UNLIMITED Duality-build thread

[SkyknightJohn]

Next up: trimming and capping the odd/misfit tube terminations, seat tube piece, bottom bracket, cable guides. Not necesarily in that order, and surely I’m forgetting something…

 

[OddJob]

This is really shaping up nicely John! Could you use a type of solder / braze technique to fill gaps, instead of adding more welds or caps?

 

[Captain Awesome]

This is really shaping up nicely John! Could you use a type of solder / braze technique to fill gaps, instead of adding more welds or caps?

I’ve seen this done before but I would caution. It is more than likely a true “forever” addition

Doing so will close out any options to repair in the future. It is nearly impossible to remove all traces of brazing rod with Silicon or Aluminum Brazing material in the joint

It is far easier to wash over the weld with small diameter wire to make it more cosmetically appealing. Something .040 or smaller in a lay wire technique and make a high speed pass

But you already have some distortion. 6 of one…….

 

[kingfish254]

WOW! I just love this frame. Excellent work!!

 

[SkyknightJohn]

This is really shaping up nicely John! Could you use a type of solder / braze technique to fill gaps, instead of adding more welds or caps?

I think for less structural spots it would be ok, but even where the dropout joins are and the tube is ovalized bigger than the dropout radius, I think it’s best to cut/cap/weld to create a structural steel joint.

The big triangle on the downtubes was trying to get them more centered-2 one-inch tubes meeting a 1-3/8” headtube. I did better with the top tubes, but there will be some remediation there, too.

 

[SkyknightJohn]

Stance shot, for fun and profit.

 

[SkyknightJohn]

Thanks for the encouragement everybody.

Afternoon work … getting hot while welding, and having to turn the fan off while also donning a long sleeve jacket….

Checked some clearances:

If only every weld looked like this one! (pay no attention nor zoom into the others! )

Cross piece in place and BB shown roughly in position.

 

[SkyknightJohn]

Also, FWIW, my welding would probably be better overall if I worked harder at a proper fitup. But since much of my mitering is by hand file or grinder, and summer is in full swing… AND this is all just for a fun bike with heavier-than-needed tubes-and twice as many as needed… I’m not stressing precision.

Very much a “good enough is good enough” attitude.

Definitely a fun foray into some curvy-swoopy design parameters! Will probably do the swag-offroad tube roller upgrades at some point. And try it out with thinner wall tubes to see how low we can go.

These are 0.049” wall and seem to have done fine on just the original HF setup. If 0.035” wall would work…. I have ideas!

 

[OddJob]

This is not a criticism, but I feel like the fork looks 'small / thin' with your frame. The look of your frame, and the hot rod nature of the thickSlicks has me yearning for a beefier fork option.

My .02.

 

[SkyknightJohn]

I smell what you’re cookin’, @OddJob

original green vs. suntour double down:

Those Suntour’s are beefier, for sure. Just so dang tall. I made ‘em work well on an ebike ages ago (retired) but have never found something to fit them well to since.

Not a bad stance, but they always seem to dominate any normal sized bike.

With the green Somas, I’m trying to tie on the curves, and got a deal on them. Who knew 1” frame tubes would seem the beefier? ¯\_(ツ)_/¯

I have some material I could try building a fork, but so far my fork building adventures have been a big goose egg.

In other news…
While central alignment looks good…

You can maybe see the slight twist in the wheel resulting in rub:

So, I’ll investigate whether it’s truly an alignment issue or a camera issue, or I just need to go back and review the dimpling thread to make things work out.

 

[kingfish254]

I really like the beefiness of a triple tree on there. Do you have a shorter triple?

 

[SkyknightJohn]

I do not. I could cut these down further, which may be the best option. I’d need to find the compression travel distance.

Still working the slight tire rub issue. Simple solitions haven’t worked out. Might require more radical surgery. I’ll think on both figure it.

 

[Pondo]

Wow, your frame is looking terrific!! Very nice work indeed. I do like the beefier looking fork but it is really tall. Maybe an old rigid mountain bike fork? Great work!

 

[El Pocho]

You have no idea how badly I want to see you build "B".

 

[The Renaissance Man]

Looks great!

Since you have 'built-not-bought' so far, why not use your skills and build your own fork? I'd like to see what you would come up with!

 

[SkyknightJohn]

Seems a lot of support for beefy forks, I’ll consider all the options for making that happen.

Looks great!

Since you have 'built-not-bought' so far, why not use your skills and build your own fork? I'd like to see what you would come up with!

I’ve tried to make 2 forks so far, and, let’s call them “learning experiences.”.
I think I have enough requisite parts & tubes to try again. Will need to assess schedule, parts, & build a better fork jig.

I’ll also see how low I can set the Suspension fork for a mockup. Probably Saturday or Sunday before I have the chance.

 

[SkyknightJohn]

Ok. So here is the double down fork lowered Vs. before Vs. the green rigid. I was able to lower it about 2”, with maybe another 1/2-1” possible between the headset races and such.

So, not as tight as the rigid, but better then before.

For the rear wheel rub— After second look/ceitical eye, Seems there is some vertical disagreement left/right causing the rub on the right “chainstay.” Frame is centered, wheel seemes centered, just canted wrong.

Probably a cut and re-weld fix.

I’ll keep looking for easier options, but nothing easy is ever worth it… or something.

 

[SkyknightJohn]

Surgery:

Cut:

Snip:

Weld:

Smooth:

Fit:

Seems that drive side “chainstay” & “downtube” just ended up closer to center.

I think with this patch we’re moving forward again.

 

[SkyknightJohn]

Worked up some BB mounting plates. Luckily, this piece of a shoebox had a pre-made 1-1/2” hole.

Still might change the height relative to the tubes, and/or where the plates meet the tubes.

This feels like enough dirty work in the heat for today.

 

[OddJob]

John, will you be able to judge the BB location with just the wheels / tires mounted, or do you need a seatpost / seat and stem / bars for riding position to dial it in?

Also, crank arm length for saddle to pedal distance, and potential toe overlap with the front wheel.