Start of a long process

c0ryrul3z

c0ryrul3z

XS400 Member
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Hello all, My name is Cory. I just purchased my first street bike. It is an '80 xs400 special. It does run however it has 28k miles so I am assuming I will have to diagnose the clearances and probably adjust the valves at a minimum. Unluckily for me, I cannot even touch it until may. I am currently in Afghanistan and wont be home for a few months. I grew up on dirt bikes and had a Yamaha Zuma for a while. I am hoping to complete the build before September. I know this is a short period of time, but I have faith it is possible. My goal is to have all the parts ready for me when I get home so I can tear it apart and go to town. My mind is stuffed full of ideas and I am bursting at the seems to put them to work. Here is the bike as it sits.

Xw6Lm3y.jpg


I also have a list of things I have already bought and things I still need to buy. :) Unfortunately, it seems like the list of things I still need to buy keeps getting longer.

e6egl75.png


I am currently ISO an older boxy tank (76-78 xs360/400) so please let me know if you one you are willing to part with. I am planning hand fabricating a custom hoop, seat pan, and 2 into 1 exhaust using the Lossa Engineering reverse cone muffler. Let me know what you think and if you have any suggestions. I would love to hear about the mistakes you have made so I might be able to skip them :laugh: thanks a bunch.
 
Yeah I saw that after I made the list, That will come in very handy and save me quite a bit of cash. I did a very basic design using Paint.
ieNwKks.png
 
Welcome to the forum:) I don't think you will be able to fit that 140 rear tire on the bike without some mods as the 130 is a tight fit. Also I would recommend using uni filters if you are going to put them directly on the carbs as they will tune much better.
 
Both. Stock is 120. 130 will fit with a few mm between the chain and swing arm/brake stay bar. The wider the tire the less responsive the handling is. I had a 130 on my 80 for a while and then went to a 120. The handling was better. Then put a 110/90-18 on and the handling was even better!
 
Well guys, Its been a few months since we last talked :p I recently got home from Afghanistan and I would say I have jumped right in to the build of my bike. I got to ride the bike around in stock form and got to get a feel for the bike. For the bike being 35 years old almost everything worked as it should and it was surprisingly unmolested. (keyword WAS:p) I did notice that the kick starter and E-start wouldn't grab and it would just spin every once in awhile. I will have to do some research on that. (maybe the kick start shaft?) So far I have completely tore down the frame and have started stripping the frame and preparing to fabricate a lovely seat hoop. My next step is disassemble the wheels and send the the hubs and new hoops off to get them laced up. I would try to lace them myself, but I am going to an 18" rear and don't have the spokes to do so. I will let the pictures talk for themselves. Sorry for the lighting in some of them. I need to add some lights in the garage.
Stock:







Here the bike is completely tore apart in my messy workshop corner.



Removing tabs and the rear part of the frame

Grinding away



Hopefully more to come soon:D
 
Well Guys,
I have been busy but have been slowly plugging away at the build. since my last update I have successfully narrowed the frame a little bit. I have my hoop and I need to turn some more slugs on the lathe to mount the hoop. Also, i have done some minor fabrication and cleaning up of the triple clamp. There is so much work to do but I am pleased with the quality of the work so far. :p Enjoy!

All Hacked up

Slugs for the bends

Bending some Metal

Clamped together

A Little compression never hurt

All Welded up. Please forgive my horrible welding. Maybe I will grind and weld over these, however they are quite strong. so eh :/

Oh yeah! A little more narrow.

UH OH! Not a saw!

wont be needing those

That looks better!

Some more cutting and a lot of grinding/sanding

More cutting, grinding, and a LOT of sanding

Finished product :p

Sorry for the long post and flood of pictures. I will try to keep the work coming. Next step will be to turn more slugs for the hoop, and weld that on. Figure out my tank situation and get some rear set mounts made.
 
Last edited:
You probably don't want to hear this, but cutting the frame like that and welding without a proper jig, is a big no no. I can assure you that it's all out of whack.
 
I was thinking the same thing about the jig, but there is a chance he is ok. Those particular bars in the rear he left dangling might stay put. I was thinking they look quite well braced where they are still attached, but I don't know!

Maybe take a whole shitload of measurements to check?

Nice pictures and work so far. Keep it up. Regardless, the entire thing is a learning process. I made plenty of mistakes on mine! :)
 
Just be sure to add a brace across the width at the shock mounts at least. In terms of things being square it probably won't matter if you are just putzing around town. The only thing that will cause you problems is narrowing it, the swingarm may be hard to fit now (may affect its movement as well) and I'd be interested to see if the tire will rub against the shock springs
 
I think that leaving the stock shock mounts in place and pulling them in .25" on both sides is not going to make a huge differece. I will be putting a brace in beteeen the shock towers. Also the hoop will add alot of rigidity. I honestly think it will be stronger than stock. I will do some rough test fitting later with the shocks and rear wheel/tire to make sure I have the clearance. I really dont expect to have any issues there. As far as geometry change the only difference is that the shocks will be maybe 3-5 degrees canted inward. At the end of the day this bike is not an r1. Its not meant to be a high speed precission machine. Its a 35 year old artsy bike for putting around. If it totally sucks than it was a fun learning project and know where to improve next time. For the time being I am having a blast building this bike and learning. Maybe at the end of the build I will have a pile of trash. Or maybe, just maybe I will have a badass cafe racer to love and enjoy for years. Only time will tell.
 
Don't take it as criticism, its just that lots of us have been there, done that. Also, with the mass fad that is 'cafe racers', 1 hour of reading forums shows hundreds of hack jobs that have gone horribly wrong. Just trying to save you the trouble ;) Better to learn from others mistakes than your own!

Back to the frame though- when they are built, a jig is used to have everything how it should. Parts get pulled and pushed, then welded. When the frame gets cut, and not in a jig, the whole thing snaps back to its 'metal memory'. And the heat from the new welds makes things go haywire moreso than you may think. For instance, I welded up my swingarm brace a few hours ago. 2 small welds at the end points, we are talking 30 seconds of heat. Well the whole thing is twisted now, by about 2 mm. Had to cut the brace off. It all went back, but now I have to order some tooling steel to make a jig.

And yes, the shocks being bent inward will screw up handling, as will any frame warpage.

Just be safe is all! Carry on! Will be watching to see it finished!
 
Okay Guys, I feel like its time for an update. I realize that last time I left you guys with a cliff hanger. I have done a lot of work to the bike since I have last posted. That being said I will begin with explaining my logic on the hackery that took place.
I realize that this hack job may seem sketchy to many and I actually agree with you. That being said there is not a lot to go wrong on chopping the rear of the frame, the main concern that I can see is maintaining suspension geometry. The rear shock towers are very close to factory locations and are VERY well braced. As you will see in the pictures the rear part of the frame is much stronger than stock.(I recently added a cross member in between the rear shock towers.) Outside of suspension geometry and strength I don't see many things that could go wrong. I will now let the pictures do the talking.
It has been months since I last posted so I will do my best to post the pictures that I have in chronological order.
IMG_0253.JPG
This is when the hoop was just sitting on the frame
IMG_0199.JPG
The next day I decided that I had had enough with frame modifications and I started reassembly.
IMG_0165.JPG
The next step was to fabricate a tray out of sheet metal to hold some of the electronics
IMG_0202.JPG
Wiring harness and some electronics chilling on the tray
IMG_0128.JPG
At this point in time I decided that i was going to make the cafe seat out of fiberglass, I made up a very nice mold out of floral foam and blue painters tape. Admittedly the mold looked far better than the fiberglass shell did.
IMG_0114.JPG
This is my fiberglass shell drying in the sun after. After spending probably 20 hours trying to hand sand and re shape my fiberglass shell I gave up on the idea of doing a fiberglass cafe seat shell. I am actually not very good at making things out of fiberglass and the materials are too expensive for me to practice getting good at it before trying my hand at another seat. I have decided that i am going a different route with the seat.
IMG_0951.JPG
not much new to see in this picture I have the wiring harness removed and I had the bike in the sun giving it a bath.
IMG_1336.JPG
This is the bike in its current state. As of today I finished my rear sets. I have the headlight mounted and ready to go. The muffler is in place and I just need to make a hanger for it. The tank is needing a good sanding and repainting. A little bondo might help a little :( Things you cannot see: I made a cross member for the frame. I have a 1/4" steel plate that is about 4" wide bracing the two shock towers together.

I also scraped the fiberglass shell and have a nice piece of diamond plate aluminum that I am going to use as my seat pan. It will be covered with foam, and upholstered. Right now I need to shorten my front brake cable. I also need to build a small battery box and finish the electronics.

After I have finished all fabrication and test riding I will do a complete disassembly, Have the frame powder coated, Paint the tank and clean the rest of the bike. I also have two black shouldered 18" rims that I am considering lacing up to the stock hubs. I am not too sure about clearance in the swing arm if I go to a 18" rear wheel.
I am open to any and all suggestions.
 
What are you using to brace those forks? I want to ditch my fender in a bad way, but I don't want no wobbles of death.
 

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