beater's kz400 build - video up!

[beater]

Re: beater's kz400 cafe build - first cafe bike build

nice progress. what made you ditch your first seat attempt and fab your own? was it simpler (I'm on the fence on the same issue)?

well even though I am a metal sculpture guy, and pretty adept at doing metal, I don't know that I would do it the same way again. I knew from the beginning that I wasn't going to do side panels if I could get away with it, and the oem seat pan without panels is flipping huge on the kz400.

I wanted a lot of simple complex curves and details that a generic cafe seat wouldn't give me. For instance, there is a flat section on the 78 and up kz's tanks, that I matched on the tail, very subtly. I wanted it to come out like a combination of the duckbilled hr1/2 tails and a cafe tail. I think I got it.

 

[diesel450]

Re: beater's kz400 cafe build - first cafe bike build

That seat pan you made looks REALLY GOOD!! Really good. It also looks pretty simple to fab. any change you could do a quick walk through on that? I just got a mig welder and am looking for some little projects to learn with. What sort of metal and gauge did you use etc.? My CB200 might look good with a slightly steeper version of that seat profile on it.

 

[beater]

Re: beater's kz400 cafe build - first cafe bike build

I built it backwards, as I didn't have any real specs. I don't know if I would call it simple though.

Here were/are the steps.

Design/layout/measure sitting area, then do math to find the radius of the curve to add that length in, while matching the slope/width of the tank. (think sine/cosine and shit). Hammer and or wheel the front of the pan to match the tank curve area. run the pan through a slip roll for desired rear curve.

Tack pan to frame made for pan (meaning, make a pan frame for the seat pan). I was planning all along to have an air-gap, and use rubber bumpers between the frame rails and the pan frame.

Use a template/curve finder or use a thin cardboard to form the pattern edge against the compound curves you put in the seat pan "lip".

Cut out more than you need except for the matching end to the "lip". Then mallet form/planish out the final shape and trim to fit, then tack to frame on pan.

I used 28ga for the pan and lip, and 22ga for the tail. the frame is 1"x10ga (1/8th) flat stock, with .125 wire for the lip at the front on the complex curve for the tank mating area.

 

[diesel450]

Re: beater's kz400 cafe build - first cafe bike build

Okay, a bit more involved than I anticipated, (hate math ) but I'm a dive right in headfirst kind of guy so I may give it a whirl. Thanks for the run through.

 

[beater]

Re: beater's kz400 cafe build - first cafe bike build

ok - got something accomplished today.

I re-made my brake side rear control. I needed quite a lot of length and offset for the brake arm, and was getting flex on most of what I was trying. So after two tries and 4 hours I came up with a fairly light set up, for steel that is.

Final mock up and stuff

Back view - bracket with bracing

Side view - rear spring on rod seams to be stiff enough to hold pedal, but we'll see.

Made a brake switch mount while I was at it.

I got my projector headlight in from the uk today, we'll see if I go that route, or if it's too modern. The piggy back kyb's I got should be in this week, along with the nos clutch cover to replace mine with the divot.

 

[noahdog]

Re: beater's kz400 cafe build - first cafe bike build

Nice solution to the lever issue. I'm afraid that won't work for my setup since my rearsets are aluminum so welding is out. I've flipped the drum lever so it's now facing up and I'll have a bent rod going back to the lever. I'm expecting the stock brake lever rod is too thin and will flex so I have a piece of 1/4" steel rod that I plan on using a dye to thread it to 6mm on each end to use if the stock one flexes too much.

 

[makotosun]

Re: beater's kz400 cafe

Does anyone know where to get new gauge rubbers? The isolation mounts on the back of the gauge?

I know nothing about that bike, however, I needed to replace the gauge isolation rubbers on a vintage Yamaha Enduro (looks to be a similar mounting setup) so I spent some time at my local Home Depot in the plumbing department and ended up getting a couple of the replacement rubber inserts for a garbage disposal. Really.

I cut out the center part so all I had was the ring and it fit perfectly under the gauge and between the mount. Plus it is rubber designed for pretty hard conditions, so it has held up well.

An idea if you can't find the originals. :-\

 

[manchestermichael]

Re: beater's kz400 cafe build - first cafe bike build

hi any chance you could get some bigger pics of your rear shock set up as all your pic are small thanks

 

[diesel450]

Re: beater's kz400 cafe build - first cafe bike build

$50 mod thread that one. Great idea.

 

[beater]

Re: beater's kz400 cafe build - first cafe bike build

Nice solution to the lever issue. I'm afraid that won't work for my setup since my rearsets are aluminum so welding is out. I've flipped the drum lever so it's now facing up and I'll have a bent rod going back to the lever. I'm expecting the stock brake lever rod is too thin and will flex so I have a piece of 1/4" steel rod that I plan on using a dye to thread it to 6mm on each end to use if the stock one flexes too much.

why would welding be out?

 

[midnightcafe]

Re: beater's kz400 cafe build - first cafe bike build

How are you going to mount that seat and cushion? I'm trying to devise my own way but I'm coming up short ???

 

[beater]

Re: beater's kz400 cafe build - first cafe bike build

hi any chance you could get some bigger pics of your rear shock set up as all your pic are small thanks

rear shocks are stock in all my pics, and you can go to http://www.flickr.com/photos/8761598@N08/ for all the big pics

I won't have the kyb's on until next week

 

[noahdog]

Re: beater's kz400 cafe build - first cafe bike build

why would welding be out?

Mainly because we have yet to figure out how to weld aluminum to aluminum let alone to anything steel.

 

[forcefanajd]

Re: beater's kz400 cafe build - first cafe bike build

tig.....but still cast aluminum is very hard to tig weld you have to get it so friggen hot because its very porous

 

[noahdog]

Re: beater's kz400 cafe build - first cafe bike build

tig.....but still cast aluminum is very hard to tig weld you have to get it so friggen hot because its very porous

Unfortunately the only welder we have is a wire fed mig welder. We've got the argon gas for it now which makes much nicer welds but still doesn't work on aluminum as far as I know.

 

[diesel450]

Re: beater's kz400 cafe build - first cafe bike build

Check the manufacturers specs on your welder. Lincoln says that the wire mig welder I bought will weld Aluminum. Probably not really well or really easily though. Nothing like a challenge though.

There's much more knowledgeable welding guys here than me though.

 

[beater]

Re: beater's kz400 cafe build - first cafe bike build

the process (mig) has little to do with the material. The issue is in the feed/drive mechanism in the welder. aluminum is very soft, and at .30 or .35 wire dia., extremely so. I have seen home kits where a light bulb is used to warm the wire prior to feed, but you will need a special roller/feed kit on most home level welders. You really need a push/pull, and most larger welders, 210 amp and above are equipped to handle a spool gun, which gives you this. In fact, most of the trailers that you see on the road in aluminum are mig welded with spool guns.

As for any cast material, pre-heat is a must, and the real problem is not the porosity of the material but the unknown mix of the alloy, be it steel, iron or aluminum. I usually use tig and 6xxx series filler for cast aluminum. I find it easier to mig aluminum than tig, due to the cleanliness requirements and such don't really lend itself to the home based shop. When my shop was primarily used for my studio, this wasn't an issue, now it is.

Contact me offline if you want to discuss it further.

j

 

[beater]

Re: beater's kz400 cafe build - first cafe bike build

How are you going to mount that seat and cushion? I'm trying to devise my own way but I'm coming up short ???

I the seat is a pan/seat combination. I welded in captured nut tabs on the rear under the hump to mount to the rear frame hoop/brace, and welded in a captured nut tab up front to secure the front. It's bolt on, but I shouldn't have to remove it often. It's held off the frame by the original seats rubber bumpers, and a urethane one up front. I am going to cut a hole in the pad for the front bolt. Should look the business.

As for the pad, that's not the one I will use, I will either use a color matched neon green minicell foam like it, or most likely, some thicker minicell contoured for the seat. Minicell is waterproof and can be shaped with an angle grinder, and is what is used on modern gp/supersport/superbike stuff. Pretty comfy actually. It will be exposed with no cover. I haven't decided on whether it will be with velcro or adhesive. I won't install it until after paint though.

j

 

[ph!L]

Re: beater's kz400 cafe build - first cafe bike build

Hey man, im really diggin' the build!
I'm a colorado guy too, so not only can i not wait to see the finished pictures, i can't wait to see it in person!
Keep up the good work!

Phil

 

[beater]

Re: beater's kz400 cafe build - first cafe bike build

wow - just like christmas! oh - wait. it is christmas!

Got some more little things done. Polished up and re-mounted the ignition. I just need to commission a friend of mine to make me a led housing. He could make many as he is in the rapid prototyping business for plastic. we'll see.

In order of appearance:

NOS right side cover. has some slight oxidation, but not one nick or scratch. My old one had a chunk out of it by the points cover. The brace is NOS as well. Over an 1/8th thick aluminum. FLat tracker syle, and may even fit over the fender. Not one scratch/blemish in it!

Shocks are piggybacks from a 750, with 600# springs. pre-load and compression, no rebound but hey, they're kyb at least!

Polished cylinder. You can see how much lower the gauges are than stock. They are about a centimeter below the handlebar bolts, as compared to 2~3 above it!

Batteries in and wired. These are 6v run in series to get 12v and 10.5ah. wires will be moved away from tire lol.

Happy Christmas/Good Solstice