Even the diameter and thickness of the rear brake rotor was reduced to match the size of a 450 Honda, there was about a pound taken out there.

The flatslide carbs also reduced overall weight.

Here is a shot of the whole rear brake with stay, and master cylinder in view.

Funny.. I posted the photo, and forgot I had a lightening hole pattern drilled into the spacers for the rear brake, you can't see them unless you remove the axle and brake. I forgot they were there.... :laugh:

Anyway there is another example of a few grams here and there.

Cory,

God question. There are many details, each one looked at rom a weight perspective. My favorite is the rear brake. The rear brake is from a Honda CR450R. The stay, caliper mount and caliper weight bout 7 pounds I think. The actual weight savings are documented somewhere in the 40 pages, so I am going from memory here. The old rear brake set up must have weighed in at 20 pounds.

The rear fender was removed, sounds simple yet there is almost ten pounds in that thing. The front fender is now plastic, more weight savings. There are some Titanium fasteners strewn about as well. I started with points which would effect the bike the most (rotation and unsprung weight) and was buying titanium bolts like a mad man until my wife asked me why 6 or7 bolts would cost 110 dollars. Trying to explain titanium to a financially oriented spouse is no easy task.

The bracing...very interesting also, there was a shit ton of globulas welding on this bike from the factory, along with many mounting points which are no longer needed. I removed all of the tubing (passenger peg mounts-etc.) that I could with out affecting the structure. The I added the extra bracing. For an entire winter I was grinding welds down, to make them nice "fillets" nstead of globs. I even swept up the shaving after a day of grinding, they actually weighed about half pound. The bikes were so overbuilt back then, that there are all kinds of places you can reduce weight.

I have some material picked out at work, and if the shop ever slows down, I will be making titanium axles. Many many little things turn into grams, then ounces, then pounds.

dohc wrote:

tk11b40 wrote: Weighs in at 440 pounds with half tank fuel. A little heavier than I was shooting for. Wanted to hold it at 425 dry. 2.2 gallons of fuel weigh about 13.75 pounds, which would give it a dry weight of 426.5 pounds. Not bad.

I believe the quoted dry weight for the Z1 was 506 lbs. So you managed to shed close to 100 lbs.

Where did that 100 lbs go? It looks like most everything is still there, even the battery. Plus you added bracing to the frame... Is there that much weight savings in the modern suspension and wheels?

Yes. Triple trees are aluminum instead of steel, swing arm is aluminum instead of steel, the stock wheels are steel hoops and spokes compared to light aluminum wheels. Then figure on the brakes. Three light discs compared to one heavy one and a real heavy drum brake. The bracing doesn't add much weight at all compared to what was taken out. FWIW that has been my finding on my build.

Cory

tk11b40 wrote: Weighs in at 440 pounds with half tank fuel. A little heavier than I was shooting for. Wanted to hold it at 425 dry. 2.2 gallons of fuel weigh about 13.75 pounds, which would give it a dry weight of 426.5 pounds. Not bad.

I believe the quoted dry weight for the Z1 was 506 lbs. So you managed to shed close to 100 lbs.

Where did that 100 lbs go? It looks like most everything is still there, even the battery. Plus you added bracing to the frame... Is there that much weight savings in the modern suspension and wheels?

Assuming your bike is ready to ride, tank empty is actually the wet weight. Dry weight is without engine oil, fork oil, battery, etc., so your bike should easily be sub-400 lbs dry.

your bike look great in orange....


.I also use the light bracket form a 81 kz that mount to the gauges bolts.

I switched from the old stock reg and rect when I put my Z1 back on the road again to the combo unit. works great, don't fry batteries anymore and leaking acid all over my machine. The one big problem over the years has been the permanent magnet rotor becomes sloppy over time causing a knocking noise. I have one extra but bought another one on ebay. At first it looked good but when I put it in a vice and moved it one way and the other, I cold tell it was starting to do the same thing. The seller ignored me and time ran out for refund.This seems to be a problem with this design. In 78 I had one seize up. I managed to get the cover off after hours of trying so I know that noise. Maybe that's why K went to the all electric type. I'm going to stiffen up the V bracket from the steering head to the down tubes. On the Z1's they always cracked in the same spot. I will also add another tube just above or below the swing arm pivot. The Susie's had a tube going from the steering head to the cross tube like yours. I'm planning to do that as well. Good Job.

Have you looked at these?

pages.ebay.com/link/?nav=item.view&alt=web&id=281441252633

Universal 35/39/41mm Motorcycle Headlight Mount Bracket Fork Ear Bobber Chrome

Now they are 41mm but I wonder if a 1.5" sanding drum could get them to work. They are pretty nice and are available in black and aluminum finish as well. Then there is always Dime City

www.dimecitycycles.com

Lastly could you adapt a head light bracket from a Kawasaki ZR7?