76 KZ900 B1 - from crates.

I've been meaning to get on here and start posting since I picked up a 1976 KZ900 B1 as a (stripped, primed and chopped) frame, tank and about 9 random cardboard boxes of parts new and old for $300 back in the summer.

I probably paid too much, but the PO had already cleaned nearly every part, there were a lot of spares and the motor seemed pretty clean (with a reported milage of 23k). As mentioned above, the frame had also already had everything behind the shock mounts chopped, the center stand brackets and most every other tab removed. This left me guilt free to start in on some modifications I've been thinking about for a while. This was no 'original example'.

I was actually looking for an early Ninja to do some of this work to, but I'm even more pleased that fate put this pile of parts in my way.

I'll try to be somewhat orderly about these posts, so a couple pics of the first few days. (in the pics I'd already cut off some of the steel that was used to cap the frame rails in preparation for a new sub-frame

Ok - second time's a charm with the pics.

another pic.

another pic (with a mock up of the tail section).

The motor. Haven't really torn into it, but seems to be good compression and I pulled the valve cover and it looks lovely inside.

Here's the subframe...

...those cams...

Subframe.

I love the Z1 bikes, but not the idea of shitty brakes and unpredictable handling. I committed almost immediately to upgrading the bike's legs. This isn't new as there seems to be lots of Kawazukis and Yamasakis out there but as Kawasaki seems to be wonderfully consistent about sizing, I figured I could do worse than to keep the machine 100% Kwaka.

I also wanted to be somewhat unified about the build. I've been looking around at various builds and Old Man Rock's A4 here at KZrider was one that I like a lot. Why not keep it Green? I also like the bikes the Wrenchmonkees.com guys do (and more recently, Shinya Kimura) so I'll try and keep it a little dirty, even if it's polished.

The first purchase was a '07-08 zx-6r swingarm assembly (from Fleabay). $75 delivered to the door fit the budget and I really like the shape. I think the curves will match the feel of the original bike.

The day it arrived I took it out the the garage to see how much work was going to be required to get the thing to fit. It slide in first try. It's probably a hair too snug and will require some grinding for a perfect fit, but chalk one up the Green Team.

Also started on the frame bracing. (welds to be cleaned up.)

Searched a lot for a front end, and then found this from '03-04 zx-6r (also on Ebay). Nearly complete with a bent brake lever, missing MC and a little damage to the underside of the top triple, but otherwise clean and straight. $250 delivered. So far so good.

I spent a bunch of time before the assembly was delivered thinking about getting the frame and triple to fit. Old Man Rock's solution of swapping the stems in the bottom triple seems a good one, and I was pretty set on going down that road. However, as I was dry-fitting in the garage, I remembered a post I saw some time ago about a front-end swap and the author said he took the frame and the triple to a bearing shop nearby, bought roller-bearings with the correct i/d and o/d and then had a machine shop knock out a couple of races for $10. Simple, elegent, and I get to keep that hollow stem from the ZX, which I like.

I'm going to see if I can't sneak away from work long enough to get into a bearing shop and see if I really can just swap bearings and races and call it good.

I measured the stems on both and there are nearly identical in height, (about 190mm from base of stem to the beginning of the threading for the head nut), so theoretically...

If anyone has heard if this works/doesn't work, I'd be appreciative of the feedback.

Thanks

This next step was a little intimidating, but really is the seed of the idea for this bike. I've had a picture in my head for a while of a Kawasaki, with it's big parallel motor in front and behind a very lightweight subframe suspended over the rear wheel.

Also, I noticed that the new swing arm hit the frame at the cover (for the underseat exhaust). So after a fair bit of thinking and planning I committed...