Jim's Speed Twin Build

This is all fabrication from your imagination, these little do overs are all part of the process. But any man with a plasma cutter , tig welder, and an Atlas lathe in his garage is up to the challenge. Tomorrow is a brand new day!

But Jeeze! Seriously, what’s with all the rain?
 
Man what a summer.... :D Work on the house, ride the SG. Work on backyard patio, ride the SG. Sue turns her back on me, ride the SG... :rolleyes:
Time flies when you're having fun.
It's done nothing but pour here all day... so lets head for the basement and see what kinda trouble we can get into... ;)
I'd already cut the lower swingarm cross tube, so I notched the 2 verticals, marked the center, and welded it on....

Marking centerline.jpg



Cut, notched and tacked the 2 lower tubes to the cross tube and axle plates.

Both lower 2.jpg


Both lowers.jpg


I went a little heavy on the tacking in some places because I'm gonna pull it off the jig at some point so I can sit on it and see how much sag the monoshock gives me. A little "geometry verification" test... if you will. Don't want it falling apart on me.
Made a temporary lower mount for the monoshock, then safetied the upper monoshock mount to the downtube. That way I could slide it up or down as required to get the lower mount where I wanted it....

Mono Wire.jpg



Mono lwr mount.jpg



Tacked the lower in position to "fix" the geometry where I "think" it will work. Remember, this is TLAR engineering at its finest...:rolleyes:

lower tacked.jpg


So now that the shock is positioned correctly in relation to the swingarm, I could go ahead and fab and tack the upper mounts.

Tack upper.jpg


The top of the shock reservoir sits just about even with where the original hoop ran across.... perfect.
So now I have to install some triangulation braces to the lower mount and I can pull it from the jig and see just how well the suspension is gonna work. Providing that works, I'll finish the triangulation of the swingarm then weld it all together. I'm shooting for a hardtail look here.... so they should go somewhere between the black and red lines in the pic below. Think Harley softail kinda swingarm...

Marked.jpg
 
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Man what a summer.... :D Work on the house, ride the SG. Work on backyard patio, ride the SG. Sue turns her back on me, ride the SG... :rolleyes:
Time flies when you're having fun.
It's done nothing but pour here all day... so lets head for the basement and see what kinda trouble we can get into... ;)
I'd already cut the lower swingarm cross tube, so I notched the 2 verticals, marked the center, and welded it on....

View attachment 150260


Cut, notched and tacked the 2 lower tubes to the cross tube and axle plates.

View attachment 150261

View attachment 150262

I went a little heavy on the tacking in some places because I'm gonna pull it off the jig at some point so I can sit on it and see how much sag the monoshock gives me. A little "geometry verification" test... if you will. Don't want it falling apart on me.
Made a temporary lower mount for the monoshock, then safetied the upper monoshock mount to the downtube. That way I could slide it up or down as required to get the lower mount where I wanted it....

View attachment 150263


View attachment 150264


Tacked the lower in position to "fix" the geometry where I "think" it will work. Remember, this is TLAR engineering at its finest...:rolleyes:

View attachment 150266

So now that the shock is positioned correctly in relation to the swingarm, I could go ahead and fab and tack the upper mounts.

View attachment 150267

The top of the shock reservoir sits just about even with where the original hoop ran across.... perfect.
So now I have to install some triangulation braces to the lower mount and I can pull it from the jig and see just how well the suspension is gonna work. Providing that works, I'll finish the triangulation of the swingarm then weld it all together. I'm shooting for a hardtail look here.... so they should go somewhere between the black and red lines in the pic below. Think Harley softail kinda swingarm...

View attachment 150270

Looks really good Jim...but I think the front tire is a bit low.

Pete
 
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