[Kreylyn]

maybe i missed it but what size tire is that? and what did you start with?

Stock size basically... 3.5" rim, with a 150/70/17 tire.

Changed to a GSXR 5.5" rim, with a 180/55/17 tire.

Krey

[Kfreak]

Looks good. Nice job. Pay close attention to your left chain adjuster. Do yourself a favor and change them to the Bandit adjusters. After all the work you did, you may end up damaging it due to a failure in an adjuster.

[CenCalKat]

WOW! what a difference. looks great. Top notch work krey!

[brenton]

good work mate , nicely done.

[Kreylyn]

I edited the original post to include more information and pictures for the entire process.

Krey

[quik89Kat]

Stock size basically... 3.5" rim, with a 150/70/17 tire.

Changed to a GSXR 5.5" rim, with a 180/55/17 tire.

Krey

Damn all that work to fit the same thing my lil zx7 has...

Nonetheless looks great I have always wanted to do something to my 1100 kat ...maybe someday...Anyway 2 things that would worry me are

that swingarm wall thickness is very thin by the looks of it .did you box it around the weld areas? An extruded piece of aluminum is very strong when its a straight run beam ,
when you cut it it loses its rigidness though you can make up for it by boxing or adding a plate or gusset over the welded area...the welds look real good but the area around the welds gets prone to cracking after the metal cools ....I'd at least have the plates welded over the welds for added strength......But IMHO that is kick *** bro real nice work

[Black_peter]

Do yourself a favor and change them to the Bandit adjusters. After all the work you did, you may end up damaging it due to a failure in an adjuster.

Ne-oublie has some beefed up ones also..

[Trackerrrr]

Great job you did. I wouldn't have noticed the mod just walking up the the bike on the street.

[Kreylyn]

Damn all that work to fit the same thing my lil zx7 has...

Nonetheless looks great I have always wanted to do something to my 1100 kat ...maybe someday...Anyway 2 things that would worry me are

that swingarm wall thickness is very thin by the looks of it .did you box it around the weld areas? An extruded piece of aluminum is very strong when its a straight run beam ,
when you cut it it loses its rigidness though you can make up for it by boxing or adding a plate or gusset over the welded area...the welds look real good but the area around the welds gets prone to cracking after the metal cools ....I'd at least have the plates welded over the welds for added strength......But IMHO that is kick *** bro real nice work

I'm going to repeat the information I got from the welder, as I am not one. I know alot about metelurgy and steels, in how they react though because of my other hobby (sword collector), so it made sense to me what he said. And yes, I know he's good enough to trust my life on it.

The geometry change combined with using Stainless Steel for the welding process increased the over all strength of the arm more so than the original. It did decrease the flex a little, but there is still some flex that will absorb alot of the stresses instead of forcing a structural failure. The SS welds are also lower temp welds and have very little heat leaching effects on the carbon surrounding it. The welding was also done with heat reducing actions (short travel weld and then draw the heat away) to further ensure as little carbon as possible was leached.

Visibly I could tell that the surounding steel did not exceed 640 degrees after the weld was done (never passed color blue in the heat oxidation lines) so I'm sure he was spot on.

His final statement "What you have now is stronger than what you started with." and I trust that.

Looks good. Nice job. Pay close attention to your left chain adjuster. Do yourself a favor and change them to the Bandit adjusters. After all the work you did, you may end up damaging it due to a failure in an adjuster.

The chain adjusters were customized a bit, but I'm still looking at a possible change for the rear plates the acorn nut snugs up too. I was thinking of doing a custom set but the bandits look like a decent option too. Thanks for the tip.

Krey

[Kreylyn]

Just an update, finally got the chain and sprockets on. I'll have pictures in the next day or 2 to add.

Krey

[ygolohcysp]

First and foremost, I'd like to say that looks awesome. It kind of makes me want to try something like that myself.

I've had a similar experience with cutting wedges out of rectangular steel tubing to and welding together to make bends. I did so to make subframe connectors in two different 73 Mach 1 Mustangs. That said, I'd just like to point out what I know of welding with regards to things that were said.

I'm going to repeat the information I got from the welder, as I am not one. I know alot about metelurgy and steels, in how they react though because of my other hobby (sword collector), so it made sense to me what he said. And yes, I know he's good enough to trust my life on it.

The geometry change combined with using Stainless Steel for the welding process increased the over all strength of the arm more so than the original. It did decrease the flex a little, but there is still some flex that will absorb alot of the stresses instead of forcing a structural failure. The SS welds are also lower temp welds and have very little heat leaching effects on the carbon surrounding it. The welding was also done with heat reducing actions (short travel weld and then draw the heat away) to further ensure as little carbon as possible was leached.

Visibly I could tell that the surounding steel did not exceed 640 degrees after the weld was done (never passed color blue in the heat oxidation lines) so I'm sure he was spot on.

His final statement "What you have now is stronger than what you started with." and I trust that.

First off, I don't have any certificates, and I did not go to school for welding. I did however read several books before I ever started, and then did lots of practicing and testing of the welds I did. The first thing is that using stainless steel, not the steel that the swing arm is made of, sets off alarms in my mind. I have no factual info I can point to for this. Just a dissimilar metals kind of thing. To my knowledge, which very well may be wrong, stainless would have a higher melting point than regular steel, which in turn has a higher melting point that straight iron. You can however reduce the melting point by using a flux, but I'm not sure how that would work with modern welding techniques.

Also, as long as the actions to leech the heat away after welding were subtle, then that's fine. If it was something like soaking the area with cold water immediately after, then that's not so good. It causes things like warping, and any parts that were still glowing would then get hardened while the rest wouldn't possibly causing microfractures, and making the welds themselves more brittle unless they were then tempered.

In general though, an area welded together should be stronger than the metal originally was. If not, it wasn't welded properly. When practicing and doing my tests, I got it to where I could weld together a couple pieces of 1/4" steel together end to end, and not damage it any worse than the metal itself testing it between a sledge hammer and anvil. The sheetmetal I'd try, I'd eventually end up ripping the sheetmetal in other places before the weld would break.

All in all, since you said or implied that this guy was a professional welder, I'd definitely trust him. I'm not trying to be arguementative, and this is just going to make me do some research and learn some more. I think the mod is awesome, and looks great.

I look forward to hearing more info on how it handles as you get more used to it.

Oh, aside from welding, I also picked up blacksmithing as a hobby for a while, and did the research to totally understand everything that went into making knives and swords at the time. I love metalurgy.

[Kreylyn]

The first thing is that using stainless steel, not the steel that the swing arm is made of, sets off alarms in my mind. I have no factual info I can point to for this. Just a dissimilar metals kind of thing. To my knowledge, which very well may be wrong, stainless would have a higher melting point than regular steel, which in turn has a higher melting point that straight iron. You can however reduce the melting point by using a flux, but I'm not sure how that would work with modern welding techniques.

As you mentioned our mutual interests with blades and the making there of, I'll just point out the common use of pattern welded blades for the example why stainless and non stainless isn't nessasarily an issue here. Steel is steel, and there are many examples of various varieties being mixed. Once "welded" together, either through forge and hammer, or with modern day welding... it's one in the same, a solid piece of steel. Properties drawn from that mix is based upon how much they are mixed, if mixed at all. (Putting aside the fact that stainless isn't good for blades over 18", but those reasons are not applicable in this usage.)

The stainless material used in the weld resists temperature hardening, preventing it from being brittle after welding. I believe that is the 300 series?... hrm.. Anyways, this provides a weld that is more suited to allow flex of the arm while greatly reducing the likelyhood of the weld cracking or breaking from normal use.

As for the hobby, did you make any?... got any pics?...

Krey

[ygolohcysp]

Thank you for the explanation. It actually does make sense even based off of what I learned about the swords. I was most interested in Japanese swords, and they are made by forge-welding low carbon and high carbon steels together. I hadn't thought about it in that way because the only difference is the amount of carbon, but that does make them dissimilar forms of steel.

In that endeavor, I only managed to forge-weld the layers together while having a helper hold the material while I used a big sledge two handed. I just couldn't get enough force by myself with a small sledge one handed. So I only ever ended up making a knife blade. It does have the layered steel, but does not have the mild steel core. I ground the angles like traditional Japanese swords by hand, and hardened it the same way the swords were done. I never entirely finished it by putting a handle on it. But in the tests I did, that thing was sharper than a razor, and held it's edge very well. I could use it to slice through wooden dowels easier than sharp knives can cut through rope. I'd have to search for any pics, but I do still have the blade. I could clean it up and take a pic or two. If you're interested though, I'll pm you. Your mods are too cool, and I've jacked your thread too much already.

Again, I appreciate the added info.

[Kreylyn]

Well, I have about 300 miles on the new swingarm now, with the GSXR rim. I thought I would post some thoughts on how it's working for me.

Took a little getting used to at first. The Kat has always felt a little ... I don't know, jumpy/squirley... I've used stock sized, 150s, 160s, of all kinds of various brands with over 50k miles on the same bike since I purchased her new in 93. Some tires gripped better, some rode a little better... but with every one of them the tail end of the bike still had a tendency to "settle" in the curves. My wife, a former horse barrel racer always referred to it as "taking it's seat". I'm thinking it was from flex in the swingarm since it didn't change between tires much at all.

Now... it doesn't do that anymore. It's there, all the time. Feels alot more solid all around, in the curves, on the straights, in the parking lot. The transistion from upright to lean in the curves is a very nice smooth transition. Never came close to feeling like that before. I used to find on occasion if I wasn't spot on, having to do lean corrections in the curves. It was like the bike wanted to drop into it a little more.

Not now, it goes where I want, and stays right there. No feeling like it wants to drop further, but that it wants to mind me and stay right where I tell it. I've smothed out my turns better than I have ever felt on this bike.

Now that I've gotten used to it, I'm finding I was correct about the effect it would have on my speed and ability to take the turns. Nothing negative at all. It's alot more solid in the turns, feels better, it's always seated, so the transitions are really smooth. I think the slightly shorter wheel base, even with the wider tire off set alot of the possible negatives I was looking at... like I thought it might.

Two up riding is a little better as well. No problems with clearance, but then I didn't expect any after flaring out the passenger pegs a little. I have room to move them back actually. Two up the bike still feels like it's ready to take the curves. It rides solid, and strong.

I've heard some mention the "rides like a tank" when talking about larger tires. I don't have that feeling at all. Comparitively, it was like going from a go cart to a sports car. It's solid, still feels fast, and it handles the curves nice and smooth.

All in all, I have to say performance related... I couldn't be happier with how it feels. This is a sporty touring bike... and to me it feels every bit as sporty, but now its alot smoother ride for touring, and alot more solid feeling when I'm getting on it.

Krey

[H3l1x]

WOW !
Insrirational, truely!!!
I am looking to something similar, but a bit more extreame.
I have learned from your experience and I thank you.