Gotchya- like I said in post #13, I don't use the stuff because I don't build any road specific, light-duty/race-only bikes.

Still, the shaped Spirit has been/still is used effectively by others- and while the OP clearly isn't ready, I wouldn't disparage a builder with the design and fab skills to utilize those tubes appropriately.

Snipped
Agreement here
I was expressing an opinion that I see no value in the very thin tubes in the real world
but for sales appeal in the www.brochure text
there is a perception in the punter's mind out in the retail world, that grams is what the performance of a bike is about.

That's a fact, Jack. :)

Does anyone have any advice on how to braze shifter bosses on the downtube? Do you need to use brass or could you just solder it on?

I don't know if you guys who build this light stuff run into this, but the main triangle tubes aren't the parts that weigh me down, its stays and forks. There are a lot of issues, but among them is that these parts are swaged (or whatever they call the tapering action). There ends up with a lot of beef in the bits, A fair amount of this could be reamed out, I don't think it's in there for any reason other than it accumulates during the process. If it was up to me on an all things equal basis I would prefer to remove metal from the ends than the middle anyway. My point being if you need to steal back 114g there would be a lot of targets in a bike, other than the main tubes. But maybe the stays on your race stuff are already processed. I don't bother on most touring size stuff.

that's why they butt stays, so the ends aren't too thick when they taper them down. I'm pretty sure that the lightweight stays and fork blades are as light as you want to go, you could always go with a carbon fork to lose a little more weight

Yeah what he said

There is light enough stuff out there
Train hard and get lean

there is a reason why you do not have .40/.35mm at the fork ends or at the rear dropout
all this stuff has been thrashed out for decades and the tube makers have been there blah blah
then the breakages occur
so the stuff is designed to work in the real world
we are not going to discover some thing that the tube makers such as Columbus are ignorant of and have over looked
My mate Joe Cosgrove has some foolish customer that wants to use .7mm 953 fork blades on a touring bike with disc brakes.
This customer is a mechanical engineer and he thinks he is f--king genius.....................................................

You guys are jumping to the end of the story. Who said anything about .035". I just said that the parts that are disproportionately heavy in my world are the stays and fork parts. By the way, how much do the lugs weigh?

Silver is fine for braze-ons.