'80 GS1100E rebuild

[cavehamster]

Howdy all,

I thought I would start a thread to track my progress on modding up my poor old '80 GS1100E

Here's what we are starting with:




Mind you, at this point, this bike was owned by a friend of mine. He stripped it down, rebuilt the poor carbs, and got it running at least.



I bought it off of him looking basically like the above, with a big tote full of the parts he removed. I put most of the stuff back on, bought a Vance and Hines street pipe for it, and took it out to the drags last Sunday. Despite the old dry rotted tires (bias ply, but we put tubes in) spinning all the way through the 60 foot traps, I was still able to turn in 12.42 as my best time. Not too bad for a first attempt!

I got it back home and decided to upgrade the rear end so I can put some new rubber on it. I already had a swingarm from a Bandit 1200, so I started prepping the bike by stripping it down even further.

[cavehamster]

After playing with the swing arm, I took it into work and removed the monoshock mount using a manual mill.



I still need to get in there with a flapwheel disc and remove the corner of what is left, but at least I got the bulk of it gone.

Last night, I used the CNC to machine up some new tophat spacers for the swingarm.



Of course, as luck would have it, I left the swing arm at home last night, and managed to make the spacers about 1/2mm too big in diameter. Whups! Going to make another set tonight. I'm attempting to use a 3mm spacer on the left, and a 11mm spacer on the right, to give clearance for the rear master cylinder plunger. I may have to shift some stuff over again depending on how the chain lines up. My order of operations for the swinger seems to be:

1) Machine spacers to allow the swinger to miss the brake master
2) Install wheel and determine spacers to put the wheel in the middle of the front wheel
3) Determine how to machine the brake bracket to work with this offset and the brake disc
4) Determine how to offset the sprockets to line up the chain

So, that's where I am at today. Yes, the spacers are made of 6061 aluminum, we'll see if that is hard enough or if I am going to have to go with steel later (I didn't have any steel billet handy).

The ultimate plan involves something close to where posplayr and etc are going with theirs, new style front and rear ends, 180 tire out back, updated paint scheme. I'm also planning on Koyo clocks, and rewiring the thing from scratch (I mean, really, do I need a battery level sensor or self canceling turn signals? Naaaaah). I may also end up with slightly different exhaust on it to give more ground clearance, but we shall see how that goes.

For a winter project, the carbs are going away, and this thing will be fuel injected with Megasquirt.

Ambitious? Probably. Hopefully I don't get too many things going at once

Anyway, your feedback and suggestions are always welcome.

[67fire]

Keep us posted on the progress please. Looks like a good start!
When you get ready to sell the carbs, please send me a PM.

Thanks,

Eric

[midnightcafe]

nice work. looking forward to seeing the progress! I have that tank, NOS in the box. pm if you're interested...

[cavehamster]

nice work. looking forward to seeing the progress! I have that tank, NOS in the box. pm if you're interested...

Thanks! I'll keep that in mind. I have two tanks right now, the original which I -thought- I got all the rust out of... the outlet kept clogging up out at the drag strip, leading to fuel starvation at the end of the 1/4, whups. The other one has been stripped, filled, and is almost ready for some paint. It is clean inside, too, but I didn't want to put it on until I had some paint on it.

[cavehamster]

A few more photos.

Here's the stock swing arm:




Brake plunger clearance on the stock arm:

[cavehamster]

Even more photos!

Here's the Bandit swinger, in mock up:




And the brake plunger clearance (no spacers installed, I just shoved the arm over to the left). I also plan on removing the little bump out on the brake lever arm to move the plunger a little more outboard.




There is really a bit more room than it looks. With the spacers, the swinger will miss the plunger completely, especially once I beat that lever arm flat

[cavehamster]

Oh, I found the -very- first photo of the bike when it was in the field, rusting away...




Ouch.

[ronin1166]

Glad you came along to alter that bike's destiny.

Good luck with the build. I'll be watching the GSF swingarm install.
Got one on the shelf here, but I need to close out some other projects first.

Sure is nice to have machine tools at your disposal, isn't it?

[cavehamster]

Glad you came along to alter that bike's destiny.

Good luck with the build. I'll be watching the GSF swingarm install.
Got one on the shelf here, but I need to close out some other projects first.

Sure is nice to have machine tools at your disposal, isn't it?

Well, I hope to post plenty of pictures and my Solidworks and CAM models once I get it figured out, so I hope it will be of help to other folks.

I love having machine tools handy. I would have done this by hand if I had to, but hey... why not take advantage of precision milling equipment?

[reddirtrider]

Forget using the stock brake plunger and save yourself a lot of headaches by simply adapting some gsxr (or similar) rear sets that have integrated master cylinders. You'll save weight, time and effort trying to salvage the old rear master cylinder, and they will look better. Not two, but three birds with one stone.

[cavehamster]

Forget using the stock brake plunger and save yourself a lot of headaches by simply adapting some gsxr (or similar) rear sets that have integrated master cylinders. You'll save weight, time and effort trying to salvage the old rear master cylinder, and they will look better. Not two, but three birds with one stone.

Interesting. I might have to look into this.

I got the swinger on tonight with the new spacers, it fits just perfect, makes me happy. With 11mm of spacing on the right, and the stock brake plunger lever beat flat, there is about 2mm of clearance for the plunger. The question, of course, is once I stuff a 180 in there, can I offset the sprocket enough to line it up somewhere.

I took pics, will post in the morning.

[cavehamster]

Got the newly machined spacers home, this time test fit in the swinger before I left the shop. Seems I had a bit too much deflection on a long end mill and not enough finish passes to compensate, ah well. The spacers fit very very well into the swinger.

Once I got home, I had to remove about 1/2mm from the small end of the spacers, as I didn't realize there is a tube trapped in the middle of the swinger hole that the spacers butt up against. The top hats now give the swinger about 1/4mm or less of side to side travel. I was then able to get it to bolt into the frame.




Again, as viewed from this photo, that's 11mm on the left (driver's right), and 3mm on the right (driver's left). The swinger feels real good in there.

Here's a side shot with a shock mocked up. The wire in the back is holding the swinger into about the right position.



Battery box clearance looks OK, especially once I go buy a flapwheel disc and remove that bump out.

With swinger in the 'down' position:



With the swinger in the 'up' position, assuming 3 inches of suspension travel (which seems to be the limit of the stock shocks, but since they are at an angle, actual tire travel may be less):



More photos next post. Silly 4 photo post limit...

[cavehamster]

Here's how the shocks seem to line up with this setup. I think even if they are not perfectly in line, there is enough slop in the setup that I won't have to worry about offsetting one side.




For giggles, I slapped on the stock tire to see how it would look:




That's about like you would expect for the stock. Of course, no engine right now, so I can't line up the sprockets just yet. Need to get an actual motorcycle jack or something, haha.

[cavehamster]

The UPS man dropped off a toy this morning!



That's a wheel off a 2001-2003 GSXR-600. Not too bad for $45, eh? No dents at all, but it'll need new paint, but I was planning on that anyway.

I may have hit a snag here, though, I gotta figure out how this wheel bolts into the stock setup, as the wheel bearings are much larger than my axle. I guess I assumed they would be the same size, perhaps I am wrong? The parts diagram shows a dust seal and what looks like another tophat spacer, so perhaps I just need to get the dust seals and make some more top hats.

I stuck the wheel into the swing arm to see how it looks.




Gonna be interesting once I get a tire and the goodies. I picked up a hub and sprocket off the fleabay for $18 shipped, should be here soon. Still need to dig up a caliper and a disc so I can finalize the placement. I'm still aiming to fit a 180 in there, should be entertaining

So anyone have any thoughts on the bearing size issue? Did I mess up buying this wheel? I might yank the wheel off my other bike and see how it goes together, as it takes the same hub and etc.