Another suzuki gs1000 chop

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jmlcolorado

Well-known member
Joined
Jul 23, 2010
Messages
1,839
Location
The flat plains of Elbert County, CO
I figured I'd start a build thread here, cause this is my favorite forum [cl

I'm helping out an friend chop up his 1981 GS1000. He's been sporting it for a while till he decided what he wanted to do to it.
He decided to tear it down this winter and I duping urged he better haul it to my garage so I can knock out the fab work before I get more busy.
So here goes nothing:

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Here's how I got it. He did the PITA work of removing all the parts and pieces. Kinda nice to start this way, gotta say!
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And now for me to do my thing.
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We decided to do a 3" stretch on the swingarm. It will be hard tailed, and the neck raked. It IS a chopper after all
So off comes the swingarm and a million measurements taken so assure it's all square once I weld it back together.
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I like how the factory installed the adapter pate for the....uh.....thingy a ma bobber. Not sure what it's called. Final drive?
So I cut the factory weld to reuse it.
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Inserted a sleeve, and then 2.5" DOM.
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Looks pretty square. Not bad considering it was cut with a reciprocating saw.

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My attempt at making sure the axle lines match up. The photo makes it look like the pointer is not square, but it really is.
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Half way done, ish.
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Onto the other side. This side won't be as easy since it is curved. No sleeping and calling it done :/
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I decided the best way was to remove the axle mount, re-fish mouth the tube back to a better angle, then sleeve it. This seemed like an easier option than just trying to get a sleeve bent to the exact right angle to match the axle mount.
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I had to laugh at the size difference in the factory tube and the DOM I'm using. It's .020". Might be a little overkill, but oh well.
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Before fish mouth
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After fish mouth. (I'm pretty proud of this fish mouth. Did it with a 4.5" angle grinder.) I bend the crap out of my arbor for the tubing saw in the drill press :/
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You might note the heat marks on the sleeve. I did have to bend it ever so slightly to line everything up.

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Did an 8" sleeve to get a good solid 2.5" on each end.
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I also did a number of holes for rosette welds to add more strength.

I had a tire clearance issue on the other side and figured I better fix that before welding up this side.
I also noticed the 3" stretched driveshaft had clearance issues inside too, so I cut the whole flat mess out and added plate to add 1/8" inside and provide clearance for the tire outside.
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Apparently I forgot to take pictures of the plate welded up.
Here it is finished.
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Tire clearance is still tight, but at least it doesn't touch. Might have to heat and tap in a little down the road. We'll see.
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Back to the other side.
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That is a nice job extending the final drive/swing arm! Now I see where the tire was, the clearance in the arm stayed, and the middle was extended, the factory had to narrow that area where the tire was originally to make it clear too =)
 
I asked the guy I'm building this bike for (we'll call him Shawn, since that's his name :) ) to bring the engine over so I could get it in the frame to get weight on the front forks. That way I can make sure the bike sits paraell to the ground when we rake his neck.
He also brought an '80 gs1000 rear wheel. This wheel is 1" larger, making it a 17" wheel vs his 16" wheel that came on the '81.
We tossed it on the newly stretched swingarm and found the tire to be offset to the left of the bike an extra 1/2" [S

Hard to see well in this photo, but the tire tread at the bottom of the picture that has chalk in it is the center of the tire.
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I pulled a factory '80 swingarm I had laying around and put it on the bike with his '80 rear wheel. That one lined it all up fine.
THIS means I can't use this swingarm I just stretched :rolleyes:
So he found another '80 swingarm locally (can't use the one I have since it's off another buddy's chop project).
So I suppose the first one was just practice. Never hurts to have practice I suppose.

We also made a deal that he would grab me a JD2 model 3 tubing bender and a set of 1" dies for the work I'm doing to his bike [cl[cl

Pretty happy about that deal. I REALLY need a tubing bender with the stuff I'm getting into now days.
 
So how did you stretch the drive shaft inside the final drive? I musta missed that somewhere.

You didn't miss it, I never posted about it.
We haven't stretched his yet, but I had a buddy's stretched. Same bike, same ideas going into that one too.
I took the driveshaft to a guy figuring he would balance it after he stretched it, but it appears he just sleeved it and called it good.
I'll probably just stretch my own and save the $150. My friend has a lathe so I can turn down the shaft to create a nice tight fit inside more dom tubing, then check for square.

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I see. I was thinking of doing the same thing on my oldwing. Thought it might be a bit cooler if I stretched it a tad. Wasn't sure I wanted to attempt it.
 
I did a Kaw VN750, the shafts are so small they don't seam to need to be balanced, my brother did the machine work and we used the method of drilling a hole in the sleeve and weld it to the shaft, there's an name for this type of weld but I don't know it [S
Also didn't seam to need to be trued up either, just good machine work, mine runs smooth like cake frosting. [cl
The bike is looking good, I would have like a ridge but my old ass won't take it any longer.

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Bike has been sitting for a while with the holidays and all.
Figured I had better tackle stretching the second swingarm.
The driveshaft side is very similar to the other swingarm, but the right side is totally different.
Here's some redundant photos, since I already did this once before :)
Swingarm #2, left side
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It's a mess here, but you might be able to see a zillion clamps holding everything square.
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Ooooo. Ahhhhh. Pretty.
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Tonight I decided to tackle the right side, not quite knowing exactly how I'd do it.
His side has a large plate the axle mounts to rather than a fish mouth tube. Not sure why the change, but the did anyways.
So I got some 1.5" Dom and just sleeved it.
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The little holes I believe are called roset welds. I agree they make these things stronger, so I utulized them again.
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Can't remember if I showed the tubing used for the sleeves before, so here it is. Pretty stout stuff.
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Starting to weld it up.
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Isn't Very pretty after being half ground down.
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I know he didn't like the look of two different sized pieces of tube to make it up, so I used some exhaust tubing to fill it in and smooth it out.
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Doesn't look half bad really.
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Never mind the shock, it's there to hold up the rear end. It's actually placing the rear end pretty close to where it's final location will be. So to give you an idea, that's how much the bike will drop.
I need to rake the front end, what I calculated to be about 4*, to get the bike that low.
Trail numbers will still be well within spec, so it'll handle just fine.
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That's it for now. :D
 
Decided to spend the day in the garage today.
Wasn't really sure what I wanted to do, but something had to be done :)

Decided to loom over the rake on Shawn's bike and get a plan.
Built a solid strut to lock the rear end right where I wanted it to be.
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Put the bike on jacks to pull the front end out. (I put a sheet up to make photos easier to see rather than a bunch of junk in the background)
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Front end pulled.
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Got the bike to the exact angle I wanted to see it, and level from left to right.
Factory neck rake was 28*
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I was initially thinking about leaving the top tube mostly attached as well as the factory gusset then make new bottom tubes, but after an hour of looking it over, there were just too many welds to deal with.
So off it came :)
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Separated the neck further
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Neck got ground down to factory diameter. I was about half tempted to take it over to my buddy's place and chuck it up in the lathe, but I was too concerned with messing with the vin. So it was done by hand.


Set it up there to figure out the angle and trail numbers
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