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Dr. Gamma wrote: I used the 4130 over mild steel because it weights less, and is a lot stronger.

this is a common mis-conception.
the two materials are the same mass for equal amounts of whatever part.
the bigest difference between the mild steel and the chromemoly material is strength.
allowing you to build lighter structures because you can use thinner wall material and still have the same strength.

Having the same diameter and wall thickness moly and mild steel have the same density (weight per area) as each other - weigh the same.
people usually use smaller wall thickness with moly as moly has a greater tensile strength (stronger) hence lighter.

thanks for posting the pics of your frame.pretty cool to see a different take on frame bracing.

leon

4130 chromemoly (or how ever you spell it!!!) is far superior to mild steel in many ways. Before I built my KZ1000, I used mild steel for all of my brackets. They would last a while, then they would fracture, not at the weld, or close to the weld. The bracket would develop a bunch of spider web cracks on the bracket. When I got hooked up with a welder extraordinaire, he explained why I should be using 4130 over mild steel. He laughed at me for using mild steel for brackets. He was also an excellent fabricator, and I learned a lot from him by just by watching him work with metal. Once I started making my brackets and other things out of 4130, no more spider web cracks or bracket breaking in two!!!!

I might explain it wrong on why I say 4130 is lighter, but like you say its lighter because you can use thinner pieces. I made my battery box out of like .063 thick flat stock. Since I built my KZ1000, I have not had any bracket or other pieces I made out of 4130 break or even crack. The factory steel plates that mount the coils kept breaking into pieces a few times during the season. I finally had to make copies of those brackets out of 4130, and guess what..... they never ever broke again!!!

Chromemoly is a bitch to work with. I was buying drill bits by the boxfull. Even cutting it was a pain. Then to bend it you had to get it cherry red before you bent it. One nice thing was it welded up super nice. I would never ever make any type of bracket out of anything but 4130..

i am myself a big fan of using chrome moly tubing.i've personally never used chrome moly sheet.
because,
i buy alot of my chrome moly tube from a local micro builder.
www.factor1racing.com/
i called them up wanting some sheet for some shock brackets that i was building for some custom chrome moly a-arms i was building for my short track/tt racing banshee.

they laughed at me for wanting to build brackets out of chrome moly sheet .saying that they used mild steel for all of there sheet gussets and brackets.
so i've always done it that way since and haven't had a problem.
my swingarm tubing of choice is 1" od .065 wall 4130 chrome moly.
i love using it because i can build stuff lighter than aluminum and stronger than steel .
my swingarm on my 80 z1r

here's an extended arm i did as well.

i've always found chrome moly to machine nicely because it has so few impurities.

if you really want some real world comparison take some same wall thickness and diameter steel,chromo & stainless in a manual tube bender and you will get a "feel" real quick for why chromoly is the superior material in motorsports.

leon

I love your swing arm!!!! A work of art in my book.

The worst thing about working with 4130 are the slivers!!! I would use a die grinder with a carbide bit when shaping the ends of some of my brackets. I would end up with some of the worst slivers in my fingers that I have ever had. Plus you can barely find them in your fingers when you want to get them out. Before I wore Scott goggles over my glasses I was grinding I got one in my eye, and I ended up at the eye doctor to get it out. That was three days of intense pain.

that's a big ten four there!
the slivers that come off when using an endmill on the side are vicious .
when using a carbide burr they will eat you up if you aren't fully covered.
thanks for the kind words about my swingarm.it has proven to be very effective in making it stable through the rough corners we deal with here in oklahoma .
leon

Here are some more shots of my KZ1000 MK II.

That bike looks amazing. Really really clean!!!

Been sitting around waiting for my fuel tank to come back from the painter. I decided to put my motor back together the exact way it was the very last time I raced it. I unpacked the big buck cylinder head that was last on the bike. I have most of the needed parts on hand to get this head put back together. I ran some Norris 440SC cams with Yoshimura shim under buckets. The head has 37.5 intake valves, and stock size exhaust valves. I forgot how much was removed from the head to raise the compression. I got the head boxed up, and ready to be shipped back to my cylinder head guy. I hope all it needs are the seats to be dressed up a bit. Got to order another set of valve springs, and thats about it to put the head back together. I even had a complete set of new Rings for the vintage Moriwaki 73mm pistons. The have to use four Yoshimura shim buckets from the head thats on the bike now. I only have four new Yosh buckets in my parts bin.

Watch now that my top end is apart on my bike, the painter will have my fuel tank finished!!!! It never fails does it!!

This bike just keeps getting better, if that's at all humanly possible....

love the pics!
thanks for posting them.

leon

Found the spec card for my Norris 440SC cams. My Yoshimura Super Bonneville cams have .410 lift, the Norris are only .030 more lift. Plus the Norris have 10 more degrees of overlap. The big difference is the duration. We now have 282 degrees of duration!!!!

I remember these Norris cams pulled pretty good on the big end. Killer power out of the corners too.

Should make a great "street" cam!!!

Its been 32 years since I shimmed up a KZ head. I spent the last two days going through my storage unit looking for my box of 650 style valve shims. After moving and opening box after box I finally found them packed away in my spare GSXR motor parts!!! Don't ask.

My cylinder head specialist has gotten around to working on my head. From what he tells me, all the shim sizes should be from 250 to 265 in all 8 valves with .006 clearance!!! I like that!!! Over the years I have accumulated a nice selection of half size shims. That way I can get all my valve clearances exactly at .006 thousands!!!!

Plus my painter just emailed me that he shipped my finished fuel tank back to me today!!!!!

God I love when a plan comes together!!!