My '82 XJ750 "Project Shadow Warrior"

this isn't a modification thread but rather "built from scratch" thread! Really awesome project, man! Thumbs up!!!

 

Sickkkkk build!!

Cant wait to see how it ends up looking!

 

i love the monoshock idea and execution but i would be concerned about moving where the force is exerted on the frame, the rather small tubing cannot be as strong as newer monoshock frame designs and with you putting out 100+ hp i would seriously consider trussing the frame. you eliminated the rear triangulated frame. so now you have just basically a hoop design.

this is just a thought, but i drew the way i see the forces acting on the frames. this is the original design with dual shocks. pretty straight forward. triangulation is one of the strongest things we know how to build, bridges are built with it, and there is triangulation between the swing arm, the shock mount, and the rear of the tank mounts. by cutting this off, i would worry that this might have impacted the rigidity of the frame.



heres your new frame, and the way i i could see the forces acting on this frame. the shock is now pushing the swing arm down, but also out away from the bike. and that swing arm will be constantly moving between acceleration and deceleration which will push and pull the swing arm mount which is now only connected by two small pieces of tube on each side. it used to be mounted between three, where there was no real way it could move in any direction, now there will be more force on those welds in a forward and rearward direction. i would think about trussing that swing arm mount before taking it on serious rides. also would consider what maxim-x said about the seat mount because your bodies weight will be pushing at almost a 90 degree angle on that small piece of tubing which is now the main structural support for the rear of the bike.



i love the build, amazing work. i just dont want to see it crack and fail , and you possibly get hurt, over being used time and time again. i love it!

 

Wow, that's some serious computing up there ^^^ sounds like somebody's an engineer? Architect? Something else?

 

My-other-XJ may be on to something. It may hold for now, but prolonged use could cause damage.
I would weld a gusset on each side of the lower frame rail(engine cradle) going up to the swingarm pivot housing and up to the downtube at the pivot housing. A couple of 1/4 by 2inch flat bar welded at 3 junctions-lower frame rail-pivot housing- downtube. Just to be on the safe side.

 

You make some good points. Thanks for the good advice with the visuals. I had my suspicions. I'll be doing some mods to the frame to beef it up. I'll keep you posted. I'm trying to get this beast running within a month (fingers crossed)!

 

I made some progress with the wiring on the bike. I can turn it on now and the lights turn on. I made some videos to show the progress.

YouTube video of bike no. 2
YouTube video of bike no. 3

 

Love it. impressive electronics!

 

I'm excited to see where this build goes. cant wait till its done

 

Very impressive.

 

Hey this is fantastic! Looks like you figured out the rear setup - did you have to end up swapping the disc after-all? I see you had to relocate the tank mounts as well - hopefully that wasn't the same hell as I went through!

Let me know if you still need pics but it doesn't look like it with the XV rear end. I apologize for not sending some before, got wrapped up in school/work :? .

 

I appreciate that! I owe a lot to you for the inspiration. I would have never known about the rear 900s wheel if it wasn't for you. Did you ever measure the offset the 900s wheel has on the xj750 diff? a couple of other guys where asking and I'm not sure. It doesn't look like very much? I moved the tank mounts in the beginning of the project, so it was hard at the time. It wouldn't be to bad now that I have a little more experience. It works well though.

 

Here is just a couple of samples I threw together from photoshop to see what paint scheme I might want to go with. What do you guys like? Any other suggestions or critiques?

 

The 1st pic needs a little more gold accent- it's too dark.
2nd pic would look better in a darker shade of red- the light shade doesn't mesh well with that shade of gold.
3rd pic-can't find a thing wrong about it. Don't care for white that much, but that goes together well.

 

I vote for the white but with a black or gold frame and accents! (depending on keeping the fork legs in it's current color or painting them black)

 

I used the string method to test for any deviation. It ended up looking close to, if not perfectly, aligned (the wheel does look a bit off in the frame but front to rear tracks straight). It's highly unscientific though and it may be worth doing a more 'rigorous' test.

 

My favorite is #1 paint scheme, it is almost perfect to my eye, i would add some gold around the number #82 (or whatever number) on the tail and on the pale part of the fairing lower.

 

So I think this weekend will be D-Day for cranking over the engine (fingers crossed)! I was wondering what you guys thought of this paint scheme on my bike. A cross between this race XS850 and the FZ750 paint scheme. You guys like or hate?

 

Personally I like a solid color with the exception of the old yellow and black Kenny Roberts scheme.

 

This is my personal favourite scheme, strangely since I normally like black/gold or metallic red but this scheme just seems to suit the bike so much better IMHO...

EDIT-: wow 1000 posts, I'm supposedly an "XJ Wizard" yet I've only been into them for 45 days!!!