming everyones way.

Looking nice, I am very interested in what you did to the frame, as I have a 82 750H that I want to do the exact thing to. It appears you cut the whole loop off and just welded a new one onto the backbone?

akolleth wrote: It appears you cut the whole loop off and just welded a new one onto the backbone?

Correct, it was a little difficult as we brought the front of the loop that connects to the backbone up, and leveled it. Required trimming just above the shock mounts off but for the longer shock look we'll be going for it should work out fine. Again this is my first substantially custom build so I still have a lot of trial and error to do so i'll see how it goes once we start getting everything lined up with the new rear shocks and the shorter fork length on the USD forks I have. I'll keep you updated!

So I'm updating this now that the project is coming to a close. For those that saw the build earlier and heard my back and forth on wheel size I ended up maintaining the stock wheel dimensions to avoid further complicating geometry. All in all the bike is a blast to ride, just need to work through some carb things and potentially an electrical gremlin with the m-unit and some high RPM issues. I thought I'd share it along. Also let me know if you have any questions about getting into fork conversion stuff, I learned A TON about what goes into a swap and some things to consider if at all interested.

Hey I have the same bike and am considering a fork swap with some sort of USD fork. I got real worried once I read the thread that mentioned that you should brace the frame. Did you end up doing this? What about the swing arm? Did you swap that out as well?


Thanks,

Dan

Brace frame just because of a fork change? You planning to ride hard enough to slide the bike sideways while riding on pavement?

Nope not in the least bit hahah! It was brought up because the stiffer fork transmits more energy from the bumps in the road to the frame since less energy dissipated via the less stiff, right side up forks. How big is the difference? I don't know but it made me nervous enough to start reconsidering.

I did not brace the frame or modify the swing arm. I would say if the frame is in good shape you're safe. I have stood on the front brakes as hard as I would like with no problem and just this weekend hit a SIZABLE hole with no problem. I remember the thread you mentioned but I would personally say that it's overkill unless you're planning on track days or anything substantially harder than riding around town. Then again I'm not an engineer so what do I know.

As for the difference. I definitely notice a difference in stiffness under braking/hard cornering but not in a bad way. I might recommend going with a longer fork than the GSXR setup i have if you're staying with the stock rear suspension height to stay closer to stock rake and trail numbers but all in-all i'm happy with the outcome.