UNLIMITED Duality-build thread

[SkyknightJohn]

"I have a plan!" he says again. However, this time his plan is a little more sophisticated than the previous build off.
Exhibits a.) current,

and b.) previous:

To those of you who have a good working relationship with CAD software, my hat's off to you. I've done numerous tutorials and the finer points, even the rougher points seem to elude me. I think CAD was made up by a left-handed dyslexic engineer with autism. A GENIUS for sure, but working an entirely different language than I am. I just want to draw with measurements, but, well, it's not that easy for me it seems.

Now, where's the Cardboard?

On the road, so this is what I've got. Tubes ordered. Other project in the works as well. Time and Life permitting, here we go!
(had to post something on day 1! )

 

[Pondo]

I'm with you on the Cardboard Aided Design system. This will be a fun one to watch!

 

[BartRidesEternal]

Looking forward to this one too.

Are you going to design a 'belly mounted bottom bracket' on this one?

 

[SkyknightJohn]

Looking forward to this one too.

Are you going to design a 'belly mounted bottom bracket' on this one?

Likely. Design is evolving and will probably change based on my success, or lack thereof, with the tube roller, and other variables.

 

[kingfish254]

I was hoping you were sticking with the triangle and square wheels from the previous sketch.

 

[Brian macumber]

Theme?

 

[SkyknightJohn]

Woot! Getting my page 2 slacker badge early this year!

I suppose I should post some work.

First tubes bent. Not bad for the first go at it.

And here’s the second set with the approximate layout. First with the big suspension fork, then a more normal sized rigid.

I did get a bit of twist on one of the S-bends, as is common with these rollers, but probably not enough to worry about.

I should do up a full-size drawing to check angles and clearances.

Might make the belly a little deeper, try to get closer to the tire radius. We’ll see.

 

[Captain Awesome]

Woot! Getting my page 2 slacker badge early this year!

I suppose I should post some work.

First tubes bent. Not bad for the first go at it.
View attachment 264586
View attachment 264587
View attachment 264588
View attachment 264589

And here’s the second set with the approximate layout. First with the big suspension fork, then a more normal sized rigid.

View attachment 264590
View attachment 264591

I did get a bit of twist on one of the S-bends, as is common with these rollers, but probably not enough to worry about.

I should do up a full-size drawing to check angles and clearances.

Might make the belly a little deeper, try to get closer to the tire radius. We’ll see.

Suspension fork mock up is FUNKY! I dig it

 

[SkyknightJohn]

Here’s a couple more shots, with the wheelbase set, tire diameter drown in, HT angle, etc. Feeling it out.

 

[SkyknightJohn]

So, while I keep trying to find another use for the Suntour Double-Down forks, I’m not digging it on this. And I found a fair priced Soma rigid fork. Once it arrives I’ll get more solid geometry set up on the jig and get some welding going.

In the meantime been working a FWD MBB frame for a friend. Nice to be able to pace a little bike work here and there, other hobbies, and otherwise keep on with life. Finding balance.

 

[OddJob]

I like that rigid fork in your first mock up. The curvy frame and nice saddle are begging for a stylish, modern twist on a classic ride.
You had me at matching thickslick tires....

 

[SkyknightJohn]

May not look like much, but I spent a lot of time getting the rear dummy axle holder set up better. Less play in the dummy axle and squared up solid for more consistancy.

Then set the Head tube distance and angle. The middle bar for the seat tube will need to go so the inner tube sits proper. The BB position isn’t decided, height is correct but distance from the axle… ¯\_(ツ)_/¯ And I want it above the lower tubes, so, work the curves, or massage it somehow.

I think you can see the direction it’s headed.

 

[BartRidesEternal]

I like where this is going. Beautiful curves!
Are those dropouts milled from one piece?

And I'm guessing you are welding in a different space?
Or else you might get holes in your shoes

 

[SkyknightJohn]

Yes, they are Paragon dropouts, placing the IS disc mount inside the stays instead of above the SS.
Like so:

Also gives a little looptail vibe, I think.

And yes, the welding happens further away. 🤣

 

[SkyknightJohn]

OK, so I set the wheelbase and HT angle, but forgot to set the axle-crown height, so the HT was way too high.

The bottom threaded rod is the center of the BB holder at a pretty standard 50mm drop from the axle line. Putting the BB on top of the tubes will put it in line with the axles. Probably not the worst for a cruiser style. Still have options.

The tubes will get closer together once trimmed to meet in the middle of the head tube, so I may not need to pull the seat tube mounting bar.

 

[kingfish254]

May not look like much, but I spent a lot of time getting the rear dummy axle holder set up better. Less play in the dummy axle and squared up solid for more consistancy.

View attachment 265137
View attachment 265138

Then set the Head tube distance and angle. The middle bar for the seat tube will need to go so the inner tube sits proper. The BB position isn’t decided, height is correct but distance from the axle… ¯\_(ツ)_/¯ And I want it above the lower tubes, so, work the curves, or massage it somehow.

I think you can see the direction it’s headed.

View attachment 265139
View attachment 265140
View attachment 265141

Great work on the DUMBAXLE!

 

[kingfish254]

I really dig the geometry you are laying out on this. Great curves and super twin bar layout. Sexy!

 

[Pondo]

I love everything about this frame build. It's going to be a beauty!

 

[SkyknightJohn]

Great curves and super twin bar layout. Sexy!

'twas the plan. I mean, you keep buying/building up all the Twin bars, (every 5 buildoffs? Still a lot.) so, I decided to make my own.

 

[SkyknightJohn]

Back from earning another Page 2 Badge…

I worked on sizing and alignment last time home, but always struggled with holding the tubes in place.

Then out on the road, on a dark desert hiway, cool wind in my hair…
I realized I was dreaming, and the simple fix came to me:

Assures tire clearance in the rear, seat “tube” clearance, and vertically even. Have to tweak a bit still, but on the right road.