Dutchz Z1 road burner - new stuff

I haven�t been hanging out much in the past year and this is part of the reason why. For those who don�t remember me, I bought a ratty �74 Z1 a few years ago and gave it a somewhat traditional (if not for a Z1, maybe) cafe treatment, this is what the bike looked like before I blew it apart:



I crashed it in November 2006, rebuilt it and decided I wanted to do something different with it. I tore it apart about 10 months ago planning on having it done before summer... Another lesson learned.

The mission:
To build a street special like someone could have done in the early to mid seventies, emulating the style of the Kawasaki 2-stroke GP bikes of those years (H1R / H2R / KR750), using as many period correct parts as possible (with a few modern cheats not visible from the outside).

The plan:

Save as much weight as possible. Shave off whatever weight I can to improve handling, acceleration and braking. The stock bike is somewhat of a whale at 511 lbs dry (no battery/oil/gas), and probably a healthy 530 lbs wet. I�m shooting for 425 lbs dry. That would be pretty damn good for a 30+ year old street bike. For comparison, a 2008 Z1000 weighs 450lbs dry.

Improve handling. Brace the frame thoroughly, swingarm bearing kit, quality rear shocks and snazzy fork internals. Aluminum rims and decent tires, ofcourse. The steering stop and the plate it lives on are bent after the crash and will be replaced. Frame will be powdercoated when all mods are done. Some time will be taken setting the bike up to get the rake/trail numbers I want.

Swingarm. A well known Z1 weak point, and often upgraded with a GS1100 swinger. But an aluminum arm is not the look I want and it makes the already substantial wheelbase longer instead of shorter. So I�ll brace the stock arm, and hell, I have room so it will be an overbrace.

Brakes. Dual front discs, the second rotor drilled to match the first one. I would have liked Lockheed or Grimeca calipers, but this is not in the budget for now. The rear brake will be an early Kawasaki H1 drum, that is cable operated. It is also 20mm smaller in diameter, with a lighter cush drive so I�ll save more weight here. It�ll count double because it�s rotational mass and unsprung weight.

Fiberglass tank and tail; rearsets. H2R/KR inspired seat and a nice big race tank that fits the stock Z chassis. I�ll use the Tarozzi controls I already have, but will modify the frame with rearset hoops.

Complete rewire. The stock wiring harness is shot after 30 years. The bike sat corroding for 12 years before I bought it, and my uneducated electrical modifications didn�t do it any good. A small sealed battery under the seat will keep the fire lit and the lights on. Don�t need a lot of cranking amps because the starter is long gone anyway.

Carbs and exhaust. Whatever hop up stuff I can get my hands on that is correct for the early seventies.

Motor. Left stock for now. I want to make this thing handle first, then add power.

I know I'm probably forgetting stuff but I have tons of pics, I'll be posting what I can in the next few days, in more or less chronological order.

Post edited by: dutchz, at: 2008/01/16 20:36

bring onthe pictures!!!!!!!!!!!!!!!!

March '07 - First thing I needed to do was lace up the rear wheel. The H1 sprocket is smaller (180mm) and a little narrower than the Z1 hub. It also has a 17mm axle, so I needed to my 20mm axle fitted using different bearings, a sprocket spacer and new wheel spacers to lace everything up along with the 530 conversion I planned. This had to be done prior to bracing the swingarm to check clearances and the cable run for the brake side.

The early (69-70) H1 hub is cable operated and has little cooling vents. Why they put the vents on the rear hub and not on the 2LS front remains a mystery, but it sure looks the part...

I ended up turning down a second H1 sprocket for the spacer on that side, and machining new internal and right hand side spacers out of aluminum.

H1 hub is lighter, with a smaller cush drive so it will save rotational and unsprung weight. You see a valanced rim and my old tire in the pic, I actually ended up relacing the hub to a non-valanced (shouldered) hub to properly fit the tire I wanted, a Brisgestone BT45 140/70.

cool,lets see how good it stops.

Well, I don't use my rear brake all that much and I have two discs up front. The smaller hub works just fine...

this thing is going to be cool!i'm droolin,keep us up to date.

dutchz wrote:

Well, I don't use my rear brake all that much and I have two discs up front. The smaller hub works just fine...

i dont use mine much either,im just wondering if there will be any differance performance wise between the cable and a brake rod which cant stretch.looks cool though!

PLUMMEN wrote:

i dont use mine much either,im just wondering if there will be any differance performance wise between the cable and a brake rod which cant stretch.looks cool though!

It should be fine once the shoes bed in. I'm glad I don't have to rely on the drum rear. The good thing is I'll have a lot less weight to stop when I'm done...

The other side of the hub, with the aluminum sprocket and sprocket spacer to mock up the 530 chain run:

Exhaust hangers... gone to make room for the rearset hoops, to line up the controls.

craigslist score... $30 along with an oil cooler, fittings and some GPZ stuff I sold on ebay... for $40 haha

Inspiration...