Hey sorry to second-guess you again, but I have a 1" butted steerer, 320 mm, and a piece of 1x0.049" tubing, 555 mm. They weigh 320 g and 410 g respectively. That corresponds to my numbers within 1-2 g so I stand by them.
No problem- Maybe it's my scale (or my eyes) but my numbers are 319g at 250mm for supplied (butted) steerer tubes vs. 170g for .049 wall tube, both 1" od.
I'm not arguing any info, but hoped someone has tried and tested what I'm proposing.
Just out of curoisity I am gonna do some testing. I'm building a fixture to support the steerer tube exactly as it's supported in the head tube (headset bearings included). Primarily I'm interested on comparing steerer tubes, but other results may be enlightening too. I really want to know what the loads are on the steerer and where failure is, and which materials produce what results. Trying to figure out actual loads under most riding conditions is way beyond my scope of this test, but that's not what I'm after. I'm thinking the deflection anywhere between the supports(top and bottom HT bearings) and load is really quite small. We'll see.
I've seen all the fork failures (steeel, aluminum, carbon/AL and carbon) but they have all failed in the blades... never the crown or steerer. Then you have frame distortion from crashes. Oh yeah- wheels collapse too. So, the question remains- How much lighter can I make the steerer tube and have it not be the weak link?